[Lasting focal signs in 2 cases of progressive multifocal leukoencephalopathy].

Two cases of progressive multifocal leukoencephalopathy, which occurred without a clinical setting of immune deficiency and developed as a unifocal brain lesion during 14 and 4 months, are reported. The diagnosis was established only by post mortem study in the first case and after five months by a brain biopsy in the second one. The difficulties of an early diagnosis in such cases should be now reduced with CT scan which may show a relatively specific picture, even when there is only one visible lesion.