Normal Pressure Hydrocephalus (NPH) is a neurological condition that is often overlooked or misdiagnosed due to its overlapping symptoms with other more common disorders, such as Alzheimer’s disease and Parkinson’s disease.
NPH symptoms, which include gait disturbances, cognitive decline, and urinary incontinence, can easily be mistaken for other age-related conditions, making timely and accurate diagnosis challenging. The role of imaging in diagnosing NPH is crucial. Through advanced imaging technologies like MRI (Magnetic Resonance Imaging) and CT (Computed Tomography) scans, healthcare providers can identify structural changes in the brain that are indicative of NPH, enabling early diagnosis and appropriate treatment or symptom management.
What is Normal Pressure Hydrocephalus?
Normal Pressure Hydrocephalus s a condition in which there is an abnormal accumulation of cerebrospinal fluid (CSF) in the brain’s ventricles. Unlike other forms of hydrocephalus, the pressure within the ventricles in NPH is relatively normal, which makes it more difficult to diagnose.
The three primary symptoms of NPH are:
- Gait Disturbance: Difficulty walking, which may present as a shuffling gait or difficulty with balance.
- Cognitive Impairment: Decline in memory, attention, and executive function.
- Urinary Incontinence: An involuntary urge to urinate, which can be disruptive to daily life.
Gait disturbance is usually the first symptom to appear, followed by cognitive impairment, then later incontinence. Not all symptoms are always present/detected in NPH. Because of the subtlety and overlap of these symptoms with other conditions such as Alzheimer’s disease, NPH is often missed or misdiagnosed, especially in elderly patients.
The importance of Radiology / Imaging in diagnosis
NPH is diagnosed through a combination of clinical symptoms and medical tests, including imaging of the brain. The two most commonly used imaging techniques for diagnosing NPH are magnetic resonance imaging (MRI) and (computed tomography) CT scans.
MRI
MRI is the preferred imaging method for diagnosing NPH due to its ability to provide high-resolution images of the brain’s structures. Key MRI findings in NPH include:
- Enlarged Ventricles: The ventricles in the brain appear larger than normal. This is one of the most distinctive features of NPH and is often the first sign of the condition. The enlargement is typically disproportionate, meaning that while the ventricles become larger, the surrounding brain tissue remains relatively unchanged, which distinguishes NPH from other types of dementia.
- Periventricular White Matter Changes: These are small areas of white matter damage near the ventricles, which can appear as dark spots on the MRI. These changes are often seen in elderly patients with NPH and can contribute to cognitive decline.
- “Communicating Hydrocephalus”: This term refers to the type of hydrocephalus seen in NPH, where cerebrospinal fluid can still circulate freely between the ventricles and the subarachnoid space. MRI helps distinguish this form of hydrocephalus from obstructive hydrocephalus, where there is a blockage preventing the normal flow of CSF.
CT Scan
While MRI is preferred for its higher resolution and detailed imaging capabilities, CT scans are sometimes used in clinical settings, especially when MRI is unavailable or not suitable for certain patients (e.g., those with metal implants or pacemakers).
CT scans provide detailed cross-sectional images of the brain and can also detect ventricular enlargement and other brain structural changes associated with NPH. However, CT scans may not provide as much detail as MRIs, particularly when it comes to detecting periventricular white matter changes.
The Importance of Imaging in the Diagnostic Process
Imaging is crucial for confirming the diagnosis of NPH and management for several reasons:
- Confirmation of ventricular enlargement and other brain changes associated with NPH
- Detecting and/or ruling out other neurological conditions
- Guiding clinical decision-making e.g. around treatment options
- Monitoring disease progression and treatment response
Imaging is also valuable in guiding clinical decision-making. For example, in some cases, patients with NPH who have not responded to conservative treatments may require surgery. Imaging can help determine if the patient’s condition is suitable for surgery and if they are likely to benefit from the procedure.
While imaging is vital for diagnosing NPH, it is important to note that imaging alone is not enough. The presence of enlarged ventricles and other brain changes on an MRI or CT scan may suggest NPH, but it does not definitively diagnose the condition. NPH must be diagnosed through a combination of clinical symptoms imaging findings, and other diagnostic tests, along with the exclusion of other potential conditions.
How can we help
We have represented a number of clients whose NPH diagnosis was significantly delayed because their treating doctors focused their investigations on other neurological conditions. If there is a delay in arranging appropriate investigations, then this can lead to a delay in the condition being diagnosed and/or treated.
If you or a loved one have been affected by a delayed or missed diagnosis we can help you. To have a free, confidential discussion with Claire Leslie or a member of our team call us today on 0800 044 8488 or fill in our contact form so we can call you back at a time convenient for you.
Enable Law are partners with Shine, the spina bifida and hydrocephalus charity. The charity has a wealth of resources and practical support in place for people diagnosed with NPH, and other conditions including hydrocephalus and spina bifida. If you want to understand more about the condition or reach out to them for support visit www.shinecharity.org.uk.
