Nerve

Question 0

EMG findings 5 weeks after denervation?

Answer 0

High number of fibrillation potentials.

Question 1

EMG findings in normal muscle?

1. With maximal voluntary contraction?
2. At rest?
3. Sharp waves?
4. Fibrillations?

Answer 1

1. Full recruitment
2. Little/no spontaneous activity
3. Absent sharp waves
4. Little/ no fibrillations

Question 2

EMG findings indicating re innervation?

Answer 2

Polyphasic action potentials.

Question 3

Findings in nerve root avulsion?

Answer 3

Intact sensory nerve action potentials despite insensate patient.

Paraspinals denervated.

Question 4

What is a Martin Gruber anastomosis and what are the four types and their prevalence?

Answer 4

It is a motor connection between the median (or anterior interosseous) nerve and the ulnar nerve.

Type 1: 60% Median to Ulnar to Median intrinsics
Type 2: 35% Median to Ulnar to Ulnar intrinsics
Type 3: 3% Ulnar to Median to Median intrinsics
Type 4: 1% Ulnar to Median to Ulnar intrinsics

Question 5

What is the nerve of Henle?

Answer 5

The sympathetic nerve branch that accompanies the ulnar artery through the forearm

Question 6

Define CMAP

Answer 6

Compound muscle action potential

The electrical potential that is created with stimulation of the motor nerve

Question 7

Define SNAP

Answer 7

Sensory nerve action potential

The sensory potential that is created with stimulation of the sensory nerve

Question 8

Define distal latency

Answer 8

The time it takes the nerve to conduct from the point of stimulation to the active electrode over the muscle or to another electrode over the sensory nerve

Question 9

Define temporal dispersion

Answer 9

In cases of myelinopathy, the electrical impulses travel at divergent speeds in the individual axons across a lesion, resulting in temporal dispersion. This occurs when the wave form that is achieved with stimulation proximal to the lesion is 20% to 30% longer than the wave form that results from stimulation of the nerve distal to the lesion.

Question 10

What are the three zones in Guyon’s canal, and what is the significance of compression in each zone?

Answer 10

Zone I–Mixed motor and sensory

Zone II–Motor only

Zone III–Sensory only

Question 11

Osteonecrosis

1. MRI findings?
2. Pathology specimen?
3. Names in:
   A. Scaphoid
   B. Lunate
   C. Capitate
   D. Capitellum
   E. Tarsal Navicular
   F. Proximal Femur

Answer 11

1. Dark on T1 and on T2
2. Empty lacunae
3. A. Preiser’s Disease
   B. Kienbock
   C. (no name in Green’s)
   D. Panner’s Disease (osteochondrosis deformans capitelli humeri)
   E. Kohler’s Disease
   F. Perthe’s Disease

Question 12

What is the name for the nerve connection between the median and ulnar nerves at the thenar level?

Answer 12

The Riche-Cannieu communication.

Question 13

What is the optimal amount of time to wait for recovery before considering reconstructive surgery after spinal cord injuries?

Answer 13

12 months