Relationship between perceived fatigue and performance fatigability in people with multiple sclerosis: A systematic review and meta-analysis

Abstract

Objective Perceived fatigue (i.e., subjective perception of reduced capacity) is one of the most common and disabling symptoms for people with multiple sclerosis (MS). Perceived fatigue may also be related to performance fatigability (i.e., decline in physical performance over time), although study findings have been inconsistent. Objective To locate all studies reporting the relationship between perceived fatigue and fatigability in people with MS, determine the population correlation, and examine moderating variables of the correlation size. Methods In accordance with PRISMA guidelines, systematic searches were completed in Medline, PsychInfo, Google Scholar, and the Cochrane Library for peer-reviewed articles published between March 1983 and August 2016. Included articles measured perceived fatigue and performance fatigability in people with MS and provided a correlation between measures. Moderator variables expected to influence the relationship were also coded. Searches located 19 studies of 848 people with MS and a random-effects model was used to pool correlations. Results The mean correlation between fatigue and fatigability was positive, “medium” in magnitude, and statistically significant, r = 0.31 (95% CI = 0.21, 0.42), p < .001. Despite moderate between-study heterogeneity (I2 = 46%) no statistically significant moderators were found, perhaps due to the small number of studies per moderator category. Conclusion There is a significant relationship between perceived fatigue and fatigability in MS, such that people reporting elevated fatigue also are highly fatigable. The size of the relationship is not large enough to suggest fatigue and fatigability are the same construct, and both should continue to be assessed independently.

Perceived fatigue and cognitive performance change in multiple sclerosis: Uncovering predictors beyond baseline fatigue

“…Therefore, whilst perceived fatigue change and reliable performance change may co-occur, it is not clear to what degree change in these is driven by fatigue per se. Contrary to other studies demonstrating relationships between perceived fatigue and cognitive performance fatigability (Cehelyk, Harvey, 2018, Wolkorte, Heersema, 2015 or motor fatigability (Loy, Taylor, 2017, Skurvydas, Brazaitis, 2011, Zijdewind, Prak, 2016, our results provide little general support for the role of fatigue variables in performance change. Whilst there was a link between cognitive impairment status and EDSS, neither had influence on perceived fatigue, fatigue change, or performance change, which are results that diverge from some other studies (Biberacher, Schmidt, 2018, Ghajarzadeh, Jalilian, 2013.…”

“…Further, the relationships between perceived fatigue and physical disability as measured using the Expanded Disability Status Scale (EDSS) (Kurtzke, 1983) have been inconsistent (Bakshi et al , 2000, Biberacher, Schmidt, 2018, Ghajarzadeh et al , 2013. Whilst some links between perceived fatigue and motor performance fatigability have been demonstrated (Loy et al , 2017, Skurvydas et al , 2011, Zijdewind et al , 2016, it has been suggested that perceived fatigue may be more closely associated with mood than neurological impairment (Bakshi, Shaikh, 2000).…”

Association Between Fatigue and Motor Exertion in Patients With Multiple Sclerosis—a Prospective Study

“…For FSMC correlations in PwMS, the sample size was small and included only two subjects without relevant fatigue (who were mainly unimpaired in all motor function tests). Nevertheless, in line with our results, the divergence of trait fatigue and disability in MS has been reported in larger cohorts with almost identical coefficients (12,35) as well as the divergence of trait fatigue and fatigability (36). The occurrence of strong trait fatigue in the absence of other neurological symptoms or structural CNS change in chronic fatigue syndrome may be taken as another piece of evidence (37).…”

Adjustments in Torque Steadiness During Fatiguing Contractions Are Inversely Correlated With IQ in Persons With Multiple Sclerosis

“…Multiple sclerosis (MS) is a neurological disorder that compromises the integrity of signaling pathways in the central nervous system through chronic inflammatory responses and neurodegeneration ( Trapp and Nave, 2008 ). Although the clinical progression of MS varies widely between individuals ( Lublin and Reingold, 1996 ; Confavreux and Vukusic, 2006 ), one of the most common symptoms of the disease is a heightened level of fatigue ( Fisk et al, 1994 ; Alvarenga-Filbo et al, 2015 ; Loy et al, 2017 ; Penner and Paul, 2017 ), the underlying mechanisms of which are poorly understood.…”

“…Intellectual capacity was measured by the Wechsler Abbreviated Scale of Intelligence. Given that intellectual capacity protects against MS-related declines in cognitive function ( Sumowski et al, 2009a , b ) and cerebral efficiency ( Sumowski et al, 2010 ) and that fatigue is associated with greater levels of cortical activity ( Enoka and Duchateau, 2016 ; Zijdewind et al, 2016 ; Loy et al, 2017 ; Severijns et al, 2017 ), we hypothesized that individuals with MS who had higher levels of intellectual capacity would experience lower levels of fatigue and fatigability.…”