Case 27-2002

Abstract

A 5 1 ⁄ 2 -year-old boy was admitted for video electroencephalographic monitoring to investigate his seizures.The boy had been born to a 21-year-old woman by spontaneous vaginal delivery after an uncomplicated, full-term, second pregnancy. He sat up at nine months of age and walked at one year. At 18 to 24 months, his vocabulary was noted to be limited, his speech difficult to understand, and his intellect inferior to that of his 7-year-old brother at those ages. His only illnesses were repeated bouts of tonsillitis, which led to a tonsillectomy at the age of four years. Between the ages of two and five years, he fell with increasing frequency. At four years of age, he was able to use the toilet on his own and to play soccer. During the two years before admission, his cognitive and motor functions declined.Eight months before admission, he had an episode in which his arms stiffened and extended and he fell backward; he recovered after a few seconds. Such episodes began to occur three or four times daily during waking hours. Occasionally, he was incontinent of urine or stool during the episodes or had a general loss of muscle tone. During subsequent months, he chewed and swallowed increasingly slowly, required soft food, and lost 5 kg in weight. He interacted progressively less with his mother. Eventually, the attacks occurred 5 to 10 times daily; he became fearful of falling backward, and instead of walking, he crawled.A magnetic resonance imaging (MRI) examination of the brain, performed elsewhere on an uncertain date, revealed diffuse cerebral and cerebellar atrophy and a poorly defined band of increased signal intensity in the periventricular white matter on T 1 -weighted images; the lateral ventricle and the cisterna magna were slightly enlarged, but the cerebellum appeared intact. The boy's IQ was 50.Six months before admission, treatment with valproate sodium-valproic acid reduced the frequency of the episodes, but the patient's family was concerned about the possible toxic effects of the medication on his liver. Carbamazepine was substituted, but his condition did not improve, and he became somnolent. Treatment with valproate sodium-valproic acid was resumed, but his parents reduced the dose from 800 mg to 200 mg daily. He was referred to this hospital.The family resided in a Middle Eastern country. His parents were first cousins. There was no family history of neurologic disease.General physical examination revealed no abnormalities. On neurologic examination, the boy was alert; he reached for toys more often with his right hand than with his left. He was able to follow simple, one-step commands. His speech was barely intelligible. Ophthalmologic examination revealed moderate limitation of the elevation of the eyelids; probable concentric reduction of the visual fields, with reduced visual acuity; retinal pallor; and bilateral, cherry-red spots. The optic nerves appeared normal. He had slow saccades and difficulty initiating saccades. Other cranial-nerve functions appeared to be intact. Muscle strength wa...