How has the diagnosis of idiopathic normal pressure hydrocephalus (iNPH) changed ?

Satoru Mori

Department of Neurology, Matsushita Memorial Hospital

Idiopathic normal pressure hydrocephalus (iNPH) characterized by the clinical triad of gait disturbance, dementia and urinary incontinence is improved by CSF shunt surgery.
Previously, image-diagnosis had been based on the presence of ventriculomegaly, periventricular lucency and ventricular reflux on cisternography. In this diagnosis method, however, it is hard to accurately select the patients who would likely respond to shunt operation. The newly published guidelines for the clinical practice regarding iNPH has facilitated the accurate selection of the patients. The diagnosis of probable iNPH, i.e. meeting the indications for shunt surgery is based on the presence of high convexity tightness and Sylvian fissure dilation on MRI and transient improvement on CSF tap-test. As the diagnostic method has changed considerably, we should become familiar with the new method.

Department of Neurology, Matsushita Memorial Hospital (5-55, Sotojima-cho, Moriguchi, Osaka 570-8540, Japan)