Motor Unit Abnormalities After Experimentally Induced Sensitization

• Status: Completed
• Trial end date: 2020-03-10
• Target enrollment: 0
• Participant gender: All

Summary

Central sensitization is a condition that represents a cascade of neurological adaptations, resulting in an amplification of nociceptive responses from noxious and non-noxious stimuli. This phenomenon presents itself in a vast majority of chronic pain syndromes. Previous evidence has shown that central sensitization results in afferent nociceptor and dorsal horn abnormalities; however, a link between whether this abnormality translates into motor output and more specifically, ventral horn abnormalities, needs to be further explored. Twenty participants were recruited and either a topical capsaicin or a placebo topical cream was applied to their back to induce a transient state of sensitization. Surface electromyography(sEMG) and intramuscular electromyography(iEMG) were used to record motor unit activity from the trapezius and infraspinatus muscles before and after application of capsaicin/placebo. Motor unit recruitment and variability were analyzed in the sEMG and iEMG respectively

• Phase: Phase 4
• Accepts Healthy Volunteers?: Accepts Healthy Volunteers

Details

• Lead Sponsor: Toronto Rehabilitation Institute
• Treatments: Capsaicin

Criteria

Inclusion Criteria:

• subject with a normal body mass index (18.5 - 24.9)

• a pain visual analogue scale (VAS) below 3 indicating low pain severity

Exclusion Criteria:

• medical history of inflammatory disorders as rheumatoid arthritis

• neurodegenerative disorders such as Parkinson's disease

• motor neurone diseases as amyotrophic lateral sclerosis, or other neuromuscular disorder