Clinical Neurophysiology

Question 1

what is clinical neurophysiology?

Answer 1

Diagnostic Specialty
Like radiology but looks at nerve function
Plenty of patient contact
But only for the “diagnostic puzzle”
“Practical Physiology”
Work with children and adults, medicine and surgery.
No in-patients, often no on-call!

Question 2

what are sensory studies?

Answer 2

Similar technique stimulating the sensory nerve fibres in the fingers allows measurement of sensory and motor function separately.

Question 3

what and where is ulnar neuropathy?

Answer 3

Site
Most often at the elbow
Occasionally at the wrist
Ulnar distribution numbness
Note dorsal cutaneous branch
Wasting of small muscles, esp FDI

Question 4

what is myaethenia gravis?

Answer 4

Antibodies to post-synaptic ACh Receptor.
Decrease effectiveness of released ACh
Present with weakness, fatigue, normal sensation.

Weakness may be generalised.
Often affects eyes
Diplopia
Ptosis

Question 5

diagnosing myaethenia gravis

Answer 5

Detect Antibodies (takes some weeks, only +ve in 70%)
Neurophysiology
Repetitive stimulation
Single fibre EMG

Question 6

what is EMG?

Answer 6

Routine EMG looks at action potentials from whole motor units.

Question 7

how is EMG different?

Answer 7

SF EMG uses filter, sensitivity and timebase settings to isolate the action potentials from individual muscle fibres within one motor unit.

Question 8

why is EMG useful?

Answer 8

Needle can be positioned to record from two fibres within the same motor unit.
Normally little variation in time of firing between two such fibres.

Question 9

what else do neurophysiology do?

Answer 9

EEGs
Assess brain function
Recording electrical activity generated by cortical neurons across multiple points on the scalp.