1. Measurement of fatigue Principal Component Analysis (PCA)
Dysfunctions of balance and vision are associated with post-stroke fatigue
Trine Schow1, Tom Teasdale2, Kirsten Krogh Jensen Quas1, Morten Arendt Rasmussen3
1 Brain Injury Center BOMI, Roskilde, Denmark; 2 University of Copenhagen, Department of Psychology, Denmark; 3 University of Copenhagen, Department of Science, Denmark
BACKGROUND:
Balance problems and binocular visual dysfunction (BVD) are common after stroke, however, evidence of an effective rehabilitation method is limited. This study is part of a longitudinal intervention research project, in which 29 people with stroke participated in a four-month rehabilitation program for balance and BVD problems, where fatigue is as dominant a problem as balance and BVD.
AIM:
To investigate fatigue after stroke and its relation to balance, gait and Binocular Visual Dysfunction.
Analytical step (1):
Measurement of fatigue
Analytical step (2):
Principal Component Analysis (PCA)
Analytical step (3):
Correlation of PCA results with vision (Fig. 2) and balance/gait (Fig.3)
(The color represent correlation values, numbers are p-values)
(The color represent correlation values, numbers are p-values)
Modified Fatigue Impact Scale
Never
Rarely
Sometimes
Often
Almost always 1
I have been less alert 2 3 4
I have had difficulty paying attention for long periods of time
I have been unable to think clearly
I have been clumsy and uncoordinated 5
I have been forgetful 6
I have had to pace myself in my physical activities 7
I have been less motivated to participate in social activities 8
I have been less motivated to do anything that requires physical effort 9
I have been limited in my ability to do things away from home 10
I have trouble maintaining physical effort for long periods 11
I have had difficulty making decisions 12
I have been less motivated to do anything that requires thinking 13
My muscles have felt week 14
I have been physically uncomfortable 15
I have had trouble finishing tasks that require thinking 16
I have had difficulty organizing my thoughts when doing things at home or at work 17
I have been less able to complete tasks that require physical effort 18
My thinking has been slowed down 19
I have had trouble concentration 20
I have limited my physical activities 21
I have needed to rest more often or for longer periods
Correlation
Correlation
Cognitive= Q2-3, Q5, Q11-12,Q15-16, Q18-19
Physical = Q4, Q6, Q10, Q13, Q17
Arousal= Q1,
Q7-9, Q20-21
Physical Dis-
comfort= Q4+Q14
Figure 3. Heatmap showing the correlation between different measures of balance (BESTest and six sub-domains of balance ), walking velocity (10MWT) and the four new MFIS components and a MFIS in a two component model: MFIS physical and MFIS cognitive, and quality of life (EuroQol) (EQ).
Figure 2. Heatmap showing the correlation between different measures of visual dysfuntion and the four new MFIS components and MFIS in a two-component model: MFIS physical and MFIS cognitive (Schiehser et al 2014), and quality of life (EuroQol) (EQ).
METHODS:
Adults with stroke (n= 29, age years), were tested with the Modified Fatigue Impact Scale (MFIS), and objective and subjective BVD measures, Balance Evaluation Systems Test (BESTest), Ten Meter Walk Test (10MWT) and a Health-Related Quality of Life questionnaire, before and after intervention and at six- month follow-up. We used principle component analysis to extract underlying factors in the MFIS. The associations between MFIS factors and BVD measures and the MFIS and physical measures were assessed using pairwise correlations.
RESULTS:
Four components were extracted from the MFIS, explaining 71% of variance: Cognitive fatigue, Physical fatigue, Arousal and Physical Discomfort/Clumsy (Figure 1). There was a strong association between Fatigue and BVD specially cognitive fatigue and reading and arousal and dizziness (Figure 2). We also found an association between Arousal and Balance, and between Cognitive Fatigue and Gait (Figure 3). Component 4 is a two-way factor and could be considered removed from the model in further investigations.
Figure 1. Spiderplot showing the PCA of MFIS: The 21 questions were extracted into 4 components
(Fisk JD, et al. Can J Neurol Sci 1994;21:9–14)
CONCLUSION:
Fatigue is correlated with visual and balance problems after stroke. It seems important to distinguish between arousal, cognitive and physical fatigue in this group of patients in relation to treatment planning. This needs to be explored further.
Contact information: Trine Schow, PhD, Brain Injury Center BOMI, Maglegaardsvej 15, 4000 Roskilde, Denmark
Phone: