Toxoplasmic encephalitis in acquired immunodeficiency syndrome.

OBJECTIVES: To study the clinical course and outcome of toxoplasmic encephalitis (TE) in patients with acquired immunodeficiency syndrome (AIDS).

METHODS: Patients infected with human immunodeficiency virus (HIV) and neurological abnormality compatible with diagnosis of TE were enrolled in the study. These patients were treated with combination of trimethoprim/sulfamethoxazole and pyrimethamine. Response to therapy was assessed by clinical examination and repeat CT/MRI scan done after three weeks of starting treatment. Those showing response were put on prophylactic therapy.

RESULTS: A total of 451 patients of HIV infections were admitted to this centre during the study period, of these 11 patients were diagnosed to have TE. The common presenting symptoms were fever (80%), seizures (45%), headache (45%) and altered sensorium (25%). Focal neurological deficit was present in 80% of cases. Nine cases had ring-enhancing lesions on CT scan while in the remaining two patient's ring lesions were seen on MRI. These were either multiple (55%) or solitary (45%). Antitoxoplasma antibody was detected in 10 patients. It was absent in one patient. Ten patients had clinical and radiological improvement with trimethoprim/sulfamethoxazole and pyrimethamine within 10 +/- 3 days of starting therapy. One patient died within 10 days of starting therapy.

CONCLUSION: Toxoplasmosis is a common opportunistic infection of the central nervous system in patients with AIDS. Majority of patients with cerebral toxoplasmosis present with focal neurological abnormality in presence of characteristic neuroradiological abnormality and positive antitoxoplasma antibody titer. Response to empirical therapy helps to confirm the diagnosis, lifelong prophylaxis there after prevents relapse of potentially fatal and easily treatable condition.