Neurophysiology Clinical Applications ; Lecture

Question 1

What are the three main tests in clinical neurophysiology?

Answer 1

Nerve conduction studies (NCS) and electromyography (EMG).
Electroencephalography (EEG).
Evoked potentials (somatosensory, visual, transcranial magnetic stimulation).

Question 2

Neurophysiology primarily investigates the _________ nervous system, brain, spinal cord, and _________ nerves.

Answer 2

peripheral; optic.

Question 3

True/False: Evoked potentials assess sensory, visual, and motor pathways.

Answer 3

True.

Question 4

What do nerve conduction studies (NCS) measure?

Answer 4

The size and speed of nerve responses.

Question 5

Small responses in NCS indicate _________ loss, while slow responses suggest _________ loss.

Answer 5

axonal; myelin.

Question 6

What condition is characterized by focal slowing across the elbow in NCS?

Answer 6

Ulnar neuropathy.

Question 7

True/False: NCS can differentiate between motor and sensory nerve dysfunction.

Answer 7

True.

Question 8

What does EMG measure?

Answer 8

The electrical activity of individual motor units in muscles using needle electrodes.

Question 9

EMG identifies _________ motor units in nerve pathology and _________ motor units in muscle pathology.

Answer 9

large; small.

Question 10

True/False: EMG is crucial in diagnosing myopathies where NCS may appear normal.

Answer 10

True.

Question 11

What abnormality does EMG detect in Myasthenia Gravis?

Answer 11

Increased “jitter” due to impaired neuromuscular transmission.

Question 12

EMG is more _________ than antibody tests for diagnosing Myasthenia Gravis.

Answer 12

sensitive.

Question 13

What is the primary clinical use of EEG?

Answer 13

Evaluating seizures and epilepsy.

Question 14

Focal EEG abnormalities indicate _________ hemisphere involvement, while generalized abnormalities affect _________ hemispheres.

Answer 14

one; both.

Question 15

True/False: EEG can be used intraoperatively to monitor for changes in brain activity.

Answer 15

True.

Question 16

What is the purpose of intracranial EEG?

Answer 16

To localize seizure origins in patients with medically intractable epilepsy being considered for surgery.

Question 17

What are the three types of evoked potentials?

Answer 17

Somatosensory evoked potentials (SSEPs).
Visual evoked potentials (VEPs).
Transcranial magnetic stimulation (TMS).

Question 18

SSEPs assess the integrity of the _________ columns by stimulating peripheral nerves and recording from the somatosensory cortex.

Answer 18

dorsal.

Question 19

What is the main use of visual evoked potentials (VEPs)?

Answer 19

To assess for demyelination of the optic nerves, commonly in multiple sclerosis (MS).

Question 20

True/False: SSEPs are used in intraoperative spinal cord monitoring

Answer 20

true

Question 21

How does transcranial magnetic stimulation (TMS) work?

Answer 21

A magnetic pulse induces an electric current in the motor cortex, which excites motor pathways and elicits a motor evoked potential in a target muscle.

Question 22

TMS can assess the _________ of the motor cortex and the integrity of _________ motor pathways.

Answer 22

excitability; central.

Question 23

True/False: TMS is only a diagnostic tool.

Answer 23

False (it is also used therapeutically for severe depression).

Question 24

In which conditions are evoked potentials most commonly used?

Answer 24

Multiple sclerosis (MS).
Intraoperative spinal cord monitoring.
Visual pathway assessment.

Question 25

EEG during _________ can classify epilepsy syndromes into focal or generalized types.

Answer 25

seizures.

Question 26

True/False: Large motor units seen on EMG suggest nerve or motor neuron pathology.

Answer 26

True

Question 27

What does NCS evaluate in peripheral neuropathies?

Answer 27

Axonal neuropathies (small responses).
Demyelinating neuropathies (slow responses).

Question 28

EMG is critical for diagnosing conditions like _________, where NCS may appear normal.

Answer 28

myopathies.

Question 29

Why is intraoperative SSEPs monitoring important?

Answer 29

It detects early spinal cord compromise, allowing surgical intervention before permanent damage occurs.

Question 30

True/False: Neurophysiological testing plays a limited role in diagnosing and managing neurological disorders.

Answer 30

False.