[Idiopathic normal pressure hydrocephalus]

In normal pressure hydrocephalus (NPH), the physiological alterations related to the ventricular dilatation that lead to the Hakim and Adams clinical syndrome (gait apraxia, incontinence and dementia) remain unclear. The correlation between the clinical syndrome and global or regional cerebral blood flow (CBF) is not established. The question whether the CBF reduction is the cause or the consequence of the neural dysfunction remains unsolved. Dementia of NPH may be a combination of fixed and potentially treatable pathologies. Expectations for improvement in the dementia of NPH must be tempered by the knowledge that they may be fixed tissue damage prior treatment. The overall poor clinical outcome after shunting with regard to dementia, when contrasted with responses in gait and continence, suggests differences in aetiology or reversibility of the pathology underlying these symptoms. It is not easy to choose elderly patients (perhaps patient with more impaired psychometric performances) that might respond to a shunt.