Raymond G. Auger

A randomized trial of intravenous immunoglobulin in inflammatory demyelinating optic neuritis.

Objective: To determine whether IV immunoglobulin (IVIg) reverses chronic visual impairment in MS patients with optic neuritis (ON). Methods: In this double-blind, placebo-controlled Phase II trial, 55 patients with persistent acuity loss after ON were randomized to receive either IVIg 0.4 g/kg daily for 5 days followed by three single infusions monthly for 3 months, or placebo. Results: The trial was terminated by the National Eye Institute because of negative results when 55 of the planned 60 patients had been enrolled. Fifty-two patients completed the scheduled infusions, and 53 patients completed 12 months of follow-up. Analysis of this data indicated that a difference between treatment groups was not observed for the primary outcome measure, improvement in logMAR visual scores at 6 months (p = 0.766). Exploratory secondary analyses suggested that IVIg treatment was associated with improvement in visual function (including logMAR visual scores at 6 months and visual fields at 6 and 12 months) in patients with clinically stable MS during the trial. Conclusions: IVIg administration does not reverse persistent visual loss from ON to a degree that merits general use.

Hemifacial spasm Clinical and electrophysiologic observations

Twenty-three patients with hemifacial spasm were studied clinically and electrodiagnostically. Seven patients had mild facial weakness. All patients had clinical evidence of synkinesis, which often varied considerably. Facial nerve conduction and blink reflex latencies were normal. Facial synkinesis could be measured objectively on the involved side in all patients by simultaneously recording from the orbicularis oculi and orbicularis oris muscles at the time of supraorbital nerve stimulation. Using this procedure, synkinesis was also observed in association with aberrant regeneration after Bell palsy but was not seen in other movement disorders involving the face. The demonstration of synkinesis and its variability in hemifacial spasm can be of value in differentiating hemifacial spasm from other movement disorders affecting the face and provides further insight into its pathogenesis.

Hemifacial spasm: results of microvascular decompression of the facial nerve in 54 patients.

During the 10-year period between January 1975 and December 1984, 367 patients with hemifacial spasm were examined at our institution. Because of the severity of the spasm, 54 patients underwent surgical management that consisted of microvascular decompression of the facial nerve. Postoperatively, the hemifacial spasm was completely resolved in 44 patients (81%), but 6 of these patients had subsequent recurrence of the condition. An additional five patients (9%) experienced improvement but were not totally free of the spasm. Five patients (9%) received no benefit from the procedure. Complications occurred in 19 patients (35%) but were usually transient. The most serious complication was permanent ipsilateral hearing loss, which occurred in eight patients (15%). Thus, in general, microvascular decompression of the facial nerve effectively alleviates hemifacial spasm.

Neurophysiologic studies in Morvan syndrome

This study was conducted to clarify the clinical and neurophysiologic characteristics of patients with Morvan syndrome, and to compare and contrast this syndrome with other forms of autoimmune encephalitis. A retrospective chart review of the clinical features and neurophysiologic studies of two cases of Morvan syndrome seen at the Mayo Clinic was performed. Neurophysiologic studies included polysomnography, comprehensive autonomic testing, MRI, positron emission tomography, EEG, and single-photon emission computed tomography. In two cases of Morvan syndrome, the clinical features, electrophysiologic findings, and immunologic studies (high levels of voltage-gated potassium channel antibodies) were consistent with previously reported findings. Several novel observations were made. Autonomic testing demonstrated peripheral autonomic neuropathy in addition to autonomic hyperactivity. Polysomnography showed complete absence of sleep. Neuroimaging study findings were largely normal. Morvan syndrome is an autoimmune disorder affecting both the peripheral and central nervous system. Neurophysiologic studies demonstrate hyperexcitability of peripheral nerves, autonomic dysfunction, and severe insomnia. The absence of abnormalities on imaging studies suggests that central nervous system symptoms are related to functional rather than structural disruption of neural networks.

Microvascular decompression of the facial nerve for hemifacial spasm Clinical and electrophysiologic observations

Eight patients with idiopathic hemifacial spasm were studied before and after decompression of the facial nerve. Seven patients had an excellent clinical response to surgery, with total resolution of the spasm. One patient had a complete facial palsy and sensorineural deafness on the involved side after surgery, with recurrence of the spasm 6 months later. In all patients, synkinetic activity was present on the involved side before surgery and disappeared after surgery. These findings suggest that the disorder involves the extra-axial portion of the facial nerve. The findings do not require an etiologic role of vascular compression because the response to surgery could be related either to mild trauma of the nerve during the surgical procedure or to subsequent fibrosis.

