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Flashcards in Peripheral Nervous System - Sachen Deck (74)
1

3 layers of peripheral nerve connective tissue

- Epineurium - whole nerve
- Supplied by vasa nervorum
- Perineurium - fascicles
- Endoneurium - fibers

2

A-alpha fibers

Large, proprioception and somatic motor

3

A-beta fibers

Large-ish, touch and pressure

4

A-gamma fibers

Medium, muscle spindle motor

5

A-delta fibers

Small-ish, pain/cold/touch

6

B fibers

Small-ish, pre-ganglionic autonomics

7

C fibers

Tiny, UNMYELINATED, pain/temp/reflexes, post-ganglionic sympathetics

8

2 main fiber types in peripheral neuropathies (NOT including DM)

A-alpha
C fibers

9

Parts of a peripheral nerve that can be affected (6)

- Cell body
- Nerve root
- Axon
- Myelin sheath
- Connective tissue
- Blood supply

10

Wallerian degeneration

Sever a nerve --> distal degeneration

11

Most common cervical nerve roots affected by a radiculopathy (w/ percentages)

Most common lumbosacral nerve roots affected (w/ percentages)

C7 = 60%
C6 = 25%

L5 = 50%
S1 = 45%

12

Causes of radiculopathy

Structural - discs, osteophytes, tumors, etc

Non-structural - DM, infections (ex. WNV), etc

13

Pain in shoulder
Loss of sensation in lateral arm
Weak shoulder abduction
Loss of biceps reflex

C5 radiculopathy

14

Pain in shoulder
Loss of sensation in lateral arm and digits 1, 2
Weak shoulder abduction and elbow flexion
Loss of biceps +/- brachioradialis reflexes

C6 radiculopathy

15

Shoulder/arm/forearm pain
Loss of sensation in 3rd digit
Weak UE extension muscles
Loss of triceps reflex

C7 radiculopathy

16

Shoulder/arm/forearm pain
Loss of sensation in digits 4, 5
Weak finger abduction and flexion

C8 radiculopathy

17

Pain in knee, anterior lateral thigh, medial calf
Loss of sensation in medial calf
Weak hip flexion, knee extension

L4 radiculopathy

18

Pain in dorsal thigh, lateral calf
Loss of sensation in lat calf, dorsal foot
Weak hamstrings, anterior leg mm

L5 radiculopathy

19

Pain in posterior thigh and calf
Loss of sensation in lateral calf and lateral foot
Weak hamstrings and posterior leg muscles

S1 radiculopathy

20

Cervical nerve roots exit (above/below) the numbered vertebra

Above (C5 root btwn C4 & C5)

21

Thumb/index finger

C6

22

Middle finger

C7

23

4th/5th finger

C8

24

Medial forearm

T1

25

Nipple line

T4

26

Umbilicus

T10

27

Inguinal area

L1

28

Medial calf

L4

29

Lateral calf

L5

30

Lateral foot and posterior calf

S1

31

Medial thigh

S2

32

Paresthesias and motor/reflex symptoms (pins and needles, numbness) are secondary to what fibers?

Large myelinated fibers

33

Pain and temp symptoms are secondary to what fibers?

Small unmyelinated fibers

34

4 types of pain symptoms w/ peripheral neuropathy (w/ definitions)

- Burning
- Dysesthesia (pain on gentle touch)
- Hyperalgesia (lower threshold to pain)
- Hyperpathia (elevated threshold, but excessively felt)

35

6 motor symptoms w/ peripheral neuropathy

- Weakness
- Cramps
- Fasciculations
- Atrophy
- Decreased DTRs
- Reduced tone

36

Paresthesia of half of 4th finger

Paresthesia of ALL of 4th finger

Median nerve issue

C8 radiculopathy

37

4 places for ulnar neuropathy

- Axilla (crutches)
- Elbow (behind medial epicondyle)
- Cubital tunnel
- Guyon's canal (wrist)

38

Froment sign

Ulnar neuropathy - grabs piece of paper w/ flexed thumb IP joint

39

Wrist drop, can't extend fingers

Radial neuropathy - compression as it winds around humerus (saturday night palsy)

40

Most common entrapment neuropathy of LE

Most common causes?

Peroneal (fibular) nerve -- at fibular head

- Sick patient lying on side for long period of time
- Sitting legs crossed

41

Distinguishing L5 radiculopathy and peroneal nerve neuropathy

Other tip-offs to radiculopathy

Ankle inversion (post. tib. m)
- Normal = Peroneal nerve
- Abnormal = L5

Hip pain, back pain, thigh pain

42

Patient gets IM injection in butt...most common neuropathy?

