22 - Peripheral Neuropathy Evaluation Flashcards Preview

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Flashcards in 22 - Peripheral Neuropathy Evaluation Deck (59):
1

Describe the nature of peripheral neuropathy sensation

Nature
- Usually burning, tingling, electrical sensations, numbness
- May say feet “feel like on fire” or get creepy, crawly sensation

2

Describe the location of peripheral neuropathy sensation

Location
- Early in disease: toes and met heads
- If only a few toes affected, think neuroma or neuritis
- Will work way up foot and leg as disease progresses
Plantar
- B/L or unilateral
- Systemic disease will be B/l
- Mechanical disease/nerve entrapments will be unilateral

3

Describe the duration of peripheral neuropathy

Duration
- Symptoms fairly constant

4

Describe the onset of peripheral neuropathy

Onset
- Gradual onset

5

Describe the course of peripheral neuropathy

- Pain worse at night
- Eventually pain will turn to numbness

6

Describe the aggrevating factors and associated symptoms of peripheral neuropathy

- Derm changes
- Xerosis, fissures, calluses, ulcers
- New foot deformities
- Muscle wasting in severe disease can cause hammering of digits and prominent met heads
- Loss of balance (with eyes closed)
- Temperature changes

7

Describe the treatment of peripheral neuropathy

Treatment
- Sometimes pt will relate massaging area will temporarily help

8

What are some other important questions to ask in the history of a patient presenting with peripheral neuropathy

Other important questions to ask (especially if diabetic)
- Hx of ulceration, amputation or infection
- Type of shoe gear worn in and out of house
- May need to counsel pt on going barefoot or sock foot

9

What do you ask in the prior medical history of peripheral neuropathy patients?

- Most podiatric patient with PN will have DM
- 10% of patients with DM and PN will have other cause for PN

MOST have diabetes***
MOST common cause of peripheral neuropathy

10

What are the causes of peripheral neuropathy?

IM DISTAL

I = idiopathic or inherited
M = metabolic or mechanical

D = drugs
I = infection
S = sarcoidosis
T = toxins or thyroid
A = autoimmune or allergy
L = lack of vitamins

11

Describe idiopathic or inherited causes

Idiopathic = don't know
Inherited = Charcot Marie Toothe

12

Describe metabolic or metabolic causes

Metabolic = most common ***
Mechanical = radiculopathy or nerve entrapments

13

Describe drug causes

Chemotherapy

14

Describe infection causes

Leprosy, myasthenia gravis, syphilis

15

Describe toxin causes

Uremia (dialysis patients), Heavy metals, alcohol

16

Describe autoimmune causes

- Guillain-Barre syndrome
- Lupus

17

Describe lack of vitamin causes

B12 insufficiency (ulcerative colitis, crohn’s)

18

What do you need to ask in the medical history of peripheral neuropathy?

- Back Sx
- Nerve releases
- Carpal tunnel
- Other Orthopedic or Podiatric Sx that may lead to numbness or pain

19

What do you need to ask in the family history?

Does patient have family with
- PN
- DM
- Hx of complications due to above
- Ulcer, amputation, foot infections

20

What do you need to ask in the social history?

Does patient have Hx of
- Alcoholism
- Tobacco use
Will not cause PN but may contribute vascular disease and delayed healing of future ulceration

What is the patient's job and activity level?
Are pain or complications of PN affecting this?
Could job be contributing?

21

What systems will you include in the ROS?

- Endocrine
- Derm
- MSK
- Vascular

22

Describe the endocrine ROS

If Diabetic, what is blood sugar, HgA1c?
High blood glucose can exacerbate symptoms
If not, have they been screened for DM?

23

Describe the derm ROS

Change in skin or nails?
May get dyshydrosis with autonomic neuropathy
Can lead to xerosis and fissuring
Nails can become thickened and dystrophic
Hx of delayed healing, infection, or ulceration

24

Describe the musculoskeletal ROS

Musculoskeletal
Hx of back pain/injury/radiculopathy?

