fatigue presentation
DESCRIPTION
hi guys ... this is a presentation on fatigue which u wont find in most of the books . i've compiled it from various journal articles and books. keep reading ... enjoyy !!TRANSCRIPT
04/08/23 2
FATIGUE
• Feeling of tiredness & lack of strength due to physical / mental strain or illness , which can be ameliorated through additional rest
04/08/23 3
MUSCLE FATIGUE
• Any exercise induced reduction in the ability of muscle to generate force or power regardless of whether or not the task can be sustained
S C Gandevia , 2001
04/08/23 4
NORMAL FATIGUE
• A state of general tiredness which is the result of overexertion & can be reversed by rest
04/08/23 5
PATHOLOGICAL FATIGUE
• A state characterized by weariness unrelated to previous exertion levels & is usually not reversible by rest
04/08/23 6
• Normal fatigue • Pathological fatigue
• Rapid onset
• Short duration
• Single identifiable cause
• Protective
• Gradual onset
• Long duration
• Multiple unknown causes
• Abnormal
04/08/23 7
CHRONIC FATIGUE SYNDROME
• Abnormally excessive
• Unexplained
• Persistent for six months or more
04/08/23 8
NEUROLOGICAL FATIGUE
• Subjective lack of physical or mental energy which is perceived by the individual or caregiver to interfere with usual & desired activities
MS council clinical practice guidelines
,1998
04/08/23 9
Types of fatigue
04/08/23 10
2 types :
1.Physical fatigue
2.Mental fatigue
04/08/23 11
PHYSICAL FATIGUE
• Inability to exert force within one’s muscles to the degree that would be expected given the individual’s general physical fitness
Muscle weakness
True weakness Perceived weakness
04/08/23 12
Objective weakness
A condition where the instantaneus force exerted by the muscle is less than that would be expected
04/08/23 13
Subjective weakness
A condition where it seems to the patient that more than normal effort is required to exert a given amount of force
04/08/23 14
Enhanced perception of limited endurance of sustained mental activities
Manifests as somnolence or just decrease of attention
04/08/23 15
Mental stress
Lack of sleep
Depression
Chemical causes04/08/23 16
04/08/2317
04/08/23 18
Reduction in the ability of muscle to perform work because of impairment anywhere along the command from neuromuscular transmission to the actin – myosin cross bridging
04/08/23 19
Peripheral model assumes fatigue at one or more sites which initiates muscle contraction
Therefore dependent on the localized chemical conditions of the muscles
04/08/23 20
Depletion of energy substrates Aerobic metabolism Anaerobic
metabolism
Change in intracellular ion levels leak of calcium ions
04/08/23 21
04/08/23 22
Decline in force output due to reduction in the neural drive or nerve based motor commands to the working muscles
04/08/23 23
Protective phenomenon
Works to preserve the integrity of system by initiating muscle fatigue through muscle decruitment
04/08/23 24
Failure in integration of limbic input & the motor functions within basal ganglia
04/08/23 25
TNF-ALPHA INTERLEUKIN – 6
Metabolic abnormalities of frontal cortex & basal ganglia
04/08/23 26
Hypofunctioning
Reduced Cortisol secretion
04/08/23 27
Increased level of serotonin in brain during exercise , peak at fatigue
Effects on arousal , lethargy , sleepiness & mood
04/08/23 28
04/08/2329
04/08/2330
Change in the force response to electric stimulation during rest following exercise relative to pre stimulation force
Reveals any loss of force in the muscle tissue after constant activation
Decline in force reflects the severity of fatigue
04/08/23 31
Rest twitches before & after MVC
Attenuation of post stimulation twitches indicate peripheral fatigue
Dominant slowing of the relaxation phase
04/08/23 32
Changes in sarcolemma
Variables : Amplitude Frequency Muscle fiber conduction velocity
04/08/23 33
Amplitude increases during submaximal exercise
During high contraction , amplitude declines
Change in frequency spectrum & MFCV
04/08/23 34
04/08/2335
MVC + Electrical stimulation to motor end plate
Increased exertion of force demonstrates Central Activation Failure
The technique allows quantification of CAF
Can’t differentiate between various central causes
04/08/23 36
Magnetic & electrical stimulation of motor cortex
Artificially activates CNS
Response is measured at output site
Studies reported diminished output after fatiguing contraction
04/08/23 37
Responses following magnetic stimulation are often submaximal
Any change in motor output is interpreted as change in excitability of motor cortex as induced by stimulus
Not the actual diminished voluntary drive
04/08/23 38
Negative movement related cortical EMG potential over the scalp 1 sec before a self paced motor act
Generated by supplementary motor area & primary motor cortex
04/08/23 39
During high force voluntary contraction , RP increases
Provides measure to determine changes at the motor cortex level instead at the output site
Does not require artificial stimulation
Prominent tool to study central changes during natural repetitive contractions
04/08/23 40
04/08/2341
70 % of patients with MS
Present even at rest
Both physical & cognitive components
04/08/23 42
Worsened by stress & increase in temperature
No correlation with age, neurological impairment , sleep disturbance
04/08/23 43
25 % - 92 % of stroke survivors
Persists despite excellent neurological recovery
