PNS disorders

Question 1

Peripheral senses with heavily myelinated fibers

Answer 1

Touch
Vibration
Proprioception

Question 2

Peripheral senses with less myelinated or unmyelinated fibers

Answer 2

Pain and temperature

Question 3

Mildest grade of peripheral nerve injury where axonal continuity is maintained

Answer 3

Neuropraxia

Question 4

Causes of neuropraxia

Answer 4

Compression
Ischemia
Metabolic derangement
Demyelinating disease

Question 5

Peripheral nerve injury grade where axon is damaged, but there is preservation of surrounding CT

Answer 5

Axonotmesis

Question 6

Wallerian degeneration

Answer 6

Axon and myelin degeneration distal to site of injury

Question 7

Characteristics of central chromatolysis

Answer 7

Swelling of neuronal body
Disruption of Nissl granules in center
Displacement of nucleus to periphery

Question 8

Peripheral nerve injury grade characterized by complete nerve transection

Answer 8

Neurotmesis

Question 9

Benign painful nodular thickening that can be produced by failure of the outgrowing axons to find their distal target

Answer 9

Traumatic neuroma

Question 10

Acute peripheral neuropathy timing

Answer 10

<4 weeks

Question 11

Subacute peripheral neuropathy timing

Answer 11

4-8 weeks

Question 12

Chronic peripheral neuropathy timing

Answer 12

> 8 weeks

Question 13

Pattern of peripheral nerve injury characterized by several nerves in a haphazard fashion

Answer 13

Mononeuropathy multiplex

Question 14

Another name for Guillain Barre syndrome

Answer 14

Acute inflammatory demyelinating polyneuropathy (AIDP)

Question 15

Rapidly evolving, areflexic, motor paralysis with or without sensory disturbance of PNS. Ascending, symmetric, flaccid paralysis

Answer 15

Guillain Barre syndrome

Question 16

Complication of lower cranial nerve involvement in Guillain Barre syndrome

Answer 16

Causes bulbar weakness with difficulty in handling secretions and maintaining an airway

Question 17

Antibodies implicated in Guillain Barre syndrome

Answer 17

Against unidentified myelin antigens and GM1/GD1b

Question 18

Histology shows endoneurial inflammatory infiltration in PNS

Answer 18

Guillain Barre syndrome

Question 19

Nerve conduction study findings in Guillain Barre syndrome

Answer 19

Slow conduction velocity
Prolonged distal latency
Preserved amplitude

Question 20

CSF analysis shows albumino-cytological dissociation with normal cell count and elevated proteins. There is little to no CSF pleocytosis.

Answer 20

Guillain Barre syndrome

Question 21

Treatment for Guillain Barre syndrome

Answer 21

Plasmapheresis and IV immunoglobulin

Question 22

Types of infectious polyneuropathies

Answer 22

Leprosy
Diphtheria
Shingles

Question 23

Pathophysiology of leprosy polyneuropathy

Answer 23

Schwann cells are invaded by Mycobacterium leprae

Question 24

Segmental demyelination, remyelination, and loss of both myelinated and unmyelinated axons, often affecting superficial cutaneous nerves of the ears and distal limbs

Answer 24

Leprosy

Question 25

Pathophysiology of diphtheria polyneuropathy

Answer 25

Exotoxin

Question 26

Mutation in CMT type 1

Answer 26

Peripheral myelin protein PMP22 in chromosome 17p12 leading to formation of unstable myelin

Question 27

Pt presents between first to third decade with distal symmetrical leg weakness and calf atrophy, sensory loss, and pes cavus.

Answer 27

CMT type 1

Question 28

Nerve conduction study findings in CMT type 1

Answer 28

Decreased conduction velocity

Question 29

Nerve biopsy shows segmental demyelination and remyelination with onion bulb formations

Answer 29

CMT type 1

Question 30

Defect in CMT type 2

Answer 30

Mitofusin 2

Question 31

Secondary vascular changes in diabetic polyneuropathy

Answer 31

Diabetic microangiopathy Endoneurial arteriole hyalinization

Question 32

Pt presents with distal, ascending, symmetric, sensorimotor neuropathy with loss of pain and temperature. Non-healing ulcers are present on the feet.

Answer 32

Diabetic polyneuropathy

Question 33

Autonomic features of diabetic polyneuropathy

Answer 33

Postural hypotension Erectile dysfunction Gastroparesis

Question 34

Nerve biopsy findings in diabetic neuropathy

Answer 34

Axonal degeneration Endothelial hyperplasia Occasional perivascular inflammation

Question 35

EMG findings in diabetic neuropathy

Answer 35

Reduced amplitudes Mild to moderate slowing of conduction velocities

Question 36

Characteristics of neuropathy associated with uremic nephropathy

Answer 36

Length-dependent numbness and tingling Allodynia Mild distal weakness

Question 37

Allodynia

Answer 37

Pain to a stimulus that does not normally produce pain

Question 38

Characteristics of generalized sensorimotor neuropathy associated with chronic liver disease

Answer 38

Numbness and tingling Minor weakness in the distal aspects

Question 39

Sural nerve biopsy findings in neuropathy associated with chronic liver disease

Answer 39

Segmental demyelination Axonal loss

Question 40

Presentation of neuropathy associated with vit B12 deficiency

Answer 40

Subacute paresthesias in hands and feet Loss of vibratory and position sense Progressive spastic and ataxic weakness

Question 41

Degeneration of spinocerebellar tract, corticospinal tract, and dorsal columns

Answer 41

Vit B12 deficiency

Question 42

Progressive peripheral nerve injury due to thiamine deficiency

Answer 42

Alcoholic neuropathy

Question 43

Deficiency associated with isoniazid therapy

Answer 43

Vit B6

Question 44

Paraneoplastic neuropathy of direct infiltration is associated with this cancer

Answer 44

Small cell lung cancer

Question 45

Target antigens in direct infiltration paraneoplastic neuropathy

Answer 45

HuD, HuC, Hel-N1 Family of RNA-binding proteins expressed by neurons

Question 46

Antibodies detected in serum in direct infiltration paraneoplastic neuropathy

Answer 46

Anti-Hu antibodies

Question 47

Mononeuropathy associated with neoplasm at the apex of the lung

Answer 47

Brachial plexopathy

Question 48

Mononeuropathy associated with malignant neoplasms in the pelvis

Answer 48

Obturator palsy

Question 49

Reparative lesion at the site of traumatic injury of peripheral nerves that presents as a painful/tender, firm nodule near the stump of the injured nerve

Answer 49

Traumatic neuroma

Question 50

Gross appearance of traumatic neuroma

Answer 50

Circumscribed, grayish-white appearance

Question 51

Disorganized proliferation of nerve fascicles, Schwann cells, and fibroblasts embedded within the scar tissue adjacent to the cut ends of the nerve

Answer 51

Traumatic neuroma

Question 52

Inheritance of spinal muscular atrophy

Answer 52

Autosomal recessive

Question 53

Mutation in spinal muscular atrophy

Answer 53

Defect in SMN1 gene on chromosome 5q causing apoptosis of LMNs

Question 54

Other names for SMA 1

Answer 54

Infantile SMA Werdnig-Hoffman disease

Question 55

Other names for SMA III

Answer 55

Juvenile SMA or Kugelberg-Welander disease

Question 56

Nerves not affected in SMA

Answer 56

CN III, IV, and VI Sacral motor neurons Sensation is preserved