Faculty Bibliography

We report a 76-yr-old man with left femoral nerve distribution weakness resulting from a nontraumatic retroperitoneal hematoma associated with coumadin anticoagulation. Although electric root stimulation was relatively contraindicated, magnetic lumbosacral root stimulation identified a proximal conduction block allowing more extensive assessment of the nerve damage. To our knowledge, this is the first report of magnetic root stimulation in assessment of lumbosacral plexus dysfunction in retroperitoneal hematoma

Acute Quadriplegic Myopathy with selective Thick Filament Loss (AQM-TFL) is likely an under-recognized cause of acquired areflexic quadriplegia in the ICU setting. An autopsy study of a patient with AQM-TFL revealed widespread limb thick filament loss, but with complete diaphragmatic and cardiac sparing and relative intercostal muscle sparing, was observed. Due to increased lipid accumulation, biochemical studies were performed and showed an increased free carnitine percentage, suggesting possible impaired carnitine esterification. These findings suggest that moving muscles might be resistant to the deleterious effects of AQM-TFL. These findings may have therapeutic implications

PURPOSE: Hepatitis C viral [HCV] infection is a chronic multisystem disorder that may have an indolent course initially. Peripheral neuropathy associated with cryoglobulinemia and a systemic vasculitis is a well-described complication of HCV infection. But this neuropathy is not known to have a late-onset acute fulminant phase. This acute fulminant phase is characterized by quadriparesis associated with pulmonary and/or renal insufficiency, and it may occur despite adequate treatment for HCV infection. The purpose of this study is to report that patients treated for chronic HCV infection may manifest a secondary progressive acute fulminant neuropathy associated with respiratory and/or renal insufficiency that is responsive to cyclophosphamide. METHODS: Case series retrospective data analysis. RESULTS: Three patients with biopsy-proven HCV associated vasculitic neuropathy manifested a secondary progressive acute fulminant course resulting in quadriparesis within 5 years of the initial diagnosis. Complete remission was achieved with cyclophosphamide therapy such that all patients became ambulatory. CONCLUSIONS: HCV-associated vasculitic neuropathy may manifest a secondary phase, which is acute, fulminant and progressive that is superimposed on an otherwise slowly progressive disorder. Cyclophosphamide therapy may abort progression and induce remission of this acute fulminant phase

Clinical, laboratory and electrodiagnostic (EDX) characteristics of 62 patients with sensory neuropathy with abnormal skin biopsies were reviewed. Reduced epidermal nerve fibre density (ENFD) was seen in 71% and morphological changes with normal ENFD were seen in 29% of the patients. Patients with small fibre sensory neuropathy may have associated large fibre loss undetected by routine EDX. Identified associations included abnormal glucose metabolism, Lyme vaccination, monoclonal gammopathy, vitamin B12 deficiency, coeliac disease, and diseases of the connective tissue, inflammatory bowel and thyroid. Sensory neuropathy remained undetermined in 50% of the patients

The authors report six patients with multifocal axonal polyneuropathy and the subsequent diagnosis of celiac disease (CD). Five patients did not improve or had only modest improvement following dietary intervention or immune therapies; one patient with marked weakness and mild electrodiagnostic findings had complete resolution of the neuropathy following immunomodulatory therapy. CD may be a cause of multifocal axonal polyneuropathy

The chronic autoimmune neuropathies are a diverse group of disorders, whose diagnosis and classification is based on the clinical presentations and results of ancillary tests. In chronic inflammatory demyelinating polyneuropathy, controlled therapeutic trials demonstrated efficacy for intravenous gamma-globulins, corticosteroids, and plasmaphereis. In multifocal motor neuropathy, intravenous gamma-globulins have been shown to be effective. In the other immune-mediated neuropathies, there are no reported controlled therapeutic trials, but efficacy has been reported for some treatments in non-controlled trials on case studies. Choice of therapy in individual cases is based on reported efficacy, as well as severity, progression, coexisting illness, predisposition to developing complications, and potential drug interactions

BACKGROUND: Celiac disease (CD) is increasingly recognized in North America and is associated with a peripheral neuropathy. OBJECTIVE: To report the clinical characteristics and skin biopsy results in patients with CD and small-fiber neuropathy symptoms. DESIGN: Case series. SETTING: Academic peripheral neuropathy clinic. PATIENTS: Eight patients with CD and neuropathy symptoms.Intervention Three-millimeter punch biopsy using the panaxonal marker protein gene product 9.5 to assess epidermal nerve fiber (ENF) density and a gluten-free diet. MAIN OUTCOME MEASURE: Clinical data and ENF density. RESULTS: All patients had asymmetric numbness and paresthesias. Three had more prominent involvement of hands than feet, and 3 had facial numbness. Celiac disease was diagnosed in 5 after their neuropathy began. The following serum antibody levels were elevated: tissue transglutaminase (n = 6), IgA gliadin (n = 4), and IgG gliadin (n = 7). Results of nerve conduction studies were normal in 7 patients. One patient had mildly reduced sural amplitudes. The ENF density was reduced in 5 patients. The ENF density was at the low limit of the normal range in 3 additional patients, 2 of whom had morphologic changes in axons. Three patients had decreased ENF density at the thigh or forearm, which was more severe than at the distal leg, compatible with a non-length-dependent process. Four reported improvement with a gluten-free diet. One had no improvement after 4 months. Symptoms developed in 2 while receiving a gluten-free diet. CONCLUSIONS: Patients with CD may have a neuropathy involving small fibers, demonstrated by results of skin biopsy. The pattern of symptoms, with frequent facial involvement and a non-length-dependent pattern on skin biopsy findings, suggests a sensory ganglionopathy or an immune-mediated neuropathy. Improvement of symptoms in some patients after initiating a gluten-free diet warrants further study

The electrodiagnostic studies of 13 consecutive patients with multifocal sensory and motor neuropathy of unknown etiology were reviewed to determine whether they exhibit features of demyelination or axonal degeneration. The type and frequency of demyelinating features, fulfillment of electrodiagnostic criteria for chronic inflammatory demyelinating polyneuropathy (CIDP), and response to immunotherapy were noted. Of 13 patients, 11 had at least one electrodiagnostic feature of demyelination at presentation and 2 had none. Seventeen percent to 77% of the patients fulfilled at least one of the published electrodiagnostic CIDP criteria, depending on the criteria used, but the number of demyelinating features per patient was less than reported for unselected patients with CIDP. Patients with multifocal sensory and motor neuropathy had a similar percentage of nerves with partial conduction block or F-wave prolongation as reported for unselected CIDP, but a smaller percentage of nerves exhibiting prolonged distal compound muscle action potential duration, distal latency prolongation or slowed conduction velocities. All treated patients, including 2 who did not meet any CIDP criteria, had at least a moderate response to immunotherapy. The results indicate that a large majority of, but not all, patients with idiopathic multifocal sensory and motor neuropathies exhibit electrodiagnostic features of demyelination, although fewer than seen in classic CIDP

The exact cause of narcolepsy-cataplexy syndrome remains unclear; however, the recent discovery of hypocretin deficiency in the lateral hypothalamus of narcoleptic patients has increased our understanding of its etiology. The authors performed masseter reflex, tibial F response, and blink reflex excitability studies during and between attacks in a 66-year-old man with status cataplecticus. Masseter reflex and F responses were inhibited while the blink reflex R2 component was enhanced during attacks, suggesting either hyperexcitability or disinhibition of pontine and/or medullary interneurons but hypoexcitability of pontine and spinal motor neurons during cataplexy