04/08/23 44
Tends to decrease with time
Independent of stroke severity, localization or functional impairment
Correlation with brainstem or thalamic stroke
04/08/23 45
Incidence – 40%
Related to Dopamine deficiency
Levodopa normalizes cortical motor neuron excitability
04/08/23 46
04/08/2347
Muscle weakness – the commonest symptom
Metabolic / mitochondrial disorders : Fatigue
Exercise intolerance
Weak atrophic muscles functioning at their limits metabolically
Energy supply fails because of metabolic compromise
04/08/23 48
Abnormal rise in sEMG potential
04/08/23 49
Reported by 25- 40 %
Post encephalitic damage
Reticular Activating System
Dopaminergic neurons in Substantia Nigra
04/08/23 50
Manifests at the onset
Persists for months regardless of full recovery of PNS
Central fatigue component
04/08/23 51
04/08/2352
To ascertain whether normal or pathological
To identify possible predisposing factors
04/08/23 53
Onset
Duration
Severity
Daily pattern
Aggravating / Relieving factors
Impact on daily living
04/08/23 54
04/08/2355
9 item measure
7 point likert scale format
Ranges from : 1 ( strongly disagree) 7 ( strongly agree)
04/08/23 56
1. My motivation is lower when I am fatigued.2. Exercise brings on my fatigue.3. I am easily fatigued.4. Fatigue interferes with my physical functioning.5. Fatigue causes frequent problems for me.6. My fatigue prevents sustained physical
functioning.7. Fatigue interferes with carrying out certain duties
and responsibilities.8. Fatigue is among my three most disabling
symptoms.9. Fatigue interferes with my work, family or social
life
04/08/23 57
Total score - Mean score across the 9 statements
FSS score > 4 : Severe fatigue
Most widely used measure in neurological conditions
Able to differentiate between patients & healthy subjects
04/08/23 58
High validity
Internal consistency ( cronbach alpha = 0.81 – 0.95 )
Test retest reliability ( 0.8 ) in patients with MS & Polyneuropathies
04/08/23 59
Modification of VAS for pain
Scores range from : 0 (no fatigue) to
10 ( worst fatigue )
VAS score > 4.4 : Severe fatigue
04/08/23 60
Simple , practical , reproducible & fast to apply
Used to measure fatigue changes over time intervals (minutes, hours )
To closely estimate average intensity changes over longer time period ( weeks , months )
04/08/23 61
4 statements
7 point likert scale
Total score = mean score of the 4 statements
Able to differentiate between patients & healthy subjects
Internal consistency ( cronbech alpha = 0.81)
04/08/23 62
Developed for patients with MS
40 independent symptom based questions
Scale of : “ 0 (no problem )” to
“ 4 ( extreme problem)”
Total score = Sum of responses to all 40 entries
04/08/23 63
Minimum score = 0 ( No fatigue)
Maximum score = 160 ( Extreme fatigue)
FIS score of 80 or higher correlates with moderate to severe fatigue
04/08/23 64
Energy category - one of the 6 categories of NHP
Consists of 3 yes / no questions
Total score = no. of questions answered with yes *
100 total no. of questions
04/08/23 65
0 ( No complaints ) 100 ( Answered yes to all
complaints )
Internal consistency ( Cronbach α = 0.71)
Test retest reliability (Spearman ρ = 0.77 – 0.86) in patients with stroke
04/08/23 66
Fatigue scores are not interchangeable
Structure & attributes of questionnaire differ remarkably
Weight of individual components of fatigue contribute to significant interscale score deviation
04/08/23 67
FSS : Asseses neuromuscular fatigue
VAS : No identifiable domains
FIS : Less emphasis on physical
fatigue More on emotional, cognitive
& social elements of fatigue 04/08/23 68
04/08/2369
04/08/2370
Identification & optimum management of potential factors
Nutrition counselling
Drugs : Antidepressants Amantadine Modafinil
04/08/23 71
04/08/2372
Combination of cognitive & behaviour therapy approaches
Identification of unhelpful, anxiety provoking thoughts & challenges
04/08/23 73
Stress management techniques : -
Relaxation Hypnosis Guided imagery Distraction
04/08/23 74
Moderate intensity :
Aerobic training
Strength training
Flexibility training
Group therapy
Level II evidence
04/08/23 75
Fatigue dairy
Restricting timing of daily activities
Prioritizing tasks
04/08/23 76
Imp to make the patient aware that fatigue is real
Recognition by patients, caregivers & family members
04/08/23 77
Goals :
To improve understanding in patients care giving
To involve patient, caregivers in setting goals, directing & evaluating the intervention
04/08/23 78
Relaxation training
04/08/23 79
Chinese technique of inserting needles into the body
Strengthen the vital essence of human body
Removes the blockage of channels
04/08/23 80
S C Gandevia : Spinal and Supraspinal Factors in Human Muscle Fatigue .Physiological Reviews , 2001 ; 81 : 4
Abhijit Chaudhuri, Peter O Behan :Fatigue in neurological disorders ; The Lancet ; 2004 ; 363, 20
Marloon groot et al : Fatigue associated with stroke and other neurologic conditions: implications for stroke rehabilitation Archives of Physical Medicine and RehabilitationVolume 84, Issue 11, November 2003, Pages 1714-1720
04/08/23 81
M J Zwartz : Clinical neurophysiology of fatigue ; Clinical neurology , 119 , (2008), 2-10
William s, B Krupp : Multiple sclerosis related fatigue ; Phys Med Rehab Clin N Am , 16 (2005) , 483
Physiolological Basis Of Movement : Latash
04/08/23 82
04/08/2383