Muscle Pathologies Flashcards
Contracture
Shortening of connective tissue supporting structures over or around a joint.
Results in reduced ROM.
Scar
Collagen based tissue that develops as a result of inflammation
Weaker than tissue it replaces.
Adhesion
When reduced motion of a joint allows cross-links to form among collagen fibres, causing even more reduction in ROM.
Scar tissue adhesion
Occurs with an injury or acute inflammatory process.
Adhesions/contractures occur in random pattern. ROM decreases.
Fibrotic adhesion
Results from chronic inflammation and causes moderate to severe restrictions in ROM.
Difficult to eradicate.
Irreversible contracture
Fibrotic tissue or bone replaces muscle and connective tissue.
ROM can only be recovered surgically.
Proud Flesh
Abnormal raised, thick dermal granulation tissue that results from abnormal healing.
Hypertrophic scarring
Overgrowth of dermal tissue that remains in the boundaries of the wound.
Collagen fibres randomly organized in a nodular or whirl pattern.
Associated with: deep partial or full thickness burns, skin grafts, sutures.
Sternum, upper back, shoulder/delt, buttock, dorsum of foot.
Keloid scarring
Dermal scar tissue that grows beyond the boundaries of the original wound.
More collagen more randomly placed than hypertrophic scarring.
More common ear to waist, elbow to wrist, in darker skinned people.
Muscular dystrophies
Largest and most common group of inherited progressive neuromuscular disorders.
Characterized by progressive weakness and degeneration of striated muscles.
Duchenne’s MD
Most common
Sex linked. 1/3300 males
Lack of dystrophin (anchors thin filaments to cell membrane).
Muscle wasting begins in utero.
Affects all striated muscle.
Life expectancy: 20 years
Backers MD
1/20000 males
Faulty or decreased dystrophy
Begins in late childhood
Life expectancy: 40-50s
Myotonic dystrophy
AKA Steinert’s disease
Inability to relax muscles. Characterized by myotonia.
Autosomal dominant.
Onset 10-30 years. Initially affects muscles of eyelids, face, distal limbs.
Facioscapulohumeral
AKA Landouzy-Dejerine Disease
Onset teens-twenties.
Autosomal dominant
Difficulty whistling, closing eyes, raising arms.
Normal life expectancy
Limb Girdle Dystonia
Onset 3-20 years
Initially affects shoulders and hips; proximal limb distribution.
Moderate weakness
Slow progression.
Congenital dystrophy
Muscular dystrophies symptomatic at birth, not otherwise specified.
Includes several rare forms.
General muscle weakness and joint deformities.
Oculopharyngeal Dystrophy
Affects eyes and throat
Initial sign – eye drooping
Onset – middle age (40-69)
Slow progression
Distal dystrophy
Involves hands, feet, forearms, lower legs.
Middle age onset
Slow progression.
Emery Dreifuss dystrophy
Begins in muscles of the shoulders, upper arms, and shins.
Onset: early teens
Frequently involves heart.
Slow progression.
Inflammatory myopathy es
Group of diseases that involve chronic muscle inflammation and weakness
Three main types:
Polymyositis
Dermatomyositis
Inclusion body myositis
Inclusion body myositis
Idiopathic chronic myopathy
Chronic, progressive muscle inflammation.
May be asymetrical
Men > women
First symptoms: falling or tripping; may begin with weakness in the wrists and fingers. Difficulty swallowing.
Polymyositis
Uncommon CT disease. Inflammatory myopathy. Idiopathic.
Symmetrical
More common in women 2:1
Blacks > whites
More common in 30-50 years.
Difficulty going up stairs, getting out of chairs, lifting above shoulders. Speech.
First sign: lifting head from pillow.
Dermatomyositis
Uncommon. Distinctive skin rash
Can occur at any age. Most common 40-60 and 5-15. Women > men
Idiopathic
Slow development, possible periods of remission.
Dusty or violet rash. Face, eyelids, around nails, knuckles, elbows, knees, chest and back.
Dysphagia. Calcinosis cutis. Lung problems.
Myasthenia Gravis
Motor end plate disorder. Autoimmune disorder associated with abnormal thymus
Antibodies block ACh receptors in NMjunctions.
Weakness, rapid fatigue of voluntary muscles.
Women under 40; men over 60.
Ptosis, diploplia, strabismus
Test with edrophomium – blocks ACherase, allowing ACh to bind and some muscle contraction
Tx: corticosteroids, AchE inhibitors, thymus surgery, plasmapheresis
Necrotising fasciitis
Rare bacterial infection (strep pyrogenes)
Small reddish bump –> bronze/purple patch –> centre grows black and does.
1cm/hour
Myofascial pain dysfunction
Regional pain disorder characterized by TrPs.
Related to dysfunctional end plates of skeletal muse fibres.
TrPs, pain, reduced ROM, weakness, pares thesis
