Difficulty walking. Memory problems. Urinary incontinence. Alone or in combination, these symptoms can indicate a variety of diseases and conditions. That’s why making a definitive diagnosis for a collection of symptoms such as these isn’t always easy.

THIS ILLUSTRATION SHOWS THE ANATOMY OF THE BRAIN AFFECTED BY NORMAL PRESSURE HYDROCEPHALUS. CLINICAL SYMPTOMS RESULT FROM ENLARGED VENTRICLES (IN BLUE) DISTORTING THE CENTRAL PORTION OF THE CORONA RADIATA (IN ORANGE).
Image courtesy of Science Photo Library / DNA illustrations

This is especially true for a condition called normal pressure hydrocephalus, or NPH, which can involve any or all of these three symptoms. The condition occurs in older adults when cerebrospinal fluid builds up, for unknown reasons, inside a system of interconnected cavities in the brain called ventricles, which causes them to enlarge. These changes within the brain affect its function.

“This is a difficult diagnosis to make,” says Gregory Zipfel, MD, a Washington University neurosurgeon at Barnes-Jewish Hospital, “and requires special expertise.” He adds that diagnosis is easier when a team of physicians from various specialties collaborate to determine the source of symptoms and the people most likely to benefit from treatment.

Zipfel is part of such a team at the Washington University Normal Pressure Hydrocephalus Center. The specialists there—neurosurgeons, neurologists, a neuroradiologist and a psychologist—work together to assess and diagnose people with NPH symptoms.

Working together from different perspectives, the team can rule out other conditions that mimic NPH. If brain imaging using an MRI or CT scan shows evidence of enlarged ventricles, and a person is experiencing walking, memory or bladder problems, it is crucial to rule out conditions such as Parkinson’s disease or Alzheimer’s disease, which are treated very differently than NPH.

Mwiza Ushe, MD, also a Washington University neurologist at Barnes-Jewish Hospital, is a member of the Normal Pressure Hydrocephalus Center team. He notes that people with a history of traumatic brain injury, bleeding in the brain or brain tumor may in fact have excess fluid in the brain due to such events rather than to NPH, and they should be treated as such. “My role is to have that first conversation with a patient to determine whether the constellation of symptoms fits with the diagnosis of normal pressure hydrocephalus,” Ushe says.

MY ROLE IS TO HAVE THAT FIRST CONVERSATION WITH A PATIENTTO DETERMINE WHETHER THE CONSTELLATION OF SYMPTOMS FITS WITH THE DIAGNOSIS OF NORMAL PRESSURE HYDROCEPHALUS.

One component of Ushe’s evaluation is gait analysis, important because some people with NPH have a particular way of walking. They may appear to hesitate in lifting their feet or seem as if their feet are stuck to the ground. They often have balance problems as well. Once a person is diagnosed with NPH, there is one treatment option: placement of a shunt. During this procedure, a neurosurgeon inserts a tube about the size of a smartphone cord into the brain. This tubing is threaded through the body down to the abdomen, allowing the excess fluid from the brain to drain through the tube and be reabsorbed in the abdomen. A programmable valve makes it possible to adjust the amount of fluid being drained as needed.

Zipfel estimates that at least 80% of people with NPH who undergo shunting have substantial improvement in their symptoms. However, not everyone with the condition is a good candidate for treatment. Those whose primary symptoms are walking difficulty or urinary incontinence are likely to benefit from the surgery; those with memory problems are less likely to improve. “We want to treat the patients who have the best chances of improving,” Zipfel says. “Shunting can be a lifesaving treatment, but we don’t want to perform the procedure on people who are unlikely to benefit.”

To determine whether a patient is indeed likely to benefit from shunting, Zipfel and colleagues perform a lumbar drain, in which a tube is placed in the lower spine to drain fluid for two or three days. If the patient’s walking improves as a result, he or she is likely a good candidate for the permanent shunt. Ushe says he is eager to learn more about NPH through research. “We want to determine how prevalent this condition actually is and how independent it is from other neurodegenerative illnesses,” he says. “This will help us better diagnose, evaluate and treat this illness.”