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Motor Sequence Learning and Consolidation in Unilateral De Novo Patients with Parkinson's Disease.

Dan X, King BR, Doyon J, Chan P - PLoS ONE (2015)

Bottom Line: LH-S patients demonstrated impaired learning during the initial training session and both LH-S and LH-A patients demonstrated decreased performance compared to controls during the next-day retest.Critically, the impairments in later learning stages in the LH-A patients were evident even before the appearance of traditional clinical symptoms in the tested hand.Results may be explained by the progression of disease-related alterations in relevant corticostriatal networks.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurobiology and Neurology, Key Laboratory of Ministry of Education on Neurodegenerative Disorders, Beijing Key Laboratory on Parkinson's Disease, Xuanwu Hospital of Capital Medical University, Beijing, China.

ABSTRACT
Previous research investigating motor sequence learning (MSL) and consolidation in patients with Parkinson's disease (PD) has predominantly included heterogeneous participant samples with early and advanced disease stages; thus, little is known about the onset of potential behavioral impairments. We employed a multisession MSL paradigm to investigate whether behavioral deficits in learning and consolidation appear immediately after or prior to the detection of clinical symptoms in the tested (left) hand. Specifically, our patient sample was limited to recently diagnosed patients with pure unilateral PD. The left hand symptomatic (LH-S) patients provided an assessment of performance following the onset of clinical symptoms in the tested hand. Conversely, right hand affected (left hand asymptomatic, LH-A) patients served to investigate whether MSL impairments appear before symptoms in the tested hand. LH-S patients demonstrated impaired learning during the initial training session and both LH-S and LH-A patients demonstrated decreased performance compared to controls during the next-day retest. Critically, the impairments in later learning stages in the LH-A patients were evident even before the appearance of traditional clinical symptoms in the tested hand. Results may be explained by the progression of disease-related alterations in relevant corticostriatal networks.

No MeSH data available.


Related in: MedlinePlus

Performance Index (PI) in Session 1 (A) and Session 2 (B).Data points represent group means for each block and error bars depict standard errors. Black squares = healthy controls; blue circles = left hand asymptomatic (LH-A) patients with PD; red crosses = left hand symptomatic patients (LH-S) with PD. Thick solid lines represent group-averaged trajectories based on a single exponential fit.
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pone.0134291.g004: Performance Index (PI) in Session 1 (A) and Session 2 (B).Data points represent group means for each block and error bars depict standard errors. Black squares = healthy controls; blue circles = left hand asymptomatic (LH-A) patients with PD; red crosses = left hand symptomatic patients (LH-S) with PD. Thick solid lines represent group-averaged trajectories based on a single exponential fit.

Mentions: As both movement speed and accuracy were modulated by practice, we computed an aggregate speed / accuracy dependent measure (PI; depicted in Fig 4A). Results from the 3 (Group) x 14 (Block) ANCOVA with age as the covariate revealed a significant Block main effect (F(13,884) = 51.4; p<0.001) as PI increased as a function of practice. A significant Group main effect was also evident (F(2,67) = 7.57; p = 0.001) and follow-up analyses indicated that performance of the LH-S patients with PD was significantly worse relative to both the LH-A patients (F(1,39) = 4.92; p = 0.032) and the healthy controls (F(1,44) = 16.00; p<0.001). Interestingly, there was a trend for a difference between the LH-A and controls (F(1,50) = 3.63; p = 0.063), a result that can be attributed predominantly to a deficit in movement accuracy. The Block x Group interaction was marginally significant (F(26,884) = 1.45; p = 0.07), indicating a trend for a difference among the three groups in the rate of performance improvement. Follow-up analyses were conducted to decompose this effect; however, as the initial ANCOVA only indicated a trend for a significant effect, significance thresholds for the follow-up contrasts were Bonferroni corrected to a value of 0.017 (e.g., 0.05 / 3). Results revealed that the PI improvement in the LH-S patients was significantly different compared to the healthy controls (F(13,585) = 2.25; p = 0.007), suggesting impaired learning in the LH-S patients. By contrast, the LH-A patients did not differ from the LH-S patients or the healthy controls (p > 0.18) with respect to the rate of PI improvement in Session 1.


