Abnormal cisternogram associated with Diamox therapy.

A cisternogram characteristic of normal-pressure hydrocephalus was obtained from a patient on Diamox who was being evaluated for rapid mental deterioration. A repeat cisternogram after Diamox was discontinued was nearly normal. We hypothesize that the initial abnormality resulted from reduced cerebrospinal fluid production caused by carbonic anhydrase inhibition; this defect (reduced flow) led to a net reflux of tracer into the ventricles. The reflux is believed to be due to the reduction of bulk cerebrospinal fluid from the ventricles.