Lecture 19 Muscle and Nerve Disease Flashcards
Symptoms of muscle disease
• Weakness of skeletal muscle
– Short of breath (respiratory muscles)
– Poor swallow / aspiration (bulbar muscles)
• Cardiomyopathy
• Cramp, pain, stiffness, myoglobinuria
(Babies: poor suck / feeding / failure to thrive / floppy)
Signs of muscle disease
- Wasting / hypertrophy
- Normal or reduced tone and reflexes
- Motor weakness…NOT sensory
Muscle Disease Investigation
• History and examination • Creatine Kinase (CK) • EMG- Electromyography (EMG) Muscle bx Genetic Testing
What are the groups of muscle disease classification
Congenital/genetic
Acquired
Name Congenital/Genetic muscle diseases
Muscular dystrophies
Congenital Myopathies
Channelopathis
Enzyme/mitochondira
Name Acquired Muscle Diseases
– Metabolic (Ca2+, K+)
– Endocrine (thyroid, adrenal, vit D)
– Inflammatory muscle disease
– Iatrogenic: medication (steroids / statins)
Describe Channelopathies
- disorders of Ca2+, Na+, K+ and Cl- channels
- often paroxysmal symptoms e.g. periodic paralysis / myotonia
- partially treatable
Early exercise induced metabolic myopathy
Disorders of carbohydrate metabolism
Mitochondrial problems- partially treatable
Late exercise induced metabolic myopathy
Disorders of lipid metabolism
Mitochondrial problems- partially treatable
Name 2 inflammatory muscle diseases
Polymyositis
Dermatomyositis
What are the symptoms of Inflammatory muscle disease
- Acute or subacute, painful, weak muscles
* Characteristic rash of DM
Investigations for inflammatory muscle disease
• High CK, autoantibodies, tumour screen (esp DM)
• EMG & biopsy
– Polymyositis: CD8 cells
– Dermato: humeral-mediated, B cells and CD4 cells
Whats the treatment to inflammatory muscle disease
Immunosuppression
What is Myasthenia Gravis
Disorder of neuromuscular junction
Clinical presentation of Myasthenia Gravis
Fatiguable weakness Ptosis Diplopia Bulba (chew, swallow, talk) Breathinh
Investigations for disorders of the neuromuscular junction
- AChR, Anti MuSK antibodies
- Neurophysiology (Repetitive stimulation, Jitter)
- CT chest (thymoma)
Treatment of Myasthenia Gravis
• Symptomatic
– Acetylcholinesterase inhibitor (pyridostigmine)
• Immunosuppression
– Prednisolone
– Steroid saving agent (e.g. azathioprine)
• Immunoglobulin / plasma exchange
• Thymectomy
What does the peripheral nerve consist of
• Sensory axons – Small fibres (pain + temperature) – Large fibres (joint position sense + vibration) • Motor axons • Autonomic axons • Nerve sheath (myelin)
Causes of generalised peripheral neuropathy
– Hereditary – Metabolic: diabetes, alcohol, renal failure, B12 – Toxic: drugs – Infectious: Lyme, HIV, leprosy – Malignancy: paraneoplastic – Inflammatory demyelinating: Acute = Guillain Barre syndrome Chronic = chronic inflammatory demyelinating polyneuropathy
Nerve root disease symptoms
– Myotomal wasting and weakness
– Reflex change
– Dermatomal sensory change
Individual nerve disease symptoms
– Wasting and weakness of innervated muscle
– Specific sensory change
Symptoms of generalised neuropathy
– Sensory and motor symptoms, usually starting distally and moving proximally
Investigations of Nerve disease
- Blood tests
- Genetic analysis
- Nerve Conduction Studies
- Lumbar puncture (CSF analysis)
- Nerve biopsy (nb sensory nerve)
Treatment of nerve problem
• Treat the cause eg stop drug, surgery, immunoglob
