"The main finding of our study is that the causes of stroke in HIV-infected patients continue to be more variable than in the general population of stroke patients," Dr. Alejandro Rabinstein told Reuters Health. "Thus, work-ups in HIV patients with stroke should be comprehensive to prevent recurrences and exclude mechanisms commonly considered atypical such as hypercoagulability and vasculitis."

Dr. Rabinstein and associates from the University of Miami School of Medicine, Florida investigated the distribution of stroke mechanisms in 88 HIV-infected patients admitted to a large metropolitan hospital between 1996 and 2004.

Among the 77 patients with ischemic stroke, the authors report, 10 (13%) had larger artery atherosclerosis, 15 (19%) had cardioembolism without atherosclerotic disease, 15 (19%) had small vessel occlusion, 10 (13%) had vasculitis, 7 (9%) had hypercoagulability, 1 had vertebral artery dissection, and 19 were of undetermined etiology.

A significant number of patients tested had anticardiolipin antibodies (29%) or protein S deficiency (45%), the report indicates.

Antiretroviral treatment did not correlate with the type of ischemic stroke, the researchers note, and there were no differences in CD4 counts between atherothrombotic and non-atherothrombotic stroke groups.

An unfavorable outcome, however, was associated with a lower CD4 count, and all 10 patients who died had CD4 counts below 100 cells/mm³.

"When we were planning the study, we were particularly interested in assessing the possible effect of highly active antiretroviral therapy (HAART) in causing accelerated atherosclerosis," Dr. Rabinstein commented. "Although we did not see such relationship in our study population, most of our patients were severely immunosuppressed. Our study does not exclude the possibility that HAART could induce strokes from accelerated atherosclerosis in patients with good response to the antiviral therapy."

Dr. Rabinstein also pointed out that, based on previous research data, it is "very important for clinicians taking care of HIV patients receiving HAART to monitor them for emergence of manifestations of the metabolic syndrome, since those patients are likely at risk for premature atherosclerosis."

He concluded: "I just hope research in this area continues, since I anticipate that it will be very important for the future health of HIV patients, considering that HIV infection in developed countries has become a chronic disease."

Neurology 2007;68:1257-1261.

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