Phantom limb pain is a restricting condition for a substantial number of amputees with quite different characteristics of pain. Here, we report on a forearm amputee with constant phantom pain in the hand, in whom we could regularly elicit the rare phenomenon of referred cramping phantom pain by touching the face. To clarify the underlying mechanisms, we followed the cramp during the course of an axillary blockade of the brachial plexus. During the blockade, both phantom pain and the referred cramp were abolished, while a referred sensation of “being touched at the phantom” persisted. Furthermore, to identify the cortical substrate, we elicited the cramp during functional magnetic imaging. Imaging revealed that referred cramping phantom limb pain was associated with brain activation of the hand representation in the primary sensorimotor cortex. The results support the hypothesis that referred cramping phantom limb pain in this case is associated with a substantial brain activation in the hand area of the deafferented sensorimotor cortex. However, this alone is not sufficient to elicit referred cramping phantom limb pain. Peripheral inputs, both, from the arm nerves affected by the amputation and from the skin in the face at which the referred cramp is evoked, are a precondition for referred cramping phantom limb pain to occur, at least in this case.
Phantom limb pain Cramping Brachial plexus Referred sensation Sensorimotor cortex
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Thanks to Gerd F. Volk, Winfried Meissner, and Holger Hecht for help with data acquisition. This work was supported by the German Social Accident Insurance (DGUV-FR145 and FR196). DGUV neither influenced the study goals of study design; authors are fully responsible for goals, design, and results. The funding source had no involvement in the collection, analysis and interpretation of data; in the writing of the report; and in the decision to submit the article for publication.
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Conflict of interest
There is no conflict of interest for any author of this study.
Kikkert S, Kolasinski J, Jbabdi S, Tracey I, Beckmann CF, Johansen-Berg H, Makin TR (2016) Revealing the neural fingerprints of a missing hand. Elife 5Google Scholar
Klingner CM, Hasler C, Brodoehl S, Witte OW (2010) Dependence of the negative BOLD response on somatosensory stimulus intensity. Neuroimage 53:189–195CrossRefPubMedGoogle Scholar
Knecht S, Henningsen H, Elbert T et al (1995) Cortical reorganization in human amputees and mislocalization of painful stimuli to the phantom limb. Neurosci Lett 201:262–264CrossRefPubMedGoogle Scholar
Knecht S, Henningsen H, Elbert T, Flor H, Hohling C, Pantev C, Taub E (1996) Reorganizational and perceptional changes after amputation. Brain 119:1213–1219CrossRefPubMedGoogle Scholar
Knecht S, Henningsen H, Hohling C, Elbert T, Flor H, Pantev C, Taub E (1998) Plasticity of plasticity? Changes in the pattern of perceptual correlates of reorganization after amputation. Brain 121:717–724CrossRefPubMedGoogle Scholar
Kuner R, Flor H (2017) Structural plasticity and reorganisation in chronic pain. Nat Rev Neurosci 18:20CrossRefGoogle Scholar
Raffin E, Richard N, Giraux P, Reilly KT (2016) Primary motor cortex changes after amputation correlate with phantom limb pain and the ability to move the phantom limb. NeuroImage 130:134–144CrossRefPubMedGoogle Scholar
Ramachandran VS (1993) Filling in gaps in perception: part II. Scotomas and phantom limbs. Curr Dir Psychol Sci 2:56–65CrossRefGoogle Scholar
Sens E, Knorr C, Preul C, Meissner W, Witte OW, Miltner WH, Weiss T (2013) Differences in somatosensory and motor improvement during temporary functional deafferentation in stroke patients and healthy subjects. Behav Brain Res 252:110–116CrossRefPubMedGoogle Scholar
Sherman RA (ed) (1997) Phantom pain. Plenum Press, New YorkGoogle Scholar