25

Describe the vascular ROS

Vascular
Any cramping in legs with walking?
Does pain at night get better when legs in dependent position?
If yes to one or both, pain likely due to PVD and not neuropathy

26

Describe general ROS

General
Hx of heavy metal exposure

27

Describe GI ROS

GI
Diarrhea, nausea, vomiting
Ulcerative colitis or Crohn’s

28

Describe the parts of the physical exam

- Vascual
- Derm
- MSK
- Neruo

29

Describe the vascular PE

Vascular
Are pedal pulses palpable?
If not, vascular problem may be contributing factor

30

Describe the derm PE

Derm
Note any
xerosis, calluses, nail changes, skin atrophy
scars from previous sx
If ulcer present and patient not complaining of pain, neuropathy very likely present

31

Describe the MSK PE

Musculoskeletal
- Note any amputations
- Clawing of digits and weakness with muscle strength testing
- May indicate motor neuropathy
- Diabetic PN can cause intrinsic muscle wasting and fat pad displacement/atrophy
- Patient may have ataxic gait due sensory loss

32

What things will you do in the neurological exam?

Neurologic exam
- Reflexes
- Tinnel’s
- Vibration
- SWM
- Proprioception
- Sharp/Dull
- Light touch
- Temperature

33

Describe the neurologic exam

Usually sensory loss will be equal and symmetric for one or more tests
Vibration perception diminishes prior to loss SWM sensation
Typical DM PN and other systemic neuropathies will be in stocking/glove pattern***

34

Describe type A fibers

Characteristics
- Heavily myelinated
- 1-20 micrometer diameter
- 15-120 m/sec conduction velocity

Function
- High velocity fibers
- Acute pain, temperature, touch, pressure, proprioception, somatic efferent fibers

35

Describe type B fibers

Characteristics
- Less heavily myelinated
- 1-3 micrometer diameter
- 3-15 m/sec conduction velocity

Function
- Moderate-velocity fibers
- Visceral afferents, preganglionic autonomics

36

Describe type C fibers

Characteristics
- Unmyelinated
- 0.5-1.5 micrometer diameter
- 0.5-2 m/sec conduction velocity

Function
- Slow-velocity fibers
- Postganglionic autonomic, chronic pain

37

Describe the monofilatment test

- 5.07 monofilament which exerts 10 grams of pressure
- Apply only enough pressure to just bend monofilament
- Pt eyes should be closed and should be able to tell where being touched
- Need loss of 4 of 10 areas to diagnose
- If 0/10 felt keep testing up leg to knee to find level of sensation

38

Describe the study about monofilament testing

- Studied 40 healthy college aged students
- Tested 14 plantar and 5 dorsal locations with all 20 monofilaments in set
- Mean sensitivity was 3.63 (approximately 200 mg)
- Showed that inability to feel 5.07 monofilament represented a sensory threshold 50 x’s greater than normal
- 98% of sensory ability lost

39

Describe how you test vibratory perception

- 128 Hz tuning fork
- Apply to 1st and 5th MPJ
- Test at malleoli if not felt
- Also can test at pulp of hallux
- Practitioner should be able to feel for 5 seconds longer than patient
- If more than 10 seconds, nerve damage

Apply to bony prominances ***

40

What is the more sophisticated machine used to test vibratory sensation?

Biothesiometer
- Machine that vibrates at 100 Hz
- Apply tip of device to pulp of hallux
- Adjust voltage from 0-50
- A mean of 3 readings over 25 V indicates PN
- More accurate than tuning fork but not every practitioner has one

41

Describe the study testing biothesiometer

Prospective – case control study
- 30 cases and 85 age matched diabetic controls
- Looked at ability of SWM, biothesiometer testing and UT questionnaire to predict ulceration

Asked questions
- Do your feet ever feel numb?
- Do your feet ever tingle, as if electricity were traveling into your foot?
- Do your feet ever feel as if insects were crawling on them?
- Do your feet ever burn?

