Working memory in Parkinson's disease patients: clinical features and response to levodopa.
OBJECTIVE
To evaluate the clinical features of the working memory (WM) in Parkinson's disease (PD) patients and to test the effect of levodopa on WM.


METHODS
The paradigm was based on the 'n-back' tasks, which enables to study the level of executive demand (three levels of difficulty) and the domain of the information being processed (spatial items, faces and letters). The effect of levodopa was studied by testing PD patients in "on" and "off" states.


RESULTS
PD patients performed less well in WM tasks than controls. There was no interaction between groups and complexity. Levodopa therapy had a positive effect only on spatial WM tasks but no effect on complexity.


CONCLUSIONS
Our results suggest that impairment observed may result from a maintenance deficit within WM regardless the level of processing and levodopa therapy presents a positive effect on spatial WM.
Beato
Rogério
R
INSERM U610, Groupe Hospitalier de la Pitié-Salpêtrière, Paris, France.
Levy
Richard
R
Pillon
Bernard
B
Vidal
Christine
C
du Montcel
Sophie Tezenas
ST
Deweer
Bernard
B
Bonnet
Anne-Marie
AM
Houeto
Jean-Luc
JL
Dubois
Bruno
B
Cardoso
Francisco
F
D000368:Aged; D000704:Analysis of Variance; D000978:Antiparkinson Agents / Q000627:therapeutic use*; D016022:Case-Control Studies; D015259:Dopamine Agents / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D007980:Levodopa / Q000627:therapeutic use*; D008297:Male; D008568:Memory / Q000187:drug effects* / Q000502:physiology; D008570:Memory, Short-Term / Q000187:drug effects; D008875:Middle Aged; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000188:drug therapy / Q000503:physiopathology; D013028:Space Perception / Q000187:drug effects* / Q000502:physiology
D000978:Antiparkinson Agents; D015259:Dopamine Agents; D007980:Levodopa