Cortical disinhibition occurs in chronic neuropathic, but not in chronic nociceptive pain

BMC Neuroscience

Research Article

Oliver Höffken¹  Peter Schwenkreis¹  Martin Tegenthoff¹  Christoph Maier²  Anne-Kathrin Rönnau²  Andrea Scherens² 

[1] Department of Neurology, Ruhr-University Bochum, BG-Universitätsklinikum Bergmannsheil, Bürkle-de-la-Camp-Platz 1, 44789, Bochum, Germany;Department of Pain Management, Ruhr-University Bochum, BG-Universitätsklinikum Bergmannsheil, Bürkle-de-la-Camp-Platz 1, 44789, Bochum, Germany;

关键词: Transcranial Magnetic Stimulation;    Motor Evoke Potential;    Complex Regional Pain Syndrome;    Motor Evoke Potential Amplitude;    Abductor Pollicis Brevis;   

DOI  :  10.1186/1471-2202-11-73

 received in 2009-12-31, accepted in 2010-06-11,  发布年份 2010

来源: Springer

【 摘 要 】

BackgroundThe aim of this study was to examine the relationship between chronic neuropathic pain after incomplete peripheral nerve lesion, chronic nociceptive pain due to osteoarthritis, and the excitability of the motor cortex assessed by transcranial magnetic stimulation (TMS). Hence in 26 patients with neuropathic pain resulting from an isolated incomplete lesion of the median or ulnar nerve (neuralgia), 20 patients with painful osteoarthritis of the hand, and 14 healthy control subjects, the excitability of the motor cortex was tested using paired-pulse TMS to assess intracortical inhibition and facilitation. These excitability parameters were compared between groups, and the relationship between excitability parameters and clinical parameters was examined.ResultsWe found a significant reduction of intracortical inhibition in the hemisphere contralateral to the lesioned nerve in the neuralgia patients. Intracortical inhibition in the ipsilateral hemisphere of neuralgia patients and in both hemispheres of osteoarthritis patients did not significantly differ from the control group. Disinhibition was significantly more pronounced in neuralgia patients with moderate/severe pain intensity than in patients with mild pain intensity, whereas the relative compound motor action potential as a parameter of nerve injury severity did not correlate with the amount of disinhibition.ConclusionsOur results suggest a close relationship between motor cortex inhibition and chronic neuropathic pain in the neuralgia patients, which is independent from nerve injury severity. The lack of cortical disinhibition in patients with painful osteoarthritis points at differences in the pathophysiological processes of different chronic pain conditions with respect to the involvement of different brain circuitry.

【 授权许可】

CC BY   
© Schwenkreis et al; licensee BioMed Central Ltd. 2010