Normal pressure hydrocephalus

This chapter is on normal pressure hydrocephalus (NPH) and deals with aspects from theories of pathogenesis, clinical presentation, and management, surgical management, and complications, as well as the assessment of outcome. It provides a concise overview of a challenging topic; many theories have been advanced to explain the underlying mechanisms by which the NPH syndrome develops. However, the basic pathophysiological processes still remain unclear. The major theory streams proposed for the pathogenesis of NPH can be loosely organized into structural, cerebral blood flow, and cerebrospinal fluid flow subgroups. The components of each theory stream are expanded in this chapter, although the list of studies supporting each section is by no means exhaustive.