Faculty Bibliography

Neuropathy following vaccination has been reported; however, biopsy-confirmed small fiber neuropathy has not been described. We report five patients who developed paresthesias within one day to two months following vaccination for rabies, varicella zoster, or Lyme disease. On examination, there was mild sensory loss in distal extremities, preserved strength, normal or minimally abnormal electrodiagnostic findings, and decreased epidermal nerve fiber densities per skin biopsy. Empiric immunomodulatory therapy was tried in two patients and was ineffective. All patients' symptoms have improved, but persist. We conclude that an acute or subacute, post-vaccination small fiber neuropathy may occur and follow a chronic course

OBJECTIVE: The objective of this study was to evaluate how the number of demyelinating findings (DF) on nerve conductions affects sensitivity and specificity of electrodiagnostic criteria for chronic inflammatory demyelinating polyneuropathy (CIDP). METHODS: Electrodiagnostic findings of 26 consecutive patients with CIDP were compared with amyotrophic lateral sclerosis (ALS) and diabetic polyneuropathy controls. Patients with CIDP were divided into typical and atypical CIDP, as defined elsewhere. RESULTS: Depending on the minimal required number (MRN) of DF on nerve conductions, sensitivities decreased from an arbitrary 100% to 58% and 54%, for an MRN of 1, 2, and 3, respectively, as specificities increased, from 48% to 81% and 95%, respectively. The number of DF per patient was higher in typical CIDP than in atypical CIDP. CONCLUSIONS: The considerable gap between specificity and sensitivity is the reason for controversy regarding the MRN for the diagnosis of CIDP. Requiring 2 or more DFs to identify CIDP increases specificity from 48% to 81% but lowers sensitivity from 100% to 58%. For patients with other potential causes of neuropathy, the requirement of 2 or more DFs could further increase specificity

BACKGROUND: Cerebellar syndrome and small fiber neuropathy may complicate celiac disease (CD) and may be resistant to a strict gluten-free diet. METHODS: Case series. RESULTS: We report three patients with biopsy-proven CD who developed cerebellar ataxia and neuropathic pain despite strict adherence to a gluten-free diet. A small fiber neuropathy was suggested by skin biopsy findings in two patients. All patients' symptoms, including small fiber neuropathy symptoms, responded to treatment with intravenous immunoglobulin (IVIG). Discontinuation of IVIG in two patients resulted in worsened ataxia that reversed after resumption of IVIG. CONCLUSION: Intravenous immunoglobulin may be effective in treating cerebellar ataxia and small fiber neuropathy associated with CD, suggesting an immune pathogenesis. Further prospective, controlled studies are necessary to determine the long-term response to IVIG or other immunomodulation therapy

Myelin protein zero (MPZ) mutations cause demyelinating neuropathies that range from severe neonatal to milder adult forms. We report a 65-year-old woman with slowly progressive leg weakness starting at 47. Examination revealed distal weakness and atrophy in all extremities, impaired light touch in both feet and pin perception to proximal calves, absent leg reflexes, and unsteady gait. Electrodiagnostic studies revealed a severe sensorimotor polyneuropathy with conduction velocities of 25 m/s - to normal. The conduction velocities in the upper 20's were seen in lower extremities with severe reduction of the corresponding compound muscle action potential amplitudes. She had a MPZ mutation with A-C transversion (nucleotide: 116, codon: 10, histidine-to-proline). Her sister has an identical mutation, with high arches, distal leg weakness, decreased vibration sensation in toes and ankle areflexia. Nerve conduction studies revealed a moderate-severe sensorimotor polyneuropathy with nerve conduction velocities of 36 m/s - to normal. Their mother had an abnormal gait and conduction velocities of 29-30 m/s. A third sister is clinically and genetically unaffected. One report has previously described four patients with this mutation with similar clinical and electrodiagnostic features. In patients tested for possible CMT, the frequency of MPZ His-Pro codon 10 substitutions was 0.11% (27 of 24,076 alleles)

