Normal Pressure Hydrocephalus (NPH) is a neurological disorder that primarily affects older adults. It’s characterized by an abnormal accumulation of cerebrospinal fluid (CSF) in the brain’s ventricles, which can lead to a specific set of symptoms. Despite the name, the CSF pressure is often within the normal range, which can make diagnosis challenging. This comprehensive guide aims to provide a detailed understanding of NPH, covering its symptoms, diagnostic processes, and available treatment options.
Understanding Normal Pressure Hydrocephalus
Hydrocephalus, in general, is a condition where there is an excessive accumulation of CSF within the brain. CSF is a clear fluid that surrounds the brain and spinal cord, providing cushioning, nutrient distribution, and waste removal. In NPH, the normal flow and absorption of CSF are disrupted, leading to enlarged ventricles. This enlargement can put pressure on surrounding brain tissue, resulting in a variety of neurological symptoms.
NPH was first described in 1964 by Dr. Salomon Hakim, who identified a unique set of symptoms occurring in patients with normal CSF pressure. It primarily affects individuals over the age of 60, although it can occur in younger adults as well. The condition is often underdiagnosed or misdiagnosed because its symptoms can mimic those of more common disorders like Alzheimer’s disease and Parkinson’s disease.
There are two main types of NPH:
- Idiopathic NPH: This is the most common form, where the cause of the CSF flow disruption is unknown.
- Secondary NPH: This type occurs as a result of another underlying condition, such as subarachnoid hemorrhage, meningitis, traumatic brain injury, or previous brain surgery.
The Classic Triad of Symptoms

NPH is characterized by a classic triad of symptoms, often referred to as Hakim’s triad. These include:
- Gait Disturbances: This is often the first and most prominent symptom of NPH. Individuals may experience a wide-based, shuffling gait, described as “magnetic gait,” where the feet appear stuck to the floor. They may have difficulty initiating movement, turning, or maintaining balance. The gait disturbance is often slow and unsteady, increasing the risk of falls.
- Cognitive Impairment: Cognitive symptoms can range from mild forgetfulness and difficulty concentrating to more significant memory loss and impaired executive function. Patients may struggle with planning, organizing, and problem-solving. The cognitive decline in NPH is often slower and less severe than in Alzheimer’s disease.
- Urinary Incontinence: This symptom typically presents as urinary urgency or frequency, progressing to urge incontinence. Patients may have difficulty controlling their bladder, leading to accidental urine leakage. Incontinence can significantly impact a person’s quality of life and social interactions.
It’s important to note that not all individuals with NPH will experience all three symptoms. Some may present with only one or two of the triad, making diagnosis more challenging. The severity of symptoms can also vary significantly from person to person.
Diagnose

Diagnosing NPH can be complex due to the overlap of symptoms with other neurological conditions. A thorough evaluation by an experienced neurologist is crucial for accurate diagnosis. The diagnostic process typically involves the following steps:
- Medical History and Neurological Examination: The neurologist will review the patient’s medical history, including any prior illnesses, injuries, or surgeries. A comprehensive neurological examination will assess gait, balance, coordination, reflexes, cognitive function, and bladder control.
- Brain Imaging: Brain imaging techniques, such as MRI and CT scans, play a vital role in diagnosing NPH. These scans can reveal enlarged ventricles and help rule out other conditions that may be causing similar symptoms. MRI is often preferred over CT scans because it provides more detailed images of the brain and can better assess CSF flow.
- Cerebrospinal Fluid (CSF) Studies:
- Lumbar Puncture (Spinal Tap): This procedure involves inserting a needle into the lower spine to collect a sample of CSF. The CSF pressure is measured to confirm that it is within the normal range or only slightly elevated.
- Large-Volume CSF Tap Test: This test involves removing a larger amount of CSF (30-50 ml) during a lumbar puncture. The patient’s symptoms, particularly gait and cognitive function, are assessed before and after the CSF removal. If symptoms improve significantly after the tap, it suggests that the patient may benefit from shunt surgery.
- CSF Infusion Test: During this test, fluid is slowly injected into the lower spine while measuring the pressure. If the body cannot absorb the extra fluid, the pressure will rise, which could indicate NPH and that surgery will be helpful.
- Lumbar Drainage Test: A tube is inserted between the bones in your spine to drain a large amount of CSF over a few days, to see whether your symptoms improve.
- Gait Assessment: A licensed physical therapist can perform a gait assessment to quantify the patient’s gait abnormalities and track changes over time. This assessment can help determine the severity of gait impairment and monitor response to treatment.
Treatment Options

