In normal pressure hydrocephalus (NPH), a condition primarily restricted to older adults, accumulating cerebrospinal fluid enlarges the ventricles but may not increase intracranial pressure. Nonetheless the abnormal collection of fluid causes a triad of symptoms: urinary incontinence, progressive gait ataxia, and cognitive deficits. The latter can include disorientation, confusion, apathy, decreased attention span, mental slowing, agitation, paranoid ideation, anxiety, and eventually memory loss—symptoms that resemble primary dementias. Although published rates vary widely, NPH may account for as many as 10% of all dementias.
Because these same symptoms can characterize the aging process, NPH is greatly underdiagnosed or is misdiagnosed as other conditions common among the elderly such as Parkinson’s or Alzheimer’s disease. In fact, the mean time that elapses between a patient seeking treatment and receiving the correct diagnosis is about 7 years. Even when NPH is diagnosed, neurologists and neurosurgeons may hesitate to institute treatment because traditional approaches to management with fixed flow shunts have been associated with high rates of serious complications. As a result, individuals with NPH can lose many years of what otherwise might have been an active, vigorous retirement. With this insidious disease afflicting perhaps 350,000 people over the age of 65 years in the United States, it is clear that the human cost is enormous. And in some cases unnecessary.
This issue of the Barrow Quarterly, spearheaded by Dr. Harold L. Rekate and underwritten with a generous donation from Codman, a division of Johnson and Johnson, is devoted to changing this unfortunate situation. Codman has introduced a unique programmable shunt that Dr. Rekate, among others, has implanted in select patients with NPH. After implantation of the shunt, its pressure settings can be adjusted noninvasively in a few seconds to control the symptoms of an individual patient; further surgery is unnecessary. Some individuals with NPH have improved remarkably after undergoing this procedure, regaining a lifestyle both they and their loved ones had thought impossible. We hope that this issue will help raise awareness of this sometimes treatable form of dementia among physicians so that patients everywhere can benefit from appropriate management.
Robert F. Spetzler, MD