Brain biopsy is becoming increasingly more important in the accurate detection of neurological complications. Incidence of brain biopsies may vary due to the reluctance of patients, and the reluctance of surgeons to operate if they believe that no treatment may be helpful. Other methods of neurological evaluation remain valuable tools. PML is difficult to study. Neurological manifestations of HIV infection are further complicated by the lack of an animal model to test potentially effective treatments.
Human trials are currently the only means to test potential agents.
The improved ability to diagnose PML by brain biopsy has increased the reported number of cases, and should allow for clinical trials large enough to provide definitive answers. Most information concerning PML treatments now comes from small studies and anecdotal reports. As it is now, many doctors assert that PML is not treatable. But some individuals have responded to various treatments. In some cases, anti-HIV drugs have had some effect.