Background and aims
Patients suffering from Complex Regional Pain Syndrome (CRPS) of the upper limb show a changed cortical representation of the affected hand. The lip area invades the former hand area contralateral to the affected hand. This change in cortical representation is correlated to the intensity of ongoing pain in patients with CRPS. Further studies revealed that restoration of the original representation coincides with a decrease of pain. Sensory-motor training protocols can increase and/or relocate cortical somatosensory and motor representation areas of the fingers, as shown, for example, in Braille reading individuals and professional violin players. Further, there is evidence that sensory-motor discrimination training has a beneficial effect on both the intensity of pain and the mislocalization of sensory-motor cortical areas in CRPS patients. Based on these propositions, we developed a novel sensory-motor self-training paradigm for CRPS patients to use in a home-based manner.
Ten CRPS patients performed the sensory-motor training for 2 weeks. The training consists of a braille-like haptic task with different training modes (bi-manual, speed and memory training). During the training, as well as 1 week before and after, patients were asked to fill out pain diaries. Furthermore, measures of impairment were acquired at baseline and post training.
Patients showed significant pain reduction after the 2 week training period. The overall disability as well as the depression scores showed a trend to improve after the 2 week training. The reduction in pain was correlated with the total amount of training performed.
This is a first proof of principle study of a novel sensory-motor self-training protocol to reduce pain in CRPS patients. The more consistent the patients trained the larger the pain reduction. Sensory-motor training, which can be performed on a regular basis at home might provide a novel interventional strategy to improve symptoms of CRPS.
Although a larger study needs to be conducted to confirm our findings, including long-term follow-up, the results show, that a sensory-motor home-based training is a strategy worth exploring further for the reduction of pain as well as high frequency training for patients with CRPS.
DOI of refers to article: http://dx.doi.org/10.1016/j.sjpain.2017.02.003.
Author contributions: All authors discussed the results and commented on themanuscript.
Ethical issues: Written informed consent was obtained from all subjects according to the Declaration of Helsinki (www.wma.net/en/30publications) and withapproval from the local Ethics Committee of the Medical Faculty of the University of Tuebingen.
Funding: This study was supported by Bundesministerium für Bildung und Forschung (BMBF grant D 20.01667) and Deutsche Forschungsgesellschaft (DFG grant BI195/63–1).
Conflict of interest: The authors certify that they have NO affiliations with or involvement in any organization or entity with any financial interest (such as honoraria; educational grants; participation in speakers’ bureaus; membership, employment, consultancies, stock ownership, or other equity interest; and expert testimony or patent-licensing arrangements), or non-financial interest (such as personal or professional relationships, affiliations, knowledge or beliefs) in the subject matter or materials discussed in this manuscript.
Abd Al-Jabbar Al-Shukry, Merlin Evers, Hendrik Heinzl, Harrison Norman, Daniela Palme, Myriam Wurst helped with the data acquisition.
 van Velzen GA, Perez RS, van Gestel MA, Huygen FJ, van Kleef M, van Eijs F, Dahan A, van Hilten JJ, Marinus J. Health-related quality of life in 975 patients with complex regional pain syndrome type 1. Pain 2014;155:629–34.10.1016/j.pain.2013.12.017Search in Google Scholar
 Veldman PH, Reynen HM, Arntz IE, Goris RJ. Signs and symptoms of reflex sympathetic dystrophy: prospective study of 829 patients. Lancet 1993;342:1012–6.10.1016/0140-6736(93)92877-VSearch in Google Scholar
 Moseley GL, Zalucki NM, Wiech K. Tactile discrimination, but not tactile stimulation alone, reduces chronic limb pain. Pain 2008;137:600–8.10.1016/j.pain.2007.10.021Search in Google Scholar PubMed
 O’Connell NE, Wand BM, McAuley J, Marston L, Moseley GL. Interventions for treating pain and disability in adults with complex regional pain syndrome. Cochrane Database Syst Rev 2013;30.10.1002/14651858.CD009416Search in Google Scholar
