Highlights
- •Cortical excitability in patients with complex regional pain syndrome (CRPS) was studied.
- •Transcranial magnetic stimulation at rest and during motor tasks was used.
- •Results for healthy controls and patients with an immobilized hand were compared.
- •Motor cortical excitability in CRPS patients is similar to that in healthy controls.
- •Immobilization results in an absence of cortical excitation during explicit tasks.
Abstract
Motor dysfunction in complex regional pain syndrome (CRPS) is often considered a functional
movement disorder. Earlier studies in patients with functional movement disorders
found evidence of cortical inhibition during explicit but not implicit motor tasks,
suggesting active inhibition from other brain areas. In this study, we explored whether
active inhibition occurs in CRPS patients. We compared patients with CRPS with 2 control
groups: healthy controls matched for age and sex, and patients whose hand was immobilized
to treat a scaphoid fracture. We used transcranial magnetic stimulation to measure
corticospinal excitability at rest and during motor imagery (explicit motor task)
and motor observation (implicit motor task). Motor corticospinal excitation measured
at rest and during implicit and explicit motor tasks was similar for CRPS patients
and healthy controls. Patients with an immobilized hand showed an absence of motor
cortical excitation of the corresponding hemisphere during motor imagery of tasks
involving the immobilized hand, but not during motor observation. The normal motor
cortical processing during motor imagery and motor observation found in the corresponding
hemisphere of CPRS patients suggests that the nature of motor dysfunction in this
condition differs from that described in literature for patients with functional paresis
or under circumstances of limb immobilization.
Perspective
This study shows that the nature of motor dysfunction in CRPS patients differs from
that encountered in patients with functional paresis or under circumstances of limb
immobilization. This information is important for patients and pain clinicians and
could help prevent implementation of therapeutic strategies based on incorrect assumptions.
Key words
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References
- Force requirements of observed object lifting are encoded by the observer’s motor system: A TMS study.Eur J Neurosci. 2010; 31: 1144-1153
- Motor dysfunction of complex regional pain syndrome is related to impaired central processing of proprioceptive information.J Pain. 2013; 14: 1460-1474
- Training the motor cortex by observing the actions of others during immobilization.Cereb Cortex. 2013; 24: 3268-3276
- Validity and reliability of a rating scale for the primary torsion dystonias.Neurology. 1985; 35: 73-77
- Sensory signs in complex regional pain syndrome and peripheral nerve injury.Pain. 2012; 153: 765-774
- Cerebral activation during motor imagery in complex regional pain syndrome type 1 with dystonia.Pain. 2008; 134: 302-309
- Psychogenic movement disorders.Curr Opin Neurol. 2009; 22: 430-436
- Functional properties of brain areas associated with motor execution and imagery.J Neurophysiol. 2003; 89: 989-1002
- Development of a severity score for CRPS.Pain. 2010; 151: 870-876
- Proposed new diagnostic criteria for complex regional pain syndrome.Pain. 2007; 8: 326-331
- Movement disorders in complex regional pain syndrome.Pain Med. 2010; 11: 1274-1277
- Moving differently in pain: A new theory to explain the adaptation to pain.Pain. 2011; 152: S90-S98
- Motor Cognition: What Actions Tell the Self.Oxford University Press, Oxford2006
- Decreased cortical excitability during motor imagery after disuse of an upper limb in humans.Clin Neurophysiol. 2003; 114: 2397-2403
- Dystonia in complex regional pain syndrome type 1.Neurology. 2009; 67: 412-414
- Motor imagery: A window into the mechanisms and alterations of the motor system.Cortex. 2008; 44: 494-506
- Abnormal motor excitability in patients with psychogenic paresis. A TMS study.J Neurol. 2009; 256: 121-126
