scholarly journals The Effect of Aging, Parkinson’s Disease, and Exogenous Dopamine on the Neural Response Associated with Auditory Regularity Processing

2019 ◽  
Author(s):  
Abdullah Al Jaja ◽  
Jessica A. Grahn ◽  
Björn Herrmann ◽  
Penny A. MacDonald

AbstractProcessing regular patterns in auditory scenes is important for navigating complex environments. Electroencephalography (EEG) studies find enhancement of sustained brain activity, correlating with the emergence of a regular pattern in sounds. How aging, aging-related diseases such as Parkinson’s disease (PD), and treatment of PD affect this fundamental function remain unknown. We addressed this knowledge gap. Healthy younger and older adults, and PD patients listened to sounds that contained or were devoid of regular patterns. Healthy older adults and PD patients were tested twice—on and off dopaminergic medication in counterbalanced order. Regularity-evoked, sustained EEG activity was reduced in older, compared to younger adults. PD patients and older controls had comparable attenuation of the sustained response. Dopaminergic therapy further weakened the sustained response in both groups. These findings suggest that fundamental regularity processing is impacted by aging-related neural changes but not those underlying PD. The finding that dopaminergic therapy attenuates rather than improves the sustained response coheres with the dopamine overdose response and implicates brain regions receiving dopamine from the ventral tegmental area in regularity processing.

2021 ◽  
pp. 154596832110413
Author(s):  
Samuel Stuart ◽  
Johanna Wagner ◽  
Scott Makeig ◽  
Martina Mancini

Background. Gait impairments are common in Parkinson’s disease (PD) and increase falls risk. Visual cues can improve gait in PD, particularly freezing of gait (FOG), but mechanisms involved in visual cue response are unknown. This study aimed to examine brain activity in response to visual cues in people with PD who do (PD+FOG) and do not report FOG (PD-FOG) and explore relationships between attention, brain activity and gait. Methods. Mobile EEG measured brain activity during gait in 20 healthy older adults and 43 PD participants (n=22 PD+FOG, n=21 PD-FOG). Participants walked for 2-minutes with and without visual cues (transverse lines to step over). We report power spectral density (PSD) in Delta (1-4 Hz), Theta (4-7 Hz), Alpha (8-12 Hz), Beta (14-24 Hz) and Gamma (30-50 Hz) bands within clusters of similarly brain localized independent component sources. Results. PSDs within the parietal and occipital lobes were altered when walking with visual cues in PD, particularly in PD+FOG. Between group, differences suggested that parietal sources in PD, particularly with PD+FOG, had larger activity compared to healthy older adults when walking. Within group, visual cues altered brain activity in PD, particularly in PD+FOG, within visual processing brain regions. In PD participants, brain activity differences with cues correlated with gait improvements, and in PD+FOG those with worse attention required more visual attentional processing (reduced alpha PSD) in the occipital lobe. Conclusions. Visual cues improve gait and influence brain activity during walking in PD, particularly in PD+FOG. Findings may allow development of more effective therapeutics.


2021 ◽  
pp. 1-13
Author(s):  
Matthew N. Petrucci ◽  
Sommer Amundsen Huffmaster ◽  
Jae Woo Chung ◽  
Elizabeth T. Hsiao-Wecksler ◽  
Colum D. MacKinnon

Background: An external cue can markedly improve gait initiation in people with Parkinson’s disease (PD) and is often used to overcome freezing of gait (FOG). It is unknown if the effects of external cueing are comparable if the imperative stimulus is triggered by the person receiving the cue (self-triggered) or an external source. Objective: Two experiments were conducted to compare the effects of self- versus externally triggered cueing on anticipatory postural adjustments (APAs) during gait initiation in people with PD. Methods: In experiment 1, 10 individuals with PD and FOG initiated gait without a cue or in response to a stimulus triggered by the experimenter or by the participant. Experiment 2 compared self- versus externally triggered cueing across three groups: healthy young adults (n = 16), healthy older adults (n = 11), and a group with PD (n = 10). Results: Experiment 1: Externally triggered cues significantly increased APA magnitudes compared to uncued stepping, but not when the same cue was self-triggered. Experiment 2: APAs were not significantly improved with a self-triggered cue compared to un-cued stepping in both the PD and healthy older adult groups, but the young adults showed a significant facilitation of APA magnitude. Conclusion: The effectiveness of an external cue on gait initiation in people with PD and older adults is critically dependent upon whether the source of the trigger is endogenous (self-produced) or exogenous (externally generated). These results may explain why cueing interventions that rely upon self-triggering of the stimulus are often ineffective in people with PD.


