Normal pressure hydrocephalus (NPH) is characterized by dilated ventricles and a combination of gait impairment, cognition impairment, and loss of urinary control (urgency and incontinence). The only effective treatment for NPH is a CSF shunt; however, only a small percentage of patients ever receive it. The features of gait impairment in patients with NPH are difficult to distinguish from patients of neurodegenerative disorders with motor involvement, such as parkinsonism or dementia with Lewy bodies. CT or MRI imaging is required for the diagnosis of idiopathic normal pressure hydrocephalus. An Evans ratio of more than 0.3 indicates large ventricles, and a ratio of more than 0.33 indicates very large ventricles, but is not specific for idiopathic normal pressure hydrocephalus. The international and Japanese guidelines support shunt surgery as effective treatment of idiopathic normal pressure hydrocephalus, as does the American Academy of Neurology practice guideline. There is a need to provide longitudinal care of patients with idiopathic normal pressure hydrocephalus after shunt surgery as all symptoms respond well to shunt surgery.
Part of the book: New Insight into Cerebrovascular Diseases