Pseudocataplexy and transient functional paralysis: a spectrum of psychogenic motor disorder.

The authors describe and discuss a syndrome of transient psychogenic weakness usually mistaken for cataplexy but which has a close association with a depressive mental state. Four patients were referred to the authors with suspected neurological causes of transient weakness, including cataplexy in three cases, for whom the eventual diagnosis was of a functional or psychogenic motor disorder, related in most cases to depression. This variety of transient functional weakness is related to conditions such as nonepileptic attack disorder, persistent functional weakness, catatonia, and depressive motor retardation. These cases point to the existence of a syndrome of transient motor weakness which resembles cataplexy and has features in common with other forms of mood induced psychogenic weakness such as psychomotor retardation and catatonia. Psychogenic "pseudocataplexy" is a diagnostic consideration in patients with atypical cataplexy, especially in the context of mood disturbance. Despite its close resemblance to cataplexy, pseudocataplexy has a different pathogenesis and requires a different approach to management.