PHTY208 Lecture Notes - Lecture 7: Hyperthyroidism, Dermis, Splints
Metabolic, rheumatic and degenerative bone disease
• Disorders of the muscular system
o Myopathy
• Muscle disease
• Classified as neuromuscular or musculoskeletal
• Muscle fibres do not function properly
• Common symptoms
▪ Proximal, symmetric limb weakness with preserved reflexes and
sensation
▪ Muscle pain
▪ Muscle enlargement and atrophy
• Treatments range from treatment of the symptoms to very specific cause-
targeting treatments
• Inherited myopathy
▪ Dystrophies - characterised by degeneration and regeneration
▪ Congenital myopathies - microscopic muscle changes
▪ Mitochondrial myopathies - due to defects in mitochondria
▪ Inflammatory myopathies – autoimmune disease
▪ Metabolic myopathies - which result from defects in biochemical
metabolism affect muscle
• Acquired myopathy
▪ Drug-induced myopathy and alcoholic myopathy
▪ Glucocorticoid myopathy is caused steroids increasing the breakdown
of the muscle proteins (atrophy)
▪ Myopathy due to other toxic agents
▪ Dermatomyositis - produces muscle weakness and skin changes
▪ Polymyositis - inflammation of many muscles
▪ Inclusion body myositis - slow progressive disease producing weakness
of hand grip and straightening of the knees
▪ Myositis ossificans
▪ Rhabdomyolysis and myoglobinurias
• Muscular dystrophy
▪ Muscular dystrophy refers to a group of hereditary progressive diseases
▪ Progressive skeletal muscle weakness, defects in muscle proteins, and
the death of muscle cells and tissue
▪ Most types of MD are multi-system disorders
▪ Common types of muscular dystrophy include
• Duchenne – before 5 years old
• Becker – early childhood to adult
▪ Treatment
• No cure
• Physiotherapy, aerobic exercise, low intensity anabolic steroids,
prednisone supplements
▪ Signs and symptoms of Duchenne
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• Fibromyalgia
▪ Muscle and connective tissue pain
▪ Other symptoms may include
•
Debilitating fatigue, sleep disturbance, and joint stiffness
•
Some patients may also report difficulty with swallowing, bowel and
bladder abnormalities, numbness and tingling, and cognitive
dysfunction
▪ Frequently comorbid with psychiatric conditions
• Myasthenia gravis
▪ Autoimmune neuromuscular disease leading to fluctuating muscle
weakness and fatigability
▪ Weakness is caused by circulating antibodies that block acetylcholine
receptors
▪ Muscles become progressively weaker during periods of activity and
improve after periods of rest
▪ Muscles that control eye and eyelid movement, facial expressions,
chewing, talking, and swallowing are especially susceptible
▪ The muscles that control breathing and neck and limb movements can
also be affected
▪ Myasthenic crisis - a paralysis of the respiratory muscles occurs
▪ Necessitating assisted ventilation to sustain life
▪ Crises may be triggered by infection, fever, an adverse reaction to
medication, or emotional stress
• Hereditary and congenital deformities
o Present at birth
o Range in severity from mild limb deformities (common) to major limb
malformations (rare)
o Common anomaly of digits
• Macrodactyly – larger than surrounding digits
• Polydactyly – extra digit
• Syndactyly – webbing
o More serious
• Absence of a bone – phalanx, rib or clavicle
• Absence of joint or limb
• Joint contractures and dislocations produce more severe deformity
o Congenital deformities are caused by
• Hereditary influences
• External agents – radiation, alcohol, drugs, viruses
• Intrauterine environmental factors
o Osteogenesis imperfecta
• One of the most common hereditary bone disease
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• Characterised by defective synthesis of type I collagen - loss of flexibility
• Manifestations
▪ Extreme skeletal fragility
▪ Thin poorly developed bones
▪ Short limbs and a soft cranium with bifrontal prominences
▪ Problems associated with defective connective tissue
• Treatment
▪ Bisphosphonates can increase cortical bone width and an increase in
bone strength
▪ Physiotherapy used to strengthen muscles and improve motility
• This often involves hydrotherapy and the use of support cushions
to improve posture
• Individuals are encouraged to change positions regularly
throughout the day
• Children often develop a fear of trying new ways of moving due
to movement being associated with pain
o Osteochondrosis
• Diseases of the joint that occur in children and adolescents
• Characterised by interruption of the blood supply of a bone, in particular to
the epiphysis
• Conditions may be classified into three groups with many diseases in each
group
▪ Spinal: Scheuermann's disease
• Condition where the vertebrae grow unevenly with respect to the
sagittal plane
• Uneven growth results the signature "wedging" shape of the
vertebrae, causing kyphosis
• Significantly worse deformity than postural kyphosis
• Apex of their curve, located in the thoracic vertebrae
• Notorious for causing lower and mid-level back pain
• Many sufferers of the disorder have loss of vertebral height
• May have a visual 'huhak' or 'roudak
• Often have an excessive lordotic curve in the lumbar spine
• Often patients have tight hamstrings
▪ Articular: Legg-Calvé-Perthes disease
• Idiopathic osteonecrotic disease of the proximal femoral
epiphysis
• = No known cause of death of tissue
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Document Summary
Inherited myopathy: dystrophies - characterised by degeneration and regeneration, congenital myopathies - microscopic muscle changes, mitochondrial myopathies - due to defects in mitochondria, metabolic myopathies - which result from defects in biochemical. Fibromyalgia: muscle and connective tissue pain, other symptoms may include, debilitating fatigue, sleep disturbance, and joint stiffness, some patients may also report difficulty with swallowing, bowel and bladder abnormalities, numbness and tingling, and cognitive dysfunction. Syndactyly webbing: more serious, absence of a bone phalanx, rib or clavicle, absence of joint or limb. Joint contractures and dislocations produce more severe deformity: congenital deformities are caused by, hereditary influences, external agents radiation, alcohol, drugs, viruses. Spinal: scheuermann"s disease: condition where the vertebrae grow unevenly with respect to the sagittal plane, uneven growth results the signature wedging shape of the vertebrae, causing kyphosis. Idiopathic osteonecrotic disease of the proximal femoral epiphysis: = no known cause of death of tissue, unknown cause but may be associated with acute trauma, manifestations.
