What is the appropriate shunt system for normal pressure hydrocephalus?

Normal pressure hydrocephalus (NPH) represents a common disorder among older people with mild elevation of cerebrospinal fluid pressure and certain clinical manifestations. We present a patient with such a disorder in whom a programmable valve was implanted. With the use of a lower opening pressure, the patient developed a subdural hematoma although the symptoms subsided. After evacuating the hematoma and by setting the valve pressure higher, the patient recovered without any symptomatology. We observed that only the higher pressure was the right one, although in two different pressure values the symptoms had subsided.