REVERSIBLE HYPOPERFUSION OF THE CEREBRAL-CORTEX IN NORMAL-PRESSURE HYDROCEPHALUS ON TECHNETIUM-99M-HMPAO BRAIN SPECT IMAGES AFTER SHUNT OPERATION

A man with dementia underwent radionuclide cisternography to establish the diagnosis of communicating hydrocephalus. Technetium-99m-HMPAO br ain SPECT images showed marked hypoperfusion of both posterior cerebra l cortices and three-dimensional displays that demonstrated perfusion defects at both of the posterior parietotemporal regions. A successful ventriculoperitoneal shunt operation was performed. Five and one-half months later, repeat three-dimensional display showed that the perfus ion defects had resolved and a repeat brain SPECT image showed marked improvement of the hypoperfusion. This concurred with postoperative cl inical improvement. Technetium-99m-HMPAO brain SPECT, which provides o bjective documentation of clinical recovery after surgery, could be ro utinely used to evaluate patients with normal-pressure hydrocephalus.