Normal Pressure Hydrocephalus (NPH)
Page Contents
What is NPH
Cerebrospinal fluid (CSF) is produced in the fluid chambers (ventricles) in your brain. It then circulates through these spaces to the spinal canal and back up again to the brain in a loop. Fluid is then reabsorbed in the brain.
Hydrocephalus is a build-up of CSF in the ventricles. Hydrocephalus has many different causes, but normal pressure hydrocephalus (NPH) is a condition that mainly affects adults over 60 years old. In NPH the ventricles become enlarged although the pressure is often normal. The condition can cause problems with walking and balance, cognitive difficulties and urinary incontinence.
People with NPH might benefit from an operation to divert fluid from the brain to the abdomen. This is called a shunt. There is no single test or scan that can tell us whether someone has NPH so at University Hospitals Plymouth we have a dedicated service to assess and investigate people who might have this condition.
Peninsula Normal Pressure Hydrocephalus Service
The Peninsula Normal Pressure Hydrocephalus Service is a unique and collaborative specialist service which includes Neurosurgery, Neurology, Neuropsychology, and therapy teams. This is to ensure a comprehensive, holistic assessment of the patient, using diagnostic tools which help us to make an accurate diagnosis and offer appropriate treatment.
Referral Process
Patients with suspected NPH can be referred to us by any healthcare professional but these usually come from a neurologist, elderly care doctor, GP or old age psychiatrist. NPH should be considered as a possibility in older adults who have a deterioration in their walking ability (gait) or balance, cognitive impairment and urinary urgency or incontinence. Not all patients with NPH will have all these symptoms but the vast majority do have some gait and balance difficulties. If these symptoms are present and a CT or MRI scan shows enlargement of the ventricles then a referral can be made. It’s also important to confirm that the patient would be happy and able to travel to Plymouth for assessment and would at least consider surgical intervention.
Initial Appointment
Your initial appointment with the NPH specialist service will be in person at our outpatient clinic at Derriford Hospital or Mount Gould Hospital in Plymouth. We also hold occasional clinics at Bodmin Hospital. It is best to attend with a relative or close friend and bring with you any walking aids, reading glasses and hearing aids if you use them.
You will be seen by a neurosurgeon, neuropsychologist and advanced clinical practitioner, who will ask about your symptoms, your medical history and your ability to carry out normal daily activities. We will also look at any scans that you have had.
We will assess your walking and balance, asking you to walk a short distance (10 meters) as well as you can. It is important that you bring with you any walking aids (stick or frame) that you usually use.
You will also undertake some memory and thinking tests that will help us understand any cognitive changes that are usually associated with NPH.
At the end of the appointment we will discuss all the findings with you and explain whether we think that you might have NPH or whether your symptoms relate to another condition.
If we think that you might have NPH then we may recommend some further investigations.
Investigations
Imaging
Some scans may be required to help us make a more accurate diagnosis and offer you possible treatment options. This might include MRI of the head and spine.
Lumbar Puncture (Tap Test)
This test simulates the effect of a shunt so can give us a good indication of whether you would benefit from an operation.
The procedure will be done at Derriford Hospital and you can go home on the same day.
You will be seen by a neuropsychologist and our advanced clinical practitioner, who will perform memory and walking assessments.
The lumbar puncture will be done under local anaesthesia. You will need to lie on your side, with your legs curled up to your chest. After numbing the skin, a small needle is inserted into the spinal canal in the lower back and about 40-50mls of spinal fluid is drained. The test normally takes about 30-45 minutes.
Once the needle is removed, you may want to rest by lying down on a bed for about 30 minutes. One hour after the end of the test, we will repeat the walking and memory tests to see whether there has been any improvement.
You should be able to eat and drink as normal, but you will need to drink plenty of fluids over the following 24 hours. You will also be given information about things to watch out for that might be early signs of problems (for example, infection). You should be able to resume your normal activities the next day.
Sometimes we don’t see any improvement immediately, so we ask you to complete a diary for 7 days to monitor any changes in your symptoms. If you do have some improvement, then we would anticipate this to wear off over a few days.
Extended Lumbar Drain Test
This test simulates the effect of a shunt so can give us a good indication of whether you would benefit from an operation. For some people we recommend this instead of a lumbar puncture or when there has been no response to lumbar puncture.
An extended lumbar drain involves the insertion of a small flexible tube into the spinal canal in the lower back. This can be done under local anaesthetic or light sedation and you will be admitted to Derriford Hospital for 2 or 3 days. The drain system removes spinal fluid slowly over this period and is the most sensitive test for diagnosing NPH.
Before the procedure, you will be seen by a neuropsychologist and either our advanced clinical practitioner or neuro-physiotherapist, who will perform memory and walking assessments.
During your stay, your nurse will check the status of the drain regularly, however, if you have any concerns in between the nurse’s visits please call them as soon as possible.
For safety reasons, you and or your relatives should not touch any part of the drainage system at any time. You must not go out of the ward while you have the drain inserted. If for any reason you are to go off the ward for clinical reasons, you will be accompanied by a trained staff member.
After removal of the drain your walking and memory tests will be repeated.
Medication before Surgical Investigations
Please tell the team about all the medicines you normally take, either prescribed by a doctor or bought over the counter.
IMPORTANT:
You should not take Aspirin as pain relief 7 days prior to your procedure. If you are on blood thinners such as Rivaroxaban, Edoxaban, Apixaban, Dabigatran, Warfarin, Aspirin, Clopidogrel or Di-Pyridamole, please let your clinical team know and they will advise you when to stop taking the medications if it is safe to do so.
