Neuroimaging in HIV infection: a preliminary quantitative MRI study and review of the literature

A review of both functional and structural imaging of the brain through the course of HIV infection leads to a fairly consistent pattern of involvement. Brain involvement in asymptomatic HIV positive individuals remains controversial. However, in symptomatic subjects, less controversy exists. Subcortical structures appear to be vulnerable early, followed by cortical and eventual diffuse involvement. Specific abnormal findings include symmetrical atrophy, hyperintense white matter lesions, both subcortical and cortical ventricular enlargement and focal metabolic abnormalities. It has' not been possible to correlate the specific underlying pathological mechanisms responsible for each of -these lesions and the pathophysiology probably involves multiple mechanisms, both direct and indirect. Some of these lesions are reversible with treatment, but the full implications of this reversibility with regard to pathogenesis and prognosis remain speculative. New evidence presented here suggests that both gray and white matter are involved in the atrophy.