Background: Multiple enhancing computed tomography (CT) brain lesions are common neuroimaging abnormalities in India. Several published case reports suggest that multiple enhancing lesions of the brain can occur with a wide variety of infective and non-infective etiologies.
Methods: In this prospective follow up study, 110 consecutive patients with two or more than two enhancing brain lesions were subjected to a clinical evaluation and a battery of common investigative tests.
Results: Infective pathologies were the most common etiology for multiple enhancing lesions of the brain. Tuberculosis was the commonest infective pathology, followed by neurocysticercosis. Neoplastic diseases were common non-infective causes. In majority, brain lesions were metastatic manifestation of a systemic neoplastic disorder. Lung carcinoma was the commonest primary malignancy. One patient each had multiple brain abscesses, Behcet's syndrome and systemic lupus erythematosus. Among 4 human immunodeficiency virus-infected patients, one had toxoplasmosis and two patients were diagnosed to have cryptococcal meningitis. In 45 patients, after initial work up, etiological diagnosis could not be ascertained. These undiagnosed patients were empirically treated with antituberculous drugs and corticosteroids. Six undiagnosed patients showed pulmonary metastasis on repeat X-ray chest. In 10 patients CT lesions completely disappeared. In 5 patients number of CT lesions decreased. Six patients died. However, in majority of the undiagnosed patients follow up CT scans of brain remained unaltered.
Conclusion: A large number of infectious and non-infectious diseases can cause multiple enhancing lesions of the brain. The work up of these patients should include clinical evaluation, imaging and a battery of laboratory tests. The specific diagnosis may remain a challenge in several cases.