Subependymal nodular heterotopia in patients with encephalocele.

Only incidental mention has been made to date of the combined occurrence of subependymal heterotopia and posterior encephalocele. We evaluated the presence of disseminated nodular subependymal heterotopia in two series of patients with posterior encephalocele. The first series consisted of all six patients who were treated in our hospital for encephalocele during the last 11 years and who underwent magnetic resonance imaging (MRI). In three, subependymal nodular heterotopia was found by MRI. The second series consisted of eight autopsy cases with encephalocele, representing all cases of encephalocele that came to autopsy during a 10-year period on whom full microscopic examination could be performed. Nodular heterotopia was found in four. The combined occurrence of these two rare conditions may not be accidental.