Schröder A, Rehfeld E, Ornb⊘l E, Sharpe M, Licht RW, Fink P. Cognitive-behavioural group treatment for a range of functional somatic syndromes: randomised trial. Br. J. Psychiatry 200, 499–507 (2012).
This randomized controlled trial included patients with a variety of severe functional somatic syndromes, such as fibromyalgia, irritable bowel and whiplash-associated disorder, grouped under the unifying diagnostic category of bodily distress syndrome. A complex intervention based on cognitive behavioral therapy entitled Specialised Treatment for Severe Bodily Distress Syndromes (STreSS) was more effective than enhanced usual care participants. STreSS was effective on the primary outcome, which was the mean change in aggregate score on the 36-item Short Form Health Survey subscales, ‘physical functioning‘, ‘bodily pain‘ and ‘vitality‘ from baseline to 16 months, i.e. 1 year after the STreSS intervention was completed, and on many secondary outcome measures. The treatment effect was of clinical significance and was sustained at follow-up. The authors suggested that STreSS offers an effective and acceptable treatment approach for patients with severe functional somatic syndromes.
– Written by Nanna B Finnerup
Gustin SM, Peck CC, Cheney LB, Macey PM, Murray GM, Henderson LA. Pain and plasticity: is chronic pain always associated with somatosensory cortex activity and reorganization? J. Neurosci. 32, 14874–14884 (2012).
It is often assumed that somatosensory cortical reorganization is associated with chronic pain. Using functional and anatomical magnetic resonance imaging, this study found that patients with neuropathic pain displayed cortical reorganization and changes in somatosensory cortex activity; however, patients with non-neuropathic chronic pain did not. This suggests that pain per se is not associated with cortical plasticity. In addition, the authors carefully review existing literature and point to inconsistency in results. They conclude that there is no consistent evidence for a relationship between cortical reorganization and pain. What we can conclude from this study is that it is not definite that treatments aimed at reversing cortical reorganization will relieve pain.
– Written by Nanna B Finnerup
Silberstein SD, Dodick DW, Saper J et al. Safety and efficacy of peripheral nerve stimulation of the occipital nerves for the management of chronic migraine: results from a randomized, multicenter, double-blinded, controlled study. Cephalalgia 32(16), 1165–1179 (2012).
A randomized, controlled, multicenter study of occipital nerve stimulation in 157 patients with intractable chronic migraine headache was carried out. Those meeting the inclusion criteria had 15 or more headache days per month for longer than 3 months and had failed both two acute and two prophylactic migraine medications. Additionally, those included had pain originating in the occipital or cervical region, and visual analog scale scores of at least six out of ten. Those excluded were comprised of patients having undergone C2/C3 destructive procedures, those within 8 weeks of beginning new headache medication therapy and those within 6 months of undergoing neurotoxin therapy.
Patients were required to achieve at least 50% relief of pain or display adequate paresthesia coverage with the temporary stimulator in order to proceed to surgical implant. Subjects were implanted with occipital neurostimulators in a 2:1 fashion, with 105 receiving active and 52 receiving sham stimulation. The primary outcome measured was achievement of at least 50% reduction in the mean daily headache visual analog scale at 12 weeks. Secondary outcomes considered were reduction in the number of headache days, Migraine Disability Assessment questionnaire scores, self-reported pain relief and presence of adverse events.
No significant difference between groups was noted in those achieving 50% relief of headache pain. There was a significant difference in favor of active stimulation found in those achieving 30% pain relief, number of headache days, Migraine Disability Assessment scores and self-report of pain. No significant difference in adverse events was reported between groups.
– Written by Michael Erdek
Kleggetveit IP, Namer B, Schmidt R et al. High spontaneous activity of C-nociceptors in painful polyneuropathy. Pain 153, 2040–2047 (2012).
The role of C-polymodal nociceptors in pain generation in patients with peripheral neuropathy has been controversial for many years. In this study, 11 patients with painful peripheral neuropathy were contrasted electrophysiologically with eight patients who had nonpainful peripheral neuropathy. A total of 214 C-fiber action potentials were recorded in these 19 patients by microneurography. Hyperexcitability of C-fibers was significantly more common in those patients with pain than those without it. This was particularly prominent in the mechanoreceptor component of C-fibers. Increased spontaneously active nociceptors, mechanical sensitization of these fibers and faster recovery from activity-dependent slowing were all observed in those patients who reported spontaneous pain. The molecular mechanism underlying these changes remains unknown. This study is important, for it clearly demonstrates that pain can be generated in the periphery by nociceptors in the absence of the customary tissue-damaging stimulus. Of course, pain can also be generated centrally by both peripheral and central events.
– Written by John D Loeser
Financial & competing interests disclosure
The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.
No writing assistance was utilized in the production of this manuscript.