Nonabsorptive hydrocephalus associated with nephropathic cystinosis.

A child with nephropathic cystinosis developed seizures and coma. CT showed prominent sulci and slight ventricular enlargement. Nuclear cisternogram was normal. Despite successful renal transplantation and treatment of hypothyroidism, neurologic recovery was poor. CT and nuclear cisternogram 5 months later showed moderate panventricular and subarachnoid space enlargement and abnormal ventricular isotope retention. Ventriculoperitoneal shunt placement was followed by improved intellectual function, resolution of pyramidal tract signs, and control of seizures. Anisotropic crystals consistent with cystine were demonstrated in biopsy samples of arachnoid and cerebral cortex. Nonabsorptive hydrocephalus may have resulted from deposition of cystine in the meninges.