Who is affected by NPH?
- Experts estimate that about 375,000 people in the U.S., or 5 percent of all patients with dementia, including Alzheimer’s disease, may actually be affected by another condition – normal pressure hydrocephalus (NPH)
- Also mistaken for Parkinson’s or attributed to the effects of aging
- Typically affects adults over 55
- Number of cases is expected to grow as elderly population increases
Prevalence and Diagnosis Information
What is NPH?
- Progressive neurological disorder resulting from build-up of cerebrospinal fluid (CSF) that causes ventricles in the brain to enlarge
- Pressure created in the brain causes a triad of main symptoms, including difficulty walking or shuffling gait, dementia or mild confusion, and urinary urgency or incontinence
- NPH symptoms typically get progressively worse over time and the rate of progression varies in each patient; many patients become extremely debilitated and require constant care
- NPH is one of the few forms of dementia that can be controlled or reversed with treatment
What causes NPH?
- Most cases of NPH have no identifiable cause
- In some cases, NPH can be attributed to previous brain surgery or injury such as a hemorrhage, aneurysm, trauma, tumor or cyst, infection, or a blood clot in the brain
How is NPH diagnosed?
- Diagnostic procedures may include one or more of the following:
- MRI (Magnetic Resonance Imaging): uses radio signals and very powerful magnet to create picture of brain; takes approximately 30 minutes to perform and is the most widely used test because it provides greater detail of enlarged ventricles – an indicator of NPH compared to a CT Scan
- CT Scan (Computerized Tomography): creates picture of brain using x-rays and special scanner; takes about 15 minutes to perform
- Lumbar Puncture or Spinal Tap: under local anesthetic, a thin needle is inserted to remove CSF to see if any symptoms are relieved
- 3-day External Lumbar Drain (ELD): inpatient admission for 3-days, placement of ELD to remove cerebrospinal fluid (CSF), daily testing of walking, balance and mental capacities while spinal fluid is drained
- Generally, early diagnosis of NPH improves outcomes and the potential for successful treatment. However, some people who have been experiencing symptoms for years can improve with treatment
What are the implications for an aging population?
- By 2030, the number of older Americans is expected to reach 71 million, or roughly 20 percent of the U.S. population
- The number of people age 65 and over with Alzheimer’s disease is estimated to reach 7.7 million in 2030, a greater than 50 percent increase from the 5 million age 65 and over who are currently affected
- 60,000 new cases of Parkinson’s disease are diagnosed each year in the U.S., adding to the 1.5 million Americans who currently have Parkinson disease
- Without a breakthrough in the treatment of dementia, the number of people 65 and older living in nursing homes will likely double by the year 2020
How is NPH treated?
- Surgical implantation of a shunt (thin, flexible tube and valve) by a neurosurgeon to drain excess fluid and relieve pressure in the skull
- Shunt carries away excess fluid to another part of the body, typically the abdomen, where it is re-absorbed into the blood stream and discarded through the urine
- Procedure generally lasts one to two hours; patients stay in hospital from three to seven days
How is the shunt implanted?
- Patient placed under general anesthesia and incisions made in head and abdomen to allow neurosurgeon to pass the shunt under the skin between the two areas
- Shunt is well tolerated by body tissue; therefore remains inside the body
- Valve in the shunt continues to maintain cerebrospinal fluid (CSF) at normal pressure within the brain
Shunt Technology
- Programmable Shunts
- Available in the U.S. since 1998; increasingly popular alternative to fixed pressure shunts
- Programmable shunts have multiple settings that can be adjusted outside the skull with a magnetic device
- Ability to adjust without additional surgery may help to optimize treatment, relieve symptoms and avoid repeated surgery
- Fixed Pressure Shunts
- In use the longest (since the 1960s) and have the simplest mechanism
- Neurosurgeon must choose from among several pressure settings at time of implantation
- If different pressure is needed after implantation, additional surgery is required to replace the shunt or adjust the setting
Outcomes
- Approximately 85 to 90 percent of patients who are properly diagnosed and screened for shunt responsiveness will experience improvement in their condition, often within days, but could take weeks or months
- Higher success rates have been reported from centers using more demanding diagnostic tests and with experience in diagnosing and treating NPH
- According to industry estimates, only 11,500 shunt procedures for NPH were performed in 2003 due to lack of awareness, although shunting is a relatively common surgical procedure for other conditions
Potential Complications
- May include infection of the surgical wound or of the CSF (meningitis), bleeding into the brain or ventricles, or a seizure
- Shunt infection may be indicated by fever, redness or swelling along the shunt track
- Subdural hematoma (blood clot) is the most serious complication that can occur following insertion of a shunt; risk of developing is approximately 5 to 10 percent
- Shunt malfunction, disconnection and catheter blockage can also occur
- Individuals need to discuss their own situation with their doctor to determine if the possible benefits of surgery outweigh the risks
Shunt Treatment
Shunts are not for everyone. Only a specialist can decide if it is appropriate for a specific patient. Individual results may vary. Patients receiving anticoagulants (blood thinners) or having a history of bleeding disorders should not use a shunt. Prior to shunt implantation, patients should discuss any infection they may have with their doctor and have it treated