[Neurophysiological parameters and CD4 lymphocyte count in patients infected by human immunodeficiency virus]

The human immunodeficiency virus (HIV) causes serious, irreversible, progressive deterioration of the immune and nervous systems. The main target cells are the 'helper' T lymphocytes and monocyte-macrophage cells with CD4 molecules on the surface acting as virus receptors. In this study we attempt to find whether the immune state and the nervous system are involved in parallel, or whether, on the contrary, HIV neurotropism is such that it leads to early nerve involvement, out of proportion to that of the immune system.

We studied a total of 66 persons, 30 seronegative and 36 seropositive, with different CD4 lymphocyte counts. In all cases motor and sensory conduction studies were done in the arms and legs, namely auditory, visual and somatosensory evoked potentials and also endogenous potentials (mainly P300).

There are neurophysiological parameters which give pathological figures, even when immunity is maintained (figures of CD4 greater than 500/mm3) especially with regard to the figures for sensitivity of the legs, somatosensory evoked potentials and P300. Moreover, these are increased and others added at the same time as the CD4 count falls as the disease advances.