Authors:

Doyon, J., OWEN, A. M. Jackson, P. L., Lafleur, M., Cesaro, P., Remy, P.

Reference:

Year of publication:

1999

CBU number:

3838

Abstract:

While improvements in motor functions have been reported following intrastriatal grafts of fetal ventral mesencephalic tissue in Parkinson’s disease (PD) (e.g., Peschanski et al., 1994), the effects of this procedure on cognitive functions have not been fully evaluated. We previously described the results from four patients in whom no cognitive changes were observed 3-6 months after unilateral putamen implantations (Lafleur et al., 1997). We now report the results from a follow-up study after bilateral putamen grafts. Seven patients were assessed prior to surgery using several motor tests and [18F]-Fluorodopa uptake according to the CAPIT. Two visuo-motor and one cognitive skill learning tasks, a standard neuropsychological battery, and selected sub-tests of the Cambridge automated battery (CANTAB) were also administered. Four of these patients were reevaluated 6-10 months following tissue implantation into the second putamen. The results showed amelioration of deficits on various measures of motor, but not of cognitive function. For example, better scores were obtained on tests of the UPDRS in the off-drug condition. Improvements in speed of response and hand-eye coordination on skill acquisition tests were also observed in the absence of differences in learning capacities. Finally, motor latencies were decreased on the Tower of London task, but the ability to solve problems remained impaired following grafts. These findings demonstrate that bilateral putamen grafts improve bradykinetic symptoms in PD, but have no effect on bradyphrenia (speed of thinking) and other aspects of cognitive functioning. This dissociation concurs fully with the known role of the putamen in motor function. Published in French only.