Computed tomography of the head in the evaluation of microcephaly.

Eighty-five infants and children found to have microcephaly had computed tomographic (CT) brain scans performed. A greater degree of microcephaly correlated with the finding of atrophy or ventricular dilation on CT scan. Patients who had known preceding destructive brain insults had the highest incidence of abnormal findings on scans (20/22). Patients who had CNS dysfunction of unknown etiology had the lowest frequency of abnormal findings (12/33); however, in three of these patients, a previously unsuspected brain malformation was found on CT scan. Patients who had other congenital anomalies had an intermediate proportion of abnormal findings on CT scans (20/30), and in 11 of these scans, a previously unsuspected or only partly suspected brain malformation was diagnosed. Discovering previously unsuspected information or finding supportive data regarding the basis for the underlying disease process, being able to provide a more specific developmental prognosis and accurate genetic counseling, justifies the inclusion of a CT scan of the head in the evaluation of the microcephalic child.