Proton magnetic resonance spectroscopy pattern of progressive multifocal leukoencephalopathy in AIDS

The objective was to determine whether the use of intermediate echo times ( 135 ms) in proton magnetic resonance spectroscopy (H-1-MRS) detects a homog enous pattern in progressive multifocal leukoencephalopathy (PML) in HIV-1 infected people, and to confirm the results of previous studies. Six patients infected with HIV-1, with PML established by biopsy, and six h ealthy age and sex matched volunteers were evaluated to define their spectr oscopic pattern. H-1-MRS spectra performed at 1.5 T were obtained with the STEAM sequence: TE/TM/TR, 20 ms/13.7 ms/2000 ms; 2500 Hz, size 2048 points, 256 acquisitions (STEAM-20) and with the PRESS sequence; TE/TR, 135 ms/200 0 ms; 2500 Hz, size 2048 points, 256 acquisitions (PRESS-135). A single vox el was placed on the lesions and on the parieto-occipital white matter of c ontrols. The peaks of N-acetylaspartate (NAA), choline (Cho), myoinositol ( mI), lactate, and lipids were considered, and the results were expressed us ing creatine as reference. Spectra of PML lesions were characterised by significantly reduced NAA, lac tate presence, and by significantly increased Cho and lipids compared with control group values. These results indicate that H-1-MRS detects a homogenous pattern in PML les ions. Recent studies, together with this, suggest that H-1-MRS may help in the diagnostic approach to patients with suspected PML lesions associated w ith AIDS.