2003 ◽  
Vol 27 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Leslie D. Frazier ◽  
Victoria Cotrell ◽  
Karen Hooker

This study examined how future self-representations are affected by two different chronic illnesses, one focused on cognitive losses, early-stage Alzheimer's disease (AD), and one focused on physical losses, Parkinson's disease (PD). The impact of illness on possible selves (perceptions of self in the future) was made salient by a comparison with healthy older adults in order to better understand developmental issues in later life. Findings show that although there were no differences in the total number of domains reported by the groups, specific domains were reported differently by patient groups and all domains were likely to become infused with illness. As expected, patient groups had less self-efficacy and lower outcome expectancies for their future selves, and PD patients reported less distance from their feared selves. Although these findings are intuitive, this is the first empirical effort to document the impact of illness on older adults' self-representations. Group differences are explained in terms of disease context, and the importance of possible selves and self-regulatory functions as therapeutic mechanisms for adaptation to illness are emphasised.


2018 ◽  
Author(s):  
John Patrick Grogan ◽  
Lisa Emily Knight ◽  
Laura Smith ◽  
Nerea Irigoras Izagirre ◽  
Alexandra Howat ◽  
...  

ABSTRACTRationaleParkinson’s disease (PD) impairs working memory (WM) - the ability to maintain items in memory for short periods of time and manipulate them. There is conflicting evidence on the nature of the deficits caused by the disease, and the potential beneficial and detrimental effects of dopaminergic medication on different WM processes.ObjectivesWe hypothesised that PD impairs both maintenance and manipulation of items in WM and dopaminergic medications improve this in PD patients but impair it in healthy older adults.MethodsWe tested 68 PD patients ON and OFF their dopaminergic medication, 83 healthy age-matched controls, and 30 healthy older adults after placebo and levodopa administration. We used the digit span, a WM test with three components (forwards, backwards and sequence recall) that differ in the amount of manipulation required. We analysed the maximum spans and the percentage of lists correctly recalled, which probe capacity of WM and the accuracy of the memory processes within this capacity, respectively.ResultsPD patients had lower WM capacity across all three digit span components, but only showed reduced percentage accuracy on the components requiring manipulation (backwards and sequence spans). Dopaminergic medication did not affect performance in PD patients. In healthy older adults, levodopa did not affect capacity, but did impair accuracy on one of the manipulation components (sequence), without affecting the other (backwards).ConclusionsThis suggests a non-dopaminergic deficit of maintenance capacity and manipulation accuracy in PD patients, and a potential “overdosing” of intact manipulation mechanisms in healthy older adults by levodopa.


2018 ◽  
Vol 26 (1) ◽  
pp. 84-88 ◽  
Author(s):  
Lei Zhou ◽  
Marie-Anne Gougeon ◽  
Julie Nantel

We investigated the impact of Nordic walking (NW) on gait patterns in individuals with Parkinson’s disease (PD) following a 6-week NW familiarization. Twelve participants with PD and 12 healthy older adults took part in a gait analysis walking with and without poles (NP). Results showed larger knee power (knee extensor: K2) on the most affected leg in NW compared to NP (P = .01). On the less affected side, larger power absorption (knee extensor: K3) was found during preswing (K3) compared to older adults in both NP and NW (P = 0.01). NW showed longer stride length and single support time (P < .01) compared to NP. Walking with poles improved gait spatial–temporal characteristics and power profiles at the knee joint both on the less and most affected sides in individuals with PD. NW could be beneficial to help regain a more functional gait pattern in PD.


2016 ◽  
Vol 34 (2-3) ◽  
pp. 113-123 ◽  
Author(s):  
Chad Swank ◽  
Elaine Trudelle-Jackson ◽  
Ann Medley ◽  
Mary Thompson ◽  
Allen Jackson

2012 ◽  
Vol 260 (2) ◽  
pp. 580-589 ◽  
Author(s):  
Lucia Bartmann Wild ◽  
Daiane Borba Lima ◽  
Joana Bisol Balardin ◽  
Luana Rizzi ◽  
Bruno Lima Giacobbo ◽  
...  

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