Hx, PE, and LP. If the history and physical exam suggests nph then continuous spinal fluid drainage with pre and post testing of cognition and gait can determine if the patient meets the criteria for nph and will or will not benefit from a vp (ventriculoperitoneal) shunt. The classic triad of pd is a rest tremor, rigidity (stiffness), and bradykinesia (slowness of movement). I hope this helps.
Why do you wonder? Check out these links: http://www.lifenph.com http://www.ninds.nih.gov/disorders/normal_pressure_hydrocephalus/normal_pressure_hydrocephalus.htm http://www.nlm.nih.gov/medlineplus/ency/article/000752.htm http://www.webmd.com/brain/normal-pressure-hydrocephalus.