Sporadic paroxysmal non-kinesigenic dyskinesia: a frequently-misdiagnosed movement disorder.

Paroxysmal non-kinesigenic dyskinesia is a very rare movement disorder. Few cases have been reported in the literature so far. We present a 40-year-old man with non-kinesigenic paroxysmal dyskinesia, which was initially diagnosed as a psychogenic disorder. This case highlights the varied presentation of this condition and an excellent response to clonazepam.