Sunday, November 2, 2008
The hamstring reflex
Since the knee jerk is L4 and the ankle jerk S1, the L5 root is usually omitted from exam. The biceps (of the hamstring) and semitendinosis reflexes are tested, both high sciatic reflexes. Biceps is primarily L5 and is lateral, semitendinosis is L4 and medial.
Crossed adductor measures at L2
More DTR pearls:
1. Prolonged reflex is not just with hypothyroid, but also cerebellar disease, (pendular oscillating), protein malnutrition (change in elastic quality of tendons), hyponatremia and syphilis.
CRPS I and II
Five components of:
1. Pain, especially mechanical and thermal allodynia, hyperalgesia and hyperpathia
2. neurogenic edema
3. autonomic dysregulation with abnormal circulation, livedo reticularis and hyperhidrosis
4. Movement disorder with inability to initiate or maintain maovements, dystonia, weakness, spasms and tremor
5. atrophy and dystrophy.
In type I there is no identifiable nerve injury, in type 2 there is. Its regional, non nerve dependent and spreads, initially is sympathetic dependent later not.
Brachial plexitis examination pearls sensation
Sensory loss
1. The lateral cord encompasses the thumb and index finger and splits the middle finger
2. The medial cord splits the third finger to the unlar side and encompasses the ring and pinky fingers and medial forearm.
3. The lower trunk innervates the fourth and fifth fingers and continues up the forearm
4. The ulnar nerve innervates only a small triangular region across the wrist, as well as the ulnar distributed area on the hand.
5. Schwartzman describes additional techniques for the exam of plexus: The Roos abduction maneuver== holding hands up to imitate a goal post elicits numbness after 30 seconds
6. The Wright maneuver-- holding hands straight up, does same
7. The plexus can be palpated at various points: in the supraclavicular fossa (upper trunk); between the clavicle and the first rib; the neurovascular bundle against the medial humerus; at the elbow in the arcade of Frohse (entry of radial sensory and posterior interosseous nerves);
8. The intercosticobrachial nerve, from the medial cord, innervates the anterior chest and can be misdiagnosed as cardiac disease. acid reflux, gall bladder disease (if on the right) or costochondritis.
Pain
1. Upper trunk pain (C5-6 roots) radiates across trapezius ridge and down medial scapula, whereas radiculopathic pain from c6-7 GOES DOWN SPINE. Upper trunk is palpable in supraclavicular fossa, and radiation to tip of scapula (notalgia) is usually painful.
2. Middle trunk persterior cord plexus radiations are on dorsal arm across triceps, enters the forearm through the arcade of Frohse (medial to the lateral epicondyle) to innervate the forearm, and extensor surface of the thumb, index and third fingers.
3.
1. The lateral cord encompasses the thumb and index finger and splits the middle finger
2. The medial cord splits the third finger to the unlar side and encompasses the ring and pinky fingers and medial forearm.
3. The lower trunk innervates the fourth and fifth fingers and continues up the forearm
4. The ulnar nerve innervates only a small triangular region across the wrist, as well as the ulnar distributed area on the hand.
5. Schwartzman describes additional techniques for the exam of plexus: The Roos abduction maneuver== holding hands up to imitate a goal post elicits numbness after 30 seconds
6. The Wright maneuver-- holding hands straight up, does same
7. The plexus can be palpated at various points: in the supraclavicular fossa (upper trunk); between the clavicle and the first rib; the neurovascular bundle against the medial humerus; at the elbow in the arcade of Frohse (entry of radial sensory and posterior interosseous nerves);
8. The intercosticobrachial nerve, from the medial cord, innervates the anterior chest and can be misdiagnosed as cardiac disease. acid reflux, gall bladder disease (if on the right) or costochondritis.
Pain
1. Upper trunk pain (C5-6 roots) radiates across trapezius ridge and down medial scapula, whereas radiculopathic pain from c6-7 GOES DOWN SPINE. Upper trunk is palpable in supraclavicular fossa, and radiation to tip of scapula (notalgia) is usually painful.
2. Middle trunk persterior cord plexus radiations are on dorsal arm across triceps, enters the forearm through the arcade of Frohse (medial to the lateral epicondyle) to innervate the forearm, and extensor surface of the thumb, index and third fingers.
3.
Saturday, October 11, 2008
Sensory nerve injuries after uterosacral lig suspension
Flynn MK et al. AJOG 2006;195: 1869-72. The procedure is done to suspend the prolapsed vaginal apex. 7 of 182 women reviewed developed buttock/posterior thigh pain to the popliteal fossa. 3 women had removal of the suture within 2 days resulting in immediate improvement of the pain and the other 4 were treated conservatively with gradual resolution of the pain. In some of the women, pelvic exam showed exacerbation of the pain pulling on the suture. This is the posterior femoral cutaneous nerve that arises from S2-3 roots.
Sunday, September 7, 2008
Ulnar neuropathy pearls
Most distal muscle of ulnar nerve is adductor pollicis reached at the first free web space between the thumb and forefinger. It adducts the thumb. Unlike abductor digiti minimi itmay be involved in lesions of Guyon's canal. Like ADM its involved in other ulnar entrapments (cubital tunnel, tardy ulnar palsy, cervical rib).
Klumpke's paralysis (avulsion of C8 T1 roots) will involve these plus abductor pollicis brevis (APB median C8 T1).
The FDI may occassionally get innervation from the median nerve / musculocutaneous nerve
Tuesday, August 19, 2008
Thoracic Outlet Syndromes
True TOS is a clear syndrome with weakness and sensory loss in the arm and hand usually caused by a fibrous band over which the lower trunk of the brachial plexus is stretched and angulated. It may coexist with a small rudimentary cervical rib.
Arterial TOS involves ischemia or even emboli in fingers and hands from a cervical rib causing stenosis and poststenotic dilatation of the subclavian artery. This type is more common in athletes.
Venous TOS is an acute or chronic syndrome with swelling of the arm due to stenosis or thrombotic occlusion of the subclavian vein.
Disputed (or nonspecific nonneurologic) TOS are chronic aching and pains or paresthesias in arms and shoulders with no findings. This is a large group, but neurologic signs are "either nonexistent or meager."
Posttraumatic TOS asociated with clavicular fracture and associated brachial plexopathy see separate article.
Clinical presentations
True TOS young to middle aged women develop paresthesias , pain and weakness on the ulnar border of the hand, rarely much pain, and no vascular symptoms. Per Thomas Swift they may have hand,arm, shoulder and neck pain. They have low set shoulders, long graceful "swan" necks and horizontal or downsloping clavicles. Muscle wasting resembles CTS with wasted APB but usually some ulnar innervated muscles waste as well. Sensory loss does not split the fourth digit. There is often weakness of the forearm flexors. The differential is median and ulnar neuropathy, lower trunk plexus lesion, radiculopathy. CT and MRI usually miss the fibrous band but may show other causes of plexus lesion. Plain films show characteristic bony abnormality most of the time. Treatment is supraclavicular exploration with division of the band.
Notes-- Adson;s test is valueless, because 11-80 % healthy controls obliterate radial pulse by holding hand above head. Other similarly useless tests are photoplethysmographic studies of blood flow in the fingers following Adson's test, the elevated arms stress test (east) with the arm abducted to 90 degrees, the elbow flexed and braced, the fist opened and closed for several minutes. Bruits are of no significance in the subclavian fossa. Arteriography and dopplers are useless. In contrast, there may be a Tinel's in the fourth and fifth fingers tapping the brachial plexus, and symptoms may be exacerbated pulling arm down to ground and relieved by pushing up (again from Swift). Patients are better when lying down (contrast to CTS) and by using armrests.
Plain films may show upper 3-4 thoracic vertebrae due to shoulders. OBLIQUE CERVICAL SPINE FILMS WILL SHOW CERVICAL RIBS IF THEY ARE PRESENT! Symptoms are usually unilateral but cervical rib may be bilateral, usually C 7 also occassionally C 6. The cervical rib has a one percent prevalence, again not all symptomatic. The fibrous band extending off the rib technically compresses the C8 and T1 roots.
