[Cerebral SPECT with thallium-201 in the differential diagnosis of focal cerebral lesions in patients with AIDS].

BACKGROUND

The aim of this study was to analyze the usefulness of cerebral SPECT with thallium-201 in patients with the acquired human immunodeficiency syndrome (AIDS) and focal cerebral lesions.

METHODS

Six patients with AIDS and focal cerebral lesions in whom a cerebral SPECT was performed with thallium-201 are described. Treatment was initiated with antiToxoplasma drugs in all patients. The clinical response, serology for positive toxoplasma and radiologic improvement were criteria for the diagnosis of encephalitis by Toxoplasma. In the remaining cases, cerebral biopsy and/or necropsy study were carried out.

RESULTS

In the 2 patients in whom cerebral SPECT demonstrated enhancement of the lesion, the pathologic diagnosis was cerebral lymphoma. Of the 4 remaining cases in whom no enhancement was observed, three corresponded to cerebral toxoplasmosis and one to progressive multifocal leucoencephalopathy.

CONCLUSIONS

Cerebral SPECT with thallium-201 is a simple, specific and useful technique for the differentiation of primary cerebral lymphoma from the remaining inflammatory cerebral lesions which may be present in AIDS patients.