Reversible ALS-like disorder in HIV infection.

OBJECTIVE: To describe the clinical features, treatment, and outcome of six cases of HIV-1-associated ALS-like disorder.
METHODS: The authors reviewed patients with HIV infection with neurologic symptoms seen over a 13-year period. Patients were identified by using the El Escorial research diagnostic criteria defining three categories of certainty for definite, probable, or possible ALS. Clinical features, EMG, CSF, serum analyses, and imaging and virological studies were assessed.
RESULTS: Six patients with immunodepression (mean CD4(+) cells = 86.2/mm(3); mean age = 34 years) developed distal motor weakness mimicking a monomelic amyotrophy that subacutely progressed regionally or assumed a symmetric distribution on more than one region. EMG was characteristic of motor neuron disease with no multifocal conduction block. Causes other than HIV-1 were ruled out. The unusual rapid extension of the disease and the positive response to antiretroviral therapy suggest that ALS syndrome and HIV infection are etiologically related. HIV-1 might cause an ALS-like disorder by several mechanisms-via neuronal infection, by secretion of toxic viral substance, by inducing the immune system to secrete cytokines, or by inducing an autoimmune disease.
CONCLUSION: These cases suggest that the association between some motor neuron diseases and HIV infection is not coincidental but pathogenetically related and that ALS-like disorder should be considered an HIV-related neurologic complication.