Global rostral midbrain dysfunction secondary to shunt malfunction in hydrocephalus.

Two cases of congenital hydrocephalus with shunt malfunction are described. Both patients presented with clinical syndromes suggestive of global rostral mesencephalic dysfunction, including the sylvian aqueduct syndrome, a parkinsonian-like state, and quadriparesis. Each had computed tomographic findings that showed marked dilatation of the lateral and 3rd ventricles, and both improved with revision of their shunts. The anatomical substrates of the clinical findings are reviewed. A discussion of the probable mechanism proposes that dilatation of the 3rd ventricle and rostral aqueduct sufficiently explains the entire syndrome. (Neurosurgery, 7: 322-325, 1980).