TY - JOUR
T1 - Reduced short- and long-latency afferent inhibition following acute muscle pain
T2 - A potential role in the recovery of motor output
AU - Burns, Emma
AU - Chipchase, Lucinda Sian
AU - Schabrun, Siobhan May
N1 - © 2016 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: [email protected].
PY - 2016/7/1
Y1 - 2016/7/1
N2 - OBJECTIVE: . Corticomotor output is reduced in response to acute muscle pain, yet the mechanisms that underpin this effect remain unclear. Here the authors investigate the effect of acute muscle pain on short-latency afferent inhibition, long-latency afferent inhibition, and long-interval intra-cortical inhibition to determine whether these mechanisms could plausibly contribute to reduced motor output in pain.DESIGN: . Observational same subject pre-post test design.SETTING: . Neurophysiology research laboratory.SUBJECTS: . Healthy, right-handed human volunteers (n = 22, 9 male; mean age ± standard deviation, 22.6 ± 7.8 years).METHODS: . Transcranial magnetic stimulation was used to assess corticomotor output, short-latency afferent inhibition, long-latency afferent inhibition, and long-interval intra-cortical inhibition before, during, immediately after, and 15 minutes after hypertonic saline infusion into right first dorsal interosseous muscle. Pain intensity and quality were recorded using an 11-point numerical rating scale and the McGill Pain Questionnaire.RESULTS: . Compared with baseline, corticomotor output was reduced at all time points (p = 0.001). Short-latency afferent inhibition was reduced immediately after (p = 0.039), and long-latency afferent inhibition 15 minutes after (p = 0.035), the resolution of pain. Long-interval intra-cortical inhibition was unchanged at any time point (p = 0.36).CONCLUSIONS: . These findings suggest short- and long-latency afferent inhibition, mechanisms thought to reflect the integration of sensory information with motor output at the cortex, are reduced following acute muscle pain. Although the functional relevance is unclear, the authors hypothesize a reduction in these mechanisms may contribute to the restoration of normal motor output after an episode of acute muscle pain.
AB - OBJECTIVE: . Corticomotor output is reduced in response to acute muscle pain, yet the mechanisms that underpin this effect remain unclear. Here the authors investigate the effect of acute muscle pain on short-latency afferent inhibition, long-latency afferent inhibition, and long-interval intra-cortical inhibition to determine whether these mechanisms could plausibly contribute to reduced motor output in pain.DESIGN: . Observational same subject pre-post test design.SETTING: . Neurophysiology research laboratory.SUBJECTS: . Healthy, right-handed human volunteers (n = 22, 9 male; mean age ± standard deviation, 22.6 ± 7.8 years).METHODS: . Transcranial magnetic stimulation was used to assess corticomotor output, short-latency afferent inhibition, long-latency afferent inhibition, and long-interval intra-cortical inhibition before, during, immediately after, and 15 minutes after hypertonic saline infusion into right first dorsal interosseous muscle. Pain intensity and quality were recorded using an 11-point numerical rating scale and the McGill Pain Questionnaire.RESULTS: . Compared with baseline, corticomotor output was reduced at all time points (p = 0.001). Short-latency afferent inhibition was reduced immediately after (p = 0.039), and long-latency afferent inhibition 15 minutes after (p = 0.035), the resolution of pain. Long-interval intra-cortical inhibition was unchanged at any time point (p = 0.36).CONCLUSIONS: . These findings suggest short- and long-latency afferent inhibition, mechanisms thought to reflect the integration of sensory information with motor output at the cortex, are reduced following acute muscle pain. Although the functional relevance is unclear, the authors hypothesize a reduction in these mechanisms may contribute to the restoration of normal motor output after an episode of acute muscle pain.
KW - Experimental muscle pain
KW - Long-interval intracortical inhibition
KW - Long-latency afferent inhibition
KW - Sensorimotor integration
KW - Short-latency afferent inhibition
KW - Transcranial magnetic stimulation
UR - http://www.scopus.com/inward/record.url?scp=85014472251&partnerID=8YFLogxK
U2 - 10.1093/pm/pnv104
DO - 10.1093/pm/pnv104
M3 - Article
C2 - 26874884
AN - SCOPUS:85014472251
SN - 1526-2375
VL - 17
SP - 1343
EP - 1352
JO - Pain Medicine (United States)
JF - Pain Medicine (United States)
IS - 7
ER -