Ankylosing spondylitis is associated with back pain and fatigue and impacts mobility but can be treated with tumor necrosis factor inhibitors (TNFi). The differential effects of TNFi treatment on multiple symptoms and the brain is not well delineated. Thus, we conducted a 2-part study. In study 1, we conducted a retrospective chart review in 129 ankylosing spondylitis patients to assess TNFi effects on pain, fatigue, motor function, mobility, and quality of life (QoL). After at least 10 weeks of TNFi treatment, patients had clinically significant improvements (>30%) in pain (including neuropathic pain), most disease and QoL factors, and normalized sensory detection thresholds. However, residual fatigue (mean = 5.3) was prominent. Although 60% of patients had significant relief of pain, only 22% of patients had significant relief of both pain and fatigue. Therefore, the preferential TNFi treatment effect on pain compared with fatigue could contribute to suboptimal effects on QoL. Part 2 was a prospective study in 14 patients to identify TNFi treatment effects on pain, fatigue, sensory and psychological factors, and brain cortical thickness based on 3T magnetic resonance imaging. Centrally, TNFi was associated with statistically significant cortical thinning of motor, premotor, and posterior parietal regions. Pain intensity reduction was associated with cortical thinning of the secondary somatosensory cortex, and pain unpleasantness reduction was associated with the cortical thinning of motor areas. In contrast, fatigue reduction correlated with cortical thinning of the insula, primary sensory cortex/inferior parietal sulcus, and superior temporal polysensory areas. This indicates that TNFi treatment produces changes in brain areas implicated in sensory, motor, affective, and cognitive functions.
Tumor necrosis factor inhibitor treatment for ankylosing spondylitis had greater effects on pain relief than fatigue with corresponding differential changes in cortical thickness.
aDivision of Brain, Imaging and Behaviour-Systems Neuroscience, Toronto Western Research Institute, Toronto, ON, Canada
bDivision of Rheumatology, Toronto Western Hospital, Toronto, ON, Canada
cInstitute of Medical Science, University of Toronto, Toronto, ON, Canada
Departments of dMedicine and
eSurgery, University of Toronto, Toronto, ON, Canada
Corresponding author. Address: Toronto Western Hospital, Room MP14-306, 399 Bathurst St, Toronto, ON M5T 2S8, Canada. Tel.: (416) 603-5662; fax: (416) 603-5745. E-mail address: email@example.com (K. D. Davis).
Sponsorships or competing interests that may be relevant to content are disclosed at the end of this article.
Received July 09, 2014
Received in revised form October 21, 2014
Accepted November 19, 2014