[Cystinuria with symptoms of cerebellar atrophy--a case report]

We report cystinuria and symptoms of cerebellar atrophy in a 45-year-old man. His parents were first cousins, and many members of his family had stones of urinary tract or gait impairment. Neurological examination disclosed cerebellar signs resembling those of spinocerebellar degeneration. Urinalysis disclosed high cystine, lysine, ornitine and arginine output. Cystine was 1153.8 micro mol/day (normal range, 22-170); lysine, 3443.9 (normal range, 44-1000); ornitine, 283.8 (normal range, 7-40); and arginine, 154.0 (normal range, 9-50). Neurological complications reported to be associated with cystinuria include mental retardation, muscular dystrophy, hypotonia and dwarfism, mongolism, paroxysmal dyskinesia, myopathy, migraine, spastic paraplegia, multiple sclerosis, subacute combined degeneration and cranial polyneuropathy. Cerebellar signs have been reported in only two cases, and to our knowledge, this is the first case of cystinuria with cerebellar atrophy ever reported. Some common metabolic errors may have caused both disorders, although they also may have developed independently.