The best treatment of nonspecific neurologic TOS may involve posture correction, stretching and strengthening exercises (of rhomboids, levator and trapezius, the shoulder elevators), and an orthosis designed to elevate the shoulder. Operate if a band is present it will help.
The association of TOS in musicians is debated by Stewart
Arterial TOS involves ischemia or even emboli in fingers and hands from a cervical rib causing stenosis and poststenotic dilatation of the subclavian artery. This type is more common in athletes.
Venous TOS is an acute or chronic syndrome with swelling of the arm due to stenosis or thrombotic occlusion of the subclavian vein.
Disputed (or nonspecific nonneurologic) TOS are chronic aching and pains or paresthesias in arms and shoulders with no findings. This is a large group, but neurologic signs are "either nonexistent or meager."
Posttraumatic TOS asociated with clavicular fracture and associated brachial plexopathy see separate article.
Clinical presentations
True TOS young to middle aged women develop paresthesias , pain and weakness on the ulnar border of the hand, rarely much pain, and no vascular symptoms. Per Thomas Swift they may have hand,arm, shoulder and neck pain. They have low set shoulders, long graceful "swan" necks and horizontal or downsloping clavicles. Muscle wasting resembles CTS with wasted APB but usually some ulnar innervated muscles waste as well. Sensory loss does not split the fourth digit. There is often weakness of the forearm flexors. The differential is median and ulnar neuropathy, lower trunk plexus lesion, radiculopathy. CT and MRI usually miss the fibrous band but may show other causes of plexus lesion. Plain films show characteristic bony abnormality most of the time. Treatment is supraclavicular exploration with division of the band.
Notes-- Adson;s test is valueless, because 11-80 % healthy controls obliterate radial pulse by holding hand above head. Other similarly useless tests are photoplethysmographic studies of blood flow in the fingers following Adson's test, the elevated arms stress test (east) with the arm abducted to 90 degrees, the elbow flexed and braced, the fist opened and closed for several minutes. Bruits are of no significance in the subclavian fossa. Arteriography and dopplers are useless. In contrast, there may be a Tinel's in the fourth and fifth fingers tapping the brachial plexus, and symptoms may be exacerbated pulling arm down to ground and relieved by pushing up (again from Swift). Patients are better when lying down (contrast to CTS) and by using armrests.
Plain films may show upper 3-4 thoracic vertebrae due to shoulders. OBLIQUE CERVICAL SPINE FILMS WILL SHOW CERVICAL RIBS IF THEY ARE PRESENT! Symptoms are usually unilateral but cervical rib may be bilateral, usually C 7 also occassionally C 6. The cervical rib has a one percent prevalence, again not all symptomatic. The fibrous band extending off the rib technically compresses the C8 and T1 roots.
The best treatment of nonspecific neurologic TOS may involve posture correction, stretching and strengthening exercises (of rhomboids, levator and trapezius, the shoulder elevators), and an orthosis designed to elevate the shoulder. Operate if a band is present it will help.
The association of TOS in musicians is debated by Stewart
Brachial plexitis causes and differential and foils
Avulsions occur with traction injuries and may be overlooked in patients with multi-trauma.
Clavicle fractures can injure the plexus through bone fragments or hematomas, scar tissue (in a healed fracture) or development of a subclavian pseudoaneurysm.
Stingers and burners (See separate post http://emgnotes.blogspot.com/2007/04/traunmatic-neuropathy-stingers.html ). Compression of the upper brachial plexus may occur between the shoulder pad and upper medial scapula and may be prevented with an orthosis (Markey et al, 1993, Am J Sports Med). Lesion can also be in the ventral rami, cord, roots or cervical cord but in professional players is more likely to be spinal stenosis .
Intraoperative plexopathy of brachial plexus can be due to hyperabduction of the relaxed arm, plexitis (autoimmune) following surgery, during median sternotomy such as CABG (5-7 % of time) which can mimic an ulnar neuropathy, with variable locale and severity. It can occur with traction on the plexus during wide sternotomy, during jugular cannulation, and is tenfold higher when the internal mammary artery is used for bypass grafting. Forceful traction can also fracture the first rib that then can cause plexopathy. Upper trunk damage can occur if the patient is held head down and the arm is abducted simultaneously.
Acute compression occurs with coma, or carrying heavy backpacks causing a bilateral syndrome especially affecting serratia anterior.
Hematomas during axillary angiograms can cause blood leak at edge of pectoralis muscle and recovery IF blood is removed rapidly. False aneurysms can occur years after trauma to plexus, median or radial nerve.
Newborns do not have a falling incidence of brachial plexus injury (0.05-0.3 % births) with Erb's being most common (weak shoulder abduction and elbow flexion), Klumpke's less common.
Malignant plexopathy is most often due to cancer of lung, breast, or lymphoma, rarely early except in the Pancoast tumor syndrome. It usually presents with shoulder pain radiating down the arm (medial most often) followed by paresthesias and weakness. The differential includes radiation plexopathy, intraoperative plexus trauma, and unrelated brachial plexitis.
Pancoast syndrome due to tumor at apex of the lung causes pain down inner arm with two thirds developing Horner's syndrome, and one third, weakness and sensory changes in lower trunk distribution.
Primary tumors of brachial plexus include neurofibromas (often/usually plexiform) with pain, supraclavicular mass, and mild neurologic deficit. Schwannomas with "dumbbell" lesions and sensory symptoms withouu deficit. Intraneural perineurioma (or localized hypertrophic neuropathy) presents with slowly progressive upper limb deficits. Malignant nerve tumors are rare.
Radiation plexitis can occur within 26 years of radiation of the plexus and presents with sensory and motor signs and swelling. Horner's occurs less frequently than in malignant plexitis but it can happen. Radiation is commonly, but not universally thought to be more likely to affect the upper trunk. It may be relentlessly progressive and lead to a useless arm. Occassionally it may stop or respond to PT or OT.
Radiation can also cause malignant nerve sheath tumors with painful enlarging mass and dysfunction. Ischemic plexitis can occur due to radiation induced segmental occlusion of the subclavian artery.
Thoracic outlet syndromes are discussed in another post.
Parsonage-Turner syndrome causes pain then weakness. It may mimic a shoulder joint lesion.
Hereditary neuropathy with liability to pressure palsies (HNPP) often affects the brachial plexus.
Patients with plexitis due to diabates have a subacute onset and good recovery. Plexitis in heroin addicted patients has less severe pain, and involvement of the lower part of the plexus.
Clavicle fractures can injure the plexus through bone fragments or hematomas, scar tissue (in a healed fracture) or development of a subclavian pseudoaneurysm.
Stingers and burners (See separate post http://emgnotes.blogspot.com/2007/04/traunmatic-neuropathy-stingers.html ). Compression of the upper brachial plexus may occur between the shoulder pad and upper medial scapula and may be prevented with an orthosis (Markey et al, 1993, Am J Sports Med). Lesion can also be in the ventral rami, cord, roots or cervical cord but in professional players is more likely to be spinal stenosis .
Intraoperative plexopathy of brachial plexus can be due to hyperabduction of the relaxed arm, plexitis (autoimmune) following surgery, during median sternotomy such as CABG (5-7 % of time) which can mimic an ulnar neuropathy, with variable locale and severity. It can occur with traction on the plexus during wide sternotomy, during jugular cannulation, and is tenfold higher when the internal mammary artery is used for bypass grafting. Forceful traction can also fracture the first rib that then can cause plexopathy. Upper trunk damage can occur if the patient is held head down and the arm is abducted simultaneously.
Acute compression occurs with coma, or carrying heavy backpacks causing a bilateral syndrome especially affecting serratia anterior.
Hematomas during axillary angiograms can cause blood leak at edge of pectoralis muscle and recovery IF blood is removed rapidly. False aneurysms can occur years after trauma to plexus, median or radial nerve.
Newborns do not have a falling incidence of brachial plexus injury (0.05-0.3 % births) with Erb's being most common (weak shoulder abduction and elbow flexion), Klumpke's less common.
