[A case of progressive supranuclear palsy dramatically improved with L-threo-3,4-dihydroxyphenylserine]

We report a 67-year-old female with progressive supranuclear palsy (PSP) who dramatically improved when given L-threo-3,4-dihydroxyphenylserine (L-DOPS). This patient developed dysarthria, lack of facial expression, and slowness at age 64. She was admitted to a local hospital, diagnosed as having parkinsonism and treated with antiparkinsonian drugs. Despite this treatment, she had difficulty in turning over in bed and standing up from a seat, and began to fall backward at age 65. One year later, she had trouble in walking due to frequent falls and became bedridden. The patient was admitted to our hospital in July 1991 under treatment with 20 mg/200 mg of carbidopa/L-dopa and 4 mg of trihexyphenydyl hydrochloride per day. Neurological examination revealed masked face, pseudobulbar palsy, and dystonic rigidity of the neck and upper trunk. Eye movements were normal except for impaired vertical saccades and convergence inability. Deep tendon reflexes were generally brisk and the plantar responses were flexor bilaterally. Tests of pulsion showed that her postural reflex was markedly disturbed, especially in retropulsion. Her gait showed severe unsteadiness. Neuropsychological tests showed intellectual impairment, frontal lobe dysfunction, and memory disturbance. Computed tomography showed an atrophic midbrain with prominent enlargement of ambient and quadrigeminal plate cisterns. Single photon emission computed tomography (SPECT) using 123-I-isopropyl-iodoamphetamine demonstrated marked frontal hypoperfusion. L-DOPS was administered at a dose of 100 mg per day and gradually increased up to 600 mg per day over a period of five weeks, while carbidopa/L-dopa and trihexyphenidyl hydrochloride were continued as on admission.(ABSTRACT TRUNCATED AT 250 WORDS)