Muscle & Nerve Diseases Flashcards
How can muscle diseases present?
Weakness of skeletal muscle Shortness of breath Cardiomyopathy Cramp, pain Myoglobinuria Wasting/hypertrophy
Give five of the major muscular dystrophies
Duchenne's MD Becker's MD Facioscapulohumeral MD Myotonic dystrophy Limb-Girdle MD
What type of genetic linkage applies to Duchenne’s?
X linked
What are the Ix for Duchenne’s?
Creatine kinase
Genetic testing
Muscle biopsy
What is a common heart condition associated with Becker’s MD?
Cardiomyopathy
What type of genetic disorder causes myotonic dystrophy?
Autosomal dominant trinucleotide repeat disorders
What is a channelopathy?
A disorder of Ca, Na or Cl
What are three main forms of metabolic muscle disease?
Disorders of carbohydrate metabolism
Disorders of lipid metabolism
Mitochondrial myopathies/cytopathies
What are the two main types of inflammatory muscle disease?
Polymyositis
Dermatomyositis
What skin manifestation is indicative of dermatomyositis?
A characteristic rash
What are the Ix for inflammatory muscle disease?
Creatine Kinase - increased is indicative
EMG
Muscle Biopsy
What is the treatment for inflammatory muscle disease?
Immunosupression
What is the clinical presentation of myasthenia gravis?
Fatiguable weakness - Limbs Eyelids Muscles of mastication Talking SOB Diplopia
What is the Ix for myasthenia gravis?
ACh receptor antibody test
Anti muscle specific kinase (MuSK) antibody test
EMG
Tension test
(CT chest)
What is the symptomatic treatment for Myasthenia gravis?
Acetylcholinesterase inhibitor
What is the long term treatment for myasthenia gravis?
Immunosuppression -
Prednisolone
Steroid saving agent (azathioprine)
What is the link between myasthenia gravis and the thymus?
In young associated with thyme hyperplasia
In old associated with malignant thymoma
What fibres can be affected by peripheral nerve disease?
Sensory axons (first order (ascending)) Motor axons (second order (descending))
What forms of root disease are peripheral nerve diseases?
Degenerative spine disease
Inflammation
Infiltration
Give to forms of lesions of individual peripheral nerves in peripheral nerve disease
Compressive/entrapment neuropathy
Vasculitis
What is generalised peripheral neuropathy?
Disease of the motor or sensory or both types of peripheral nerve, with or without autonomic features
What are the causes of generalised peripheral neuropathy?
Metabolic - DM, alcohol, B12 Toxic - drugs Hereditary Infectious - HIV, leprosy Malignancy - paraneoplastic Inflammatory demyelinating - acute: Guillain Barre chronic: CIDP
What symptoms are caused by nerve root forms of peripheral nerve disease?
Dermatomal sensory changes
Myotomal wasting and weakness
Fasciculations
What symptoms are caused by individual nerve lesion forms of peripheral nerve disease?
Specific sensory change
Wasting and weakness of innervated muscle
Fasiculations
What are the symptoms of generalised peripheral neuropathy?
Sensory and motor symptoms starting distally and moving proximally
What are the investigations for suspected nerve disease?
Blood tests Genetic analysis NCS/EMG LP Nerve biopsy
What type of nerve disease is motor neurone disease?
Anterior/ventral horn cell disease
What unique combination of signs indicates motor neurone disease?
A combination of both UMN and LMN signs
What are UMN signs?
Pyramidal weakness, stiffness, brisk reflexes
What are LMN signs?
Wasting, weakness, muscle fasiculations
What is required for diagnosis of MND?
Unique combination of UMN and LMN diseases
EMG
What is the treatment for MND?
Supportive treatment
Riluzole
