orthopedic pathology (muscle pathologies) Flashcards
atrophy
decrease in size (cells/muscle)
hypertrophy
increase in size (cells/muscle)
hyperplasia
Increase in number of muscle fibers
Does not occur under normal conditions
contracture
A contracture is the shortening of tissues surrounding a joint, leading to decreased range of motion
includes muscles, but also other tissues such as tendons or ligaments
contractures causes
burns, scars, disuse, many pathologies (cerebral palsy, muscular dystrophy, etc)
Ischemic Necrosis
Some texts say muscles will undergo necrosis after 6 hours
(some texts say 3 hours)
muscular dystrophy
largest and most common group of inherited progressive neuromuscular disorders
how many types MD
more than 30 genetic diseases
MD characterized by
progressive weakness and degeneration of skeletal muscles
Most common form of MD
Most severe form of MD
Duchenne’s MD
differ in types of
type of inheritance, area affected, age at onset, and rate of progression/prognosis
Duchenne’s MD rate
1/3500 male births
Duchenne’s MD – lack in which muscle protein
dystrophin
dystrophin function
Protein that helps muscle fibers maintain their shape/strength
“helps link thin filaments to the sarcolemma for stability”
Duchenne’s MD etiology
Etiology - Genetic (x-linked recessive)
x linked recessive inheritance
X-linked recessive inheritance refers to genetic conditions associated with mutations in genes on the X chromosome.
A male carrying such a mutation will be affected, because he carries only one X chromosome.
A female carrying a mutation in one gene, with a normal gene on the other X chromosome, is generally unaffected.
when symptoms appear?
at 2 - 4 years of age
when loss of unassistec ambulation
Loss of ambulation occurs between 7 – 13 years of age
respirator?
“Night ventilation by body respirators for patients in chronic respiratory failure due to late stage Duchenne muscular dystrophy”
Duchenne’s MD respiratory system
eventually resulting in loss of ambulation, loss of respiratory muscle strength, and death from respiratory insufficiency.
The majority of patients develop cardiomyopathy.
Duchenne’s MD life expectancy
Life expectancy is 20 – 30 years of age
Usually die due to cardiopulmonary issues
Duchenne’s MD initially affects (which part of body)
Initially affects the girdles (shoulders and hips)
SSx
Muscle weakness
Lack of coordination
Spastic movements
Weight loss
Contractures, loss of ROM, deformities – painful
where is there pseudohypertrophy in Duchenne’s MD?
calves
fat storage, not muscle (?)
Gowers’s sign
The sign describes a patient that has to use their hands and arms to “walk” up their own body from a squatting position due to lack of hip and thigh muscle strength
Duchenne’s MD Gower’s sign
Difficulty getting up from seated or lying position
walking, respiratory muscles
Waddling gait
Respiratory muscle failure
mental disability (?)
not always, but very common
dystrophin role in brain
Duchenne causes abnormal expression of dystrophin in the brain.
The function of dystrophin in the brain is not as well understood,
but recent studies have shown individuals with Duchenne to be more prone to ADHD, learning difficulties, anxiety, and autism spectrum disorder (ASD).
Duchenne’s MD posture
APT (weak abdominal muscles, weak hamstrings/glutes)
—> distended belly (weak abdominal muscles)
hyperextended knees to bear weight (due to weak quads)
—> Thin weak anterior thigh
tight calcaneal tendon (walking on toes)
weak muscles of dorsiflexion (footdrop)
poor balance, falling often
Less common and less severe than Duchenne’s MD
Becker’s MD
Becker’s MD rate
1/ 20,000 males
dystrophin levels in Becker’s vs Duchenne’s
Duchenne’s almost none
(Becker’s) Dystrophin levels are higher than in Duchenne’s MD
Becker’s vs Duchenne’s symptoms
Symptoms are same as Duchenne’s,
except occur later in life and progress more slowly
Becker’s when do signs/symptoms appear?
late childhood
diagnosed between 5 – 10 years of age
when is muscle weakness apparent?
Muscle weakness not significant until midlife
when is ambulation affected?
Can walk into teens/early adulthood
Loss of ambulation by late 20’s
Becker’s life expectancy
Lifespan into 40’s or 50’s
MD diagnosis – blood test
blood test (creatine kinase test?)
