Inflammatory lesions of the basal ganglia and thalamus: review of twenty-one cases.

We report a series of 21 patients with basal ganglia and thalamic granulomas or abscesses treated over 7 years. Among them, 15 were tubercular, 5 were pyogenic, and 1 was fungal. Pyogenic abscesses, usually hematogenous, also occurred secondary to osteomyelitis of the skull and chronic otitis media. The fungal abscess developed in a nonimmunocompromised patient with no intercurrent malignancy. Evidence of tuberculosis elsewhere in the body was detected in only 7 patients with tuberculomas. The computed tomographic (CT) image morphology characterizing an abscess or a tuberculoma was present in all except 2 patients with tuberculomas. The fungal abscess resembled a malignant glioma. The only hospital mortality occurred in a deeply unconscious patient with a thalamic pyogenic abscess. A 12-month or longer follow-up in 16 patients showed that 3 continued to be handicapped neurologically, and 2 died 13 and 16 months later, respectively. We conclude that inflammatory lesions at these sites are not uncommon and that CT scans are diagnostic in the great majority. Doubtful diagnosis merits stereotactic aspiration or biopsy of the lesion. Satisfactory results follow adequate medical therapy.