Rapidly fatal neuropathies and an ALS clinical presentation

OBJECTIVES - The objective of this report is to describe patients with an unusually severe, rapidly fatal acquired polyneuropathy. METHODS - The clinical, electrodiagnostic (EDX), laboratory, and pathological findings in three patients with a distinctive form of neuropathic illness are discussed. RESULTS - Three patients, ages 67, 54, and 50, had clinical findings that met accepted clinical criteria for amyotrophic lateral sclerosis (ALS) - definite in two and probable in one. The EDX studies in these patients had abnormalities that would be highly atypical for ALS. There were features consistent with an asymmetrical, non-length-dependent process as well findings consistent with demyelination - features consistent with a chronic acquired polyneuropathy. All patients had a rapidly progressive course with death because of respiratory failure in 4-30 months. The patients did not respond to immunomodulating therapies. Extensive evaluations in these patients did not reveal a cause for the patients' neuropathies. Postmortem examination in two of the patients did not reveal evidence for ALS. In one of these patients, there were pathological findings thought possibly consistent with an immunologically mediated process. CONCLUSION - This report emphasizes the importance of considering other diagnoses in patients who clinically appear to have ALS and raise the specter of an as of yet poorly understood, severe neuropathic illness.