title: Left is where the L is right. Significantly delayed reaction time in limb laterality recognition in both CRPS and phantom limb pain patients.
abstract: The body schema is based on an intact cortical body representation. Its disruption is indicated by delayed reaction times (RT) and high error rates when deciding on the laterality of a pictured hand in a limb laterality recognition task. Similarities in both cortical reorganisation and disrupted body schema have been found in two different unilateral pain syndromes, one with deafferentation (phantom limb pain, PLP) and one with pain-induced dysfunction (complex regional pain syndrome, CRPS). This study aims to compare the extent of impaired laterality recognition in these two groups. Performance on a test battery for attentional performance (TAP 2.0) and on a limb laterality recognition task was evaluated in CRPS (n=12), PLP (n=12) and healthy subjects (n=38). Differences between recognising affected and unaffected hands were analysed. CRPS patients and healthy subjects additionally completed a four-day training of limb laterality recognition. Reaction time was significantly delayed in both CRPS (2278±735.7ms) and PLP (2301.3±809.3ms) compared to healthy subjects (1826.5±517.0ms), despite normal TAP values in all groups. There were no differences between recognition of affected and unaffected hands in both patient groups. Both healthy subjects and CRPS patients improved during training, but RTs of CRPS patients (1874.5±613.3ms) remain slower (p<0.01) than those of healthy subjects (1280.6±343.2ms) after four-day training. Despite different pathomechanisms, the body schema is equally disrupted in PLP and CRPS patients, uninfluenced by attention and pain and cannot be fully reversed by training alone. This suggests the involvement of complex central nervous system mechanisms in the disruption of the body schema.
authors.affiliation: Department of Pain Management, Berufsgenossenschaftliches Universitätsklinikum Bergmannsheil GmbH Bochum, Ruhr-University Bochum, Bürkle-de-la-Camp-Platz 1, 44789 Bochum, Germany. annika.reinersmann@rub.de
authors.forename: Annika
authors.initials: A
authors.lastname: Reinersmann
authors.forename: Golo Sung
authors.initials: GS
authors.lastname: Haarmeyer
authors.forename: Markus
authors.initials: M
authors.lastname: Blankenburg
authors.forename: Jule
authors.initials: J
authors.lastname: Frettlöh
authors.forename: Elena K
authors.initials: EK
authors.lastname: Krumova
authors.forename: Sebastian
authors.initials: S
authors.lastname: Ocklenburg
authors.forename: Christoph
authors.initials: C
authors.lastname: Maier
mesh_terms: D000328:Adult; D000377:Agnosia / Q000175:diagnosis / Q000503:physiopathology* / Q000523:psychology; D057215:Body Dysmorphic Disorders / Q000175:diagnosis / Q000503:physiopathology* / Q000523:psychology; D020918:Complex Regional Pain Syndromes / Q000175:diagnosis / Q000503:physiopathology* / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010468:Perceptual Disorders / Q000175:diagnosis / Q000503:physiopathology* / Q000523:psychology; D010591:Phantom Limb / Q000175:diagnosis / Q000503:physiopathology* / Q000523:psychology; D011930:Reaction Time / Q000502:physiology*; D055815:Young Adult