Perturbation-evoked cortical responses are associated with balance ability in healthy young adults and in older adults with Parkinson's disease

Payne, Aiden M.

Title:

Perturbation-evoked cortical responses are associated with balance ability in healthy young adults and in older adults with Parkinson's disease

dc.contributor.advisor	Ting, Lena H.
dc.contributor.author	Payne, Aiden M.
dc.contributor.committeeMember	Hajcak, Greg
dc.contributor.committeeMember	McKay, Lucas
dc.contributor.committeeMember	Borich, Michael
dc.contributor.committeeMember	Cope, Tim
dc.contributor.committeeMember	Jaeger, Dieter
dc.contributor.committeeMember	Wichmann, Thomas
dc.contributor.department	Biomedical Engineering (Joint GT/Emory Department)
dc.date.accessioned	2020-09-08T12:40:08Z
dc.date.available	2020-09-08T12:40:08Z
dc.date.created	2019-08
dc.date.issued	2019-05-21
dc.date.submitted	August 2019
dc.date.updated	2020-09-08T12:40:08Z
dc.description.abstract	Balance and cognitive impairments negatively impact quality of life in old age and in Parkinson's disease (PD) and are associated through unknown mechanisms. Measuring brain activity during reactive balance recovery may yield insight into the relationship between balance and cognitive function, facilitating the development of better treatment strategies. Electroencephalography (EEG) recordings show that sudden perturbations to standing balance reliably evoke a cortical N1 response localized to the supplementary motor area. The cortical N1 response is known to be influenced by cognitive processes because it is smaller when perturbations are predictable and enhanced when people are afraid or paying more attention to balance. Because the cortical N1 response is evoked by balance perturbations and influenced by cognition, it has the potential to reflect a site of interaction between balance and cognitive function. Despite knowledge of these cognitive influences on the cortical N1 response, there are no existing theories of how the cortical N1 response might influence subsequent balance recovery behavior. Through a series of studies, I present a novel hypothesis that perturbation-evoked cortical responses reflect cortical contributions to balance recovery, which are greater in people with lower balance ability. First, I show in healthy young adults (HYA) that a very small proportion of the cortical N1 response amplitude can be explained by the magnitude of sensory inputs, and that cortical N1 responses differ to a much larger extent between individuals. Then, I demonstrate that cortical N1 responses are larger for HYA who have lower balance ability, and that the cortical N1 response is larger when people take compensatory steps, suggesting that the cortical N1 response may reflect the need for cortically-mediated compensatory motor outputs. Then, I show that perturbation-evoked cortical responses in older adults with and without PD contain two component peaks, with smaller amplitudes of the second peak reflecting balance impairment in PD. Finally, I show that perturbation-evoked cortical responses are impacted by PD in a different manner than a related cortical response called the error-related negativity, which occurs when mistakes are made in computer-based cognitive tasks. The basic science work presented in this thesis may inform future studies into the relationship between balance and cognitive impairments, thereby facilitating the development of better rehabilitation strategies for balance impairments in Parkinson's disease.
dc.description.degree	Ph.D.
dc.format.mimetype	application/pdf
dc.identifier.uri	http://hdl.handle.net/1853/63508
dc.language.iso	en_US
dc.publisher	Georgia Institute of Technology
dc.subject	Cortical N1
dc.subject	Balance
dc.subject	Parkinson's disease
dc.subject	Perturbation
dc.subject	EEG
dc.subject	EMG
dc.subject	Motor control
dc.title	Perturbation-evoked cortical responses are associated with balance ability in healthy young adults and in older adults with Parkinson's disease
dc.type	Text
dc.type.genre	Dissertation
dspace.entity.type	Publication
local.contributor.advisor	Ting, Lena H.
local.contributor.corporatename	Wallace H. Coulter Department of Biomedical Engineering
local.contributor.corporatename	College of Engineering
relation.isAdvisorOfPublication	a864fd73-fe93-4e7d-ae91-814802f5cf26
relation.isOrgUnitOfPublication	da59be3c-3d0a-41da-91b9-ebe2ecc83b66
relation.isOrgUnitOfPublication	7c022d60-21d5-497c-b552-95e489a06569
thesis.degree.level	Doctoral