Clinical Neurophysiology Flashcards
What are some clinical neurophysiology investigations?
- Nerve conduction studies/Electromyography (EMG)
- To investigate problems of peripheral nerve and muscle
- EEG
- Electrical activity within the brain, investigate epilepsy and states of altered consciousness
- Evoked potentials
- Visual and somatosensory, investigate problems in central pathways
What does EMG stand for?
Electromyography
What do nerve conduction studies/Electromyography (EMG) investigate?
Problems of peripheral nerve and muscle
What does EEG investigate?
- Electrical activity within the brain, investigate epilepsy and states of altered consciousness
What does evoked potentials investigate?
Visual and somatosensory, investigate problems in central pathways
What does nerve conduction studies examine?
- Conduction velocity
- Level of myelination
- Amplitude
- How many working nerves
What does the conduction velocity in nerve conduction studies indicate?
- Level of myelination
What does the amplitude in nerve condition studies indicate?
How many working nerves there are
How are nerve conduction studies performed?
Measurement of activity is taken at two different points of nerve (such as along arm) and the distance measured, this can be used to work out the conduction time and velocity
How are sensory studies performed?
Similar technique to nerve conduction studies stimulating the sensory nerve fibres in the fingers to allow for measurement of sensory and motor function separately
What is ulnar neuropathy?
disorder involving the ulnar nerve, may be caused by entrapment of the ulnar nerve
Where is the site of ulnar neuropathy normally?
- Most often at the elbow
- Occasionally at the wrist
What is the clinical presentation of ulnar neuropathy?
Ulnar distribution numbness
Wasting of small muscles, especially FDI
First thing that occurs with a trapped nerve in demyelination, which causes the action potential to decay and die away, progressing slowly (known as conduction block)
Conduction velocity should be measures in different parts of the nerve path, slow areas are where the neuropathy occurs
Amplitude of sensory fibres becomes small because has lost axons
What is seen in investigations for ulnar neuropathy?
First thing that occurs with a trapped nerve in demyelination, which causes the action potential to decay and die away, progressing slowly (known as conduction block)
Conduction velocity should be measures in different parts of the nerve path, slow areas are where the neuropathy occurs
Amplitude of sensory fibres becomes small because has lost axons
How does ulnar neuropathy impact conduction velocity?
Conduction velocity should be measures in different parts of the nerve path, slow areas are where the neuropathy occurs