CT Scans and Tuberous Sclerosis

To the Editor.— The article by Martin et al (235:2323, 1976) indicates that the diagnosis of tuberous sclerosis in a patient may be confirmed by identification of subependymal calcifications on computerized axial tomography (CT). From their series of patients, they imply that a normal CT scan (eg, patient 6) may exclude the diagnosis of tuberous sclerosis. We have performed numerous CT scans on patients at risk for tuberous sclerous. Two patients with the diagnosis of tuberous sclerosis on the basis of retinal astrocytomas, seizures, mental retardation, and depigmented lesions did not have CT evidence of subependymal calcification, whereas an asymptomatic mother of an infant with tuberous sclerosis had an abnormal CT scan (Figure). This mother is a registered nurse and has no stigmata of tuberous sclerosis by history or physical examination. From these and other observations, we have concluded that, like many other laboratory studies, the CT scan is helpful