The primary treatment for NPH is the surgical placement of a shunt to drain excess CSF from the brain3. There are two main types of shunts:
- Ventriculoperitoneal (VP) Shunt: This is the most common type of shunt used to treat NPH. A catheter is inserted into one of the brain’s ventricles and then tunneled under the skin to the abdomen. A valve regulates the flow of CSF from the brain to the abdominal cavity, where it is absorbed.
- Lumboperitoneal (LP) Shunt: In this procedure, a catheter is inserted into the lumbar spine and tunneled under the skin to the abdomen. This type of shunt drains CSF from the spinal canal to the abdominal cavity.
Shunt Surgery: The surgery takes about an hour. The surgery typically includes the following5:
- A small incision followed by a small hole is made in the scalp and skull
- A tiny hole is made in the meninges (the protective covering of the brain) to allow the placement of a catheter in the lateral ventricle
- The neurosurgeon will make a few small incisions behind the ear to insert the shunt valve.
- The catheter is placed under the skin
- The other end of the catheter will be situated in the abdomen or above the internal jugular vein
- After the procedure, sterile bandages are placed over each incision
Shunt Complications: While shunt surgery can be highly effective in treating NPH, it’s essential to be aware of potential complications. These can include:
- Infection: Shunt infections can occur and may require antibiotic treatment or shunt removal.
- Bleeding: Bleeding in the brain can occur as a result of shunt placement.
- Shunt Malfunction: Shunts can become blocked or malfunction, requiring revision surgery.
- Over-drainage or Under-drainage: These can lead to headaches, seizures, or a return of NPH symptoms.
Post-operative care: It’s important that you and your family are aware of these possible complications. If you have this surgery, be sure to follow all of your doctor’s directions and keep any follow-up appointments to make sure it’s working properly.
Alternatives to Shunt Surgery: While shunt surgery is the most common and effective treatment for NPH, other treatment options may be considered in certain cases.
- Endoscopic Third Ventriculostomy (ETV): This minimally invasive procedure creates a small opening in the floor of the third ventricle, allowing CSF to flow more freely. ETV is typically reserved for patients with obstructive hydrocephalus, where there is a blockage in the CSF pathways.
- Medical Management: Medications may be used to manage some of the symptoms of NPH, such as bladder control problems or cognitive impairment. However, medication alone cannot address the underlying cause of NPH.
The Importance of Early Diagnosis and Treatment
Early diagnosis and treatment of NPH are crucial for improving patient outcomes. If left untreated, NPH can lead to progressive neurological decline and significant disability. With timely intervention, many individuals with NPH can experience significant improvement in their symptoms and regain a better quality of life.
It is also important to have an accurate diagnosis by an experienced team is essential to getting the best treatment.
Conclusion
Normal Pressure Hydrocephalus is a treatable condition that can significantly impact the lives of older adults. By understanding the symptoms, diagnostic process, and treatment options, individuals and their families can work with healthcare professionals to achieve an early diagnosis and appropriate management.
Shunt surgery remains the most effective treatment for NPH, offering the potential for improved gait, cognitive function, and bladder control. If you or a loved one is experiencing symptoms of NPH, seeking prompt medical attention is essential for optimizing outcomes and enhancing quality of life.
Speak With Us
At Southern California Brain & Spine Surgery, we understand the complexities of neurological conditions like Normal Pressure Hydrocephalus. Our dedicated team of experts is committed to providing comprehensive and personalized care for all your brain and spine health needs. If you or a loved one is experiencing symptoms of NPH or any other neurological concerns, we encourage you to contact us today.

Our experienced neurologists and neurosurgeons will conduct a thorough evaluation, utilize advanced diagnostic techniques, and develop a tailored treatment plan to help you regain your quality of life. Trust Southern California Brain & Spine for compassionate and cutting-edge care. Visit socalbrainspine.com or call us today to schedule a consultation. Your brain and spine health are our top priority.