December 2001: rapidly progressive motor weakness, starting in pregnancy.

A 25-year-old woman presented with rapidly progressive motor weakness necessitating ventilation 10 months after the onset. Despite immunosuppressive therapy she died 27 months later, without developing significant extramotor features. Autopsy revealed evidence of both upper and lower motor neuron loss with wide-spread motor and extramotor intraneuronal basophilic inclusions, most of which did not show ubiquitin immunoreactivity. Motor neuron disease with basophilic inclusions appears to be a rare, but distinctive pathological subtype, with most reported cases occurring sporadically in young women and having a rapid clinical progression.