2.5 Neuropathology of Peripheral Nerve Disorders

Question 1

• Schwann cell or myelin damage, preserved axons devoid of myelin
• remyelination: shorter internodes and thin myelin
• sequential episodes lead to onion bulbs

Answer 1

segmental demyelination

Question 2

• axonal injury, leads to secondary myelin loss
• caused are focal (trauma, ischemia), or generalized (metabolic, toxic, hereditary)
• histo shows distended axon, degenerating organelles and dense bodies

Answer 2

axonal degeneration

Question 3

Acute inflammatory demyelinating polyradiculopathy (AIDP) is also known as what syndrome?

Answer 3

guillan-barre

Question 4

• symptoms: proximal muscle weakness with rapid ascending paralysis, often cranial nerve involvement
• incidence increases with age, peaks in 60s

Answer 4

AIDP/Guillan Barre

Question 5

about 2/3 of patients with Guillan Barre have an antecedent ______________ illness

Answer 5

influenza like

Question 6

inflammation and demyelination of peripheral nerves and spinal roots
-treatment is supportive care, IVIG, plasmapheresis

Answer 6

AIDP/Guillan Barre

Question 7

• proximal and distal weakness, sensory change, hyporeflexia over 2 months or more
• subacute, chronic course
• progressive or relapsing/remitting
• corticosteroids, IVIG, or plasma exchange
• histo: lymphocytic infiltrates, thinly myelinated axons, macrophages, onion bulbs

Answer 7

Chronic inflammatory demyelinating polyradiculoneuropathy (CIPD)

Question 8

• symmetric polyneuropathy with loss of pain
• Schwann cells infected by ________
• demyelination/remyelination

Answer 8

lepromatous leprosy, M. leprae

Question 9

• exotoxin related weakness, parasthesias

- demyelination

Answer 9

diptheria

Question 10

• latent virus travels sensory nerves to skin
• sensory ganglia neuronal degeneration
• axonal degeneration follows

Answer 10

varicella zoster

Question 11

• most common hereditary peripheral neuropathy, hypertophic
• demyelinating
• chromosomal duplication of chromosome 17, PMP22 trisomy

Answer 11

charcot-marie-tooth

Question 12

• distal lower extremity weakness, wasting
• onset usually by age 20
• distal muscle weakness, atrophy, decreased reflexes, hammertoes
• increased size of nerve fascicles with reduced large and small myelinated fibers
• onion bulbs

Answer 12

charcot-marie-tooth

Question 13

• distal symmetric sensorimotor neuropathy
• axonal neuropathy, relative loss os small myelinated fibers, unmyelinated fibers
• thickening of small arterioles

Answer 13

diabetic neuropathy

Question 14

• affects cutaneous or peripheral nerve

- can be solitary or plexiform

Answer 14

neurofibroma

Question 15

plexiform neurofibroma associated with ______ which produces the protein __________-

Answer 15

NF-1, neurofibromin

Question 16

autosomal dominant, deletion of tumor suppressor gene that produces neurofibromin, features are neurofibromas, gliomas of optic nerve, lisch nodules, cafe au lait spots

Answer 16

NF-1

Question 17

• arise de novo of from plexiform neurofibroma
• have directionality, pleomorphism, celullarity, large chromatin
• mitotic figures

Answer 17

malignant peripheral nerve sheath tumor (MPNST)

Question 18

• neural crest derived, benign, compress
• NF2 association
• encapsulated
• locations in CPA or spinal cord

Answer 18

Schwannoma

Question 19

shwannomas show _____________ patterns and ______ bodies

Answer 19

antoni A and B, verocay