Effects of Acute Pain on Motor Learning in Young vs Older Adults

Study Overview
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Brief Summary
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To date, the effects of pain on motor learning have not been thoroughly investigated, particularly in older adults. Broadly, the purpose of this research is to investigate the impact of acute pain on locomotor learning and its retention in older adults. The investigators hypothesize that acute pain impairs retention of locomotor learning in young and older adults and that in older adults, these deficits are worsened and are related to the degree of normal age-related cognitive decline.

Official Title
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Effects of Acute Pain on Motor Learning in Young vs Older Adults

Conditions
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Aging, Pain, Acute, Cognitive Decline, Motor Activity

Intervention / Treatment
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* Procedure: pain delivery
* Procedure: distractor delivery


Participation Criteria
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Eligibility Criteria
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Abbreviations: YA= young adult; OA= older adult; HR= heart rate, bpm= beats per minute; BP= blood pressure; ADD= attention deficit disorder; ADHD= attention deficit hyperactivity disorder; MoCA= Montreal Cognitive Assessment; GAD-7= Generalized Anxiety Disorder 7 Scale; PHQ-2, PHQ-9= Patient Health Questionnaire-2 and -9. Inclusion Criteria: 18-35 (YA group only) or 55-85 (OA group only) years old Sex-matched to a participant in the OA group (YA group only) Self-identifying as generally medically healthy Able to read, write and speak English Able to provide informed consent and attend all testing sessions Willing to undergo the experimental pain or non-painful electrical stimulation, if selected Exclusion Criteria: Resting HR < 50 or > 100 bpm Resting BP < 90/60 or > 140/95 mmHg (YA group only) or > 165/95 (OA group only) Any history or current mental health condition, learning/developmental disability or cognitive impairment, including ADD/ADHD, severe anxiety, severe depression, autism spectrum disorder, insomnia, mild cognitive impairment, etc. Score on the MoCA <23 Score on the GAD-7 ≥ 10 Score on the PHQ-2 ≥ 2 and score on the PHQ-9 ≥ 10 Any current (within last 3 month) or chronic medical conditions, including any musculoskeletal, cardiovascular, endocrine, pulmonary, metabolic, psychiatric or neurological diagnosis that (for OA group only) affects activities of daily living or would confound testing or place the subject at risk by participating, such as a significant cardiovascular condition or event (e.g., heart attack < 3 months ago, uncontrolled atrial fibrillation, uncontrolled angina, or congestive heart failure, chronic obstructive pulmonary disorder, peripheral vascular disease) Any implanted electronic medical devices (i.e., cardiac pacemakers, cardiac defibrillators, spinal cord neurostimulators) Any impaired sensation or weakness in either lower extremity or in the area targeted for the stimulus History of serious concussion or head injury, defined as a loss of consciousness for > 5 minutes and/or requiring medical treatment, or > 2 concussions over the lifespan Any history of acute or chronic problems with balance, any dizziness, or > 1 fall in the last 12 months Taking 4 or more medications (YA group only) Currently or regularly using any analgesic medications, over-the-counter remedies, or any other treatment for the purposes of pain relief (i.e., baby aspirin for heart health permitted, etc.) Any current or chronic pain condition during the last year, located anywhere in the body with a (OA group only) pain intensity of > 2/10 Allergy to capsaicin or hot peppers Any skin lesion, breakage or irritation in the area targeted for the painful stimulus Skin sensitivity to soaps/creams/perfumes or to heat Poor circulation in the area targeted for the painful stimulus Prior participation in a locomotor learning study in this lab within the last 2 years.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 85 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Pain Stimulus<br>Capsaicin combined with heat applied to intact skin | Procedure: pain delivery<br>* Experimental pain paradigm delivered that is short-term and painful but not harmful.<br>|
| Active Comparator: Distractor Somatosensory Stimulus<br>Sensory transcutaneous electrical nerve stimulation (TENS) applied to intact skin | Procedure: distractor delivery<br>* Distractor stimulus delivered that is short-term and attention-demanding but not painful.<br>|
| No Intervention: No Stimulus<br>Nothing applied to skin | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Motor Retention Magnitude | degree to which the learned locomotor pattern has been remembered (in step length % change, normalized to the amount learned from day 1) | 24 hours post learning (day 2) | 
| Motor Learning Magnitude | degree to which the new locomotor pattern has been acquired (in step length % change) | immediately after learning (day 1) | 
| Digit Span Backward Test | number of digits (numbers) that can be repeated back in the reverse order from which they were presented | the change between baseline and during application of intervention | 
| Digit Span Forward Test | number of digits (numbers) that can be repeated back in the same order as they were presented | the change between baseline and during application of intervention | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Pain, Acute pain, Adults, Cognition, Elderly, Learning, Memory, Cognitive ability, Motor learning, Young adults, Older Adults, Gait, Locomotion, Walking, Motor Consolidation