Muscular pathologies Flashcards
Duchenne Muscular Dystrophy
Caused by a single gene defect on the X chromosome, affecting males, whilst females can be carriers. Affects 1 in 3500 males
Paraphysiology:
• Associated with a lack of protein ‘dystrophin’ in muscle cells, which anchors the cytoskeleton to the extracellular matrix.
• If this protein is missing, when cell contracts there’s no support and the cell membrane becomes leaky, allowing materials to flood in.
• This results in muscle degeneration & necrosis
Signs and symptoms:
• Delayed walking
• Delayed motor skills
• Difficulty getting up from sit or lying position
• Clumsiness, frequemt falls
• Waddling gain
• Speech delay
• Gowers sign (use own body to push them up)
• Usually diagnosed 3-5 years of age
Diagnostic:
• Serum creatine kinase (10-100 x normal). Often raised in carriers
• Genetic analysis & muscle biopsy
Other
• All muscle types are affected; skeletal, smooth and cardiac
• Small amounts of dystrophin also present in nerve cells (IQ is affected)
• Prognosis is poor – usually wheelchair support by 10 years and ventilation by 20 years
• Most die in their late 20’s, often from pneumonia & cardio-respiratory failure
Fibromyalgia
Fibromyalgia is a chronic pain disorder, heavily associated with widespread musculoskeletal pain and fatigue
Pathophysiology;
• Neurophysiologic basis, characterised by abnormalities in pain processing by CNS
• Associated with ‘central sensitisation’; a central disturbance to pain processing :
• Normally sensory input such as light touch & temperature is sent as nerve signals to brain/spinal cord where it synapses with nerves
• Alterations occur in pain processing in the spinal cord & brain (centrally)
• High levels of substance P are found in synapses; this makes nerves more sensitized to pain
• Excess post-synaptic nitric oxide production also causes the synapses to amplify pain signals
Causes:
• Biological, environmental & possibly genetic factors are thought to contribute:
• Poor mitochondrial functioning – damaged by free radicals (oxidative stress)
• Altered stress response (i.e. excess cortisol, adrenal fatigue)
• Post-viral & chronic toxic load e.g. heavy metals, chemicals
• Poor gut health – dysbiosis, leaky gut syndrome, candida, fungus, parasites, bacteria
• Serotonin & noradrenaline deficiencies – play a role in pain tolerance
• Sleep dysregulation – fatigue, increased pain, decreased activity)
• Often accompanied by multiple unexplained symptoms, anxiety, depression and functional impairment of daily activities
Signs and symptoms:
• Widespread (diffuse) musculoskeletal pain
• Pain that results from gentle pressure
. Feelings of ‘swollen joints’, often no swelling
• Debilitating fatigue & severely-disturbed sleep
• Headaches (muscular or migraine type)
• IBS symptoms, numbness, tingling & weakness
• Anxiety and depression
Diagnostic:
• Excess pain on palpation in at least 11 of 18 predefined anatomical points
Allopathic treatment;
• Medications e.g. pain relief
• Pain clinics
Impingement syndrome
Impingement syndrome describes a shoulder condition in which movements of the shoulder can be painful and limited
Pathophysiology:
• Rotator cuff tendons &/or bursa can become inflamed/damaged. Most notable when compressing sub-acromial space they are both in
• The sub-acromial space is the area between the humeral head & acromion
• Rotator cuff tendons connect humerus & scapula. Normally when moving the shoulder, the rotator cuff has to manoeuvre intricately in order to prevent impingement
Causes:
• Overuse
• Working with arms raised overhead
• Age
• Positional fault
• Bone spurs
• Oddly sized acromion – reduced space
Signs and symptoms:
• Shoulder ache (early stages)
• Pain when abducting the shoulder or rotating
• Painful arc of movement
• A catching sensation when lowering the arm
• Weakness/inability to raise arm = indicates tear
Allopathic treatment;
• Cortisone injection
• NSAIDs
• Surgery
Muscular Dystrophies
A group of inherited muscular diseases that cause muscular degeneration and weakness.
(N/B Many types of muscular dystrophies exist)
Signs and symptoms:
Characterised by:
• Progressive skeletal muscle atrophy
• Death of muscle cells and tissue (final stages)
• Defects in muscle proteins
Muscle fatigue
Muscle fibres can fatigue if overused
Pathophysiology:
• Associated w/ a depletion of metabolic reserve
• Cell respiration becomes anaerobic & by-products that can cause pain, such as lactic acid, are produced
Causes:
• Common in sports, occupational overuse & poor posture
Muscle shortening
If a muscle is continuously contracted, the actin-myosin filaments remain attached
Causes:
• Overuse
• Stress
Chronic muscle contracture causes muscle fatigue but also places a strain on the skeletal muscle attachments
Muscle strain
Over-stretching of muscle fibrils or the tendon, occurring when a joint is forced beyond its normal range (pulled muscle)
Strain:
• The muscle remains whole and blood supply intact to permit healing
Causes:
• Over stretching
Signs and symptoms:
• Pain
• Inflammation
Allopathic treatment:
• RICE; rest, ice, compress, elevate
Muscle tear
More significant, where the muscle tears and is no longer whole
Causes:
• Over stretching
Signs and symptoms:
• Pain
• Inflammation
• More likely if movement is not possible
• Bruising more likely
Allopathic treatment;
• RICE; rest, ice, compress, elevate
Complications:
• Blood supply affected can prevent natural complete healing. Can lead to fibrosis
Myasthenia Gravis
An autoimmune disease of the neuromuscular junction, characterised by fluctuating muscle fatigue and weakness
Pathophysiology:
• Antibodies block acetylcholine receptors on the motor end plate preventing a nerve impulse being sent to the muscle fibres. The muscle becomes progressively weaker
Signs and symptoms:
• Weakness of ocular muscles; double vision & ptosis
• Weakness in facial muscles, spreads to proximal limbs
• Difficulty with speech, chewing, swallowing
• Death may result from failure of respiratory muscles
• Symptoms worsen throughout day
Allopathic treatment;
• Acetylcholinesterase inhibitors
• Corticosteroids (reduce effects of antibodies)
• Plasma exchange in severe cases; injections of normal immunoglobulins from healthy donors