Symptoms

The causes are unclear. However, always present are:

• An abnormality in absorption or excess production of, cerebrospinal fluid (CSF) leading to a build-up of this fluid in the brain;
• Increased blood volume in the vessels around the brain;
• Swelling of the brain.

The symptoms reported are those usually associated with raised intracranial pressure (ICP); these will commonly include headache, visual disturbances, photophobia, vomiting, problems with balance and spatial awareness, disorientation, loss of short-term memory (sometimes long-term memory loss), “pins and needles” or loss of sensation in hands. 

In some cases, CSF leaks down the nose. It is important to exclude cerebral tumour as a cause of the symptoms.

People with raised ICP may find it difficult to cope with previously learnt everyday tasks, eg handling money or using the telephone. They may be unable to find their way around a previously familiar town: traffic is confusing, they can be unaware of kerb height (sometimes afraid to step off the kerb in case they step “into space”); crossing the road can be a nightmare.