Evidence for altered basal ganglia and cortical functions in transient idiopathic dystonia.

Idiopathic dystonia with onset in the first year of life has been described as a transient movement disorder, in contrast to other forms of idiopathic dystonia We report on a girl who showed, from her 5th month, episodes of dystonic postures of her neck and arm, which lasted for seconds and occurred several times a day. Neurologic findings and the psychomotor development were and remained normal. Neurometabolic screening tests and cerebral magnetic resonance imaging showed normal results. Functional cerebral imaging showed decreased perfusion of the basal ganglia and the left temperomesial cortex using single photon emission computed tomography (SPECT with technetium 99m hexamethylpropyleneamine oxime [99mTc-HMPAO]) and decreased glucose metabolism in the basal ganglia and the cerebellum using positron emission tomography (PET with [18F]fluorodeoxyglucose [18FDG]). Follow-up revealed that the episodes disappeared at the age of 16 months. The findings of PET and SPECT give evidence of an alteration in basal ganglia function but also in functions of other central nervous system regions, which may, however, be temporary.