[Bilateral hypodensity of the basal ganglia. Clinico-evolutionary correlation in children].

The presence in neuroimaging of areas of symmetrical bilateral hypodensity in the basal ganglia (SBHBG) is a striking and unusual finding. To determine the aetiology, clinical significance and evolution of a group of paediatric patients with SBHBG. We made a study of 21 patients with neuroimaging studies (CT or MR) showing SBHBG. The affected area was related to the aetiology, clinical features and evolution. The ages varied between 4 months and 16 years. In 7 cases Leigh s disease was diagnosed, 5 had had acute hypoxia, 4 type I glutaric aciduria, and 1 case each of methylmalonic aciduria, Ia gluconeogenesis, CO intoxication, acute striatal necrosis and bacterial meningitis. The putamen was affected in 6 cases, globus pallidus in 4 cases and the lenticular nucleus was damaged in the rest. Three cases also had lesions in the caudate nucleus. MR was better than CT for localization of the precise area involved. Clinically, 13 cases had extrapyramidal signs. We found no relation between the size, localization of the lesion and the prognosis, which was more dependent on the aetiology, only one patient (CO intoxication) recovered and eight died (Leigh s disease and 1 case of hypoxia). The presence of SBHBG in a patient makes extensive study necessary to find the aetiology. It is a nonspecific finding, usually of metabolic origin and with little correlation with the clinical condition. Its presence implies a poor prognosis and raises suspicion of the presence of certain neurological disorders.