title: Normal sensorimotor plasticity in complex regional pain syndrome with fixed posture of the hand.
abstract: Movement disorders associated with complex regional pain syndrome type I have been a subject of controversy over the last 10 years regarding their nature and pathophysiology, with an intense debate about the functional (psychogenic) nature of this disorder. The aim of this study was to test sensorimotor plasticity and cortical excitability in patients with complex regional pain syndrome type I who developed a fixed posture of the hand.
  
  
  
  Ten patients with complex regional pain syndrome type I in the right upper limb and a fixed posture of the hand (disease duration less than 24 months) and 10 age-matched healthy subjects were enrolled. The following parameters of corticospinal excitability were recorded from the abductor pollicis brevis muscle of both hands by transcranial magnetic stimulation: resting and active motor thresholds, short-interval intracortical inhibition and facilitation, cortical silent period, and short- and long-latency afferent inhibition. Sensorimotor plasticity was tested using the paired associative stimulation protocol.
  
  
  
  Short-interval intracortical inhibition and long-latency afferent inhibition were reduced only in the affected right hand of patients compared with control subjects. Sensorimotor plasticity was comparable to normal subjects, with a preserved topographic specificity.
  
  
  
  Our data support the view that motor disorder in complex regional pain syndrome type I is not associated with abnormal sensorimotor plasticity, and it shares pathophysiological abnormalities with functional (psychogenic) dystonia rather than with idiopathic dystonia. © 2016 International Parkinson and Movement Disorder Society.
authors.affiliation: Dipartimento di Medicina Clinica e Sperimentale, Università di Messina, Messina, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Morgante
authors.affiliation: IRCCS Centro Neurolesi "Bonino-Pulejo", Messina, Italy.
authors.forename: Antonino
authors.initials: A
authors.lastname: Naro
authors.affiliation: Dipartimento di Medicina Clinica e Sperimentale, Università di Messina, Messina, Italy.
authors.forename: Carmen
authors.initials: C
authors.lastname: Terranova
authors.affiliation: IRCCS Centro Neurolesi "Bonino-Pulejo", Messina, Italy.
authors.forename: Margherita
authors.initials: M
authors.lastname: Russo
authors.affiliation: Dipartimento di Medicina Clinica e Sperimentale, Università di Messina, Messina, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Rizzo
authors.affiliation: Unità Funzionale di Ortopedia e Traumatologia, Casa di Cura "Cappellani-GIOMI", Messina, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Risitano
authors.affiliation: Dipartimento di Medicina Clinica e Sperimentale, Università di Messina, Messina, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Girlanda
authors.affiliation: Department of Biomedical, Dental Sciences, and Morphological and Functional Images, University of Messina, Messina, Italy.
authors.forename: Angelo
authors.initials: A
authors.lastname: Quartarone
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D020918:Complex Regional Pain Syndromes / Q000503:physiopathology*; D004421:Dystonia / Q000503:physiopathology*; D005260:Female; D006225:Hand / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000503:physiopathology*; D009473:Neuronal Plasticity / Q000502:physiology*; D011187:Posture / Q000502:physiology; D066191:Sensorimotor Cortex / Q000503:physiopathology*; D050781:Transcranial Magnetic Stimulation / Q000379:methods*; D055815:Young Adult
keywords: CRPS type I; dystonia; functional movement disorders; plasticity; psychogenic