BRAIN HMPAO-SPECT AND OCULAR MICROANGIOPATHIC SYNDROME IN HIV-1-INFECTED PATIENTS

Objective: The pathogenesis of neurologic and neuropsychologic dysfunc tion in HIV-1 infection is unclear. The purpose of the study was to de termine an association between cerebral perfusion and HIV-1-related oc ular microangiopathic syndrome. Methods: We studied 28 HIV-1-infected patients, seven of whom presented with asymptomatic HIV infection, nin e with lymphadenopathy syndrome or AIDS-related complex, and 12 with A IDS. Cerebral perfusion was semiquantitatively measured by single phot on emission computed tomography of the brain using technetium-99 hexam ethyl-propylenamine oxime (HMPAO-SPECT). The conjunctival manifestatio n of HIV-1-related microangiopathic syndrome was measured by a rating scale determining blood-flow sludging and by counting retinal cotton-w ool spots. CD4 count, neopterin, beta2-microglobulin (beta2M), haemogl obin, and age were determined as putative confounding variables. Resul ts: Mean conjunctival sludge in patients with normal HMPAO-SPECT findi ngs was 1.3+/-0.5 (mean+/-s.e.m.); no cotton-wool spots were present. In patients with slightly impaired HMPAO-SPECT, it was 2.1+/-0.6 and m ean cotton-wool spot count was 1.1+/-0.4. In patients with severely im paired HMPAO-SPECT, mean conjunctival sludge was 4.5+/-0.3 and mean co tton-wool spot count was 4.9+/-1.1 HMPAO-SPECT findings were closely a ssociated with conjunctival sludge (r=0.72; P<0.001) and number of cot ton-wool spots (r=0.78; P<0.001), whereas only a slight association wi th staging of HIV disease was found (P= 0.052). Analysis of covariance controlling for CD4 count, neopterin, beta2M, age, and haemoglobin de monstrated a significant difference between the three HMPAO-SPECT grou ps for both the number of cotton-wool spots (P<0.001) and the conjunct ival sludge rating (P<0.001). Conclusion: There was a close associatio n between severity of HIV-1-related ocular microangiopathic syndrome a nd severity of cerebral hypoperfusion. Microvascular alterations might contribute to the pathogenesis of neurological and neuropsychological symptoms in patients with HIV-1 disease. Furthermore, the conjunctiva l sludge rating and the number of cotton-wool spots might be appropria te indicators for severity of microvascular changes of the central ner vous system.