Neural indices of multimodal sensory and autonomic hyperexcitability in fibromyalgia

Ksenija Marinkovic; Denali Woodruff; David R White; Morgan M Caudle; Terry Cronan

doi:10.1016/j.ynpai.2023.100140

Neural indices of multimodal sensory and autonomic hyperexcitability in fibromyalgia

Neurobiol Pain. 2023 Jul 22:14:100140. doi: 10.1016/j.ynpai.2023.100140. eCollection 2023 Aug-Dec.

Authors

Ksenija Marinkovic^{1

2

3}, Denali Woodruff¹, David R White¹, Morgan M Caudle^{1

2}, Terry Cronan^{1

2}

Affiliations

¹ Department of Psychology, San Diego State University, 5500 Campanile Dr., San Diego, CA 92182, USA.
² San Diego State University/University of California, San Diego, Joint Doctoral Program in Clinical Psychology, 5500 Campanile Dr., San Diego, CA 92182, USA.
³ Department of Radiology, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA 92093, USA.

Abstract

Fibromyalgia (FM) is characterized by chronic widespread musculoskeletal pain and psychological distress. Research suggests people with FM experience increased somatosensory sensitization which generalizes to other sensory modalities and may indicate neural hyperexcitability. However, the available evidence is limited, and studies including measures of neural responsivity across sensory domains and both central and peripheral aspects of the neuraxis are lacking. Thirty-nine participants (51.5 ± 13.6 years of age) with no history of neurological disorders, psychosis, visual, auditory, or learning deficits, were recruited for this study. People with FM (N = 19) and control participants (CNT, N = 20) did not differ on demographic variables and cognitive capacity. Participants completed a task that combined innocuous auditory stimuli with electrocutaneous stimulation (ECS), delivered at individually-selected levels that were uncomfortable but not painful. Event-related potentials (ERPs) and electrodermal activity were analyzed to examine the central and sympathetic indices of neural responsivity. FM participants reported greater sensitivity to ECS and auditory stimulation, as well as higher levels of depression, anxiety, ADHD, and an array of pain-related experiences than CNT. In response to ECS, the P50 deflection was greater in FM than CNT participants, reflecting early somatosensory hyperexcitability. The P50 amplitude was positively correlated with the FM profile factor obtained with a principal component analysis. The N100 to innocuous tones and sympathetic reactivity to ECS were greater in FM participants, except in the subgroup treated with gabapentinoids, which aligns with previous evidence of symptomatic improvement with GABA-mimetic medications. These results support the principal tenet of generalized neural hyperexcitability in FM and provide preliminary mechanistic insight into the impact of GABA-mimetic pharmacological therapy on ameliorating the neural excitation dominance.

Keywords: Electrodermal activity; Event-related potentials; Fibromyalgia; GABA-mimetic therapy; Hyperexcitability.