Malignant plexopathy is most often due to cancer of lung, breast, or lymphoma, rarely early except in the Pancoast tumor syndrome. It usually presents with shoulder pain radiating down the arm (medial most often) followed by paresthesias and weakness. The differential includes radiation plexopathy, intraoperative plexus trauma, and unrelated brachial plexitis.
Pancoast syndrome due to tumor at apex of the lung causes pain down inner arm with two thirds developing Horner's syndrome, and one third, weakness and sensory changes in lower trunk distribution.
Primary tumors of brachial plexus include neurofibromas (often/usually plexiform) with pain, supraclavicular mass, and mild neurologic deficit. Schwannomas with "dumbbell" lesions and sensory symptoms withouu deficit. Intraneural perineurioma (or localized hypertrophic neuropathy) presents with slowly progressive upper limb deficits. Malignant nerve tumors are rare.
Radiation plexitis can occur within 26 years of radiation of the plexus and presents with sensory and motor signs and swelling. Horner's occurs less frequently than in malignant plexitis but it can happen. Radiation is commonly, but not universally thought to be more likely to affect the upper trunk. It may be relentlessly progressive and lead to a useless arm. Occassionally it may stop or respond to PT or OT.
Radiation can also cause malignant nerve sheath tumors with painful enlarging mass and dysfunction. Ischemic plexitis can occur due to radiation induced segmental occlusion of the subclavian artery.
Thoracic outlet syndromes are discussed in another post.
Parsonage-Turner syndrome causes pain then weakness. It may mimic a shoulder joint lesion.
Hereditary neuropathy with liability to pressure palsies (HNPP) often affects the brachial plexus.
Patients with plexitis due to diabates have a subacute onset and good recovery. Plexitis in heroin addicted patients has less severe pain, and involvement of the lower part of the plexus.
Thursday, July 17, 2008
Differential C8-T1 radiculopathy
C8-T1 root lesion--
C8
Finger extensors, finger flexors, wrist flexors, hand intrinsics
T1
Hand intrinsics
Pancoast-- C8-T1 plus Horner's
Lateral cord-- muscles to forearm and sensation in distribution of median nerve
Medial cord-- all median and ulnar intrinsic muscles weak
Thoracic outlet syndrome- neurogenic, vascular, combined or traumatic. Vascular, that presents with pain, pallor and coolness is uncommon. TOS affects C8,T1 and lower trunk.
Compression may occur from a cervical (C7) rib (seen in 10%), an enlarged C7 transverse process (incomplete rib), a fibrous band (most common) from C7 TP to the clavicle, or fibrotic scalene mucles. The clinical presentation is
mild aching pain of ulnar forearm/hand (66%) without neck pain. Weakness occurs in all hand muscles (ulnar and median – thenar, hypothenar, and interossei). Ulnar (not median) numbness occurs. Hand weakness/clumsiness is prominent. Atrophy (“guttering”) of the lateral thenar eminence (APB) is characteristic. Thenar, hypothenar, and interossei atrophy – Gilliat-Sumner hand. TOS is bilateral in 50%, but less affected side is usually subclinical . No reliable provocative test exists, but 90° abduction + external rotation has best predictive value. Patients may have Tinel’s sign over supraclavicular fossa. Adsons test: turn head back & to affected side & lose radial pulse (for vascular variant) but this sign has been considered mythological (ie rarely present) by some authors.
EMG/NCV: Low APB (median) amplitudes (ulnar amplitudes are normal or slightly low). Low ulnar sensory potentials with normal median sensory potentials. Some say unreliable.
Chest or (oblique) c-spine Xrays or CT to look for C7 TP, cervical rib, etc. Treatment is ???
surgical. Medical treatment, physical therapy is not indicated for true TOS (per Kline)
§ Anterior supraclavicular approach: favored. Incision usually supraclavicular, parallel to clavicle.
§ Posterior subscapular approach: used for morbidly obesity, large cervical ribs, previous anterior surgery. See N10/04.
§ Transaxillary cervical rib resection: favored by vascular surgeons, orthopedists. Per Kline has higher complication rate, less success
Parsonage Turner-- pain then weakness, 90 % recovery within 3 years, affects males predominantly (4:1).
Ulnar neuropathy (see separate entry)
C8
Finger extensors, finger flexors, wrist flexors, hand intrinsics
T1
Hand intrinsics
Pancoast-- C8-T1 plus Horner's
Lateral cord-- muscles to forearm and sensation in distribution of median nerve
Medial cord-- all median and ulnar intrinsic muscles weak
Thoracic outlet syndrome- neurogenic, vascular, combined or traumatic. Vascular, that presents with pain, pallor and coolness is uncommon. TOS affects C8,T1 and lower trunk.
Compression may occur from a cervical (C7) rib (seen in 10%), an enlarged C7 transverse process (incomplete rib), a fibrous band (most common) from C7 TP to the clavicle, or fibrotic scalene mucles. The clinical presentation is
mild aching pain of ulnar forearm/hand (66%) without neck pain. Weakness occurs in all hand muscles (ulnar and median – thenar, hypothenar, and interossei). Ulnar (not median) numbness occurs. Hand weakness/clumsiness is prominent. Atrophy (“guttering”) of the lateral thenar eminence (APB) is characteristic. Thenar, hypothenar, and interossei atrophy – Gilliat-Sumner hand. TOS is bilateral in 50%, but less affected side is usually subclinical . No reliable provocative test exists, but 90° abduction + external rotation has best predictive value. Patients may have Tinel’s sign over supraclavicular fossa. Adsons test: turn head back & to affected side & lose radial pulse (for vascular variant) but this sign has been considered mythological (ie rarely present) by some authors.
EMG/NCV: Low APB (median) amplitudes (ulnar amplitudes are normal or slightly low). Low ulnar sensory potentials with normal median sensory potentials. Some say unreliable.
Chest or (oblique) c-spine Xrays or CT to look for C7 TP, cervical rib, etc. Treatment is ???
surgical. Medical treatment, physical therapy is not indicated for true TOS (per Kline)
§ Anterior supraclavicular approach: favored. Incision usually supraclavicular, parallel to clavicle.
§ Posterior subscapular approach: used for morbidly obesity, large cervical ribs, previous anterior surgery. See N10/04.
§ Transaxillary cervical rib resection: favored by vascular surgeons, orthopedists. Per Kline has higher complication rate, less success
Parsonage Turner-- pain then weakness, 90 % recovery within 3 years, affects males predominantly (4:1).
Ulnar neuropathy (see separate entry)
Prognosis of nerve injuries
Nerve injury
Most injuries recover spontaneously but there is a difference by location. 40 % of C5-6 injuries, 18 % of C5-7 injuries and 5 % of C5-T1 injuries (flail arm) recover. Injuries that are progressive , eg. hematoma, compartment syndrome, and pseudoaneurysm need immediate attention and often surgery. Progression of Tinel's sign can be used to follow recovery.
Repair of lacerations should be done acutely for sharp injuries (first three days) but after several weeks for a blunt injury to allow definition of injury. Penetrating injuries can be explored early, gunshot wounds if contiguous after 3 months, or EMG or SEP every three months.
Monday, February 4, 2008
Causes of peroneal neuropathy
Argument in letters section of Neurology 2003;60:1559-1560; letter writer lists "known" causes of peroneal neuropathy at fibular head as etiologically identifiable in 83%: perioperative, 30.6%, postural 19 %, bedridden 13.9 %, weight loss 5.6 %, multiple trauma 5.6 %, chalk positioning 5.6 %, synovial cyst 2.8 %).
Friday, February 1, 2008
Cubital tunnel syndrome
Clinical-- impaired sensation over the fifth and half the fourth finger
Weakness and wasting of the unlar innervated hand muscles
EMG shows sparing of FCU (proximal)
afffects the ulnar half of the flexor digitorum profundus
Weakness and wasting of the unlar innervated hand muscles
EMG shows sparing of FCU (proximal)
afffects the ulnar half of the flexor digitorum profundus
Digital nerve entrapment
Small sensory branches of the median nerve may be compressed against the deep transverse metacarpal ligament, with pain in one or two fingers, worse with lateral hypewrextension of the digits and tenderness and dysesthesias over the palmar surfaces between the metacarpals.
