Neurophysiology, Plexopathy, Neuropathy

Question 1

For giant axonal neuropathy, describe the following:

1. inheritance pattern
2. disease mechanism
3. presentation
4. pathology seen on nerve analysis
5. mutation of what gene?
6. prognosis

Answer 1

1. AD
2. disease that affects the intermediate filaments of both CNS and PNS
3. sensory motor axonal neuropathy, corticospinal tract involvement with UMN signs, optic atrophy/vision loss, walking on inner edge of feet, tightly curled hair
4. large focal axonal swelling that contain tightly packed disorganized neurofilaments
5. mutation in GAN gene
6. progressive, death occurs by adolescence

Question 2

What is Refsum’s disease? Describe it’s inheritance pattern, symptoms (8), and treatment?

Answer 2

AD perioxisomal disorder due to defect in enzyme involved in fatty metabolism –> leads to accumulation of phytanic acid

sx: retinitis pigmentosa, cardiomyopathy, skin changes, large fiber sensorimotor neuropathy, hearing loss, anosmia, ataxia, cerebellar signs
txt: reduce dietary intake of phytanic acid

Question 3

Draw the brachial plexus

Answer 3

Question 4

Describe for each reflex which spinal nerve roots are involved

Answer 4

Reflex - Main Spinal Nerve Roots Involved

Biceps - C5, C6

Brachioradialis - C5, C6

Triceps - C6, C7, C8

Patellar - L2, L3, L4

Achilles Tendon - S1

Question 5

Localize

Answer 5

Question 6

Localize

Answer 6

Question 7

Localize

Answer 7

Question 8

Localize

Answer 8

Question 9

Localize

Answer 9

Question 10

Localize

Answer 10

Question 11

Localize

Answer 11

Question 12

Localize

Answer 12

Question 13

Localize

Answer 13

Question 14

Localize

Answer 14

Question 15

Localize

Answer 15

Question 16

Localize

Answer 16

Question 17

Describe the neoplasm and presentations associated with the following anti-bodies:

(1) anti-hu
(2) anti-voltage-gated calcium channel
(3) anti-Yo
(4) Anti-Ri
(5) anti-MAG

Answer 17

(1) Anti-Hu - peripheral neuropathy or other neurological manifestations; SCLC
(2) anti-voltage-gated Ca channel - LEMS; SCLC
(3) anti-Yo - cerebellar degeneration; ovarian carcinoma
(4) anti-Ri - opsoclonus-myoclonus +/- ataxia; lung or breast cancer
(5) anti-MAG - demyelinating neuropathy; MGUS

Question 18

What is multifocal motor neuropathy?

Presentation? (2)

CSF analysis?

antibody associated with this disease?

results of NCS?

treatment?

Answer 18

• purely motor demyelinating neuropathy
• presents with asymmetric weakness from involvement of individual peripheral nerves, hypo or areflexia in the affected nerves. No sensory symptoms.
• CSF will have normal protein levels
• associated with Anti-GM1 antibodies
• NCS will show conduction block. sensory NCS will be normal
• txt: poor response to steroids and PLEX. txt with IVIg

Question 19

Function of tibialis anterior?

Answer 19

ankle dorsiflexion

Question 20

Function of peroneus longus?

Answer 20

ankle eversion

Question 21

Function of tibialis posterior?

Answer 21

anke inversion

Question 23

Function of gastrocnemius?

Answer 23

ankle plantarflexion

Question 24

Function of gluteus medius?

Answer 24

hip abduction