Cerebral vasculitis: symptoms, diagnosis and treatment

Vasculitis is inflammation targeted against blood vessels. Vasculitis UK explains that the inflammation within the vessel wall damages the vessel, with varying degrees of blockage and bleeding, which causes injury to the tissues and organs the vessel supplies. When the brain is affected it is called cerebral vasculitis; when the spinal cord is included the term central nervous system (CNS) vasculitis is used.

A second UK source, written by a neurologist for Vasculitis UK, explains that vasculitis can arise within a wider inflammatory disease, such as infections or connective tissue diseases (secondary), or can be confined to the brain and spinal cord (primary). The primary form, which affects only the CNS, is called primary angiitis of the central nervous system (PACNS). Angiitis is another term for the same process.

Primary CNS vasculitis is considered a rare disease. Vasculitis UK gives an estimate of 2.4 per million people per year, says males may be slightly more likely to have it, and says onset typically occurs in people in their 50s, but people of any age can be affected. An older Vasculitis UK page from 2016 gave an estimate of fewer than 1 per million, so estimates vary and it is probably under-recognised.

Some causes of CNS vasculitis are recognised: infections such as tuberculosis, varicella zoster and hepatitis viruses, cancers such as lymphoma, drugs such as cocaine and amphetamines, and other immune-mediated conditions such as rheumatoid arthritis and sarcoidosis. In some people the immune system spontaneously attacks the brain and spinal cord and the reason is not fully understood.

The symptoms can be very different from one person to another. Vasculitis UK lists the following, and says some people have only a few symptoms while others have many. They usually develop over weeks and months but can sometimes occur more quickly, and occasionally people may become critically unwell.

• Fatigue and headache.

• Changes in behaviour or personality, confusion and memory impairment.

• Seizures.

• Limb weakness and balance problems.

• Impaired control of bowel or bladder function.

• Difficulties with hearing and vision.

• Reduced consciousness or coma in severe cases.

CNS vasculitis can be difficult to diagnose because many symptoms overlap with other neuroinflammatory conditions such as multiple sclerosis or neurosarcoidosis. Vasculitis UK says investigations may not show a pattern that clearly distinguishes it from more common conditions, so the diagnosis may be delayed and some people have initially been given an incorrect diagnosis.

Investigations include blood tests, which may be normal, and imaging of the brain and spinal cord. People often have both CT and MRI, with dedicated imaging of the vessels (angiogram and/or vessel wall imaging). The smallest vessels may be below the resolution of the scan, so imaging can appear normal. The 2016 Vasculitis UK page adds that MRI of the brain is usually abnormal, with widespread small lesions that can mimic strokes, and that the spinal fluid is usually active with a raised protein and cell count.

The definitive way to diagnose vasculitis in any organ is a biopsy showing inflamed vessels under a microscope. In the brain this is challenging because of surgical risks, but depending on the location it can often be done safely, and targeting an area that is abnormal on imaging increases the chance of an informative result. The 2016 page says it is carried out very carefully with only a very small sample taken, and the chance of problems such as bleeding or infection is very low.

When no trigger is identified, the aim is to dampen down the overactive immune system and stop the misdirected attack on the brain and spinal cord. Vasculitis UK says that, as with other serious vasculitis, high doses of steroids are often required, which work relatively quickly but can have significant side effects. If there is an underlying cause, the best treatment of the brain disease will be the same as treating the inflammatory disease elsewhere in the body.

Vasculitis UK says relapse occurs in about a quarter of cases and that with correct treatment the prognosis is much better than in the past. The older 2016 page is more cautious: it says that, because of delays in diagnosis and uncertainty about how aggressive treatment should be, residual impairments such as epilepsy and cognitive dysfunction can remain, and some people need help at home. Early diagnosis and treatment are the main message of both.

Because the condition is so rare there have not been clinical trials, according to the 2025 page, and researchers are continuing to work on understanding how and why it arises and on diagnosis and management.

Persistent new headache with confusion, personality change, seizures, weakness or visual or hearing loss needs prompt medical assessment. Sudden face drooping, arm weakness or slurred speech should be treated as a stroke and prompts a 999 call, as the 2016 Vasculitis UK page says that the onset can simulate a stroke. A first seizure, or a person who is increasingly drowsy or hard to wake, also needs emergency care.

Long-term immunosuppression means regular monitoring, and Vasculitis UK publishes a glossary of drugs, side effects and blood test monitoring, as well as a helpline. Vasculitis UK has a helpline and information on drugs and side effects, and the treating neurology and rheumatology teams can coordinate care. Because the condition is rare, ask whether your care is being supported by a specialist centre.