DETERMINANTS OF COGNITIVE DISORDERS IN AUTOSOMAL-DOMINANT CEREBELLAR-ATAXIA TYPE-1

We assessed neuropsychological performances of 22 patients affected by Autosomal Dominant Cerebellar Ataxia type 1. All subjects completed a comprehensive battery of standardized tests requiring a verbal respon se, without time constraints. In order to verify the hypothesis that d isease severity is the major factor in determining the cognitive statu s in this syndrome, patients were divided into three groups according to the severity of the clinical picture, as evaluated by the Inherited Ataxias Progression Scale (IAPS). Statistical analysis of the three g roups' raw scores showed a significant decrement in patients with more severe clinical pictures on verbal short-term memory tasks. A similar trend, but not significant, was seen for general intelligence tests a nd verbal learning tasks. The decrement of verbal short-term memory co uld be related to motor speech problems. On the other hand, the declin e of cognitive abilities over the course of the Autosomal Dominant Cer ebellar Ataxia type 1 was not homogeneous enough to ensure statistical ly reliable trends. Therefore, this cross-sectional study suggests tha t the progression of the disease is a necessary factor in determining cognitive decline, but it is not sufficient. Other disease-related fac tors (age at onset, genotypic variety) could play a critical role: amo ng these, the size of the expanded CAG repeats is significantly relate d to a decline of verbal intelligence and short-term memory in SCA2 pa tients. (C) 1998 Elsevier Science B.V.