Clinical History
A middle-aged lady presented with fever for one week and progressive left-sided weakness.
Imaging Findings
The combination of meningitis and parenchymal lesions suggests tuberculosis.
There are multifocal ring enhancing lesions with predominantly basilar meningeal enhancement.
An acute infarct with haemorrhage in the right insula associated with parenchymal lesions and meningeal enhancement is seen.
On CTA there is vasculitis predominantly in the right MCA supplying the insula with areas of vasculitis elsewhere.
Discussion
Background: Tuberculosis is caused by Mycobacterium tuberculosis and accounts for eight million deaths worldwide per year. CNS involvement is seen in about 10% of all patients with tuberculosis. However, it also occurs in up to 15% of cases with acquired immunodeficiency syndrome. CNS involvement usually results from haematogenous spread but may result from direct extensions too. [1]
Clinical Perspective: Varies from mild meningitis with no neurologic deficit to coma.
Imaging Perspective: Granulomatous inflammatory reaction in CNS manifest in a variety of forms including parenchymal and leptomeningeal tuberculomas, abscesses, cerebritis, vasculitis, infarction, meningitis, and osteomyelitis. Cerebritis is rare but has specific clinical, radiological, and pathological manifestations. The involved areas show extensive inflammatory exudates, Langerhans’ giant cells, reactive parenchymal changes, and diffuse caseating and noncaseating microgranulomas in the cortex. On MR imaging, focal cerebritis appears hypo-intense on T1, hyper-intense on T2 and small areas of patchy enhancement show on post-contrast scan. Intracranial vaculitis is a common finding in patients in TB meningitis and a major factor contributing towards residual neurological deficits. Vasculitis is initiated by direct invasion of the vessel wall by mycobacteria or may result from secondary extension of adjacent arachnoiditis. Infarction resulting from vascultits is more common in infants and children. The middle cerebral artery territories are commonly affected and the infarcts are frequently bilateral [2].
Outcome:
Multidrug therapy with Isoniazid, rifampin, pyrazinamide, ± ethambutol or streptomycin. Sometimes surgical excision is also required.
Take home message: Combination of meningitis and parenchymal lesions suggests tuberculosis.
Differential Diagnosis List
Tuberculous cerebritis with vasculitis
Primary CNS neoplasm have solid enhancement with recruitment of vessels and varying necrosis depending on grade.
Fungal infection can have same signals but is usually fulminant with associated sinus involvement.
Final Diagnosis
Tuberculous cerebritis with vasculitis