- Motor excitability during movement imagination and movement observation in psychogenic lower limb paresis.J Psychosom Res. 2011; 70: 59-65
- The motor system shows adaptive changes in complex regional pain syndrome.Brain. 2007; 130: 2671-2687
- Effects of practice, visual loss, limb amputation, and disuse on motor imagery vividness.Neurorehabil Neural Repair. 2009; 23: 449-463
- Clinical features and pathophysiology of complex regional pain syndrome.Lancet Neurol. 2011; 10: 637-648
- The role of pain coping and kinesiophobia in patients with complex regional pain syndrome type 1 of the legs.Clin J Pain. 2013; 29: 563-569
- The functional anatomy of a hysterical paralysis.Cognition. 1997; 64: B1-8
- The McGill Pain Questionnaire: Major properties and scoring methods.Pain. 1975; 1: 277-299
- The Radboud Skills Questionnaire: Construction and reliability in patients with reflex sympathetic dystrophy of one upper extremity.Disabil Rehabil. 2000; 22: 233-245
- Modulation of motor cortex excitability in the left hemisphere during action observation: A single- and paired-pulse transcranial magnetic stimulation study of self- and non-self-action observation.Neuropsychologia. 2003; 41: 1272-1278
- Primary motor cortex function in complex regional pain syndrome: A systematic review and meta-analysis.J Pain. 2013; 14: 1270-1288
- Stimulus/response curves as a method of measuring motor cortical excitability in man.Electroencephalogr Clin Neurophysiol. 1997; 105: 340-344
- Movement imagery ability: Development and assessment of a revised version of the vividness of movement imagery questionnaire.J Sport Exerc Psychol. 2008; 30: 200-221
- Muscle hyperalgesia is widespread in patients with complex regional pain syndrome.Pain. 2013; 154: 2745-2749
- Motorcortical excitability and synaptic plasticity is enhanced in professional musicians.J Neurosci. 2007; 27: 5200-5206
- The MEP in clinical neurodiagnosis.in: Wassermann E.M. Epstein C.M. Ziemann U. Walsh V. Paus T. Lisanby S.H. The Oxford Handbook of Transcranial Magnetic Stimulation. Oxford University Press, Oxford2008: 237-283
- The movement disorder of reflex sympathetic dystrophy.Neurology. 1990; 40: 57-61
- Moving toward “laboratory-supported” criteria for psychogenic tremor.Mov Disord. 2011; 26: 2509-2515
- Altered cerebral blood flow during hysterical paresthesia.Biol Psychiatry. 1995; 37: 134-135
- Short-term limb immobilization affects cognitive motor processes.J Exp Psychol Learn Mem Cogn. 2013; 39: 623-632
- Spectrum of cutaneous hyperalgesias/allodynias in neuropathic pain patients.Acta Neurol Scand. 2004; 110: 368-376
- Abnormal movements in complex regional pain syndrome: Assessment of their nature.Muscle Nerve. 2000; 23: 198-205
- Aberrant supplementary motor complex and limbic activity during motor preparation in motor conversion disorder.Mov Disord. 2011; 26: 2396-2403
- Functional neuroanatomical correlates of hysterical sensorimotor loss.Brain. 2001; 124: 1077-1090
- Phenomenology and psychopathology related to psychogenic movement disorders.Adv Neurol. 1995; 65: 231-257
- Motor evoked potentials induced by motor imagery reveal a functional asymmetry of cortical motor control in left- and right-handed human subjects.Neurosci Lett. 1999; 276: 185-188
- Modulation of motor cortex excitability after upper limb immobilization.Clin Neurophysiol. 2004; 115: 1264-1275
- TMS and drugs.Clin Neurophysiol. 2004; 115: 1717-1729
Article info
Publication history
Published online: November 04, 2014
Accepted:
October 21,
2014
Received in revised form:
October 11,
2014
Received:
April 11,
2014
Footnotes
This study was performed within TREND and supported by a grant from the Netherlands' Ministry of Economic Affairs [grant number BSIK03016].
The authors report no conflicts of interest that pertain to the subject of this study.
Supplementary data accompanying this article are available online at www.jpain.org and www.sciencedirect.com.
Identification
Copyright
© 2015 American Pain Society. Published by Elsevier Inc. All rights reserved.
