Association of Fine Motor Loss and Allodynia in Fibromyalgia: An fNIRS Study

Abstract

Recent studies showed that fine motor control dysfunction was observed in fibromyalgia (FM) syndrome as well as allodynia. However, brain signatures of this association still remain unclear. In this study, finger tapping task (FTT) and median nerve stimulation (MNS) were applied to both hands of 15 FM patients and healthy controls (HC) to understand this relationship. Hemodynamic activity was measured simultaneously using functional near-infrared spectroscopy (fNIRS). Experiments were analyzed separately by using 2x2 repeated measures ANOVA. Results for the FTT experiment revealed that HC showed higher activity than FM patients in bilateral superior parietal gyrus (SPG), left supramarginal gyrus (SMG) and right somatosensory cortex (SI). Furthermore, right-hand FTT resulted in higher activity than left-hand FTT in left SPG, left SI and right motor cortex (MI). In the MNS experiment, FM patients showed higher activity than HC in bilateral SPG, right SMG, right SI and right middle frontal gyrus (MFG). Negative correlation was observed in left SPG between FTT and MNS activities. Besides, MNS activity in left SPG was negatively correlated with left-hand pain threshold.This study revealed that left SPG might be an important indicator to associate fine motor loss and allodynia in FM.

Motor Cortex Function in Fibromyalgia: A Study by Functional Near-Infrared Spectroscopy

“…Fibromyalgia patients are affected by slowness in motor initiation [28, 29]. A study on fNIRS-related finger tapping changes in FM patients confirmed reduced motor performances and reduced activation of several brain areas that showed enhanced oxygenated hemoglobin levels in controls [30]. Our study cannot resolve the question of whether the motor impairment could be a consequence or a cause of cortical motor network dysfunction.…”

Tactile Detection in Fibromyalgia: A Systematic Review and a Meta-Analysis

“…Fourteen studies out of the 19 reported a mean pain intensity rating, either at the moment of the participation [ n = 10; ( 24 , 27 , 31 , 34 , 36 , 37 , 57 – 60 )] or within the last month prior [ n = 4; ( 30 , 33 , 35 , 61 )]. In nine studies, including five in the meta-analysis ( 32 , 57 , 59 , 61 , 62 ), individuals with fibromyalgia were instructed to stop taking their medication prior to their participation ( 27 , 30 , 32 , 33 , 57 , 59 , 61 – 63 ).…”

“…The TDT was assessed with Von Frey filaments in all studies except one ( 60 ) in which unspecified nylon filaments were used. For the TPT, five studies involved pinprick stimulators ( 27 , 28 , 30 , 32 , 35 , 36 , 61 ), five involved Von Frey filaments ( 34 , 37 , 57 , 62 , 63 ), one involved unspecified nylon filaments ( 60 ) and one involved disposable needles ( 59 ).…”

Phenotypic features of central sensitization

“…Often the standardized assessment of allodynia utilizes monofilaments or exposure to light brush strokes (Maracle et al, 2017). Many of the COPCs exhibit allodynia including fibromyalgia (Eken et al, 2017), TMD (Ernberg, Hedenberg-Magnusson, Alstergren, Lundeberg, & Kopp, 1999), migraine (Tietjen et al, 2009), and chronic fatigue (Yasui et al, 2014). In general, allodynia may be a by-product of the CS concept of “mental load” (Crettaz et al, 2013).…”