Muscle and Nerve Disease Flashcards
Where do UMN originate?
In the cortex
Where do UMN synapse with LMN?
At the anterior horn cell
Where do LMN terminate?
At the muscles
What are the symptoms on muscle disease presentation?
Weakness of skeletal muscle Shortness of breath Poor swallowing Cardiomyopathy Cramp Pain Poor suckling/feeding in babies Myoglobiruria (darkened urine)
What is myoglobinuria?
Darkened urine
What are the clinical signs of muscle and nerve disease?
Wasting Hypertrophy Normal or reduced tone and reflexes Motor weakness Not sensory
What investigations are reuqired for muscle and nerve disease?
history and examination CK EMG Muscle biopsy Genetic testing
Why is genetic testing so important in muscle and nerve disease?
Because so many of these disease are genetic so testing is important
What are the classifications of muscle and nerve disease?
Muscular dystrophies Channelopathies Inflammatory muscle disease Congenital myopathies Iatrogenic (alot of medication now used degenerate and affect the muscle)
Name 3 muscular dystrophies
Duchenne’s MD
Becker’s MD
Myotonic dystrophy
What is the commonest muscular dystrophy?
Duchenne’s MD
Is Duchenne’s MD more common in males or females?
Males
What is Becker’s MD?
A milder form of Duchenne’s MS
What are channelopathies?
Disorders of calcium
Sodium and chloride channels
What are some channelopathie diseases?
Familial hypokalemic periodic paralysis
Hyperkalemic periodic paralysis
Paramyotonia congeintal
What is the commonest channelopathie?
Familial hypokalemic periodic analysis
What is duchenne’s MD?
Genetic disorder characterised by progressive muscle degeneration and weakness
What causes duchenne’s MD?
Absence of dystrophin
What is the prognosis for duchenne’s MD?
Tends to be short survival rates
What are some typical appearances of duchenne’s MD?
Very big calves
Associated with hypertrophy of the muscle
What are symptoms experienced with facioscapulohumeral MD?
Facial weakness
Scapula weakness
Bicep weakness
What is the commonest channelopathie?
Familial hyopkalemic periodic paralysis
How does Familial hypokalemic periodic paralysis often present?
With intermittent symptoms of paralysis and muscle weakness
What is the key investigation during a familial hypokalemic periodic paralysis attack?
Measure potassium levels
What causes hyperkalemic periodic paralysis?
High potassium in the blood
What causes paramyotonia congenital?
Defects in calcium channels and release leading to a sustained depolarisation of muscles
What are the signs of paramyotonia congenital?
Can’t relax muscles
Feel stiff
Especially bad after excercise or cold temperature
What metabolic problems can affect muscles?
Disorders of carbohydrate metabolism
Disorders of lipid metabolism
Endocrinopathy
Biochemical abnormalities
What inflammatory conditions can affect muslces?
Polymyositis
Dematomyositis
What is polymyositis?
Inflammation and degeneration of skeletal muscle throughout the body
What investigations need to be done for inflammatory muscle diseases?
Creatine kinase EMG Inflammation Ð PM: CD8 cells Ð DM: humeral-mediated, B cells and CD4 cells Biopsy
What is the treatment for inflammatory muscle disease?
Immunosuppression
What does myasthenia gravis affect?
Skeletal muscle only
What is the clinical presentation of myasthenia gravis?
Fatiguable weakness Start of fine then progress to become a lot weaker - limbs - eyelids - muscles of mastication - talking (slurred speech) - SOB - Diplopia
What are the investigations for myasthenia gravis?
AChR ab - antibody that block Ach getting onto its receptor Anti MuSK ab Neurophyioslogy CT chest (thoma)
What is the treatment for myasthenia gravis?
Acetylcholinerterase inhibitor
Immunosuppresion
Thymectomy
Immunoglobulin
What causes myasthenia gravis?
Lack of Ach at the neuromuscular junction
How is myasthenia gravis linked to the thymus in the young?
Associated with thymic hyperplasia
How is myasthenia gravis linked to the thymus in the older?
May be associated with malignant thymoma
What are classifications of nerve disease?
Root disease
Lesion of individual peripheral nerve
Generalised peripheral neuropathy
What can cause root disease?
Ð Degenerative spine disease
Ð Inflammation
Ð Infiltration
Give a common disease of the neuromuscular junction?
Myasthenia Gravis
What can cause a lesion of a peripheral nerve?
Compressive/entrapment neuropathy
Vasculitic
What can cause generalised peripheral neuropathy?
DM Alcohol Chronic renal failure B12 deficiency Hereditary Malignancy Inflammatory demyelinating Infection
What is the commonest cause of peripheral neuropathy?
DM
What are the signs and symptoms of nerve root disease?
Ð Myotomal wasting and weakness
Ð Reflex change
Ð Dermatomal sensory change
What are the signs and symptoms of individual nerve disease?
Wasting and weakness of innervated muscle
Specific sensory changes
What is a signs of generalised peripheral neuropathy?
Sensory and motor symptoms starting distally and moving more proximally
What investigations need to be done for nerve diseases?
Blood tests Genetic analysis - Clear family history?? NCS (nerve conduction study) Lumbar puncture (CSF analysis)
Why would you not biopsy a nerve?
Because would generate weakness in the muscle it was supplying
Name a disease of the anterior horn cell?
Motor neuron disease
What are signs and symptoms of motor neuron disease?
Increased tone and brisk reflexes
LMN signs
No sensory involvement
Usually limb onset, later bulbar and respiratory involvement
What is the prognosis for MND?
3-5 years from symptom onset
2-3 years from diagnosis
What is the usual cause of death in MND?
Respiratory failure
What is the treatment for MND/
Supportive (MDT)
Usually patient does not want ventilation
Riluzole
