Coupling cognitive and brainstem dysfunction in multiple sclerosis-related chronic neuropathic limb pain

Peter Foley (Lead / Corresponding author), Yazhuo Kong, Ramune Dirvanskiene, Maria Valdés-Hernández, Matteo Bastian, Jonathan Murnane, Robin Sellar, Neil Roberts, Cyril Pernet, Christopher Weir, Thomas Bak, Lesley Colvin, Siddharthan Chandran, Marie Fallon, Irene Tracey

Research output: Contribution to journalArticlepeer-review

9 Downloads (Pure)

Abstract

Chronic pain in multiple sclerosis is common and difficult to treat. Its mechanisms remain incompletely understood. Dysfunction of the descending pain modulatory system is known to contribute to human chronic pain conditions. However, it is not clear how alterations in executive function influence this network, despite healthy volunteer studies linking function of the descending pain modulatory system, to cognition. In adults with multiple sclerosis-associated chronic neuropathic limb pain, compared to those without pain, we hypothesized altered functional connectivity of the descending pain modulatory system, coupled to executive dysfunction. Specifically we hypothesized reduced mental flexibility, because of potential importance in stimulus reappraisal. To investigate these hypotheses, we conducted a case-control cross-sectional study of 47 adults with relapsing remitting multiple sclerosis (31 with chronic neuropathic limb pain, 16 without pain), employing clinical, neuropsychological, structural, and functional MRI measures. We measured brain lesions and atrophy affecting descending pain modulatory system structures. Both cognitive and affective dysfunctions were confirmed in the chronic neuropathic limb pain group, including reduced mental flexibility (Delis Kaplan Executive Function System card sorting tests P < 0.001). Functional connectivity of rostral anterior cingulate and ventrolateral periaqueductal gray, key structures of the descending pain modulatory system, was significantly lower in the group experiencing chronic neuropathic pain. There was no significant between-group difference in whole-brain grey matter or lesion volumes, nor lesion volume affecting white matter tracts between rostral anterior cingulate and periaqueductal gray. Brainstem-specific lesion volume was higher in the chronic neuropathic limb pain group (P = 0.0017). Differential functional connectivity remained after correction for brainstem-specific lesion volume. Gabapentinoid medications were more frequently used in the chronic pain group. We describe executive dysfunction in people with multiple sclerosis affected by chronic neuropathic pain, along with functional and structural MRI evidence compatible with dysfunction of the descending pain modulatory system. These findings extend understanding of close inter-relationships between cognition, function of the descending pain modulatory system, and chronic pain, both in multiple sclerosis and more generally in human chronic pain conditions. These findings could support application of pharmacological and cognitive interventions in chronic neuropathic pain associated with multiple sclerosis.

Original languageEnglish
Article numberfcac124
Number of pages15
JournalBrain Communications
Volume4
Issue number3
Early online date17 May 2022
DOIs
Publication statusPublished - May 2022

Keywords

  • pain
  • neuropathic
  • multiple sclerosis
  • cognition
  • brainstem

Fingerprint

Dive into the research topics of 'Coupling cognitive and brainstem dysfunction in multiple sclerosis-related chronic neuropathic limb pain'. Together they form a unique fingerprint.

Cite this