Carpal tunnel associations
Amyloidosis (primary or secondary)
Acromegaly, 35 %
Rheumatoid arthritis, 23 % (differentiate from disuse, c spine disease, or ulnar n at elbow)
eosinophilic fasciitis
myxedema
lupus erythematosus
hyperparathyroidism
toxic shock syndrome
Colles fracture
Fracture of the capitatum or hamate
soft tissue swelling around wrist after injury
intraneural hemorrhage
anomaly of distal radius
subluxed carpus on distal radioulnar
rubella immunization
DM
Gout
myeloma (=Leri's pleonosteosis)
cerebral palsy
TB
pregnancy
toxic shock s
toxic oil syndrome
mucopolysaccharidosis
congenital av fistula
dialysis
brachial hypertrophy
SLE
scleroderma
Signs/symptoms of CTS
Paresthesias and pain relieved with movement, worse at night
Raynaud's phenomenon
hypesthesias 1st 3 digits and half of fourth
Sensory loss confined to tip of third digit
Sensory splitting of fourth digit on exam
Sparing of thenar eminence
Phalen's and Tinel's signs
Flick sign (relief with shaking wrist) most reliable sign
Motor APB-- pushing up perpendicular to palm
Opponens pollicis -- touch thumb and fifth finger
Phalen's/ Tinel's signs
Differential diagnosis
high median compression at elbow
C 6 radiculopathy
handcuff neuropathy
Acromegaly, 35 %
Rheumatoid arthritis, 23 % (differentiate from disuse, c spine disease, or ulnar n at elbow)
eosinophilic fasciitis
myxedema
lupus erythematosus
hyperparathyroidism
toxic shock syndrome
Colles fracture
Fracture of the capitatum or hamate
soft tissue swelling around wrist after injury
intraneural hemorrhage
anomaly of distal radius
subluxed carpus on distal radioulnar
rubella immunization
DM
Gout
myeloma (=Leri's pleonosteosis)
cerebral palsy
TB
pregnancy
toxic shock s
toxic oil syndrome
mucopolysaccharidosis
congenital av fistula
dialysis
brachial hypertrophy
SLE
scleroderma
Signs/symptoms of CTS
Paresthesias and pain relieved with movement, worse at night
Raynaud's phenomenon
hypesthesias 1st 3 digits and half of fourth
Sensory loss confined to tip of third digit
Sensory splitting of fourth digit on exam
Sparing of thenar eminence
Phalen's and Tinel's signs
Flick sign (relief with shaking wrist) most reliable sign
Motor APB-- pushing up perpendicular to palm
Opponens pollicis -- touch thumb and fifth finger
Phalen's/ Tinel's signs
Differential diagnosis
high median compression at elbow
C 6 radiculopathy
handcuff neuropathy
Anterior interosseous syndrome (Kiloh-Nevin s.)
AI s is due to injury to the branch of the median nerve just past the pronator teres muscle and can be unilateral or bilateral. There is pain in the forearm and elbow, made worse by resisted proximal ip flexion of the middle finger. Asked to make the "OK" sign, patients will make a triangle sign instead (pinch sign). Spontaneous recovery occurs over 6 weeks to 18 months. Identical syndromes can be caused by more proximal lesions, including antecubital level or the brachial plexus, due to prearrangement of the bundles of nerves proximally. Weakness also is seen in fl dig profundus 1 and 2 and PQ.
Nerve conduction may be normal or show a delay from pronator quadratus. EMG is abnormal in the flexor pollicis longus, flexor digitorum profundus I and II, and pronator quadratus.
Associations include trauma, forearm (midshaft radial) fractures, humeral fracture, injection/phlebotomy of antecubital vein, stab wounds, fibrous bands, related to exercise. Occassionally associated with brachial neuritis, CMV infection, bronchogenic carcinoma mets or spontaneous. Consider plexitis.
Other median entrapments occur at the ligament of Struthers, Lacertus fibrosis and the tendinous insertion of FDS. Humeral spur at supracondylar site can produce brachial claudication and radial artery obliteration, exacerbation of numbness and pain by resisted elbow extension and forearm supination.
Nerve conduction may be normal or show a delay from pronator quadratus. EMG is abnormal in the flexor pollicis longus, flexor digitorum profundus I and II, and pronator quadratus.
Associations include trauma, forearm (midshaft radial) fractures, humeral fracture, injection/phlebotomy of antecubital vein, stab wounds, fibrous bands, related to exercise. Occassionally associated with brachial neuritis, CMV infection, bronchogenic carcinoma mets or spontaneous. Consider plexitis.
Other median entrapments occur at the ligament of Struthers, Lacertus fibrosis and the tendinous insertion of FDS. Humeral spur at supracondylar site can produce brachial claudication and radial artery obliteration, exacerbation of numbness and pain by resisted elbow extension and forearm supination.
Median nerve syndromes: pronator teres syndrome
The median nerve pierces the two heads of the pt (pronator teres) before passing under it. Trauma, fracture, muscle hypertrophy or an anomalous band connecting the pt to the tendon arch of the flexor digitorum sublimis can injure the nerve here. Also tenosynovitis, muscle hemorrhage, tear, postop scarring, anomalous median artery, or increased forearm compartment pressure can be related.
Clinically, pain and tenderness appears over the pronator teres, is fatiguaibile, with the pain radiating occassionally to the shoulder. Weakness of the flexor pollicis and apb, and preserved pronation. Sensory changes over the thenar eminence help to make the diagnosis. EMG/NCS distal studies are normal with slowing in the wrist.
A different entrapment at the site of the ligament of Struthers affects the nerve near the lower humerus. The difference clinically is that here, pronator teres is affected unlike the pt syndrome in which pt is spared. Compression of the brachial artery with full extension of the arm obliterates the radial pulse.
Differentiate from CTS with Tinel's over site of entrapment, absent Phalen's sign, rare nocturnal exacerbation, weak mm over forearm worse with pronation, elbow flexion or contraction of the superficial flexor of second digit. Consider CTS, plexopathy, other median neuropathy syndromes, or radiculopathy.
Clinically, pain and tenderness appears over the pronator teres, is fatiguaibile, with the pain radiating occassionally to the shoulder. Weakness of the flexor pollicis and apb, and preserved pronation. Sensory changes over the thenar eminence help to make the diagnosis. EMG/NCS distal studies are normal with slowing in the wrist.
A different entrapment at the site of the ligament of Struthers affects the nerve near the lower humerus. The difference clinically is that here, pronator teres is affected unlike the pt syndrome in which pt is spared. Compression of the brachial artery with full extension of the arm obliterates the radial pulse.
Differentiate from CTS with Tinel's over site of entrapment, absent Phalen's sign, rare nocturnal exacerbation, weak mm over forearm worse with pronation, elbow flexion or contraction of the superficial flexor of second digit. Consider CTS, plexopathy, other median neuropathy syndromes, or radiculopathy.
Suprascapular neuropathy
Injury from pressure on/trauma to the shoulder, stab wounds above the scapula, improper use of crutches, stretching of the nerve, eg. volleyball players during serving, r/o rupture of the rotator cuff. In athletics intense activity over weeks may cause it. Baseball pitchers are susceptible. Volleyball players, weight lifters and wrestlers are susceptible to developing it. Many athletes have exclusive or predominant involvement of the infraspinatus muscle.
Clinically one sees difficulty initiating abduction of the arm and externally rotating the arm, with an aching pain in the shoulder joint.The sign is selective wasting and weakness of the supraspinatus and infraspinatus muscles. Testing the deltoid separately means taking the fully abducted arm and having the patient pull backwards; also looking for deltoid atrophy. Also useful are tenderness in the suprascapular notch and pain evoked by forced adduction of the arm.
Gradual onset neuropathies may be due to ganglia in the suprascapular notch and spinoglenoid notch, or malignant tumors from the scapula. True entrapment neuropathies within the notch to a spur or ligament. Inherited calcification of the ligament may occur.
