Tuesday, May 19, 2009
Nerve conductions in POEMS synrdome
Presentation is symmetric peripheral neuropathy resembling CIDP, with areflexia and mixed demyelinating.axonal features. The systemic features include organomegaly, endocrinopathy, monoclonal serum protein ( M protein), and dermatologic abnormalities In a study of 138 patients with POEMS seen over 47 years, Mauermann et al found slowed motor and sensory velocity, prolonged distal latiencues and F waves. However, unlike CIDP there was rarely temporal dispersion or conduction block.
Saturday, February 21, 2009
Glycogenosis type II in adults
Bembi et al. Diagnosis of glycogenosis type II. Neurology 2008; 71: S2: S4-S11.
Also known as glycogen storage disease type II, Pompe d or acid maltase deficiency caused by a mutation in the gene encoding acid alpha-glucosidase (GAA) enzyme leading to accumulation of glycogen in lysosomes of several tissues including cardiac skeletal and smooth muscle cells.
In juvenile/adult type, phenotype may vary somewhat and more than 200 mutations of the GAA gene are reported. In adults, skeletal muscle involves the proximal lower limbs, and paraspinal muscles often followed by severe diaphragmatic and accessory muscle failure. Complaints may include exertional pain, cramps and aches, back pain, slow disease progression. Respiratory involvement may occur early and may be presenting symptom in 30 % of cases. Sleep apnea, exertional dyspnea and RTI's are common.
Evaluation should include CPK (high in 95%), ALT, AST, DH, +/- urinary Glc4 . NCS are normal. EMG is nonspecific shows fibs, myotonic and myopathic findings. Classic muscle biopsy may show acid phos positive cytoplasmic vacuoles but may be negative. Biochemical assays for GAA activity are often needed to confirm. Skeletal muscle or skin fibroblasts may be used. Molecular analysis of the gene may also be needed. In adults cardiac muscles is usually not affected, unlike infants and juveniles.
The differential diagnosis includes Becker, limb girdle, scapuloperoneal, rigid spine s, other glycogen related diseases (debrancher deficiency, branching enzyme def, myophosphorylase def, PFK def, Danon disease, mitochondrial disease, polymyositis.
MRI's in adults (n=11) with confirmed disease showed adductor magnus, semimembranosus, semitendinosis involved early on. Later, fatty infltration occurs in long head of biceps femoris, 3 heads of vastus, with SPARING OF SHORT HEAD OF BICEPS, SARTORIUS, RECTUS, GRACILIS AND PERIPHERAL PART OF VASTUS LATERALIS. CALF MUSCLES ARE NORMAL.
PEARL 2 DISTINGUISHING FEATURES FROM OTHER MYOPATHIES IS SPARING OF SHORT HEAD OF BICEPS AND TENSOR FASCIA LATA WITH ATROPHY OF OTHER PELVIC MUSCLES.
Respiratory management: Cough peak expiratory flow (CPEF) is single best test to determine if patient can clear secretions with a threshold value of 160 L/min being adequate. A high negative maximal inspiratory pressure (>80 cm H2O) or high positive maxinal expiratory pressure (>90 cm H2O) excludes relavant inspiratory or expiratory weakness. Sniff expiratory pressure should also be checked.
Sleep disordered breathing refers to central, obstructive or mixed apnea, hypoventilation or both during sleep. SDB occurs in two thirds. Hypoventilation during REM sleep is due to decreased tidal volume especially during REM sleep. OSA may be life threatening. Orthopnea and dyspnea may be late findings. Late tachypnea at rest occurs. On exam look for failure of outward distension of abdomen during breathing (inspiration) accessory recruitment and mucus encumbrance of upper and lower airways.
No outpatient surgery should be done, and anesthesia consulted.
Genetics usually is AR. Risk of being a carrier for a sib of an affected patient is 2/3, and risk of being a carrier for sibs of a parent of an affected patient is 1/2. Risk of an affected child for a sib of an affected patient is > 1/600 and for sibs of a parent, > 1/800.
A clinical trial with a Genzyme drug, alglucosidase alfa resulted in improved walking distance and stabilized pulmonary function over an 18 month period (van der Ploeg et al., A randomized study of alglucosidase alfa in late onset Pompe's disease NEJM 2010; 362: 1396-1406) (ClinicalTrials.gov.number, NCT00158600). Outcome measures were six minute walk and percentage of predicted FVC.
Also known as glycogen storage disease type II, Pompe d or acid maltase deficiency caused by a mutation in the gene encoding acid alpha-glucosidase (GAA) enzyme leading to accumulation of glycogen in lysosomes of several tissues including cardiac skeletal and smooth muscle cells.
