Raising awareness of normal pressure hydrocephalus: an often misdiagnosed condition

Summary

Normal pressure hydrocephalus (NPH) is a progressive neurological disorder affecting mainly older adults. Diagnosis can be difficult due to symptom overlap with other conditions, but early and accurate diagnosis is essential. Early treatment, especially shunt surgery, can significantly improve patient outcomes. In this blog, charity Shine describes NPH and explains why it is often misdiagnosed. It shares a story from one of their members who has the condition.

Content

What is NPH? 

NPH is a progressive neurological condition that comes under the dementia umbrella. In NPH, the cerebrospinal fluid-filled ventricles within the brain expand and distort the surrounding tissues. This process causes the neurological symptoms of NPH. Unlike other forms of hydrocephalus, NPH does not result in significantly raised intracranial pressure. NPH is often misdiagnosed as it is similar to neurodegenerative conditions such as Parkinson’s disease and other causes of dementia, such as Alzheimer's disease. However, unlike these other conditions, if diagnosed early there is an effective treatment that can significantly slow disease progression and potentially improve, or even reverse, symptoms in some people. 

Who is affected by NPH? 

NPH mainly affects older adults. Prevalence is difficult to estimate but 0.8% of people over 65 has been calculated in multiple studies.[1][2] In the UK that would be approximately 100,000 people. 

What are the signs of NPH? 

NPH is characterised by: 

• Gait disturbances: difficulty walking, shuffling steps or feeling as if the feet are stuck to the floor. Difficulty balancing and falls, particularly backwards are common. 
• Cognitive impairment/mild dementia: memory loss, confusion and difficulty concentrating. 
• Urinary incontinence: loss of bladder control, which may worsen over time. 

Because NPH symptoms can resemble those of Alzheimer’s or Parkinson’s disease, and comorbidity is possible, NPH diagnosis is often missed, delayed or mistaken. Additionally, not everyone will experience all three symptoms. NPH is usually diagnosed through a combination of clinical presentation and imaging and diagnostic tests.

How is NPH treated? 

The treatment of choice for NPH is shunt surgery, where a small tube (shunt) is implanted to drain excess cerebrospinal fluid (CSF) from the brain to the abdomen. This procedure can significantly improve symptoms, especially if performed early.  Evidence suggests that 76% of people experience some improvement after shunt surgery. Gait (walking) improves in 75% of patients, cognitive function improves in 61%, and improvement of incontinence can be seen in 55%.[3] 

Patients with treated and untreated NPH can benefit from ongoing multidisciplinary support from neurology and other services, including physiotherapy, medication, occupational therapy and neuropsychology. 

Since treatment response is generally better with earlier treatment, early and accurate diagnosis and treatment can greatly enhance quality of life for individuals with NPH.  

*Jackie’s story

I'm currently aged 77. I was, until around six years ago, very lucky. I had had very good health. I was happily married with three wonderful children and six lovely grandchildren. I was enjoying life. Then in 2019 I started developing distortion in my gait. Friends suggested I might be developing Parkinson's disease, but my difficulties were relatively mild so I didn't seek any medical advice at the time.  

By March 2020 my symptoms had slightly worsened. I first went to my GP, then a neurologist in the local hospital. The neurologist arranged a brain scan and afterwards reported that my ventricles were consistent with atrophy allowing for age. He diagnosed Parkinson's disease, though he said at the time he couldn’t be certain. My condition was still quite mild then and I didn't need any treatment.  

The following year, I found my condition had deteriorated. I had been a keen cyclist but found I couldn't ride a bicycle. I was frequently losing my balance and my gait was getting much worse. I was having sleeping problems and so needed to take sleeping aids, but was experiencing daytime drowsiness. My handwriting deteriorated and I couldn't write letters anymore. I was also experiencing incontinence. 

I visited a different neurologist, who, after eventually getting hold of my original scans, diagnosed me with NPH. I had never heard of NPH but he showed me the scan with two large white blobs that were the enlarged, CSF-filled ventricles. To my amateur eye, these looked very obvious. I expressed surprise that the original radiologist and neurologist didn’t detect or pick up on the significance of the changes. My second neurologist explained that untreated NPH is progressive but unlike Parkinson's disease, there is a potentially very effective treatment. Neurosurgery to drain the excess CSF was urgently recommended.  

It was in August 2022, and I initially struggled to find a surgeon that could take me in quickly. I eventually found a clinic in London who could admit me the following day. My first procedure fitted a temporary drain to remove CSF and see if I would be a good candidate for shunt surgery. I was amazed at the effectiveness. I could walk almost normally without a stick for the first time in two years. I could rise from a chair and generally felt much younger and more mobile. I was also able to sleep properly.

My neurosurgeon was impressed by my rapid recovery and so a more permanent treatment was arranged. Five weeks later I had a ventricular shunt fitted to help drain the CSF long-term. Again, the effect was dramatic: I could walk, my brain fog had lifted, I felt much better and my incontinence vastly improved. The relief was incredible, and I've continued to prosper.

My take-home message is please consider the possibility of NPH as a diagnosis where there are clinical signs. If a patient has symptoms that overlap with NPH, such as Parkinson's disease or Alzheimer's disease, even if they’re already diagnosed, please check they’ve had a brain scan and make sure it’s reviewed by someone with the expertise to diagnose or rule out NPH.

Just think “could it be NPH?” if it is, it could be treatable, and a patient’s life could be transformed as mine has been.   

Where can I learn more about NPH? 

• BMJ best practice guidelines for NPH. 
• Shine NPH support services across England, Wales and Northern Ireland. Support and information can be requested by patients and carers by phone (01733 555988) or email: [email protected]
• Healthcare professionals wanting to know more about NPH can join Shine Professionals and completing our free CPD accredited e-learning module on the condition.

References 

1. O Conn H. (Normal pressure hydrocephalus (NPH): more about NPH by a physician who is the patient. Clinical Medicine 2011; 11(2): 162–5. 
2. Kiefer M, Unterberg A. The differential diagnosis and treatment of normal-pressure hydrocephalus. Dtsch Arztebl Int. 2012; 109(1-2): 15-25.
3. Giordan E, Palandri G, Lanzino G, et al. Outcomes and complications of different surgical treatments for idiopathic normal pressure hydrocephalus: a systematic review and meta-analysis. Journal of Neurosurgery 2019; 131(4), 1024-36. 

*The names in this blog have been changed to ensure anonymity. 

About the Author

The charity Shine provides specialist support from before birth and throughout the life of anyone living with spina bifida and/or hydrocephalus, as well as to parents, families, carers and professional care staff. Shine is a community of 75,000 individuals, families, friends, and professionals, sharing achievements, challenges and information on living with hydrocephalus or spina bifida and related issues.