Patients with multiple sclerosis (MS)-related chronic pain were found to have spectral abnormalities within the dynamic pain connectome regions, especially in the case of mixed-neuropathic pain, according to a study published in Pain.
In the current study, researchers examined regional spectral power changes in the dynamic pain connectome of patients with chronic MS pain (n=27) and in healthy controls (n=26) using resting state magnetoencephalography (MEG). The areas of examination included the ascending nociceptive pathway, the salience network, and the default mode network. Investigators used the Brief Pain Inventory, painDETECT, and the Expanded Disability Status Scale to assess the presence and level of pain, occurrence of neuropathic pain, and interference of pain with daily living activities. Participants underwent 5-minute MEG sessions and the data were co-registered to their magnetic resonance imaging scans using the appropriate points needed for inverse solution/source reconstruction.
Patients with MS exhibited significant increases in alpha band power within the ascending nociceptive pathway nodes at 9 Hz to10 Hz compared with the control group in the right posterior insula (P =.007; FDR <0.05; d=0.94), the left posterior insula (P =.0001; FDR <0.05; d=1.2), the right thalamus (P =.007; FDR <0.05; d=0.78) and left thalamus (P =.004; FDR <0.05; d=0.92), and the right S1 and S2 (P =.01; FDR <0.05; d=0.73 and P =.006; FDR <0.05; d=1, respectively). Participants with MS also had decreases of beta band power in the nodes of the salience network (middle cingulate cortex: P =.008; FDR <0.05; d=0.78 and right anterior insula: P =.024; FDR <0.05; d=0.62). Further analysis revealed that these abnormalities were most often observed in patients with mixed-neuropathic pain, suggesting that this spectral profile alteration could be a hallmark of this type of neuropathic pain.
Study investigators conclude that “correlations with pain interference scores suggested that altered resting state spectral power may be a robust neural correlate for pain interference in patients with MS mixed-neuropathic pain.”
Kim JA, Bosma RL, Hemington KS, et al. Neuropathic pain and pain interference is linked to alpha band slowing and reduced beta band MEG activity within the dynamic pain connectome in patients with multiple sclerosis. Pain. 2018 Sep 3. doi: 10.1097/j.pain.0000000000001391.