MRI IN CORTICOBASAL DEGENERATION

Corticobasal degeneration (C.B.D.) is a neurodegenerative disorder cha racterized mainly by an asymmetrical akineto-rigid syndrome associated with fronto-parietal cortical signs, particularly apraxia. Convention al imaging, even magnetic resonance imaging (M.R.I.), has often been c onsidered as poorly contributive for the diagnosis of C.B.D. We retros pectively studied routinely performed M.R.I. scans of 15 patients pres enting a clinical and metaboiic (P.E.T./S.P.E.C.T.) syndrome character istic of probable C.B.D. M.R.I. scans were assessed by 3 investigators , not aware of the clinically most affected side, laking into account M.R.I, technical parameters. We quantified, on each side, the cortical atrophy (frontal, parietal and temporal) and the white matter changes , by using the semi-quantified method of Victoroff et al (1994). Abnor malities were considered if observed by at least 2 of the 3 investigat ors. Abnormalities were then correlated with the side initially and mo st severely affected The most contributive findings were the asymmetri c parietal atrophy (clinically correlated in 93 p, 100 of cases), asym metric frontal atrophy (clinically correlated in 60 p. 100) and asymme tric dilatation of the lateral ventricles (clinically correlated in 60 p. 100). 80 p. 100 of affected subjects displayed at least 2 of these M.R.I. abnormalities. These results are in accordance with the metabo lic and pathologic features of C.B.D. This study demonstrates that M.R .I. evaluation oi the cortical atrophy asymmetry may contribute to the diagnosis of C.B.D.