Differential includes ABN (acute brachial neuritis) , and less commonly shoulder joint/rotator cuff disorders, disuse wasting, or combined shoulder/nerve injury. EMG is definitive. MRI can look at entrapment in the suprascapular notch, and determine which muscles and hence which nerves are involved.
Treatment may involve rest, physiotherapy, injections, suprascapular notch exploration (supraglenoid notch if only infraspinatus is involved).
Clinically one sees difficulty initiating abduction of the arm and externally rotating the arm, with an aching pain in the shoulder joint.The sign is selective wasting and weakness of the supraspinatus and infraspinatus muscles. Testing the deltoid separately means taking the fully abducted arm and having the patient pull backwards; also looking for deltoid atrophy. Also useful are tenderness in the suprascapular notch and pain evoked by forced adduction of the arm.
Gradual onset neuropathies may be due to ganglia in the suprascapular notch and spinoglenoid notch, or malignant tumors from the scapula. True entrapment neuropathies within the notch to a spur or ligament. Inherited calcification of the ligament may occur.
Differential includes ABN (acute brachial neuritis) , and less commonly shoulder joint/rotator cuff disorders, disuse wasting, or combined shoulder/nerve injury. EMG is definitive. MRI can look at entrapment in the suprascapular notch, and determine which muscles and hence which nerves are involved.
Treatment may involve rest, physiotherapy, injections, suprascapular notch exploration (supraglenoid notch if only infraspinatus is involved).
Ataxic v. painful form of paraneoplastic neuropathy
Oki Y, Koike H, Iijima M et al. Neurology 2007; 69:564-572.
Group one-- dep sensory disturbance, shows sensory ataxia, markedly abnormal sural nerve,
Group 2-- superficial sensory disturbance- shows severe hyperalgesia, involvement small myelinated fibers and unmyelinated fibers.
Both groups showed an axonal sensory neuropathy with greater diminution of SNAPs in first (sensory ataxia) group. Both groups had about 50% presence of antiHu antibodies. Both groups had some cases with benefit from treating the cancer; immunotherapy was of transient benefit.
Group one-- dep sensory disturbance, shows sensory ataxia, markedly abnormal sural nerve,
Group 2-- superficial sensory disturbance- shows severe hyperalgesia, involvement small myelinated fibers and unmyelinated fibers.
Both groups showed an axonal sensory neuropathy with greater diminution of SNAPs in first (sensory ataxia) group. Both groups had about 50% presence of antiHu antibodies. Both groups had some cases with benefit from treating the cancer; immunotherapy was of transient benefit.
Genitofemoral nerve
Arises from L1 and L2 roots, and branches into the lumboinguinal and external spermatic nerves, supplies the skin over femoral triangle, the cremasteric muscle and the inner upper thigh, labia or scrotum
Branches of the Nerves of forearm
Anterior interosseous:
Flexor pollicus longus
Pronator quadratus
Flexor digitorum profundus I and II
Ulnar:
Flexor carpi ulnaris
Flexor digitorum III and IV
Intrinsic hand muscles
Median-- most flexors in forearm, lumbric alsI and II, and muscles of thenar eminence
Flexor pollicus longus
Pronator quadratus
Flexor digitorum profundus I and II
Ulnar:
Flexor carpi ulnaris
Flexor digitorum III and IV
Intrinsic hand muscles
Median-- most flexors in forearm, lumbric alsI and II, and muscles of thenar eminence
Tuesday, January 8, 2008
Criteria for the diagnosis of multifocalmotor neuropathy
Definite MMN
1. Weakness without objective sensory loss in the distribution of two or more named nerves; during the early stage, the finding of diffuse symmetric weakness rules out MMN
2. Definite conduction block in two or more sites outside common entrapment sites (defined as a decrease of more than 40 % in median or ulnar (not radial) CMAP area or 50 % or more in CMAP amplitude with an increase of less than 30 % in CMAP duration).
3. Normal sensory nerve conduction velocity across the sites with block.
4. Normal sensory nerve conductions for all nerves tested with a minimum of three tested.
5. Absent UMN signs including spastic tone, clonus, extensor plantars, and pseudobulbar palsy
Probable MMN
1. Weakness without objective sensory loss in the distribution of two or more named nerves; during the early stage, the finding of diffuse symmetric weakness rules out MMN
2. The presence of one of the following: probably conduction block in two or more sites outside common entrapment areas, or definite block in one segment and probable block in another outside common entrapment areas.
3. Normal sensory velocities outside the same areas with motor conduction block when study of the segment is technically feasible (ie. not required for segments proximal to the axilla or popliteal fossa).
4. Normal sensory nerve conductions for all nerves tested with a minimum of three tested.
5. Absent UMN signs including spastic tone, clonus, extensor plantars, and pseudobulbar palsy.
(as cited in NEJM 2007; 357:2710, adapted from Olney et al. Muscle Nerve 2003;27:117-121).
1. Weakness without objective sensory loss in the distribution of two or more named nerves; during the early stage, the finding of diffuse symmetric weakness rules out MMN
2. Definite conduction block in two or more sites outside common entrapment sites (defined as a decrease of more than 40 % in median or ulnar (not radial) CMAP area or 50 % or more in CMAP amplitude with an increase of less than 30 % in CMAP duration).
3. Normal sensory nerve conduction velocity across the sites with block.
4. Normal sensory nerve conductions for all nerves tested with a minimum of three tested.
5. Absent UMN signs including spastic tone, clonus, extensor plantars, and pseudobulbar palsy
Probable MMN
1. Weakness without objective sensory loss in the distribution of two or more named nerves; during the early stage, the finding of diffuse symmetric weakness rules out MMN
2. The presence of one of the following: probably conduction block in two or more sites outside common entrapment areas, or definite block in one segment and probable block in another outside common entrapment areas.
3. Normal sensory velocities outside the same areas with motor conduction block when study of the segment is technically feasible (ie. not required for segments proximal to the axilla or popliteal fossa).
4. Normal sensory nerve conductions for all nerves tested with a minimum of three tested.
5. Absent UMN signs including spastic tone, clonus, extensor plantars, and pseudobulbar palsy.
(as cited in NEJM 2007; 357:2710, adapted from Olney et al. Muscle Nerve 2003;27:117-121).
Sunday, January 6, 2008
Accessory neuropathy
1. Intracranially, a tumor such as a schwannoma or meningioma can cause .
2. In jugular foramen, the IX, X, XI nerve involvement is called " Vernet's syndrome" which is due, in order of frequency, to metastases, primary tumors such as schwannomas, an idiopathic syndrome with spontaneous recovery, and sarcoidosis.
3. In the neck, lymph node dissection in the posterior triangle remains the commonest cause, and may also affect the lesser occipital nerve. Other neck dissections, postoperative radiation, carotid endarterectomy, and cannulation of the IJ vein are also reported. Trauma to the posterior triangle from blunt injury, compression from wearing slings, hanging attempt- related injuries, stretch injuries from heavy lifting, glass or knife lacerations, tuberculosis of the cervical lymph nodes (scrofula) or idiopathic causes.
Presentation: Shoulder weakness and pain, and drooping of the shoulder. Trapezius wasting may occur. Paresthesias over the shoulder and scapula may occur.
Examination: Wasting of any part of the three parts of the trapezius. Scapular winging occurs at rest and with movement affecting the upper part of the scapula (v. the lower part with serratus anterior weakness). Shrugging of the shoulders is "worthless" because the levator scapulae (direct innervation from C3 and C4) can do this. Ask the patient to abduct the arms through 180 degrees from side to above the head, straight sideways. The second ninety degrees is accomplished by rotation of the scapula by the upper trapezius and cannot be accomplished otherwise. The middle trapezius is tested by asking the patient to lie prone, and abduct the arm at 90 degrees from the body. The middle trap can be palpated and the stability of the scapula can be assessed. The lower third is assessed with the patient prone, arms lying alongside head, lifting arms, and palpating the lower traps.
If the damage is proximal, the scm (sternocleidomastoid) is usually wasted. Its hard to assess the deltoid/rhomboid,spinati, and serratus anterior if scapula is not stabilized by the trapezius.
