Fibromyalgia Pain & Cognitive Impairment: New Insights

January 7, 2019

Recent studies address two of the most troubling symptoms of fibromyalgia: pain and cognitive impairment.

Facet blocks are the second most frequently performed procedures for chronic pain, yet they remain mired in controversy. In addition, cognitive impairment is one of the major manifestations of fibromyalgia.

Three recent studies address these common issues: (1) lumbar facet joint blocks have predictive value before radiofrequency denervation in patients with chronic pain, such as those who have fibromyalgia; (2) radiofrequency ablation is less helpful for pain but is effective for anxiety and sleep disturbance; and (3) patients with fibromyalgia who smoke cigarettes are more likely to have cognitive impairment, colloquially referred to as “fibrofog.”^1-3 Scroll through the slides for the latest findings and their clinical implications.

A randomized study included 229 patients with chronic pain who received intra-articular facet injections with bupivacaine and a corticosteroid, medial branch blocks, or saline. Those in the intra-articular and medial branch block groups with a positive diagnostic block (50% or more relief) who experienced a negative outcome underwent radiofrequency ablation. All saline group patients underwent ablation.¹

Mean reduction in average numerical rating scale pain score at 1 month was similar in all groups. The proportions of positive blocks were higher in the intra-articular (54%) and medial branch (55%) groups than in the placebo group (30%).

Radiofrequency ablation was performed on 135 patients. The average numerical rating scale pain score at 3 months was 3.0 in the intra-articular, 3.2 in the medial branch, and 3.5 in the control group. At 3 months, the proportions of positive responders in the intra-articular, medial branch block, and placebo groups were 51%, 56%, and 24%, respectively.

Clinical Implications: “This study establishes that facet blocks are not therapeutic. The higher responder rates in the treatment groups suggest a hypothesis that facet blocks might provide prognostic value before radiofrequency ablation,” stated the researchers, led by Steven P. Cohen, MD, of The Johns Hopkins School of Medicine in Baltimore, MD.

A prospective, observational study included 141 patients; 55 underwent radiofrequency ablation and 51 completed follow-up questionnaires at 3 months. Validated self-report measures were used to record pain, mood, and function.²

Patients with higher fibromyalgia scores had less improvement in overall body pain, but this was not statistically significant. A secondary analysis found the fibromyalgia score was not associated with changes in back pain. In addition, all participants reported significant decreases in anxiety, physical function, centralized pain score, overall body pain, site-specific pain, catastrophizing, and sleep disturbance at 3 months after radiofrequency ablation.

Clinical Implications: “Although patients without baseline centralized pain exhibited more improvement in overall pain compared with subjects with centralized pain, this trend did not reach statistical significance, possibly due to insufficient power in the study. The same trend was not seen with respect to change in spine pain, with both groups improving equally. This suggests that patients with a centralized pain phenotype may derive similar benefit in their spine pain from radiofrequency ablation without the same global pain improvement,” stated the researchers, led by Dayaris Morffi, MD, of the University of Michigan in Ann Arbor.

A prospective, cohort study surveyed 668 patients with fibromyalgia; 94 (14%) patients identified themselves as smokers.

Univariate analysis adjusted for age, gender, body mass index, marital status, and education level revealed smoking as a risk factor for lower total cognitive functional scores and lower scores in language, verbal memory, visual-spatial memory, and attention. In addition, smoking was a risk factor for greater fibromyalgia symptom severity, worse quality of life measures of bodily pain and mental component scale, greater sleep problems, and increased anxiety and depression.³

Clinical Implications: “In fibromyalgia patients, smoking is a risk factor for cognitive dysfunction. Moreover, fibromyalgia patients who smoked were also more likely to report increased fibromyalgia symptom severity, worse quality of life indices, worse sleep, and increased anxiety and depression,” stated the researchers, led by Ryan D’Souza, MD, of the Mayo Clinic in Rochester, MN.

References

1. Cohen SP, Doshi TL, Constantinescu OC, et al. Effectiveness of lumbar facet joint blocks and predictive value before radiofrequency denervation: The Facet Treatment Study (FACTS), a randomized, controlled clinical trial.Anesthesiology. 2018;129:517-535. doi: 10.1097/ALN.0000000000002274.

2. Morffi D, Larach DB, Moser SE, et al. Medial branch radiofrequency ablation outcomes in patients with centralized pain. Presented at: 17th Annual Pain Medicine Meeting; November 16, 2018; San Antonio, TX. Abstract 6220.

3. D’Souza RS, Ge L, Oh T, et al. Tobacco use in fibromyalgia is associated with cognitive dysfunction: a prospective cohort study. Presented at: 17th Annual Pain Medicine Meeting; November 16, 2018; San Antonio, TX. Abstract 5832.