To the Editor: Primary cerebral vasculitis (PCV) is a potentially fatal disease. Early diagnosis and therapy are vital. We describe a case where confounding factors delayed diagnosis.

A 42-year-old woman presented with headache, nausea, vomiting, malaise and binocular blindness for 3 days. Two weeks previously, she had presented to the emergency department with headache and vomiting, but investigations, including computed tomography (CT) of the brain and lumbar puncture, gave normal results. She had a history of depression, was a smoker (20 pack-year history), and used cannabis regularly and alcohol occasionally, but denied other recreational drug use.

Her mood appeared depressed. Vital signs and findings from a general examination were normal. Eye movements were full, direct and indirect pupillary reflexes were intact, and optic fundi were normal. Results of a CT angiogram were reported as normal by a consultant radiologist. Results of blood tests, including inflammatory markers, and a repeat lumbar puncture, were unremarkable. A toxicology screen was not performed. Depression with conversion disorder was diagnosed, and admission with analgesia was advised. A neurologist’s review on Day 2 did not detect organic disease. The mental health team diagnosed severe depression and prescribed antidepressants.

On Day 4, the patient’s condition deteriorated and she become non-communicative with signs of right hemiplegia. An electroencephalogram showed polyrhythmic generalised slow waves consistent with encephalopathy. She was transferred to a tertiary centre where magnetic resonance imaging (MRI) and CT angiography of the brain showed multiple bilateral infarcts (Figure, A) with beaded arteries, the classic appearance of vasculitis. She was given high-dose prednisolone and cyclophosphamide. Investigations were negative for causes of secondary vasculitis. Her condition continued to deteriorate and she died 8 days after admission. Autopsy was refused. Subsequent review of the second CT scan detected irregular cerebral vessels (Figure, B).

PCV is an uncommon disorder of the central nervous system, with unknown aetiology and no specific characteristic features, affecting small cerebral arteries but not extracranial vessels. Symptoms and signs vary but include headache, encephalopathy, seizures, personality change, weakness, and altered level of consciousness, as well as superimposed focal cranial neuropathy or hemiplegia. Recognition is difficult, but differentiation from reversible cerebral vasoconstriction syndrome is important.1,2

Brain biopsy is seen as the “gold standard” for diagnosing PCV. CT angiography may show diffuse or localised changes, with vessel beading, aneurysms, and luminal narrowing. MRI may show areas of white and grey matter infarction, or haemorrhage. MRI is more sensitive than CT, but less sensitive than CT angiography. Up to 100% of biopsy-positive cases appear abnormal on MRI. Suspected cases require careful clinical appraisal and either CT angiography or MRI, probably followed by an image-guided brain biopsy.3

Initial reported cases of PCV had a poor prognosis; most patients died within a few weeks.2 Immunosuppressive therapy with glucocorticoids and cyclophosphamide (as used in secondary severe vasculitis) may be beneficial, although there are no clinical trials.4 A future therapeutic alternative may be infliximab, which has been used successfully for one patient with cerebral vasculitis secondary to Behçet’s disease who had known elevated levels of tumour necrosis factor α.5

Despite increasing awareness and advances in angiography, PCV remains an uncommon diagnostic and therapeutic problem which should be considered in cases of severe, non-febrile neurological illness with stroke-like features.

A: Magnetic resonance image showing multiple bilateral infarcts.

B: Computed tomography angiogram showing irregular cerebral vessels (“beading”, arrows).