Chapter 28: PNS

Question 1

A 52 yo patient presents with dizziness, bilateral sensorineural hearing loss, and tinnitus. On further investigation and imaging, you discover schwannomas. What inherited genetic disorder is he likely to have? What tumor cell marker is present?

Answer 1

NF2

Tumor cells are S-100 positive

Question 2

Your patient was recently diagnosed with type II diabetes mellitus. She has heard about potential nerve complications of the disease and is wondering what she should look out for in the future. What do you tell her?

Answer 2

Peripheral neuropathies from diabetes can manifest as:

• distal sensorimotor polyneuropathy (symmetric)
• autonomic neuropathy
• mononeuropathy
• mononeuropathy multiplex

** Distal sensory polyneuropathy is the most common type associated with diabetes (also most common associated with HIV infection)

Question 3

A 40 yo female presents with severe pain and a swelling on her leg stump. She had a recent amputation of her left leg above the knee due to a crush injury during a plane crash. Her surgical site seems to be well healed and there is no sign of infection; what could be causing the severe pain?

Answer 3

Traumatic neuroma: Regenerating axons growing haphazardly into the scar tissue

Question 4

You’re on neurology service and the attending pimps you:

• benign, slowly growing tumor
• neoplastic cells are Schwann cells
• when associated with a certain genetic disorder, may degenerate to malignant peripheral nerve sheath tumor

What is the tumor and what is the associated genetic disorder?

Answer 4

Neurofibromas, associated with NF1

Question 5

A 15 yo presents with slowly progressive weakness and loss of sensation in the glove and stocking distribution pattern. When you do the workup, you notice demyelination and onion bulbs. What hereditary disease and subtype do you suspect?

Answer 5

Charcot-Marie-Tooth Disease, subtype 1

** slowly progressive distal sensorimotor polyneuropathy presenting in child/early adult

Question 6

A 21 yo presents to the ER with paralysis in her upper and lower extremities. You notice her speech is a bit slurred and her smile is not full. She has had a fever and bloody diarrhea for the past three days, but had been beginning to feel better. Her CSF protein is increased. What is the likely diagnosis?

Answer 6

Acute Inflammatory Demyelinating Polyradiculoneuropathy (Guillain-Barre syndrome).

• immune-mediated neuropathy that often follows bacterial, viral, or mycoplasmal infection.
• causes acute symmetric neuromuscular paralysis
• can affect any/all levels of PNS
• usually resolves 2-4 weeks after onset