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Taxol has recently been approved for the treatment of ovarian cancer that has failed to respond to other chemotherapeutic agents. A predominantly sensory neuropathy has been reported in patients receiving taxol, but corresponding nerve changes have not been described. The patient described herein received taxol at a dose of 275 mg/m2 every 21 days. The sural nerve biopsy performed after 17 courses of taxol (cumulative dose, 6603 mg) showed severe nerve fiber loss, axonal atrophy, and secondary demyelination. Axonal regeneration was absent. The findings are compatible with a cell body disease or a length-dependent, distal neuropathy with failure of axonal regeneration. The findings observed in taxol-induced neuropathy are important to document for comparison with other neoplastic and paraneoplastic neuropathies affecting patients with cancer.

OBJECTIVE: To determine if response to immunosuppressive treatment in motor neuron syndromes could be predicted on the basis of clinical features, anti-GM1 antibodies, or conduction block. DESIGN: Prospective, uncontrolled, treatment trial using prednisone for 4 months followed by intravenous cyclophosphamide (3 g/m2) continued orally for 6 months. SETTING: All patients were referred to university hospital medical centers. PATIENTS: Sixty-five patients with motor neuron syndromes were treated with prednisone; 11 patients had elevated GM1 antibody titers, and 11 patients had conduction block. Forty-five patients received cyclophosphamide, eight of whom had elevated GM1 antibodies and 10 had conduction block. RESULTS: One patient responded to prednisone, and five patients responded to cyclophosphamide treatment. Only patients with a lower motor neuron syndrome and conduction block improved with either treatment. Response to treatment did not correlate with GM1 antibodies. CONCLUSIONS: GM1 antibodies did not serve as a marker for improvement in patients with motor neuron syndrome treated with immunosuppressive drugs. Patients with amyotrophic lateral sclerosis failed to improve irrespective of laboratory findings.

• OBJECTIVE. —To define clinically an unusual acute paralytic syndrome with features distinctive from those of the Guillain-Barré syndrome and similar to those described in Chinese children and young adults. DESIGN. —Case series. SETTING. —University medical centers. PATIENTS. —Three North American men (mean age, 29 years) who presented with acute symmetric weakness and muscle cramps after a preceding gastrointestinal tract illness. These patients had no sensory symptoms, developed no respiratory insuffiency or facial weakness, and had normal to brisk muscle stretch reflexes. RESULTS. —Results of serial nerve conduction studies were normal except for low-amplitude motor potentials. Needle electromyography revealed diffuse denervation potentials. Cerebrospinal fluid showed an elevated protein level and, in one case, a mild pleocytosis. A sural nerve biopsy specimen in one patient was normal; muscle biopsy specimens showed denervation atrophy. CONCLUSIONS. —These cases resemble those described in Chinese children and young adults and may represent a postviral monophasic process affecting the anterior horn cell or distal motor nerve terminal. Further pathologic correlation will be required to identify the exact site of the lesion. Differentiation is important when considering modes of treatment.

• Four infants presented with severe hypotonia, weakness, and hypoventilation or apnea at birth. Their clinical presentations and courses resembled those of the x-linked recessive form of centronuclear myopathy. Histologic examination of their muscle biopsy specimens showed patterns ranging between centronuclear myopathy and type-1 hypotrophy without central nuclei. Regardless of their gender or the appearance of their biopsy specimens, the children all had a poor outcome. The clinical and biopsy findings in these infants suggest that centronuclear myopathy and type-1 hypotrophy without central nuclei do not represent distinct nosologic entities. It seems more likely that the histologic changes represent abnormalities in fiber size distribution and development, which are nonspecific and which reflect a primary defect at one or more sites in the neuraxis.

• OBJECTIVE. —In individuals who were infected with the human immunodeficiency virus (HIV) we determined the prevalence of peripheral neuropathies (PNs) and explored the relationship between immunologic competence and nerve function. DESIGN. —Cohort survey. SETTING. —US Air Force medical center. PATIENTS. —A population-based cohort of 817 individuals, 798 of whom were HIV-positive as identified by the US Air Force HIV screening program from 1985 to 1989. The average age was 29.2 years, and the majority were male with early-stage HIV disease. MAIN OUTCOME MEASURES. —Neurologists examined all subjects for symptoms and signs of PN. We grouped patients by CD4 T-lymphocyte count. We further studied 300 HIV-infected volunteers without clinical evidence of PN by nerve conduction studies. RESULTS. —Twelve of the 798 HIV-positive subjects had symptoms or signs of PN. All patients with PN had CD4 counts of less than 0.30×109/L (300 cells/mm3. Of the 300 HIV-infected volunteers without clinical evidence of PN who had nerve conduction studies performed, 296 had normal nerve conduction study parameters. Subjects in the group with the lowest CD4 count (<0.20×109/L [<200 cells/mm3]) had significantly lower nerve conduction study parameters than subjects in groups with higher CD4 counts (P<.05). CONCLUSIONS. —Peripheral nervous system involvement is rare in patients with early HIV infection and is predominantly seen in immunologically compromised, HIV-infected persons.

• Eighteen patients with chronic inflammatory demyelinating polyneuropathy were studied with evoked potentials to assess for evidence of central nervous system demyelination. Both visual and brain-stem auditory evoked responses were obtained, and the results were compared with magnetic resonance imaging (MRI). An evoked potential was abnormal in nine of 18 patients, five of whom had central nervous system evidence of demyelination by MRI. Evoked potentials identified four patients with probable anterior optic pathway involvement that was not demonstrable by MRI. These findings continue to support that chronic inflammatory demyelinating polyneuropathy is associated with a central demyelinating disorder and more importantly emphasize the possibility of a common pathogenic mechanism in central and peripheral nerve demyelination.

IN REPLY Pestronk criticized our article1 in two areas. First, he comments that inaccurate statements were made regarding measurements of anti-GM1 ganglioside antibodies in his laboratory. He insists that his methods "correspond closely to the reciprocal of true dilutions," despite the fact that a close inspection reveals that his assay is based on a method of extrapolation. In his assay, serum samples are titered to levels that provide optical densities in a linear range. From the linear range, the expected (not measured) optical density of a 1:100 dilution of the serum is calculated. This value is then multiplied by 1000 and the activity is expressed in units. In the method we1 and others2 employ to measure GM1 antibodies, the results represent the maximum dilution at which reactivity to GM1 is maintained at a level of 3 SDs above normal.A less important point relates