Understanding Fatigue After Daily Activities

1. Understanding Fatigue After Daily Activities Dr Lorna Paul, Physiotherapist Reader in Rehabilitation

2. Fatigue after daily activities • Post-exertional fatigue is one of the main symptoms of ME • Lots of studies of exercise tests where people manage the exercise at the time but are not followed up for 24 or 48 hours later • Post-exertional fatigue/malaise not just after strenuous activity • Update of study funded by ME Association

3. Purpose of the study • What goes wrong within the body which leads to post exertional malaise/fatigue in ME? • Examining three things 1) HPA function 2) autonomic functioning 3) inflammatory response • Examining these 3 things before and after 3 different tasks 1) cognitive task 2) cycling task 3) daily task (vacuuming)

4. Participant Groups 4 groups of people – 30 people in each group • ME • MS • Post breast cancer (within one year of end of treatment) • Healthy controls

5. Immunological response to exercise

6. Hypothalamic-Pituitary Axis (HPA axis)

7. What is cortisol? Cortisol (or hydrocortisone) is • a steroid hormone • released in response to stress • increases blood sugar • suppresses the immune system • aids in fat, protein and carbohydrate metabolism

8. Autonomic Function • The autonomic nervous system is part of the peripheral nervous system • It controls many systems subconsciously eg The ANS affects heart rate, breathing, digestion, perspiration, size of pupils • The hypothalamus ‘central control area’ for the autonomic nervous system • Split into sympathetic and parasympathetic nervous systems

9. Immunological response to exercise

10. Immune response Immune cells produce cytokines which would be pro-inflammatory or anti-inflammatory

11. Each person attends four times • Introduction and Induction • 3 ‘fatiguing’ tests • Computer based cognitive task • Submaximal exercise bicycle task • Standardised daily physical activity task (vacuuming)

12. Computer based cognitive task - PASAT • Paced Auditory Serial Addition Test • The PASAT is a measure of cognitive function that assesses auditory information processing speed and flexibility, as well as calculation ability. • Single digits are presented every 3 seconds and the patient must add each new digit to the one immediately prior to it. • The PASAT is presented on CD to ensure standardisation

13. Submaximal exercise bicycle task The Aerobic Power Index test is a submaximal exercise test on a static bicycle It consists of gradual increments in power output The test is stopped when people reach 75% of their predicted maximum heart rate (220-age)

14. Standardised daily physical activity task (vacuuming)

15. Outcome Measures – First visit • Basic demographic details – age, height, weight, medications • Questionnaires – eg. Hospital Anxiety and Depression Scale (HADS) • Autonomic assessment

16. Outcome measures – Autonomic regulation

17. Outcome measures (cont) • Heart rate and blood pressure monitoring during and after the task • QuestionnairesSF36Checklist individual strength (CIS) - contains 20 items that measure 4 aspects of fatigue: 1. Subjective Fatigue; 2. Concentration; 3. Motivation; 4. Activity. • Physical activity monitoring (7 days between tests)

18. Immunological markers - cytokines Bloods have been taken and frozen Still deciding on which cytokines to test Expensive tests to do!

19. Lorna.Paul@glasgow.ac.uk 0141 330 6876