Results Appointment
Your results appointment may take place either in person at our outpatient NPH clinic, or over the phone. Based on the results from your investigations, your symptoms, and your medical history, we will be more certain about your diagnosis, as well as discussing the treatment options available for you. You may be offered CSF shunt surgery.
Shunt Surgery
A shunt is a flexible tube placed into the brain ventricles to divert excess cerebrospinal fluid (CSF) away from the brain and towards another area of the body, usually the abdomen, where it can be absorbed. This is called a Ventriculoperitoneal Shunt (VPS).
What happens during the procedure?
-
You will receive general anaesthesia, so you will be asleep and feel no pain.
-
The surgeon makes a small hole in the skull and inserts one end of the shunt into a ventricle.
-
The other end of the shunt is threaded under your skin to your abdomen.
-
A valve on the shunt prevents fluid from flowing back to the brain and allows the surgeon to adjust the flow of CSF. This valve sits under the skin, usually behind the ear.
What are the risks of the operation?
-
Infection, particularly in the first few months after surgery, which can affect the shunt or the site of the operation.
-
Blockage or malfunction of the shunt can lead to recurrent symptoms and need for further surgery
-
Over-drainage of cerebrospinal fluid (CSF) can cause symptoms such as headaches, dizziness or lethargy.
-
General complications of having an operation: blood clots in the legs or lungs, chest infections, allergic reactions and a very small risk to life.
-
Abdominal complications such as peritonitis or hernias.
-
Rarely, seizures, haemorrhage or stroke may occur post-operatively.
What happens after the procedure?
-
Once your surgery is completed you will usually be transferred to the recovery unit where you will be looked after by specialist trained nurses. The nurses will monitor you closely until the effects of any general anaesthetic have adequately worn off and you are fully conscious. You may be given oxygen via a facemask, fluids through an intravenous drip, and appropriate pain relief, until you are comfortable enough to return to your ward.
-
You will have a CT head scan prior to being discharged home which is often the next day.
-
You will have surgical staples (clips) in the wound on your head which will need to remove by your GP nurse 7 days after the operation. The sutures on your abdomen are usually dissolvable.
-
You must not drive and you must inform the DVLA. You will normally be allowed to return to driving 6 months after your operation.
Post-Surgical follow-up
You will have an outpatient CT head scan 4-6 weeks after your operation at your local hospital. You will be seen in clinic about 3 months after your operation, usually by our Advanced Clinical Practitioner and at regular intervals after that. At these appointments we will assess your memory and walking to monitor how your symptoms are progressing. If necessary, we can adjust the setting on your shunt according to your response.
You can contact the team at any time if you have any concerns.
Teaching
The normal pressure hydrocephalus service is actively involved in providing teaching and services to the local area.
Our Team
Mr Samiul Muquit, is a Consultant Neurosurgeon who specialises in skull base and endoscopic neurosurgery. He has a keen interest in Normal Pressure Hydrocephalus, and along with Dr Noad, established the specialist NPH service in Plymouth in 2019.
Mr Samuel Jeffery is a Consultant Neurosurgeon and the departmental lead for CSF disorders. He specialises in complex hydrocephalus, Chiari malformation and other CSF disorders. He is an active member of the International Hydrocephalus Society and the UK’s Special Interest Group in NPH, developing ways to improve the care of patients with this condition.
Mrs Elizabeth Cray is an Advanced Clinical Practitioner specialising in Normal Pressure Hydrocephalus and Traumatic Brain Injury. An experienced Intensive Care nurse by background, she co-ordinates the NPH service, undertakes a regular lumbar puncture clinic and manages the longer-term follow-up of patients following shunt surgery. She is involved in research and leads our audit and service development programmes.
Dr Rupert Noad is a Consultant Neuropsychologist and Head of Neuropsychology at Derriford Hospital, Plymouth. Dr Noad has a clinical interest in early onset dementia and Normal Pressure Hydrocephalus. He is also involved in research in the field of cognition, dementia, NPH, Huntington’s Disease and, in particular, is interested in the development of new computerised measures of cognition.
Dr Thomas Davis is a Clinical Psychologist specialising in neuropsychology.
Dr Gemma Johns is a Clinical Psychologist specialising in neuropsychological assessment, formulation and brief intervention for patients with a wide range of neurological and neurosurgical problems. She provides neuropsychological support via inpatient and outpatient pathways, MDT clinics, and research clinics, in addition to teaching, consultation and supervision of other professionals.
Abigail Beard is an Assistant Psychologist within the Neuropsychology department at Derriford Hospital, Plymouth. Her main role in the service is to administer and score cognitive assessments.
Emma King are Assistant Psychologists within the Neuropsychology department. They work with the NPH team by supporting with cognitive assessments before and after lumbar punctures and lumbar drains.
Contacting the Team
Neurosurgery
Mr Samiul Muquit
Speciality co-ordinator Tina O’Farrell
Tel: 01752 437667
Email: tina.o’farrell1@nhs.net
Mr Samuel Jeffery
Speciality co-ordinator Anne-Marie Pengelly
Tel: 01752 439381
Email: anne-marie.pengelly@nhs.net
Neuropsychology
Dr Rupert Noad
Pathway Co-ordinator Martine Jones
Tel: 01752 439779
Email: martine.jones2@nhs.net
Information for Patients
About Normal pressure hydrocephalus, Shine charity
Article about Normal pressure hydrocephalus, Patient UK
Hydrocephalus and shunts, Brain and Spine Foundation
