Cognitive alterations in non-demented CADASIL patients

CADASIL is an inherited small-artery disease of the brain due to mutations of the Notch3 gene on chromosome 19. It is characterized by strokes, migraine with aura, and severe mood disturbances during mid adulthood and leads progressively to subcortical dementia. The precise onset of the cognitive decline in CADASIL remains unknown. We report here the cognitive evaluation of 8 non-demented symptomatic patients with CADASIL from 35 to 66 years of age. Altered performances were found in all subjects with the Wisconsin Card-Sorting Test (WCST), in 5/8 with the Trail-Making Test, and in 3/8 with copying of Rey's figure. Altered performances with codes and similarities of the WAIS-R, the Wechsler Memory Scale, Raven's Progressive Matrices, and the category and letter fluency task were observed less frequently (n less than or equal to 2). The score obtained with the WCST was not significantly correlated with the severity of the white-matter or basal ganglia signal abnormalities at MRI examination. Our data show that: (1) symptomatic CADASIL patients, although non-demented, can present with a subtle cognitive impairment; (2) tasks involving the frontal lobes are found most frequently altered, and (3) this subtle cognitive deficit can develop in the absence of major vascular events and does not appear to be correlated with the severity of brain lesions as seen at MRI examination.