Responsiveness to distracting stimuli, though increased in Parkinson's disease, is decreased in asymptomatic PINK1 and Parkin mutation carriers

TY - JOUR

T1 - Responsiveness to distracting stimuli, though increased in Parkinson's disease, is decreased in asymptomatic PINK1 and Parkin mutation carriers

AU - Verleger, Rolf

AU - Hagenah, Johann

AU - Weiss, Manuel

AU - Ewers, Thomas

AU - Heberlein, Ilse

AU - Pramstaller, Peter P

AU - Siebner, Hartwig R

AU - Klein, Christine

N1 - Keywords: Adult; Aged; Aged, 80 and over; Analysis of Variance; Brain Mapping; Choice Behavior; Electroencephalography; Evoked Potentials, Visual; Female; Humans; Male; Middle Aged; Mutation; Neuropsychological Tests; Parkinson Disease; Pattern Recognition, Visual; Photic Stimulation; Protein Kinases; Reaction Time; Ubiquitin-Protein Ligases

PY - 2010/1

Y1 - 2010/1

N2 - Patients with Parkinson's disease (PD) are more sensitive than healthy controls to response-triggering by irrelevant flanking stimuli in speeded choice-response tasks. This increased responsiveness may either indicate a lack of executive control or reflect compensatory efforts to cope with the reduced internal motor drive. Of interest in this context is whether responsiveness is already enhanced in the presymptomatic stage of PD. To address these questions, we studied a group of non-manifesting carriers of heterozygous Parkin and PINK1 mutations while they performed a choice-response task with response-compatible or incompatible flankers. These mutation carriers may be considered a model for pre-clinical PD because the mutant allele leads to a latent nigrostriatal dysfunction and may increase the risk for PD. For comparison, we studied groups of medicated patients with idiopathic PD and of healthy persons age-matched to the mutation carriers and to the patients. Measurements of reaction time, error rate, and the lateralized readiness potential of the EEG provided converging evidence that the mutation carriers were less responsive to distracting flankers than their healthy control group. In contrast, PD patients were more distractible by flankers than their control group, which replicated previous results. Mutation carriers also showed a smaller N2 component of the event-related EEG potential in trials with incompatible flankers relative to their control group, which might indicate reduced inhibitory control. We hypothesize that faulty executive control is the primary deficit, reflected by the reduced N2 component in the mutation carriers. To compensate for this deficit, mutation carriers change their strategy of speed-accuracy trade-off, in order to dampen the excitability of their lateral motor system. Disease progression might prevent symptomatic PD patients from using this compensatory mechanism, leading to increased disinhibition of their lateral motor system.

AB - Patients with Parkinson's disease (PD) are more sensitive than healthy controls to response-triggering by irrelevant flanking stimuli in speeded choice-response tasks. This increased responsiveness may either indicate a lack of executive control or reflect compensatory efforts to cope with the reduced internal motor drive. Of interest in this context is whether responsiveness is already enhanced in the presymptomatic stage of PD. To address these questions, we studied a group of non-manifesting carriers of heterozygous Parkin and PINK1 mutations while they performed a choice-response task with response-compatible or incompatible flankers. These mutation carriers may be considered a model for pre-clinical PD because the mutant allele leads to a latent nigrostriatal dysfunction and may increase the risk for PD. For comparison, we studied groups of medicated patients with idiopathic PD and of healthy persons age-matched to the mutation carriers and to the patients. Measurements of reaction time, error rate, and the lateralized readiness potential of the EEG provided converging evidence that the mutation carriers were less responsive to distracting flankers than their healthy control group. In contrast, PD patients were more distractible by flankers than their control group, which replicated previous results. Mutation carriers also showed a smaller N2 component of the event-related EEG potential in trials with incompatible flankers relative to their control group, which might indicate reduced inhibitory control. We hypothesize that faulty executive control is the primary deficit, reflected by the reduced N2 component in the mutation carriers. To compensate for this deficit, mutation carriers change their strategy of speed-accuracy trade-off, in order to dampen the excitability of their lateral motor system. Disease progression might prevent symptomatic PD patients from using this compensatory mechanism, leading to increased disinhibition of their lateral motor system.

U2 - 10.1016/j.neuropsychologia.2009.10.004

DO - 10.1016/j.neuropsychologia.2009.10.004

M3 - Journal article

C2 - 19822161

SN - 0028-3932

VL - 48

SP - 467

EP - 476

JO - Neuropsychologia

JF - Neuropsychologia

IS - 2

ER -