0814 - Neural Compression Syndromes?

Question 1

How are the myotomes of the upper limb laid out? Each one?

Answer 1

Proximal to distal
Shoulder - C5
Arm - C56 (flex), C7 (ext)
Forearm - C78
Intrinsic hand - T1

Question 2

How are the myotomes of the lower limb laid out? Each one?

Answer 2

Anterior proximal-distal pattern, and composed solely of lumbar roots. Posterior pattern lags 2 roots behind anterior pattern.
Anterior - Hip Flexion L23, Knee Extension L34, Ankle dorsiflexion L45
Posterior - Hip extension L45, knee flexion L5S1, ankle plantar flexion S12

Question 3

What nerve are you testing with the reflex - biceps jerk?

Answer 3

C5 (6)

Question 4

What nerve are you testing with the reflex - brachioradialis?

Answer 4

C6

Question 5

What nerve are you testing with the reflex - Triceps jerk?

Answer 5

C7

Question 6

What nerve are you testing with the reflex - finger jerk?

Answer 6

C8 (absence can be normal)

Question 7

What nerve are you testing with the reflex - knee jerk?

Answer 7

L4

Question 8

What nerve are you testing with the reflex - ankle jerk?

Answer 8

S1

Question 9

What is cauda equina syndrome?

Answer 9

compression of most of the descending nerve roots within the lumbar spinal canal. Most commonly caused by central lumbar disk prolapse, or benign/malignant neoplasm.

Question 10

What are the typical characteristics of cauda equina syndrome?

Answer 10

What are the typical characteristics of cauda equina syndrome?
Saddle area sensory loss (S2-5)
Disdended, atonic bladder
Constipation/faecal incontinence
Loss of erectile function
May have weakness in sacral myotomes.

Question 11

What are the two most common causes of radiculopathy?

Answer 11

Compression at neural exit foramen due to disk prolapse/facet joint hypertrophy/osteophytes (most commonly cervical, then lumbar, thoracic, sacral)
Compression of the descending root within the central canal (lumbar more than sacral)

Question 12

Which root is most commonly affected in a radiculopathy - named after vertebra above or below the pathology?

Answer 12

Named after lower vertebra Throughout, for 2 different reasons.
In neck - disk compresses the root as it exits, and root is named after the lower vertebra (except C8)
In lumbar/back - the disk usually compresses the root that exits one body below the pathology (roots exit in upper foramen, lower gets impinged).

Question 13

What are the typical symptoms of a radiculopathy?

Answer 13

Sensory - pain and alteration of sensation in affected dermatome.
Motor - LMN weakness in affected myotome and attenuated reflex for it.
Associated - Back pain, lumbar/cervical muscle spasm etc.