Motor Sequence Learning and Consolidation in Unilateral De Novo Patients with Parkinson's Disease.

Dan X, King BR, Doyon J, Chan P - PLoS ONE (2015)

Performance Index (PI) in Session 1 (A) and Session 2 (B).Data points represent group means for each block and error bars depict standard errors. Black squares = healthy controls; blue circles = left hand asymptomatic (LH-A) patients with PD; red crosses = left hand symptomatic patients (LH-S) with PD. Thick solid lines represent group-averaged trajectories based on a single exponential fit.
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4519305&req=5

pone.0134291.g004: Performance Index (PI) in Session 1 (A) and Session 2 (B).Data points represent group means for each block and error bars depict standard errors. Black squares = healthy controls; blue circles = left hand asymptomatic (LH-A) patients with PD; red crosses = left hand symptomatic patients (LH-S) with PD. Thick solid lines represent group-averaged trajectories based on a single exponential fit.
Mentions: As both movement speed and accuracy were modulated by practice, we computed an aggregate speed / accuracy dependent measure (PI; depicted in Fig 4A). Results from the 3 (Group) x 14 (Block) ANCOVA with age as the covariate revealed a significant Block main effect (F(13,884) = 51.4; p<0.001) as PI increased as a function of practice. A significant Group main effect was also evident (F(2,67) = 7.57; p = 0.001) and follow-up analyses indicated that performance of the LH-S patients with PD was significantly worse relative to both the LH-A patients (F(1,39) = 4.92; p = 0.032) and the healthy controls (F(1,44) = 16.00; p<0.001). Interestingly, there was a trend for a difference between the LH-A and controls (F(1,50) = 3.63; p = 0.063), a result that can be attributed predominantly to a deficit in movement accuracy. The Block x Group interaction was marginally significant (F(26,884) = 1.45; p = 0.07), indicating a trend for a difference among the three groups in the rate of performance improvement. Follow-up analyses were conducted to decompose this effect; however, as the initial ANCOVA only indicated a trend for a significant effect, significance thresholds for the follow-up contrasts were Bonferroni corrected to a value of 0.017 (e.g., 0.05 / 3). Results revealed that the PI improvement in the LH-S patients was significantly different compared to the healthy controls (F(13,585) = 2.25; p = 0.007), suggesting impaired learning in the LH-S patients. By contrast, the LH-A patients did not differ from the LH-S patients or the healthy controls (p > 0.18) with respect to the rate of PI improvement in Session 1.

Bottom Line: LH-S patients demonstrated impaired learning during the initial training session and both LH-S and LH-A patients demonstrated decreased performance compared to controls during the next-day retest.Critically, the impairments in later learning stages in the LH-A patients were evident even before the appearance of traditional clinical symptoms in the tested hand.Results may be explained by the progression of disease-related alterations in relevant corticostriatal networks.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurobiology and Neurology, Key Laboratory of Ministry of Education on Neurodegenerative Disorders, Beijing Key Laboratory on Parkinson's Disease, Xuanwu Hospital of Capital Medical University, Beijing, China.

ABSTRACT
Previous research investigating motor sequence learning (MSL) and consolidation in patients with Parkinson's disease (PD) has predominantly included heterogeneous participant samples with early and advanced disease stages; thus, little is known about the onset of potential behavioral impairments. We employed a multisession MSL paradigm to investigate whether behavioral deficits in learning and consolidation appear immediately after or prior to the detection of clinical symptoms in the tested (left) hand. Specifically, our patient sample was limited to recently diagnosed patients with pure unilateral PD. The left hand symptomatic (LH-S) patients provided an assessment of performance following the onset of clinical symptoms in the tested hand. Conversely, right hand affected (left hand asymptomatic, LH-A) patients served to investigate whether MSL impairments appear before symptoms in the tested hand. LH-S patients demonstrated impaired learning during the initial training session and both LH-S and LH-A patients demonstrated decreased performance compared to controls during the next-day retest. Critically, the impairments in later learning stages in the LH-A patients were evident even before the appearance of traditional clinical symptoms in the tested hand. Results may be explained by the progression of disease-related alterations in relevant corticostriatal networks.

No MeSH data available.


Related in: MedlinePlus