title: The role of neuroplasticity in experimental neck pain: a study of potential mechanisms impeding clinical outcomes of training.
abstract: Training is a mainstay in the clinical management of neck pain, yet, effects of various training protocols are only small to moderate and improvements are required. Previous investigations of the nervous system indicate a correlation between neuroplastic adaptation to training and functional recovery. The interaction between neck pain and training thus needs further exploration. This was a randomized experimental study of the effects of experimental neck pain and training on corticomotor excitability. Healthy volunteers were randomized to training and experimental neck pain, training and no pain, and pain and no training. Primary endpoints were corticomotor excitability assessed by transcranial magnetic stimulation and electromyography measured as changes in amplitudes and latencies of motor evoked potentials (MEPs), recorded at baseline and after 30 min, 1 h, and 1 week. Additionally, correlations between changes in MEPs and motor learning, effects of pain and concomitant neck training on pain, muscle strength, and fatigue were investigated. Data were analyzed by repeated measurement ANOVA, paired t tests, Grubbs' outlier test and correlation coefficients. Results indicated that neck pain and training significantly enhanced the inhibition of the amplitudes of the MEPs for 1 week. The results indicate that moderate neck pain and training induce long-lasting inhibition of the corticomotor pathways. This inhibition may limit the outcome of neck training in painful conditions in contrast to pain-free training conditions.
authors.affiliation: Danish Pain Research Center, Aarhus University Hospital, Aarhus, Denmark. Electronic address: brr@ki.au.dk.
authors.forename: Bjarne
authors.initials: B
authors.lastname: Rittig-Rasmussen
authors.affiliation: Department of Neurology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Helge
authors.initials: H
authors.lastname: Kasch
authors.affiliation: Department of Clinical Neurophysiology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Anders
authors.initials: A
authors.lastname: Fuglsang-Frederiksen
authors.affiliation: Clinical Oral Physiology, Department of Dentistry and Department of Oral Maxillofacial Surgery, Aarhus University, Aarhus, Denmark.
authors.forename: Peter
authors.initials: P
authors.lastname: Svensson
authors.affiliation: Danish Pain Research Center, Aarhus University Hospital, Aarhus, Denmark; Department of Neurology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Troels Staehelin
authors.initials: TS
authors.lastname: Jensen
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D004576:Electromyography; D005081:Exercise Therapy / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008962:Models, Theoretical; D053580:Muscle Strength / Q000502:physiology; D019547:Neck Pain / Q000503:physiopathology* / Q000534:rehabilitation*; D009473:Neuronal Plasticity / Q000502:physiology*; D010147:Pain Measurement / Q000379:methods*; D012016:Reference Values; D018570:Risk Assessment; D012462:Saline Solution, Hypertonic / Q000008:administration & dosage; D012965:Sodium Chloride / Q000008:administration & dosage; D050781:Transcranial Magnetic Stimulation; D055815:Young Adult
chemical_list: D012462:Saline Solution, Hypertonic; D012965:Sodium Chloride
keywords: Neck pain; Neuroplasticity; Training; Transcranial magnetic stimulation