Symptoms vary greatly between different people depending on which part of the brain affected. Some patients are brought to A&E after a fit (seizure), or patients may come to hospital or be referred by their GP or optician due to headaches, confusion or visual disturbance.

In all cases, a scan of the brain is arranged. Most people will have a CT scan (computerised tomography) scan first, but an MR scan of the brain (a magnetic resonance scan which shows more detailed images) is also usually required to confirm the diagnosis.