Pedroso JL, et al. - Authors intended to examine the spectrum of neurologic disorders associated with HIV infection in order to identify subjects who developed a pure progressive cerebellar ataxia syndrome combined with cerebellar atrophy. Results illustrated that the pathophysiological mechanisms of ataxia in HIV was probably immune-mediated or a direct neurotoxic virus effect giving rise to apoptosis of Purkinje and granular cells. Therefore, HIV infection ought to be assessed in adult patients with undetermined sporadic progressive pure ataxia with cerebellar atrophy.