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)

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.

Dermatomal map upper extemity

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 %).

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

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