Clinical neurophysiology Flashcards
What do EMGs detect?
Problems with peripheral nerves and muscle
What does an EMG measure?
Conduction velocity
Amplitude
How is an EMG carried out?
Very fine needle inserted into muscle to record activity
What does a routine EMG look at?
Action potentials from whole motor units
What does a single fibre EMG look at?
Isolate Paps from individual muscle fibres within a motor unit
How does a single fibre EMG record 2 fibres within 1 unit?
2 needle positions
Filter, sensitivity and timebase settings
What would a normal single fibre EMG result be?
Little variation
What would a single fibre EMG result be in NMJ disease?
Jitter- tight relationship lost
What does an EEG record?
Electrical activity within the brain generated by cortical neurones across multiple points on the scalp
What can be seen on an EEG?
Epileptic activity
States of consciousness
Encephalopathy
What are the types of evoked potentials?
Visual
Somatosensory
What do evoked potentials investigate?
Problems in central pahways
What do sensory studies allow measurement of?
Sensory and motor function seperately
What is the process of sensory studies?
Stimulate sensory nerves in fingers
What are the signs and symptoms of ulnar neuropathy?
Ulnar distrubution numbness
Wasting of small muscles