Muscle and Nerve Disease Flashcards
How does myasthenia gravis present?
Fatiguable weakness in the limbs, eyelids, muscles of mastication, talking, SOB or diplopia
What investigations can be done in suspected myasthenia gravis?
Anticholinergic receptor antibody testing
Antimuscarinic receptor antibody testing
Neurophysiology- repetitive stimulation, jitter
CT chest- Thymoma
How is myasthenia gravis managed?
Symptomatic- acetylcholinesterase inhibitor (pyridostigmine)
Immunosupression- Prednisolone, steroid saving agent
Immunoglobulin/plasma exchange
Thymectomy
What are the symptoms of muscular disease?
Weakness of skeletal muscle Shortness of breath Poor swallowing Cardiomyopathy Cramp, pain, stiffness, myoglobinuria In babies: poor suck, feeding, failure to thrive, floopy
What are the signs of muscular disease?
Wasting/hypertrophy
Normal or reduced tone and reflexes
Motor weakness but not sensory
What investigations can be used in muscle disease?
History/examination Creatine kinase EMG Muscle biopsy Genetic testing
How do muscular dystrophies present?
Any age onset
Progressive
Cell degeneration gives high creatine kinase
What are the different kind of muscle diseases?
Channelopathies
Muscular dystrophies
Metabolic muscle disease
Inflammatory
What are the causes of generalised peripheral neuropathy?
Hereditary Metabolic- diabetes, alcohol, renal, B12 Toxic- drugs Infectious- lyme's, HIV, leprosy Malignancy Inflammatory- Guillain Barre,
What are the signs and symptoms of nerve disease affecting a nerve root?
Myotomal wasting and weakness
Reflex change
Dermatomal sensory change
What are the signs and symptoms of nerve disease affecting an individual nerve?
Wasting and weakness of innervated muscle
Specific sensory change
What are the signs and symptoms of generalised peripheral neuropathy?
Sensory and motor symptoms, usually starting distally and moving proximally
What investigations can be useful in nerve disease?
Blood tests Genetic analysis Nerve conduction studies Lumbar puncture Nerve biopsy
How does motor neurone disease present?
A unique combination of upper and lower motor neurone lesion signs
LMN- Muscle fasciculations, wasting and weakness
UMN- Increase tone, brisk reflexes
~10% have cognitive decline
What is the usual prognosis for motor neurone disease?
3-5 years from onset of symptoms
2-3 years from diagnosis
50% die within 14 months of diagnosis
