[Compulsive repetition of movements in a case of progressive supranuclear palsy].
A 51-year-old right-handed man with an 8-year history of progressive supranuclear palsy developed a peculiar behavior including compulsive repetition of movements. At the age of 47, it was noted that he continuously scratched his trunk with the right hand. He also scratched his thighs until his trousers were torn. On the scalp, posterior neck and forearms, patches of skin were scraped away and the bleeding wounds were scratched over and over again. Although he perceived pain, he could not terminate the strange scratching movement. He could not stop his eating action even after the bowl became empty. He could not leave the bathroom because he continued to wipe the anus after defecation. Yet the patient was not demented. Psychometric assessments including Wechsler adult intelligence scale revised, meaningful and meaningless syllables memory test. Raven's color matrix test, Wisconsin card sorting test (Keio version), and modified Stroop test were within the normal range. When requested to write a letter or a figure, he was always successful, however, he endlessly wrote the same letter or figure until he was told to stop. Although he repeated the behavior and could not terminate the action by himself, he immediately stopped the action on verbal command. When another task was given during the repetitive action, he responded quickly and successfully. His strange behavior was compulsive because he wanted to cease it, but it was not compulsive-obsessive behavior because he did not feel anxiety or pain when his repetitive action was stopped. It was different from stereotypy because he repeated not only meaningless movements but also meaningful complex actions. Unlike perseveration, he changed his activity immediately and successfully when a new task was given. Magnetic resonance imaging findings were remarkable only for mild atrophy of the midbrain tegmentum. Single photon emission computed tomography with ethyl cysteinate dimer demonstrated hypoperfusion in the frontal lobes and the left thalamus. A thalamofrontal disconnection or dysfunction is suggested as the mechanism underlying the compulsive repetifim of moving its based on the SPECT findings in this patient.