PURPOSE: This paper describes an improved electrodiagnostic methodology for posterior antebrachial cutaneous nerve (PABC) neuropathy based on retrospective analysis. METHODS: Results of PABC nerve conduction studies in 14 control patients and 3 patients with left PABC neuropathy are included. Stimulation was performed 0.5 to 2.0 cm above the lateral epicondyle, and the recordings were acquired at 12 cm, 15 cm and 20 cm distally. Data was evaluated using the mean A+/- standard deviation, calculated for descriptive analysis of continuous variables whereas frequencies and percentages were determined for categorical variables. Abnormal cutoff values including side-side comparison values were established so that all normal control values would fall within the normal range. RESULTS: PABC conduction studies with 20 cm recording distance demonstrated abnormal electrodiagnostic findings in all 3 patients, while more proximal recordings failed to document the neuropathy. CONCLUSION: The recording of PABC responses at 12 cm, 15 cm and 20 cm distal to the stimulating electrode offers a more comprehensive evaluation and may be a more sensitive test for evaluation of suspected PABC neuropathy, in comparison to traditional 12 cm recording

Patients with anti-myelin associated glycoprotein (anti-MAG) neuropathy have uniform slowing without temporal dispersion, but do usually have disproportionately distal slowing. We evaluated distal compound muscle action potential (CMAP) dispersion in 29 patients with anti-MAG/sulphated glucuronyl paragloboside (SGPG) neuropathy (titres > or = 12,800). Among 138 motor responses, 15% (tibial), 7.3% (peroneal), 10.7% (median) and 13.8% (ulnar) had distal CMAP duration > 9 ms. Disproportionate distal slowing with normal distal CMAP duration in the arms may be useful to differentiate chronic inflammatory demyelinating polyneuropathy from anti-MAG/SGPG associated neuropathy

Celiac disease is an immune-mediated disorder triggered by ingestion of wheat gliadin and related proteins in genetically susceptible individuals. In addition to the characteristic enteropathy, celiac disease is associated with various extraintestinal manifestations, including neurologic complications such as neuropathy, ataxia, seizures, and neurobehavioral changes. The cause of the neurologic manifestations is unknown, but autoimmunity resulting from molecular mimicry between gliadin and nervous system proteins has been proposed to play a role. In this study, we sought to investigate the immune reactivity of the anti-gliadin Ab response toward neural proteins. We characterized the binding of affinity-purified anti-gliadin Abs from immunized animals to brain proteins by one- and two-dimensional gel electrophoresis, immunoblotting, and peptide mass mapping. The major immunoreactive protein was identified as synapsin I. Anti-gliadin Abs from patients with celiac disease also bound to the protein. Such cross-reactivity may provide clues into the pathogenic mechanism of the neurologic deficits that are associated with gluten sensitivity

Long-standing ankylosing spondylitis may predispose a patient to serious cervical injury in the setting of minor trauma. Early diagnosis is essential to a favorable outcome. We report a 75-year-old man whose relatively minor trauma in the setting of AS resulted in a cervical fracture and callus formation, which masqueraded as a tumor. The patient developed neck pain, bilateral hypoglossal nerve palsy with dysarthria, and dysphagia that ultimately resulted in his death. This case illustrates progressive neurologic signs of gradual disarticulation of the skull from the cervical spine. The situation is considered of importance because it emphasizes the need for early recognition and possible intervention in the presence of hypoglossal symptoms. The specific combination of long-standing ankylosing spondylitis and minor trauma is one setting in which a clinician must be alerted. Early consideration of neck immobilization is emphasized

PURPOSE: To correlate the electrodiagnostic and clinical features of patients with demyelinating abnormalities and neuropathy of otherwise unknown etiology. METHODS: We examined the records of patient with demyelinating abnormalities and no other cause for neuropathy that were evaluated in our electrophysiology laboratory over the course of a year, to correlate the clinical and electrodiagnostic features. RESULTS: Eight percent of all patients had one or more demyelinating abnormalities. Demyelinating features were significantly more numerous in generalized or asymmetric neuropathy than in distal polyneuropathy. The peroneal nerve was the most commonly affected in all phenotypes, and none of the patients with distal neuropathy had F-wave prolongation in the demyelinating range. CONCLUSIONS: The number and type of demyelinating abnormalities in patients with polyneuropathy vary with the clinical phenotype. The clinical presentation should be considered in developing or evaluating electrodiagnostic criteria for demyelinating neuropathies