How to avoid?

Sciatic

Inject in UPPER-OUTER quad.

43

Posterior dislocation of the hip...possible neuropathy?

Sciatic

44

Pregnant woman giving delivery in lithotomy position...possible neuropathy?

Femoral (inguinal ligament)

45

Patient has numbness and tingling along anterolateral thigh...neuropathy?

Cause?

Lateral femoral cutaneous

Tight clothing or weight gain around waist

46

Pain down lateral thigh, foot-drop, absent S1 reflex

Sciatic neuropathy

47

Foot drop, weak eversion, lost sensation to dorsum of foot

Peroneal (fibular) neuropathy

48

Weak knee extension, absent patellar reflex

Femoral neuropathy

49

Sensory loss in sole of foot

Posterior tibial neuropathy (tarsal tunnel syndrome)

50

Peripheral neuropathies can involve ___, ___, ___, and ___

Motor
Sensory
Cranial nerves
Autonomics

51

Peripheral polyneuropathy presents where?

Symmetric stocking-glove distribution of symptoms

52

3 big categories of KNOWN causes of peripheral neuropathies

- Hereditary
- Toxins/meds
- DM

53

4 metabolic/endocrine causes of peripheral neuropathy

DM, hypothyroid, uremia, porphyria

54

Patient w/ severe abdominal pain, can't find abdominal cause or psychiatric cause. Diagnosed by neurologist.

Porphyria

55

Infectious causes of peripheral neuropathy (7)

Mono, hepatitis, Lyme disease
HIV, leprosy, syphilis, VZV

56

Immune-mediated causes of peripheral neuropathy (4)

Guillan-Barre
Chronic inflam. demyel. poly.
Multifocal motor neuropathy
Paraproteins (monoclonal gam)

57

Vitamin deficiency causes of peripheral neuropathy (5)

B1, B6, **B12, E, Copper

58

Toxic causes of peripheral neuropathy

Alcohol
Heavy metals
Organic compounds

59

Vasculitic causes of peripheral neuropathy

RA, SLE, PAN

60

Child/teenager
Difficulty walking/running
Lower leg atrophy and foot deformities
Skeletal deformities
Arreflexia, mild sensory loss

Inheritance?

Charcot-Marie-Tooth type 1

Autosomal dominant

61

How does CMT type 2 differ from type 1? (2)

- Adult onset
- Axonal loss, but normal nerve velocities

62

Acute/subacute ascending motor paralysis, recent illness or surgery or immunization

Infectious causes? (5)

Guillan-Barre

EBV, Mycoplasma pneumonia, C. jejuni, HIV, Hodgkin's

63

Treating Guillan-Barre

Supportive (swallowing, respiratory, infection, DVT)

Plasmapheresis, IVIg

64

Bad symptoms of G-B that must be watched for and treated

Respiratory difficulty, sudden drops in BP

65

Poor prognosis in G-B

Axonal damage

66

Miller-Fisher Syndrome -- what is it?

- Symptoms?
- Labs?

5% variant of G-B

- Ophthalmoplegia, ataxia, arreflexia
- GQ1b antibody

67

G-B that persists for 2+ months, symmetric distal involvement, progressive

Treatment?

CIDP

**IVIg, steroids, plasma exchange

68

Adult w/ slowly progressive distal weakness of hand, no sensory or UMN symptoms. Slowly involves other nerves. GM-1 antibody.

Treatment?

Multifocal motor neuropathy

IVIg

69

Possible presentations of DM neuropathy (7)

- Distal sensorimotor
- Cranial nerve (3, 6, other)
- Mononeuropathy (ex. CT)
- Mono multiplex
- Autonomic
- Lumbosacral plexopathy
- Radiculopathy

70

DM CN3 palsy vs. Compression CN3 palsy

DM = normal light reflex
Comp = bad light reflex

71

HIV neuropathy presentations (3)

- Distal symmetric poly
- Guillan-Barre
- CIDP

72

aANCA
Anti-MAG antibodies
Anti-GM1 antibodies
Anti-GQ1b antibodies
Hu antibody

- Systemic vasculitis
- MGUS
- Multifocal motor neuropathy
- Miller Fisher syndrome
- Carcinoma sensory neurop

73

Important blood tests to get in peripheral neuropathy

CBC, chemistry, Glc, ESR, antibodies
SPEP -- looking for spikes
B12/Folate

74

EMG/NCV can be used to distinguish what?

Specific diagnoses with this?

Axonal vs. demyelinating neuropathy

GBS, CMT, MMN