Myasthenia, thymoma, presynaptic antibodies, and a continuum of neuromuscular hyperexcitability

To the Editor: We read with interest the case report by R. Staudinger and K. Henry1 describing the clinical improvement in a patient with AIDS-associated myelopathy after the use of highly active antiretroviral combination therapy. This is the first reported case of improvement of myelopathy with antiretroviral agents, and it may have important implications in the understanding of the pathogenesis and treatment of this rare but disabling complication of HIV infection. However, a number of considerations must be made before accepting the conclusions that the improvement resulted from antiretroviral treatment. First, we think that the authors should have quantified the evaluation of spinal cord function in order to strengthen their conclusions. Objective measurement of spinal cord function, such as central conduction time (CCT) of the somatosensory evoked potentials (SEPs), can be used to monitor the clinical progression of the disease.2 Neurophysiologic tests would have supported the clinical diagnosis at baseline and repeat SEPs could have helped determine whether the observed clinical improvement was accompanied by improved conduction of electrical impulses through the spinal cord. We have recently encountered a similar patient with AIDS-associated myelopathy whose symptoms improved greatly after the introduction of highly active antiretroviral combination therapy. However, despite a subjective improvement of strength a few weeks after starting therapy, he had slight worsening of CCT when SEPs were repeated. It is therefore possible that the clinical improvement observed after starting antiretroviral medications was related to the overall improvement of the patient’s general health that accompanied the dramatic increase in CD4 cell count and suppression of plasma viral load. The authors also argue that the dramatic reduction of the viral load may explain the clinical improvement, yet they do not report CSF viral load before and after starting combination antiretroviral therapy. Although the relationship between plasma and CSF viral load is not completely understood, there is a known relationship between AIDS-dementia and elevated CSF viral burden, and in individual patients there may be no association between plasma and CSF viral loads.3 Finally, although the antiretroviral regimens most effective in treating HIV-related CNS disorders have not yet been established, the regimen used in this patient included only one drug (stavudine) with favorable CSF penetration.4-6 We believe that objective measures of spinal cord function and measurement of CSF viral load should have been used to support the hypothesis that the clinical improvement was related to viral load suppression rather than the consequence of general health improvement.

Hemimasticatory spasm: Clinical and electrophysiologic observations

Hemimasticatory spasm is a rare disorder of the trigeminal nerve that produces involuntary jaw closure due to paroxysmal unilateral contraction of jaw-closing muscles. We report three patients with this disorder. Electrophysiologic studies demonstrated normal blink and masseter reflexes. The masseter inhibitory reflex was absent during periods of spasm. Needle electromyography demonstrated irregular bursts of motor unit potentials that were identical to the pattern observed in hemifacial spasm. The electrophysiologic findings suggest ectopic excitation of the trigeminal motor root or its nucleus, an abnormality that is analogous to ectopic excitation of the facial nerve in hemifacial spasm. One patient improved temporarily with surgery, one improved while on treatment with carbamazepine, and another responded favorably to botulinum toxin injection.

Management of unruptured intracranial arteriovenous malformations : a decision analysis

The management of unruptured intracranial arteriovenous malformations (AVMs) is controversial. Some authorities favor elective excision of the AVM before it bleeds, whereas others advise nonintervention unless the AVM bleeds, at which time surgical excision is performed in those who survive. A Markov model was developed that stimulates a clinical trial in which cohorts of patients with unruptured AVMs were assigned to either elective excision of their AVMs or conservative treatment (unless the AVM bled). Incremental utilities for both strategies were calculated at the end of each year after the beginning of the trial and are expressed as quality and risk-adjusted life years. The process was continued until all members of the cohorts had died. The mean quality and risk-adjusted life expectancy for members of a cohort was calculated by dividing the total number of quality and risk-adjusted life years the cohort had accumulated by the size of the cohort. If the baseline values for surgical complications were used in the computation, the quality and risk-adjusted life expectancy for the surgical cohorts was at least 1 quality and risk-adjusted life year greater than for nonsurgical cohorts up to age 44. If a more favorable complication rate were used, elective surgery could benefit selected patients in their early 60s when the location and configuration of the AVM was favorable. Elective surgical resection is justified in many instances before rupture, particularly in young patients who have intracranial AVMs that have a favorable location, size, and venous drainage.

Hemifacial spasm associated with epidermoid tumors of the cerebellopontine angle.

Hemifacial spasm (HFS) is rarely due to serious compressive lesions, such as tumors, aneurysms, or vascular malformations, located in the cerebellopontine angle. Because of the interesting association of HFS with epidermoid tumors, we reviewed the records of all patients with HFS and all patients with intracranial epidermoid tumors seen from January 1975 to December 1986. Of the 18 patients who had epidermoid tumors of the cerebellopontine angle, 3 (17%) had a facial movement disorder that resembled HFS at sometime during their illness. There were 429 patients who had HFS with no obvious serious compressive lesion of the facial nerve. Therefore, HFS was associated with epidermoid tumor in 0.7% of cases. All 3 patients developed other findings due to involvement of adjacent neural structures. Patients with HFS have a low probability of having a serious compressive lesion, but those with atypical features should be evaluated for cerebellopontine angle masses such as epidermoid tumors.

Role of the blink reflex in the evaluation of sensory neuronopathy

Article abstract Because of an incidental observation that the blink reflex was normal in paraneoplastic sensory neuronopathy (SN) and frequently abnormal in nonparaneoplastic SN, the authors reviewed the electromyographic records of patients with SN in whom blink reflex studies were performed. The blink reflex was normal in all 17 patients with paraneoplastic SN and abnormal in 20 of 43 patients with nonparaneoplastic SN. Although it does not exclude paraneoplastic SN, an abnormal blink reflex favors a nonparaneoplastic etiology.