Posted on: June 16, 2017
With the aging of the population, there is a dramatic rise in the prevalence of age-related cognitive decline or dementia. While many people fear the dementia associated with Alzheimer’s, there’s considerable hope for patients with dementia related to normal pressure hydrocephalus (NPH), the only form of dementia that currently has the capacity for real reversal. By Deborah L. Benzil, MD, FACS, FAANS, Director of the Spine Radiosurgery Program at Northern Westchester Hospital.
The Aging Brain
As we age, our brains get smaller. In response, the fluid filled sacs in our brains called ventricles enlarge to fill in the gap from our decreased brain size. In a certain percentage of patients, this transition goes awry and causes NPH. When a patient presents with neurological symptoms, a neurologist will closely evaluate for Alzheimer’s, Parkinson’s, or other potential causes. If NPH is suspected, the patient is sent to a neurosurgeon for an NPH diagnosis.
The classic presentation of NPH includes an inability to lift the feet off the floor while walking, commonly referred to as gait disorder. Dementia, or a decline in cognitive mental processes including memory, reasoning, problem solving, and speaking is also common. Finally, urinary and/or bowel incontinence are also symptoms of NPH.
In some cases, a thorough evaluation of the patient’s symptoms is all that’s needed for a neurosurgeon to determine whether NPH is present. However, most patients don’t have all three symptoms, making a diagnosis challenging, as symptoms mirror many of those associated with irreversible conditions like Alzheimer’s and Parkinson’s. Furthermore, diagnosing NPH is often delayed because symptoms can start slowly and be subtle until they advance over time, which can take years.
The majority of patients with NPH symptoms will need a lumbar drain trial to confirm that the diagnosis is NPH. At Northern Westchester Hospital, the patient undergoes the lumbar drain trial under light sedation. We insert a small tube in the spine and specially trained nurses drain a precisely measured amount of fluid every two hours. During the lumbar drain trial, cerebrospinal fluid is removed in small increments. If a patient reacts positively to the lumbar drain trial, it is likely the diagnosis is NPH. The first and most rapidly impacted symptom is the reversal of gait disorder. The response is not permanent and symptoms return shortly after the drain is removed.
The Fear of Dementia and the Procedure that May Reverse Symptoms
Once an NPH diagnosis is confirmed, a neurosurgeon will likely recommend ventriculoperitoneal (VP) shunt surgery to reverse NPH symptoms. Performed under general anesthesia, VP shunt surgery usually takes about 45 minutes or less. During the procedure, a catheter is implanted into the fluid filled sacs in the brain (ventricles) to drain excess cerebrospinal fluid out of the brain and into the abdominal cavity. Most patients stay at NWH overnight and return home the next day. The ventriculoperitoneal shunt is programmed to drain the cerebrospinal fluid according to each patient’s unique condition. Over time, we simply adjust the shunt as needed during office visits.
The fear of dementia is understandable. But for patients with NPH, there is real hope for reversal of symptoms. Ventriculoperitoneal shunt surgery is safe, effective, and straightforward, and the results can be dramatic and life changing, Families often notice a major improvement in their loved ones ability to walk and communicate immediately following the procedure. If you or a loved one suffer from symptoms of NPH, be sure to ask your primary care physician for an MRI or CT scan.