 Di Pietro F, McAuley JH, Parkitny L, Lotze M, Wand BM, Moseley GL, Stanton TR. Primary somatosensory cortex function in complex regional pain syndrome: a systematic review and meta-analysis. J Pain 2013;14:1001–18.10.1016/j.jpain.2013.04.001Search in Google Scholar PubMed
 Haag LM, Heba S, Lenz M, Glaubitz B, Hoffken O, Kalisch T, Puts NA, Edden RA, Tegenthoff M, Dinse H, Schmidt-Wilcke T. Resting BOLD fluctuations in the primary somatosensory cortex correlate with tactile acuity. Cortex 2015;64:20–8.10.1016/j.cortex.2014.09.018Search in Google Scholar PubMed PubMed Central
 Classen J, Liepert J, Wise SP, Hallett M, Cohen LG. Rapid plasticity of human cortical movement representation induced by practice. J Neurophysiol 1998;79:1117–23.10.1152/jn.19220.127.116.117Search in Google Scholar PubMed
 Juottonen K, Gockel M, Silen T, Hurri H, Hari R, Forss N. Altered central sensorimotor processing in patients with complex regional pain syndrome. Pain 2002;98:315–23.10.1016/S0304-3959(02)00119-7Search in Google Scholar
 Maihofner C, Handwerker HO, Neundorfer B, Birklein F. Patterns of cortical reorganization in complex regional pain syndrome. Neurology 2003;61:1707–15.10.1212/01.WNL.0000098939.02752.8ESearch in Google Scholar PubMed
 Vartiainen N, Kirveskari E, Kallio-Laine K, Kalso E, Forss N. Cortical reorganization in primary somatosensory cortex in patients with unilateral chronic pain. J Pain 2009;10:854–9.10.1016/j.jpain.2009.02.006Search in Google Scholar PubMed
 Flor H, Elbert T, Knecht S, Wienbruch C, Pantev C, Birbaumer N, Larbig W, Taub E. Phantom-limb pain as a perceptual correlate of cortical reorganization following arm amputation. Nature 1995;375:482–4.10.1038/375482a0Search in Google Scholar PubMed
 Pleger B, Tegenthoff M, Schwenkreis P, Janssen F, Ragert P, Dinse HR, Volker B, Zenz M, Maier C. Mean sustained pain levels are linked to hemispherical side-to-side differences of primary somatosensory cortex in the complex regional pain syndrome I. Exp Brain Res 2004;155:115–9.10.1007/s00221-003-1738-4Search in Google Scholar PubMed
 Sinis N, Birbaumer N, Schwarz A, Gustin S, Unertl K, Schaller HE, Haerle M. [Memantine and Complex Regional Pain Syndrome (CRPS): effects of treatment and cortical reorganisation]. Handchirurgie, Mikrochirurgie, plastische Chirurgie: Organ der Deutschsprachigen Arbeitsgemeinschaft fur Handchirurgie: Organ der Deutschsprachigen Arbeitsgemeinschaft fur Mikrochirurgie der Peripheren Nerven und Gefasse: Organ der Vereinigung der Deutschen Plastischen Chirurgen 2006;38:164–71.Search in Google Scholar
 Elbert T, Pantev C, Wienbruch C, Rockstroh B, Taub E. Increased cortical representation of the fingers of the left hand in string players. Science 1995;270:305–7.10.1126/science.270.5234.305Search in Google Scholar PubMed
 Pascual-Leone A, Torres F. Plasticity of the sensorimotor cortex representation of the reading finger in Braille readers. Brain 1993;116:39–52.10.1093/brain/116.1.39Search in Google Scholar PubMed
 Moseley GL, Wiech K. The effect of tactile discrimination training is enhanced when patients watch the reflected image of their unaffected limb during training. Pain 2009;144:314–9.10.1016/j.pain.2009.04.030Search in Google Scholar PubMed
 Lewis JS, Schweinhardt P. Perceptions of the painful body: the relationship between body perception disturbance, pain and tactile discrimination in complex regional pain syndrome. Eur J Pain 2012;16:1320–30.10.1002/j.1532-2149.2012.00120.xSearch in Google Scholar PubMed
 Harden RN, Bruehl S, Perez RS, Birklein F, Marinus J, Maihofner C, Lubenow T, Buvanendran A, Mackey S, Graciosa J, Mogilevski M, Ramsden C, Chont M, Vatine JJ. Validation of proposed diagnostic criteria (the “Budapest Criteria”) for Complex Regional Pain Syndrome. Pain 2010;150:268–74.10.1016/j.pain.2010.04.030Search in Google Scholar
 Harden RN, Bruehl SP. Diagnosis of complex regional pain syndrome: signs, symptoms, and new empirically derived diagnostic criteria. Clin J Pain 2006;22:415–9.10.1097/01.ajp.0000194279.36261.3eSearch in Google Scholar
