Lecture 36 Clinical Neurophysiology

Question 1

What is EMG- Electromyography used to investigate

Answer 1

Problems of peripheral nerve and muscle

Question 2

What is EEG Electroencephalogram used to investigate

Answer 2

Electrical activity within the brain, investigate epilepsy and states of altered consciousness

Question 3

What is Evoked potential used to investigate

Answer 3

Visual and somatosensory, investigate problems in central pathways

Question 4

What does conductive velocity tell us about the nerves

Answer 4

State of myelination

Question 5

What does amplitude during conduction studies tell us about the nerves

Answer 5

Transmission of electrical impulse through nerves

Question 6

What is Myasthenia Gravis

Answer 6

• Antibodies to post-synaptic ACh Receptor.
• Decrease effectiveness of released ACh
• Present with weakness, fatigue, normal sensation.
• Weakness may be generalised
• Often affects eyes
o Diplopia
o Ptosis

Question 7

How is Myasthenia Gravis Diagnosed

Answer 7

Detect antibodies
Single EMG fibre
Routine EMG- whole motor units

Question 8

What is a Jitter

Answer 8

In NM disease the tight relationship between single fibres within motor units are lost
instead of reaching threshold, touches broad top

Question 9

What is the use of EEGs

Answer 9

• Look at brain function to allow diagnosis of
– Epilepsy
– Altered states of consciousness
– Non-epileptic attacks
– Facilitate medical or surgical treatment for epilepsy