Evaluation-- EMG and NCS of the three parts of the trapezius separately. CT/MRI of base of skull/jugular foramen.
Management-- idiopathic-- none. Neck dissection-- may graft the greater auricular nerve. Surgical stabilization of scapula is better than orthotics which usually do not work. The levators and rhomboids can be transferred to scapula effectively. The procedure is effective but rarely done.
2. In jugular foramen, the IX, X, XI nerve involvement is called " Vernet's syndrome" which is due, in order of frequency, to metastases, primary tumors such as schwannomas, an idiopathic syndrome with spontaneous recovery, and sarcoidosis.
3. In the neck, lymph node dissection in the posterior triangle remains the commonest cause, and may also affect the lesser occipital nerve. Other neck dissections, postoperative radiation, carotid endarterectomy, and cannulation of the IJ vein are also reported. Trauma to the posterior triangle from blunt injury, compression from wearing slings, hanging attempt- related injuries, stretch injuries from heavy lifting, glass or knife lacerations, tuberculosis of the cervical lymph nodes (scrofula) or idiopathic causes.
Presentation: Shoulder weakness and pain, and drooping of the shoulder. Trapezius wasting may occur. Paresthesias over the shoulder and scapula may occur.
Examination: Wasting of any part of the three parts of the trapezius. Scapular winging occurs at rest and with movement affecting the upper part of the scapula (v. the lower part with serratus anterior weakness). Shrugging of the shoulders is "worthless" because the levator scapulae (direct innervation from C3 and C4) can do this. Ask the patient to abduct the arms through 180 degrees from side to above the head, straight sideways. The second ninety degrees is accomplished by rotation of the scapula by the upper trapezius and cannot be accomplished otherwise. The middle trapezius is tested by asking the patient to lie prone, and abduct the arm at 90 degrees from the body. The middle trap can be palpated and the stability of the scapula can be assessed. The lower third is assessed with the patient prone, arms lying alongside head, lifting arms, and palpating the lower traps.
If the damage is proximal, the scm (sternocleidomastoid) is usually wasted. Its hard to assess the deltoid/rhomboid,spinati, and serratus anterior if scapula is not stabilized by the trapezius.
Evaluation-- EMG and NCS of the three parts of the trapezius separately. CT/MRI of base of skull/jugular foramen.
Management-- idiopathic-- none. Neck dissection-- may graft the greater auricular nerve. Surgical stabilization of scapula is better than orthotics which usually do not work. The levators and rhomboids can be transferred to scapula effectively. The procedure is effective but rarely done.
Phrenic neuropathies
Causes:
Cervical spine-- motor neuron disease, poliomyelitis, herpes zoster
Neck-- stab wounds, surgery, anesthetic blocks in the brachial plexus; catheterization of internal jugular and subclavian veins, malignancy.
Chest-- thoracic surgery, mediastinal tumor, or irradiation
Uncertain-- Acute brachial neuropathy, diabetes mellitus, sarcoidosis, Guillian barre, idiopathic.
Muscle--NMJ -- acid maltase, polymyositis, myasthenia gravis
Pearls
1. Zoster is usually unilateral and asymptomatic, with herpetic lesions the tipoff and the chest X ray diagnostic.
2. Brachial plexus anesthesia blocks are usually temporary and asymptomatic, but bilateral blocks are not advisable due to risk of total diaphragm paralysis.
3. Metastases in the neck may also cause Horner's syndrome and the recurrent laryngeal nerve, causing vocal cord paralysis, and may be due to breast cancer.
4. The incidence during open heart surgery ranges from 10-85 % and may be due to ice slurry or topical cooling of heart during surgery. It occurs less often with an insulating pad, but may still occur after pericardiectomy or surgery for mediastinal tumors. In this situation it is often left sided. Bilateral injuries are rare but prolonged ventilator dependence is common.
5. In acute brachial plexopathy, 6 % have phrenic dyfunction and present with shoulder pain and dyspnea. Usually thoracic lesions are excluded and EMG and NCS are helpful.
6. Diabetic phrenic neuropathy is common and may account for the breathlessness of some diabetics.
Cervical spine-- motor neuron disease, poliomyelitis, herpes zoster
Neck-- stab wounds, surgery, anesthetic blocks in the brachial plexus; catheterization of internal jugular and subclavian veins, malignancy.
Chest-- thoracic surgery, mediastinal tumor, or irradiation
Uncertain-- Acute brachial neuropathy, diabetes mellitus, sarcoidosis, Guillian barre, idiopathic.
Muscle--NMJ -- acid maltase, polymyositis, myasthenia gravis
Pearls
1. Zoster is usually unilateral and asymptomatic, with herpetic lesions the tipoff and the chest X ray diagnostic.
2. Brachial plexus anesthesia blocks are usually temporary and asymptomatic, but bilateral blocks are not advisable due to risk of total diaphragm paralysis.
3. Metastases in the neck may also cause Horner's syndrome and the recurrent laryngeal nerve, causing vocal cord paralysis, and may be due to breast cancer.
4. The incidence during open heart surgery ranges from 10-85 % and may be due to ice slurry or topical cooling of heart during surgery. It occurs less often with an insulating pad, but may still occur after pericardiectomy or surgery for mediastinal tumors. In this situation it is often left sided. Bilateral injuries are rare but prolonged ventilator dependence is common.
5. In acute brachial plexopathy, 6 % have phrenic dyfunction and present with shoulder pain and dyspnea. Usually thoracic lesions are excluded and EMG and NCS are helpful.
6. Diabetic phrenic neuropathy is common and may account for the breathlessness of some diabetics.
Other high cervical and related disorders
1. Neck-tongue syndrome is due to compression of the C2 ventral ramus. There may be neck pain, occipital numbness, and tongue paresthesias on turning the head. Some patients have congenital abnormalities of the cervical spine.
2. Third occipital headache may have occipital and suboccipital pain. It is a postwhiplash injury headache with temporary and partial relief with nerve blocks. It probably is due to degenerative arthritis of the C2-3 facet joint and is not neurologic in origin.
3. Greater auricular nerve damage is commonly caused by surgery to the neck and face, especially rhytidectomy (face-lift) with numbness around the ear and later, painful neuromas. CEA, parotid surgery, and leprosy can be causative. NERVE CONDUCTIONS CAN BE CONFIRMATORY.
4. Lesser occipital nerve injury occurs during lymph node dissection in the neck (also gets the accessory nerve). The presentation is numbness behind the ear.
2. Third occipital headache may have occipital and suboccipital pain. It is a postwhiplash injury headache with temporary and partial relief with nerve blocks. It probably is due to degenerative arthritis of the C2-3 facet joint and is not neurologic in origin.
3. Greater auricular nerve damage is commonly caused by surgery to the neck and face, especially rhytidectomy (face-lift) with numbness around the ear and later, painful neuromas. CEA, parotid surgery, and leprosy can be causative. NERVE CONDUCTIONS CAN BE CONFIRMATORY.
4. Lesser occipital nerve injury occurs during lymph node dissection in the neck (also gets the accessory nerve). The presentation is numbness behind the ear.
Disorders of the cervical plexus
1. Radiculopathies usually involve C6-7 (see cervical radiculopathies); rarely the C3-4 nerve root foramen is affected with compression of the C4 root. Symptoms are pain and paresthesias in the ear region with sensory loss.
2. The cervical plexus is vulnerable in traction injuries such as motorcycle injuries that also affect the upper trunk of the brachial plexus, and during surgery of carotids (endarterectomy) or radical dissection of the neck. Motor dysfunction other than phrenic injury is hard to detect. Sensory loss in the upper cervical regions is common.
3. Herpes zoster is common in C2 and C3 dorsal root ganglia. Both zosteriform eruptions and postherpetic neuralgia may occur.