 Rolke R, Baron R, Maier C, Tolle TR, Treede RD, Beyer A, Binder A, Birbaumer N, Birklein F, Botefur IC, Braune S, Flor H, Huge V, Klug R, Landwehrmeyer GB, Magerl W, Maihofner C, Rolko C, Schaub C, Scherens A, Sprenger T, Valet M, Wasserka B. Quantitative sensory testing in the German Research Network on Neuropathic Pain (DFNS): standardized protocol and reference values. Pain 2006;123:231–43.10.1016/j.pain.2006.01.041Search in Google Scholar PubMed
 Rolke R, Magerl W, Campbell KA, Schalber C, Caspari S, Birklein F, Treede RD. Quantitative sensory testing: a comprehensive protocol for clinical trials. Eur J Pain 2006;10:77–88.10.1016/j.ejpain.2005.02.003Search in Google Scholar PubMed
 Perez MA, Cohen LG. Mechanisms underlying functional changes in the primary motor cortex ipsilateral to an active hand. J Neurosci 2008;28: 5631–40.10.1523/JNEUROSCI.0093-08.2008Search in Google Scholar PubMed PubMed Central
 Perez MA, Tanaka S, Wise SP, Sadato N, Tanabe HC, Willingham DT, Cohen LG. Neural substrates of intermanual transfer of a newly acquired motor skill. Curr Biol: CB 2007;17:1896–902.10.1016/j.cub.2007.09.058Search in Google Scholar PubMed
 Tait RC, Pollard CA, Margolis RB, Duckro PN, Krause SJ. The Pain Disability Index: psychometric and validity data. Arch Phys Med Rehabil 1987;68:438–41.Search in Google Scholar
 Hautzinger M. Die CES-D-Skala. ein Depressionsmessinstrument für Untersucungen in der Allgemeinbevölkerung. Diagnostica 1988;34:167–73.Search in Google Scholar
 Braun C, Haug M, Wiech K, Birbaumer N, Elbert T, Roberts LE. Functional organization of primary somatosensory cortex depends on the focus of attention. Neuroimage 2002;17:1451–8.10.1006/nimg.2002.1277Search in Google Scholar PubMed
 Kwakkel G, van Peppen R, Wagenaar RC, Wood Dauphinee S, Richards C, Ashburn A, Miller K, Lincoln N, Partridge C, Wellwood I, Langhorne P. Effects of augmented exercise therapy time after stroke: a meta-analysis. Stroke 2004;35:2529–39.10.1161/01.STR.0000143153.76460.7dSearch in Google Scholar PubMed
 Maihofner C, Handwerker HO, Neundorfer B, Birklein F. Cortical reorganization during recovery from complex regional pain syndrome. Neurology 2004;63:693–701.10.1212/01.WNL.0000134661.46658.B0Search in Google Scholar
 Gustin SM, Schwarz A, Birbaumer N, Sines N, Schmid AC, Veit R, Larbig W, Flor H, Lotze M. NMDA-receptor antagonist and morphine decrease CRPS-pain and cerebral pain representation. Pain 2010;151:69–76.10.1016/j.pain.2010.06.022Search in Google Scholar PubMed
 Moseley GL. Is successful rehabilitation of complex regional pain syndrome due to sustained attention to the affected limb? A randomised clinical trial. Pain 2005;114:54–61.10.1016/j.pain.2004.11.024Search in Google Scholar PubMed
 Reis J, Schambra HM, Cohen LG, Buch ER, Fritsch B, Zarahn E, Celnik PA, Krakauer JW. Noninvasive cortical stimulation enhances motor skill acquisition over multiple days through an effect on consolidation. Proc Natl Acad Sci USA 2009;106:1590–5.10.1073/pnas.0805413106Search in Google Scholar PubMed PubMed Central
 Zimerman M, Nitsch M, Giraux P, Gerloff C, Cohen LG, Hummel FC. Neuroenhancement of the aging brain: restoring skill acquisition in old subjects. Ann Neurol 2013;73:10–5.10.1002/ana.23761Search in Google Scholar PubMed PubMed Central
 Zimerman M, Heise KF, Hoppe J, Cohen LG, Gerloff C, Hummel FC. Modulation of training by single-session transcranial direct current stimulation to the intact motor cortex enhances motor skill acquisition of the paretic hand. Stroke 2012;43:2185–91.10.1161/STROKEAHA.111.645382Search in Google Scholar PubMed PubMed Central
 Wessel MJ, Zimerman M, Hummel FC. Non-invasive brain stimulation: an interventional tool for enhancing behavioral training after stroke. Front Hum Neurosci 2015;9:265.10.3389/fnhum.2015.00265Search in Google Scholar PubMed PubMed Central
 Kasschau M, Reisner J, Sherman K, Bikson M, Datta A, Charvet LE. Transcranial direct current stimulation is feasible for remotely supervised home delivery in multiple sclerosis. Neuromodulation 2016.10.1111/ner.12430Search in Google Scholar PubMed
Center for Epidemiological Studies – Depression Scale
Complex Regional Pain Syndrome
Primary motor cortex
Primary sensory cortex
Transcranial Direct Current Stimulation
Transcranial Magnetic Stimulation
Visual Analogue Scale.
Appendix A. Supplementary data
Supplementary data associated with this article can be found, in the online version, at http://dx.doi.Org/10.1016/j.sjpain.2016.11.003.
© 2016 Scandinavian Association for the Study of Pain