[Juvenile-onset dystonia with bilateral atrophy of the basal ganglia on MRI].

A 40-year-old man was hospitalized for tremor of the right upper limb, gait disturbance and dysarthria. His course of development had been normal until the age of 14, when difficulties in speaking and walking, and tremor of the upper limb became evident following an episode of fever. His symptoms have been gradually worsening for the past 25 years. His elder sister showed similar clinical symptoms and progressive course of illness. The patient showed no indication of mental retardation. Neurological examination showed dysarthria, slow dyskinetic movement of the tongue, dystonic posture of the left hand, tremor of irregular frequency of the right upper limb, diminished tendon reflex, positive Romberg's sign, diminished vibratory and position sense in the lower limbs and pyramidal signs. Cystometry indicated defective voiding of the bladder. Magnetic resonance imaging of the brain showed bilateral atrophy of the putamina, globus pallidus, caudate nuclei and substantia nigra. MRI showed similar findings in her sister. By electrophysiological and pathological examination, disorders of other systems were evident, such as upper motor neurons, and sensory tract. GM1 and GM2 gangliosidosis appeared the most likely diagnosis, but were ruled out on the basis of the result of lysozomal enzyme assay and rectal biopsy. The present patient's condition may possibly be the result of an unknown metabolic disorder, or a new disease entity affecting various components of the nervous system.