Answer

Answer 16-14. History and physical exam are paramount. There is a normal LP opening pressure. Imaging shows panventriculomegaly on CT or MR scan without prominent cortical atrophy. CSF drainage procedure (15-30 cc) followed by improved gait and bladder control is the best predictor of good response to therapy (shunting of CSF). The condition may be idiopathic or it may result from sequellae of bacterial meningitis, subarachnoid hemorrhage. Ventricular or lumbar shunt may help (50% improve; 40% morbidity).