4.C2 ganglionopathy/radiculopathy and greater occipital neuropathy (avoid term occipital neuralgia, and cervicogenic headache, and whiplash injury) presents with deep stabbing unilateral pain in the neck and back of the head, with hyper/hypesthesia of scalp and tenderness of the nerve. It is caused by trauma (whiplash), spondylosis, ligamentous entrapment, zoster, neurofibroma (dorsal ramus), and trauma/compression of the GON. "the cardinal symptom is intermittent or continuous numbness or paresthesias (with or without pain) in C2 dermatome. The C2 nerve may be tender to palpate, or patients may have vertigo. Some cases may require surgical exploration.
C2 nerve root is rarely involved in major fracture/dislocation, congenital abnormalities of the cervical spine, , subluxation of the atlas on the axis joint to to rheumatoid arthritis, or bone softening disorders such as Paget's disease, osteogenita imperfecta, and osteomalacia. Whiplash may be a cause but is probably vastly overstated.
Treatment including analgesics and acolar may or may not help, as may injections of anesthetics or corticosteroids. Surgery may reveal severe facet disease, ligamentous entrapment of a ganglion. Procedures may include C2 ganglionectomy or partial sectioning of the C1-3 rootlets.
5. The diversity of causes of "cervicogenic headache" make reports of definitive treatment difficult to evaluate.
2. The cervical plexus is vulnerable in traction injuries such as motorcycle injuries that also affect the upper trunk of the brachial plexus, and during surgery of carotids (endarterectomy) or radical dissection of the neck. Motor dysfunction other than phrenic injury is hard to detect. Sensory loss in the upper cervical regions is common.
3. Herpes zoster is common in C2 and C3 dorsal root ganglia. Both zosteriform eruptions and postherpetic neuralgia may occur.
4.C2 ganglionopathy/radiculopathy and greater occipital neuropathy (avoid term occipital neuralgia, and cervicogenic headache, and whiplash injury) presents with deep stabbing unilateral pain in the neck and back of the head, with hyper/hypesthesia of scalp and tenderness of the nerve. It is caused by trauma (whiplash), spondylosis, ligamentous entrapment, zoster, neurofibroma (dorsal ramus), and trauma/compression of the GON. "the cardinal symptom is intermittent or continuous numbness or paresthesias (with or without pain) in C2 dermatome. The C2 nerve may be tender to palpate, or patients may have vertigo. Some cases may require surgical exploration.
C2 nerve root is rarely involved in major fracture/dislocation, congenital abnormalities of the cervical spine, , subluxation of the atlas on the axis joint to to rheumatoid arthritis, or bone softening disorders such as Paget's disease, osteogenita imperfecta, and osteomalacia. Whiplash may be a cause but is probably vastly overstated.
Treatment including analgesics and acolar may or may not help, as may injections of anesthetics or corticosteroids. Surgery may reveal severe facet disease, ligamentous entrapment of a ganglion. Procedures may include C2 ganglionectomy or partial sectioning of the C1-3 rootlets.
5. The diversity of causes of "cervicogenic headache" make reports of definitive treatment difficult to evaluate.
Cervical spinal nerves-- special anatomic aspects to consider
1. The ventral rami of C1-C4 form the cervical plexus, and C5-C8 the brachial plexus.
2. Exceptionally, C1 spinal nerve divides WITHIN the spinal canal to form a ventral and dorsal ramus, that passes above the arch of C1 to supply the deep muscles of the neck, without sensory fibers. The ventral ramus joins the cervical plexus.
3. The C2 root is very short. The ventral ramus joins the cervical plexus. C2 may project to the brow, whereas pain the back of the head is more likely cervical plexus. The dorsal ramus passes between C1 and C2 and the larger medial branch becomes the greater occipital nerve (C2 dorsal ramus). The lateral branch subserves the paraspinal muscles. That supplies the back of the head. C3,4,5, T1 dorsal rami affect skin on back of the neck.
4. The four cutaneous branches are the greater auricular, lesser occipital, supraclavicular, and transverse cutaneous nerves of the neck. They all emerge from the posterior border of the sternocleidomastoid muscle into the posterior triangle of the neck.
Lesser occipital nerve (C2-3 ventral ramus) affects the skin behind the ear. It affects the lower posterior occiput whereas the greater occipital affects anteriorly.
The greater auricular nerve (C2-3 ventral ramus) affects the skin below and directly behind the ear. Preauricular nerve overlaps trigeminal distribution, pain is dull aching not lancination. Posterior auricular nerve innervates the posterior occiput, mastoid, most of the pinna and posterior parietal area.
The transverse cutaneous nerve (C2-3 ventral ramus) of the neck affects the skin of the neck.
The supraclavicular nerve (C3-4 ventral ramus)affects the skin on top of the shoulder.
5. The phrenic nerve (C5) is the major muscular branch of the cervical plexus.
6. The spinal root of the accessory nerve derives from anterior horn cells and ascends the cord through the foramen magnum and leaves it throught the jugular foramen, together with the IX and X cranial nerves.
More pearls:
1. TMJ and cervical plexus pain may coexist in young patients due to cervical plexus
2. Difficulty swallowing ("pain stuck in my throat") may be due to spasm of cricopharyngeus muscle (external esophageal sphincter) and dyssynergia of posterior pharyngeal muscles (X nerve) that pushes the bolus to the cricopoharyngeus muscle that fails to open rapidly enough.
2. Exceptionally, C1 spinal nerve divides WITHIN the spinal canal to form a ventral and dorsal ramus, that passes above the arch of C1 to supply the deep muscles of the neck, without sensory fibers. The ventral ramus joins the cervical plexus.
3. The C2 root is very short. The ventral ramus joins the cervical plexus. C2 may project to the brow, whereas pain the back of the head is more likely cervical plexus. The dorsal ramus passes between C1 and C2 and the larger medial branch becomes the greater occipital nerve (C2 dorsal ramus). The lateral branch subserves the paraspinal muscles. That supplies the back of the head. C3,4,5, T1 dorsal rami affect skin on back of the neck.
4. The four cutaneous branches are the greater auricular, lesser occipital, supraclavicular, and transverse cutaneous nerves of the neck. They all emerge from the posterior border of the sternocleidomastoid muscle into the posterior triangle of the neck.
Lesser occipital nerve (C2-3 ventral ramus) affects the skin behind the ear. It affects the lower posterior occiput whereas the greater occipital affects anteriorly.
The greater auricular nerve (C2-3 ventral ramus) affects the skin below and directly behind the ear. Preauricular nerve overlaps trigeminal distribution, pain is dull aching not lancination. Posterior auricular nerve innervates the posterior occiput, mastoid, most of the pinna and posterior parietal area.
The transverse cutaneous nerve (C2-3 ventral ramus) of the neck affects the skin of the neck.
The supraclavicular nerve (C3-4 ventral ramus)affects the skin on top of the shoulder.
5. The phrenic nerve (C5) is the major muscular branch of the cervical plexus.
6. The spinal root of the accessory nerve derives from anterior horn cells and ascends the cord through the foramen magnum and leaves it throught the jugular foramen, together with the IX and X cranial nerves.
More pearls:
1. TMJ and cervical plexus pain may coexist in young patients due to cervical plexus
2. Difficulty swallowing ("pain stuck in my throat") may be due to spasm of cricopharyngeus muscle (external esophageal sphincter) and dyssynergia of posterior pharyngeal muscles (X nerve) that pushes the bolus to the cricopoharyngeus muscle that fails to open rapidly enough.
EMG physical examination PEARLS
1. The lack of atrophy in a weak muscle indicates either an upper motor neuron lesion or purely demyelinating lesion and may represent spurious weakness.
2. The lack of weakness may be due to confusion, inattention, uncooperativeness, PAIN, feigning or a somatization disorder.
3. Fasciculations may be present in radiculopathies or other focal neuropathies as well as in disorders of the anterior horn.
4. Examination of the tendon reflexes is more objective than muscle power or sensory testing.
Sensory testing pearls:
1. Hyperesthesia, allodynia or hyperpathia are possible as well as hypesthesia.
2. The distribution of sensory loss is usually partial, often in the distal part of the dermatome,eg. the fingertips only in carpal tunnel syndrome. This may be due to damage only to selected fascicles within a proximal part of the nerve (ie. the lesion need not be distal).