In juvenile/adult type, phenotype may vary somewhat and more than 200 mutations of the GAA gene are reported. In adults, skeletal muscle involves the proximal lower limbs, and paraspinal muscles often followed by severe diaphragmatic and accessory muscle failure. Complaints may include exertional pain, cramps and aches, back pain, slow disease progression. Respiratory involvement may occur early and may be presenting symptom in 30 % of cases. Sleep apnea, exertional dyspnea and RTI's are common.
Evaluation should include CPK (high in 95%), ALT, AST, DH, +/- urinary Glc4 . NCS are normal. EMG is nonspecific shows fibs, myotonic and myopathic findings. Classic muscle biopsy may show acid phos positive cytoplasmic vacuoles but may be negative. Biochemical assays for GAA activity are often needed to confirm. Skeletal muscle or skin fibroblasts may be used. Molecular analysis of the gene may also be needed. In adults cardiac muscles is usually not affected, unlike infants and juveniles.
The differential diagnosis includes Becker, limb girdle, scapuloperoneal, rigid spine s, other glycogen related diseases (debrancher deficiency, branching enzyme def, myophosphorylase def, PFK def, Danon disease, mitochondrial disease, polymyositis.
MRI's in adults (n=11) with confirmed disease showed adductor magnus, semimembranosus, semitendinosis involved early on. Later, fatty infltration occurs in long head of biceps femoris, 3 heads of vastus, with SPARING OF SHORT HEAD OF BICEPS, SARTORIUS, RECTUS, GRACILIS AND PERIPHERAL PART OF VASTUS LATERALIS. CALF MUSCLES ARE NORMAL.
PEARL 2 DISTINGUISHING FEATURES FROM OTHER MYOPATHIES IS SPARING OF SHORT HEAD OF BICEPS AND TENSOR FASCIA LATA WITH ATROPHY OF OTHER PELVIC MUSCLES.
Respiratory management: Cough peak expiratory flow (CPEF) is single best test to determine if patient can clear secretions with a threshold value of 160 L/min being adequate. A high negative maximal inspiratory pressure (>80 cm H2O) or high positive maxinal expiratory pressure (>90 cm H2O) excludes relavant inspiratory or expiratory weakness. Sniff expiratory pressure should also be checked.
Sleep disordered breathing refers to central, obstructive or mixed apnea, hypoventilation or both during sleep. SDB occurs in two thirds. Hypoventilation during REM sleep is due to decreased tidal volume especially during REM sleep. OSA may be life threatening. Orthopnea and dyspnea may be late findings. Late tachypnea at rest occurs. On exam look for failure of outward distension of abdomen during breathing (inspiration) accessory recruitment and mucus encumbrance of upper and lower airways.
No outpatient surgery should be done, and anesthesia consulted.
Genetics usually is AR. Risk of being a carrier for a sib of an affected patient is 2/3, and risk of being a carrier for sibs of a parent of an affected patient is 1/2. Risk of an affected child for a sib of an affected patient is > 1/600 and for sibs of a parent, > 1/800.
A clinical trial with a Genzyme drug, alglucosidase alfa resulted in improved walking distance and stabilized pulmonary function over an 18 month period (van der Ploeg et al., A randomized study of alglucosidase alfa in late onset Pompe's disease NEJM 2010; 362: 1396-1406) (ClinicalTrials.gov.number, NCT00158600). Outcome measures were six minute walk and percentage of predicted FVC.
Peroneal intraneural ganglia: clinical and electrical findings
Young NP, Sorenson EJ, Spinner RJ, Daube JR. Clinical and electrodiagnostic correlates of peroneal intraneural ganglia. Neurology 2009; 72: 447-452.
Common peroneal neuropathy (CMP) with (n=22) and without (n=11) IG.
Features found with CMP + IG group but not found in -IG group: greater body mass, more pain at knee (52 v . 0 %); more likely fluctuating weakness with weight bearing ( 48 v. 4 %); and palpable mass at fibular head ( 47 v. 0 %). Less presentation of weight loss, immobility or leg crossing. There were no electrophysiologic differences. Tinel's sign and weakness were present in both groups. Higher grade of fibrillations were usually found in tibialis anterior than peroneus longus reflecting cmp. MRI or ultrasound was used to diagnose the entity.
Friday, February 20, 2009
NCS Safety with defbrillators
AANEM report 2006 patients underwent NCS with sensing pacemaker electrodes. The electrical impulses in 15 patients with varous types of defibrillators were never detected by the sensing amplifier of the defibrillator or pacemaker. It did not affect the settings or cause the defibrillator to charge. Monitoring and and pre/post interrogations were normal. Conclusion, NCS are safe in patients with implanted cardiac pacemakers and defibrillators with bipolar sensing configurations.
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.
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