HIV-1-associated cognitive/motor complex: absence of neuronal loss in the cerebral neocortex.

We performed a postmortem morphometric study in six AIDS patients and six controls to determine if a neocortical neuronal loss occurs in HIV-1-associated cognitive/motor complex. Patients were selected during a prospective study including psychometric evaluation and neuroimaging, and none had focal lesions. Two had HIV-1-associated myelopathy with mild cognitive impairment, and four had HIV-1-associated dementia complex. Planimetry did not show any cerebral atrophy. Cortical thickness, mean neuronal size, and mean neuronal densities in Brodmann's areas 4, 9, and 40 were not statistically different in patients and controls. There were no significant changes in neuronal densities of columnar and laminar samples, indicating that there was neither global nor selective neuronal loss. HIV-1-associated cognitive/motor complex is not necessarily related to neocortical neuronal loss, but could be due to subcortical lesions or metabolic dysfunction.