EEG and CT abnormalities in xeroderma pigmentosum.

Xeroderma pigmentosum associated with neurological abnormalities is a less familiar neurocutaneous disorder. In this report, 35 patients with group A xeroderma pigmentosum were assessed for neurological complications. Of these, 17 showed microcephaly and 24 mental retardation. Of 25 patients over 7 years of age, 22 had sensorineural deafness and 12 showed spinocerebellar signs such as nystagmus, dysarthria, tremor and ataxia, while none below 7 years of age had such neurological complications. Thirty-five EEG studies were performed on 29 patients, and 15 showed intermittent spindles of grouped theta waves with abnormal slow background activity and a poorly developed alpha rhythm, suggesting immature brain development or a regression from normal brain function in many areas including the diencephalon. Twenty-six patients were examined by cranial CT scan, of whom 20 showed abnormal CT findings such as ventricular dilatation, diffuse cortical atrophy, and marked thickening of the calvarial bones. The incidence of abnormal EEG and CT findings increased with advancing age in accordance with the development of neurological complications in the CNS, thus suggesting a chronic progressive degenerative disease.