Normal Pressure Hydrocephalus (NPH) as a Cause of Pre-Senile and Senile Dementia: The Complementary Role of Radionuclide Cysternography (RNC) and Cranial Computed Tomography (CCT) in The Early Recognition of The Treatable Patients

Abstract

The possibility that hydrocephalus which is associated with normal pressure of the cerebro-spinal fluid (CSF) may be a treatable form of dementia has aroused renewed interest in radionuclide cysternography (RNC) for the dynamic study of CSF circulation. Improvement of imaging devices and the development of better radiopharmaceuticals have greatly increased the value of this study with the possibility of an accurate diagnosis of communicating hydrocephalus in general and NPH in particular. The diagnosis can be reinforced by CCT study. The latter study is also useful in excluding brain atrophy as a cause of dementia and thus direct the neurosurgeon towards the decision of shunt operation with the possibility of a dramatic improvement of the demented patient. We believe that the combination of these two studies is an important tool for diagnosing NPH, predicting success of shunt operations and following up the patients’ post-surgical improvement and shunt patency. These conclusions are based on a study of 26 cases with dementia which form the basis of this report.