[Progressive multifocal leukoencephalopathy mimicking multiple sclerosis as the sole clinical manifestation of acquired immunodeficiency syndrome].

A 38 year-old wife, of belgian origin and residency, suffered from a left retrobulbar optic neuritis in 1973, with as only sequel dyschromatopsia and central scotoma enlargement. In 1985, 12 years later, she complained of a progressive weakness of the right hand, and developed a spastic tetraplegia within four months. The C.T. Scan showed white matter hypodensities, without mass effect or contrast enhancement, first limited to the left centrum semiovale and later on with multifocal character. Somatosensory evoked potentials after stimulation of the right median nerve demonstrated only lemniscus medialis response. Multiple sclerosis was initially suspected. Analysis of lymphocytes subsets however showed a markedly reduced helper population with as a result a very low H/S ratio, and the serology was found positive for HTLV-III-LAV, thus demonstrating the diagnosis of acquired immune deficiency syndrome (AIDS). Visceral autopsy demonstrated only a CMV pneumonia. Autopsy of the brain showed typical lesions of progressive multifocal leukoencephalopathy (PML). This case is compared with 20 previously published observations of PML associated with AIDS and appears rather unusual due to the association of unfrequent clinical peculiarities: previous, probably coincidental, retrobulbar optic neuritis, female patient, lack of risk factor and clinical symptoms of AIDS. The diagnostic difficulties in the present case are emphasized.