Influence of post-stroke fatigue on reaction times and corticospinal excitability during movement preparation. Issue 1 (January 2021)

• Record Type: Journal Article
• Authors: De Doncker, William; Brown, Katlyn E.; Kuppuswamy, Annapoorna
• Is Part Of: Clinical neurophysiology. Volume 132:Issue 1(2021)
• Page Start: 191
• Page End: 199
• Publication Date: 2021-01
• Subjects: Stroke -- Fatigue -- TMS -- Movement preparation; PSF post-stroke fatigue -- TMS transcranial magnetic stimulation -- M1 primary motor cortex -- EMG electromyography -- RT reaction time -- HADS hospital anxiety and depression scale -- NHPT nine-hole peg test -- FDI first dorsal interosseous -- RMT resting motor threshold -- WS warning stimulus -- IS imperative stimulus -- WP warning period -- RT30 30% Reaction time -- RT50 50% Reaction time -- RT70 70% Reaction Time -- FSS-7 fatigue severity scale -- SDMT symbol digit modalities test; Neurophysiology -- Periodicals; Electroencephalography -- Periodicals; Electromyography -- Periodicals; Neurology -- Periodicals; 612.8
• DOI: 10.1016/j.clinph.2020.11.012
• Languages: English
• ISSNs: 1388-2457

Abstract

Highlights: Higher the fatigue, lesser the inhibition in movement preparation in stroke survivors. Higher the fatigue, lesser the pre-movement facilitation and slower the reaction times. Poor excitability modulation supports sensory attenuation model of fatigue. Abstract: Objectives: Reduced corticospinal excitability at rest is associated with post-stroke fatigue (PSF). However, it is not known if corticospinal excitability prior to a movement is also altered in fatigue which may then influence subsequent behaviour. We hypothesized that the levels of PSF can be explained by differences in modulation of corticospinal excitability during movement preparation. Methods: 73 stroke survivors performed an auditory reaction time task. Corticospinal excitability was measured using transcranial magnetic stimulation. Fatigue was quantified using the fatigue severity scale. The effect of time and fatigue on corticospinal excitability and reaction time was analysed using a mixed effects model. Results: Those with greater levels of PSF showed reduced suppression of corticospinal excitability during movement preparation and increased facilitation immediately prior to movement onset (β = −0.0066, t = −2.22, p = 0.0263). Greater the fatigue, slower the reaction times the closer the stimulation time to movement onset (β = 0.0024, t = 2.47, p = 0.0159). Conclusions: Lack of pre-movement modulation of corticospinal excitability in high fatigue may indicate poor sensory processing supporting the sensory attenuation model of fatigue. Significance: We take a systems-based approach and investigate the motor system and its role in pathological fatigue allowing us to move towards gaining a mechanistic understanding of chronic pathological fatigue.