MD diagnosis (EMG)
Electromyography (EMG)
(firing pattern)
MD diagnosis – ultrasound
ultrasound (“Quality of muscle tissue”)
MD diagnosis – biopsy
muscle biopsy (Looking for dystrophin)
MD diagnosis – genetic testing
Genetic testing (Detecting presence of mutated gene)
creatine kinase test
This test measures the amount of an enzyme called creatine kinase (CK) in your blood.
CK is a type of protein. The muscle cells in your body need CK to function.
Levels of CK can rise after a heart attack, skeletal muscle injury, or strenuous exercise.
MD treatment
No cure. Treatment is aimed at increasing physical ability, allowing for a better quality of life.
alleviate symptoms, improve quality of life
treatment – PT, Speech, respiration, surgery (?)
Physical therapy
Speech therapy
Respiratory treatment
Surgery (?)
MD medication
corticosteroids to slow muscle degeneration
myotonic dystrophy (DM) – WHAT IS THE MAJOR FEATURE
inability to relax muscles
Characterized by myotonia (slow relaxation of muscles)
DM – male vs female ratio
M = F
DM onset
10-30 years old
DM most common onset
young adults
DM multisystem or local?
Multisystem disease
Variable presentation
DM etiology (genetic)
Autosomal dominant inheritance
Autosomal dominant inheritance
Autosomal dominant inheritance is a way a genetic trait or condition can be passed down from parent to child.
One copy of a mutated (changed) gene from one parent can cause the genetic condition.
A child who has a parent with the mutated gene has a 50% chance of inheriting that mutated gene.
myotonic dystrophy (DM) – SSx
..
DM – which muscles can be affected?
All voluntary muscles can be affected
DM – smooth muscles?
Some variants include smooth muscle involvement leading to GI issues
which part of body is particularly affected?
what type of movements affected?
Particularly apparent in the distal limbs
Fine movements difficult
characteristics/pattern of weakening
Progressive weakening of muscles
contractures
Joint contractures also possible
other systems affected?
Can also include
cardiovascular issues,
endocrine issues,
cataracts,
mental disability
DM features
atrophy of temporalis
ptosis (eyelids) (blepharoptosis)
drooping mouth (weak muscles of face)
thin neck (atrophy of SCM)
gynecomastia
(male breast tissue –> hormone imbalance – endocrine system involvement)
cataracts
inflammatory myopathies ***
Theinflammatory myopathiesare a group of diseases that involve chronic muscle inflammation, accompanied by muscle weakness.
3 types (chronic)
polymyositis,
dermatomyositis,
inclusion body myositis
3 types etiology
They all have a similar etiology, presentation, and treatment.
compare/contrast 3
..
etiology?
Idiopathic
Autoimmune in nature, with a possible component of viral infection, genetics, and/or environmental factors
S&S
muscle inflammation and weakness
which type of muscle?
All of them typically affect skeletal muscles,
but can sometimes affect smooth muscle leading to issues of the heart or GI tract
diagnosis of inflammatory myopathies
diagnosis by exclusion
Blood work done to rule out other pathologies
EMG
Nerve conduction study
Biopsy to confirm inflammation
treatment (inflammatory myopathies)
PT
(maintain strength and ROM)
Immunosupressive medications to reduce inflammation
(steroids such as prednisone)
no cure
polymyositis – gender ratio
Women > men (2:1)
polymyositis most common age of onset
between 30-50 years old
polymyositis onset duration
possibly rapid, but more likely 3-6 months
polymyositis – SS – bilateral or unilateral?
Symmetric weakness, tenderness and atrophy
polymyositis – which part most affected?
Proximal limb
girdle muscles
dermatomyositis – gender ratio
Women > Men (2:1)
dermatomyositis – onset age
M/C 40-60 years old
dermatomyositis – how long to develop
over weeks or months
dermatomyositis – which area most affect (?)
Weakness is also symmetric and affects girdles
similar symptoms:
Symmetric weakness, tenderness and atrophy
dermatomyositis – very characteristic symptom
very characteristic rash
“distinctive pathognomonic rash”
pathognomonic
“indicates one particular disease”
“(of a sign or symptom) specifically characteristic or indicative of a particular disease or condition.”
pathognomonic etymology
suffering
judge (gnomon)
inclusion body myositis – gender ratio
most common age
Men > Women (2:1)
M/C >50 years old
inclusion body myositis –
unilateral or bilateral?
distal or proximal?
Muscle weakness may be unilateral
Weakness often found in distal limbs
inclusion bodies?