This was used to predict ulceration in patients

42

Describe further testing modalities you can use

PSSD
EMG/NCV
MRI
Nerve biopsy
Blood testing

43

Describe a PSSD

- Pressure-Specified Sensory Device
- Device that tests 1 and 2 point discrimination, static and moving
- Is able to test variable grams of force and spacing
- 1-100 grams
- 2.7-25 mm
- Theoretically more accurate than SWM and can test variable stages of neuropathy and nerve entrapments
- Not widely used due to expense and reimbursement issues

44

Describe EMG/NCV

- Can diagnose nerve entrapments and level of dysfunction
- Can distinguish between motor vs. sensory and axonal vs. demyelination
- EMG – electromyography

45

Describe the EMG

EMG
- Involves placing needles in different muscles and recording muscle activity at rest, with minimal and maximum activity
- Muscle should be silent at rest
- If nerve degeneration present, fibrillation and sharp wave discharges at rest will be noted

46

Describe NCV

NCV – nerve conduction velocity
- Electrodes placed on skin that send charges down to peripheral nerves causing contraction of muscles
- Latency recorded - Time it takes to get from stimulus to recording
- Can determine areas of demyelination and areas of nerve lesion or entrapment

47

Describe the use of MRI

Useful if you think that problem is stemming from
- Spinal stenosis
- Lumbar disk disease
- Spinal cord tumor

48

Describe nerve biopsy

- Not often done
- Will definitively show nerve damage and demylenation
- Usually biopsy sural nerve

49

Describe blood testing

- Blood glucose, HgA1c
- B-12, folate
- Heavy metals
- Creatinine, Liver profiles
- ANA

50

Conclusion of pheripheral neuropathy evaluation

- Diabetic neuropathy is the most common cause of PN
- Early diagnosis and diabetes management/education may help slow disease and future podiatric complications
- If suspecting other cause, don’t be afraid to do additional testing and send to appropriate specialist

51

Describe the case study for peripheral neuropathy

45 year old female referred for chronic shooting pain, left worse than right
- Shoots down to right 1st interspace
- Sharp pain, relatively constant

Also has been getting progressive muscle weakness
- Now uses AFO on left
- Right leg has begun to get weaker as well

Has been taking Gabapentin for pain
- Helps minimally

Patient had previous nerve conduction studies done 7 months ago, did not bring record

52

Describe the PE

VASCULAR
Pedal pulses not palpable but easily dopplerable b/l
CFT

53

What may be the cause of her neuropathy?

- Diabetic PN
- Neuroma of the Deep Peroneal Nerve
- Nerve entrapment of the knee or back
- Tarsal tunnel syndrome
- Other systemic cause of PN

54

What is the plan for this patient?

- Patient given sample of Lyrica
- Neurology consult
- MRI of back done per neurology request
- Obtain previous nerve conduction studies

55

Describe the results of the nerve conduction studies

Axonal sensory and motor neuropathy

Possibly due to peripheral neuropathy but could not confirm

56

Describe the MRI and neurology consult results

- MRI showed some spinal stenosis and spondylosis
- Neurologist thought that back issues played some part but DM PN was larger part
- Suggested surgery to the patient to decompress nerves

57

Describe the podiatry follow up

- Patient did not fill Lyrica rx because of expense
- Given Rx of Amitriptyline prior to coming back
- Helped patient to sleep at night but did not take away all of pain
- Patient requested second Neurology opinion because she did not want surgery

58

What was the result of the neurology second opinion?

- Thought impingement was behind knee and not up in the back
- Also thought DM had major role
- Neurologist continued to treat the patient
- Did Sural nerve biopsy
- Neuropathy due to diabetes

59

Describe the final podiatry follow up

- Patient still continues to have pain
- Meds help her to sleep
- Complains of continued weakness
- Pt referred to physical therapy but she did not make an appointment
- Patient lost to follow up