Retrospective psychological evaluation of nine patients with stiff-man syndrome 
(SMS), seven of whom evidenced autoimmune disease, revealed a characteristic set 
of psychological symptoms or features: Major stressful life events preceded the 
development of permanent symptoms by 6 months or less (seven patients); 
transient motor symptoms occurred in emotionally distressing situations months 
or even years before the onset of a permanent motor deficit (five patients); 
after onset, similar situations specifically precipitated or augmented stiffness 
and spasms (five patients). We also found task-specific fear resembling 
agoraphobia (six patients) and loss or invalidation of one or both parents, or 
loss of home, in childhood (seven patients). Eight patients were initially 
misdiagnosed as having psychogenic movement disorder. We conclude that the 
common misdiagnosis of SMS as a psychogenic movement disorder is due to the 
compelling association of a set of salient psychological features, bizarre and 
fluctuating motor symptoms, and lack of approved neurologic signs.