Characterized by presence of inclusion bodies in the muscle
Protein deposits similar to those found in Alzheimers
inclusion bodies vs amyloid
Inclusion body diseases differ from amyloid diseases
inclusion bodies are necessarily intracellular aggregates of protein,
amyloid can be intracellular or extracellular.
Amyloid also necessitates protein polymerization where inclusion bodies do not.
does inclusion bodies myositis respond to immunosuppressive drugs?
Does not respond to immunosuppressive drugs
“Unlike other inflammatory and autoimmune conditions, it doesn’t respond to corticosteroids or immunosuppressant drugs.”
IBM life expectancy
Although there is no effective treatment, having inclusion body myositis does not directly affect your life expectancy.
However, it may shorten your life span indirectly through the dangerous consequences of losing your muscle strength.
fibromyalgia – syndrome or disease?
syndrome – collection of symptoms
syndrome vs disease?
A syndrome is a group of signs and symptoms that are known to go together but don’t have a clear cause, course, or treatment path.
A disease is a disorder that affects how your body functions and is more likely to have a known cause, a distinct course, and established treatments.
FM, etiology/SS
idiopathic etiology
widespread pain, abnormal pain processing, sleep disturbances, fatigue and often psychological distress
incidence FM
over 6 million people in the USA
most common musculoskeletal disorder in the US
FM age/gender
any age, but more common between ages of 20 and 55.
More common in women (4:1)
some sources state it as high as 7:1
FM etiology
Idiopathic
Many theories; probably multifactorial
POSSIBLE RISK FACTORS:
genetic predisposition
viral origin
occupational and environmental influences
sleep disorders
psychological distress
FM – risk factors for onset/flare-ups
Trauma
Emotional stress / Anxiety / Depression
Infections
Hypothyroidism
Overexertion
Lack of exercise
Sleep disturbances
Extreme temperatures
FM – SS
Main symptom: Muscle pain
diffuse pain or tender points on both sides of the body and in many muscle groups
FM other common symptoms
Visual problems
Mental and physical fatigue
Sleep disturbances
Anxiety
Cognitive problems (memory, attention span, concentration)
Irritable bowel syndrome
Headaches
Hypersensitivities to noise, odors, light, heat/cold.
FM pathogenesis – and involvement of certain regulatory systems
Which systems?
Hypothalamic-pituitary-adrenal axis
Autonomic nervous system
Reproductive hormone axis
Immune system
what happens if these regulatory systems are affected/disturbed?
This could result is disruption of the other systems and cellular function (impaired muscle function and pain).
HPA axis and FM
what does HPA axis do?
Modulates pain, sleep, mood, sex drive, appetite, energy and circulation
how does dysregulation of HPA axis affect pain perception during FM?
Increased activity of substance P (neurotransmitter for pain)
Results in an exaggerated response to normal stimuli
ANS and FM
what does ANS do?
how does FM affect ANS?
Activity of the skeletal muscles, heart, stomach, intestines, blood vessels, and sweat glands
” during daily stress tends to be excessive and responses to stimuli may be exaggerated.
reproductive hormone axis and FM
what does reproductive hormone axis do?
Interacts with HPA axis
Decrease in function can contribute to diminished reproductive capability, fatigue, and sleep disturbances
Affects sex hormone levels, which have influence over:
Menstrual cycle
Bowel and bladder function
Blood pressure
Sleep cycles
Endorphins
Serotonin levels
Thyroid function
Digestive activity
Sex drive
how does dysregulation of reproductive hormone axis affect symptoms during FM?
Menstrual cycle
Bowel and bladder function
Blood pressure
Sleep cycles
Endorphins
Serotonin levels
Thyroid function
Digestive activity
Sex drive
immune system, pain perception, and FM
Immune cells release pro-inflammatory cytokines when stimulated,
can cause glial cells in CNS to release substances involved with chronic pain as well as releasing neurotransmitters.
can create an exaggerated pain state.
which cells in which part of nervous system release NT/substances involved during chronic pain?
glial cells of CNS
what type of cytokines released by Immune system
pro-inflammatory cytokines
FM diagnosis
Diagnosis by exclusion
FM diagnosis criteria
Widespread pain (all four quadrants) for at least 3 months.
FM outdated diagnosis method
11/18 POINTS SYSTEM
Pain with 11 out of 18 tender points
NO LONGER USED
FM treatment
Medications: antidepressants
Biofeedback
Meditation
Diet/supplementation
Aerobic exercise
Cognitive behavioral therapy
Manual therapy (RMT, TCM, DC, PT)
Hypnotherapy