Anatomic pitfalls: dermatome and myotome variations
1. Tibialis anterior, in root stimulation studies, is innervated by L4 75 % of the time, not L5.
2. EDB (in foot) can be L5 or S1 even more variably.
3. Dermatomal maps are based on flimsy anatomic evidence.
2. The lack of weakness may be due to confusion, inattention, uncooperativeness, PAIN, feigning or a somatization disorder.
3. Fasciculations may be present in radiculopathies or other focal neuropathies as well as in disorders of the anterior horn.
4. Examination of the tendon reflexes is more objective than muscle power or sensory testing.
Sensory testing pearls:
1. Hyperesthesia, allodynia or hyperpathia are possible as well as hypesthesia.
2. The distribution of sensory loss is usually partial, often in the distal part of the dermatome,eg. the fingertips only in carpal tunnel syndrome. This may be due to damage only to selected fascicles within a proximal part of the nerve (ie. the lesion need not be distal).
Anatomic pitfalls: dermatome and myotome variations
1. Tibialis anterior, in root stimulation studies, is innervated by L4 75 % of the time, not L5.
2. EDB (in foot) can be L5 or S1 even more variably.
3. Dermatomal maps are based on flimsy anatomic evidence.
Hemorrage into or around nerves
1. Patients on anticoagulation or with bleeding disorders develop hematomas that compress nerves.
2. Hemorrhage into nerves occurs particularly in patients with bleeding disorders, including leukemia, hemophilia and thrombocytopenia
3. Acute stretch injuries may rupture an intraneural blood vessel and cause bleeding into a nerve. For example, the common peroneal nerve in popliteal fossa may be affected after a severe inversion injury of the ankle.
2. Hemorrhage into nerves occurs particularly in patients with bleeding disorders, including leukemia, hemophilia and thrombocytopenia
3. Acute stretch injuries may rupture an intraneural blood vessel and cause bleeding into a nerve. For example, the common peroneal nerve in popliteal fossa may be affected after a severe inversion injury of the ankle.
Injection Injuries into nerves
Mechanism
1. injection injury of nerve
2. Hematoma or hemorrhage around injection site (hours later)
3. Scarring around injection site (weeks later).
1. injection injury of nerve
2. Hematoma or hemorrhage around injection site (hours later)
3. Scarring around injection site (weeks later).
Metastases to the peripheral nerves
1. These are rare and occur with lymphoma and leukemia. It may be due to spread rather than metastasis per se.
2. Compression of peripheral nerves is much more common, eg. brachial plexopathy and lumbar plexopathy.
3. Hemorrhage into the nerve is another possible mechanism.
4. Presentation can include mononeuropathy multiplex, radiculopathy, mononeuropathy, and polyneuropathy.
5. Paraneoplastic syndromes of the peripheral nerves are described.
2. Compression of peripheral nerves is much more common, eg. brachial plexopathy and lumbar plexopathy.
3. Hemorrhage into the nerve is another possible mechanism.
4. Presentation can include mononeuropathy multiplex, radiculopathy, mononeuropathy, and polyneuropathy.
5. Paraneoplastic syndromes of the peripheral nerves are described.
Malignant peripheral nerve sheath tumors (MPNST) Pearls
1. Term includes malignant schwannoma and neurogenic sarcoma
2. In NF-1 MPNST's can occur (2-16 % of patients with NF-1 develop one over their lifetime), or they can occur sporadically, or post-radiation.
3. Occassionally a previously existing benign neurofibroma can transform and become malignant.
4. They are located in the same areas as solitary and plexiform neurofibromas.
5. Pain and nerve dysfunction are greater than in benign tumors.
6. The tumors can become large before being detected.
7. Therapy involves amputation, radiation, chemotherapy.
8. The prognosis is poor with local recurrences and metastases to the lungs.
2. In NF-1 MPNST's can occur (2-16 % of patients with NF-1 develop one over their lifetime), or they can occur sporadically, or post-radiation.
3. Occassionally a previously existing benign neurofibroma can transform and become malignant.
4. They are located in the same areas as solitary and plexiform neurofibromas.
5. Pain and nerve dysfunction are greater than in benign tumors.
6. The tumors can become large before being detected.
7. Therapy involves amputation, radiation, chemotherapy.
8. The prognosis is poor with local recurrences and metastases to the lungs.
Other benign peripheral nerve tumors
1. Besides schwannomas and neurofibromas, other types are rare.
2. The fibrolipoma is a rare fatty tumor that presents as a swelling often in the median nerve, causing motor and sensory symptoms.
3. The intraneural perineuroma (aka hypertrophic neuropathy) usually involves a single peripheral nerve and causes painless but slowly progressive wasting and weakness, with mild or no sensory loss.
4. Non-nerve sheath tumors include: ganglion cysts, hypertrophic neuropathy, lipomas, hemangiomas, and desmoid tumors. Metastases to nerves can also occur (would be classified as malignant though)
2. The fibrolipoma is a rare fatty tumor that presents as a swelling often in the median nerve, causing motor and sensory symptoms.
3. The intraneural perineuroma (aka hypertrophic neuropathy) usually involves a single peripheral nerve and causes painless but slowly progressive wasting and weakness, with mild or no sensory loss.
4. Non-nerve sheath tumors include: ganglion cysts, hypertrophic neuropathy, lipomas, hemangiomas, and desmoid tumors. Metastases to nerves can also occur (would be classified as malignant though)
Peripheral neurofibromas pearls
1. Solitary NF's in otherwise healthy patients (ie. , those without NF-1) may be painless or painful subcutaneous swelling without neurologic features, unless they arise from a major nerve trunk or plexus in which case they may have motor and sensory dysfunction.
2. Multiple neurfibromas such as seen in NF-1 do not transform and are a cardinal feature of NF-1.
3. Plexiform neurofibromas arise from deeply situated nerves and can be very damaging but are highly prevalent in NF-1; in one study 35 % of patients had them in the abdomen and pelvis and four percent in chest and supraclavicular areas. Surgical results for plexiform neurofibromas are not nearly as good as solitary type.
4. In patients without NF-1, spinal tumors are usually schwannomas.
2. Multiple neurfibromas such as seen in NF-1 do not transform and are a cardinal feature of NF-1.
3. Plexiform neurofibromas arise from deeply situated nerves and can be very damaging but are highly prevalent in NF-1; in one study 35 % of patients had them in the abdomen and pelvis and four percent in chest and supraclavicular areas. Surgical results for plexiform neurofibromas are not nearly as good as solitary type.
4. In patients without NF-1, spinal tumors are usually schwannomas.
Schwannoma of the peripheral nerve (benign)
Pearls
1. The most common peripheral nerve tumors occur in any peripheral nerve but especially the spinal nerves, peroneal nerve, ulnar nerve, sympathetic nerves and vagus nerves.
2. In a peripheral nerve the presentation is that of a mass that is often painless with paresthesias and positive Tinel's sign over the nerve. The exception of greater findings occurs if the nerve is in a restricted space such as carpal or fibular tunnel.
3. Schwannomas of deep nerves such as sciatic are difficult to detect.
4. Scwannomas that arise from spinal or sympathetic nerves may extend into and compress the spinal cord.
5. Multiple schwannomas occur primarily but not exclusively in NF-2.
6. 62% neurofibromas, 38% schwannomas
In schannomas function preserved in 89% after resection
1. The most common peripheral nerve tumors occur in any peripheral nerve but especially the spinal nerves, peroneal nerve, ulnar nerve, sympathetic nerves and vagus nerves.
2. In a peripheral nerve the presentation is that of a mass that is often painless with paresthesias and positive Tinel's sign over the nerve. The exception of greater findings occurs if the nerve is in a restricted space such as carpal or fibular tunnel.
3. Schwannomas of deep nerves such as sciatic are difficult to detect.
4. Scwannomas that arise from spinal or sympathetic nerves may extend into and compress the spinal cord.
5. Multiple schwannomas occur primarily but not exclusively in NF-2.
6. 62% neurofibromas, 38% schwannomas
In schannomas function preserved in 89% after resection
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