PNS Pathology Flashcards
What is dysesthesiae?
-that tingly feeling when your arm falls asleep -symptom of sensory neuropathy
What is a mononeuropathy?
-neuropathy involving a single nerve
What is a mononeuropathy multiplex?
-a collection of mononeuropathies
What is a polyneuropathy?
-neuropathy in symmetric bilateral nerves -symptoms begin distally
Whats the difference between a neuropathy and a radiculopathy?
-Radiculopathy has dermatomal distribution, radiculopathy is peripheral nerve territory
What does electromyography test?
-spontaneous and evoked electrical activity in skeletal muscle
What does nerve conduction velocity test?
-velocity AND amplitude of compound action potentials
What is are the nerve conduction velocity test findings in demylenating neuropathies vs. axonal neuropathies?
Demylenating: -Conduction velocity reduced -Amplitude Dispersed Axonal: -Conduction velocity normal -reduced amplitude
What are the usual causes of axonal neuropathy?
-Toxic/metabolic neuropathies -Hyperglycemia in Diabetes -EtOH -Arsenic
What are the usual causes of axonal neuropathy?
-Guillian Barre Syndrome (acquired) -Charcot marie tooth disease (genetic)
What are the differences between neuropathic and myopathic changes on a muscle biopsy?
Neuropathic: -individual (angular) atrophic fibers -fiber type grouping -group atrophy Myopathic: -fiber size variability -basophilia -central nuclei -splitting -macrophages -fibrosis
What is the normal distribution of red vs white muscle fibers in a muscle biopsy?
-mixed randomly =mosaic distribution
What are the two broad disease processes involved in mopathy?
-Degenerative (i.e. dystrophy) -Inflammatory (i.e. myositis)
What is the difference between Duchenne’s and Becker’s dystrophies?
Duchenne’s:
- severe
- early onset
- rapid progression
Becker’s:
- Milder
- Later onset
- slower progression
On what chromosome is the dystrophin gene carried?
-X chromosome
