|
|
||||||||
Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, UK
Homerton Hospital, London, UK
Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, UK
Institute of Psychiatry, London, UK
Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, UK
The basal ganglia are intimately connected to the frontal cortex via five fronto-striatal circuits. While the role of the frontal cortex in cognition has been extensively studied, the contribution of the basal ganglia to cognition has remained less clear. In Parkinson's disease, posteroventral pallidotomy (PVP) involves surgical lesioning of the internal section of the globus pallidus (GPi, the final output pathway from the basal ganglia) to relieve the motor symptoms of the disorder. PVP in Parkinson's disease provides a unique opportunity to investigate the impact of disruption of striatal outflow to the frontal cortex on cognition. We assessed executive function and working memory after withdrawal of medication in 13 patients with Parkinson's disease before and 3 months after unilateral PVP compared to 12 age- and IQ-matched normals assessed twice with an interval of 3 months. The tests used were: Wisconsin Card Sorting (WCST), Self-Ordered Random Number Sequences, Missing Digit Test, Paced Visual Serial Addition Test (PVSAT), and Visual Conditional Associative Learning Test (VCALT). After PVP, the patients performed significantly better on the Self-Ordered Random Number Sequences and the WCST, an improvement that was also observed in the normals across the two assessment and is therefore likely to reflect practice effects. Relative to the normals, the patients showed significant differential change following PVP on the Missing Digit Test and PVSAT, on which they performed worse after compared to before surgery, while the controls performed better on the second assessment. For the patients, performance on the VCALT also indicated deterioration after PVP, but the changes approached significance. The side of PVP had no effect on the results. The pattern of change observed 3 months after PVP was maintained at 15-month follow-up. The results suggest that striatal outflow to the frontal cortex may be essential for those aspects of executive function that showed deterioration after PVP.
Key Words: Parkinson's disease Pallidotomy Executive function Working memory Cognitive function Basal ganglia Striatum
This article has been cited by other articles:
![]() |
M. Fiorio, M. Gambarin, E. M. Valente, P. Liberini, M. Loi, G. Cossu, G. Moretto, K. P. Bhatia, G. Defazio, S. M. Aglioti, et al. Defective temporal processing of sensory stimuli in DYT1 mutation carriers: a new endophenotype of dystonia? Brain, January 1, 2007; 130(1): 134 - 142. [Abstract] [Full Text] [PDF] |
||||
![]() |
S D Brass, R H. Benedict, B Weinstock-Guttman, F Munschauer, and R Bakshi Cognitive impairment is associated with subcortical magnetic resonance imaging grey matter T2 hypointensity in multiple sclerosis Multiple Sclerosis, August 1, 2006; 12(4): 437 - 444. [Abstract] [PDF] |
||||
![]() |
S. M. Aglioti, M. Fiorio, B. Forster, and M. Tinazzi Temporal discrimination of cross-modal and unimodal stimuli in generalized dystonia Neurology, March 11, 2003; 60(5): 782 - 785. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. Escola, Th. Michelet, F. Macia, D. Guehl, B. Bioulac, and P. Burbaud Disruption of information processing in the supplementary motor area of the MPTP-treated monkey: A clue to the pathophysiology of akinesia? Brain, January 1, 2003; 126(1): 95 - 114. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| NEURAL COMPUTATION | J COGNITIVE NEUROSCIENCE | MIT PRESS JOURNALS |