Examination of peripheral nervous system By Dr. Usama Ragab

1. Email: usamaragab@medicine.zu.edu.eg
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2. The neurology story is…
What is the lesion?
Where is the
lesion?
What is the cause?

4. PNS
• Cranial nerves: 12 pairs
• Spinal nerves: 31 pairs
• Peripheral nerves
Contain: sensory, motor and
autonomic neurons

5. Peripheral neurology
• Root: Radiculopathy
• Multiple roots: Polyradiculopathy
• Plexus: Plexopathy
• Individual peripheral nerves:
Mononeuropathy
• Multiple, multifocal: mononeuritis
multiplex
Affection
of any
part of
the PNS

7. Definition of neuropathy
• Generalized term including disorders of any cause affecting PNS
• May involve sensory nerves, motor nerves, autonomic or any combo
• May affect one nerve (mononeuropathy), several nerves together
(polyneuropathy) or several nerves not contiguous (Mononeuropathy
multiplex)
• Further classified into those that primarily affect the cell body (e.g.,
neuronopathy or ganglionopathy), myelin (myelinopathy), and the axon
(axonopathy)

8. Patterns of neuropathy

9. Length
dependent
polyneuropathy
= progressive

10. Mononeuropathy
• Focal involvement of a single nerve and implies
a local process:
Direct trauma
compression or entrapment
vascular lesions
neoplastic compression or infiltration

11. Mononeuritis multiplex

12. Polyneuropathy
• Characterized by symmetrical, distal motor and
sensory deficits that have a graded increase in
severity distally and by distal attenuation of
reflexes
• Rarely predominantly proximal: (e.g., acute
intermittent porphyria).
• The sensory deficits generally follow a length-
dependent stocking-glove pattern

13. Most common causes
Disease Prevalence
Diabetes 11 – 41% (depends on duration, type &
control)
Paraproteinaemia 9 – 10%
Alcohol misuse 7%
CKD 4%
Vitamin B-12 deficiency 3.6%
HIV infection 16% (depending on the population studied,
usually much lower)
Chronic idiopathic axonal neuropathy 10 – 40% of different hospital series
BMJ 2010:341:c6100

14. Importance of history
• The temporal course of a neuropathy varies, based on the etiology:
With trauma or ischemic infarction, the onset will be acute, with
the most severe symptoms at onset.
Inflammatory and some metabolic neuropathies have a subacute
course extending over days to weeks.
A chronic course over weeks to months is the hallmark of most
toxic and metabolic neuropathies.

15. Importance of history (cont.)
• A chronic, slowly progressive neuropathy over many years occurs
with most hereditary neuropathies or with chronic inflammatory
demyelinating polyradiculoneuropathy (CIDP).
• Neuropathies with a relapsing and remitting course include CIDP,
acute porphyria, Refsum's disease, hereditary neuropathy with
liability to pressure palsies (HNPP), familial brachial plexus
neuropathy, and repeated episodes of toxin exposure.

16. Importance of history (cont.)
• Ischemic neuropathies often have pain as a prominent feature.
• Small-fiber neuropathies often present with burning pain, lightning-
like or lancinating pain, aching, or uncomfortable paresthesias
(dysesthesias).
• Careful past medical history, looking for systemic diseases that can be
associated with neuropathy, such as diabetes or hypothyroidism

17. The clinical response to sensory nerve injury
Loss of function
-ve symptoms
Disordered Function
+ve symptoms
Sensory “Large Fiber” ↓ Vibration
↓ Proprioception
Hyporeflexia
Sensory ataxia
Paresthesias
Sensory “Small Fiber” ↓ Pain
↓ Temperature
Dysesthesias
Allodynia

18. The clinical response to motor nerve injury
Loss of function
-ve symptoms
Disordered Function
+ve symptoms
Motor “Large Fiber” Wasting
Hypotonia
Weakness
Hyporeflexia
Orthopedic deformity
Fasciculation
Cramps

19. The clinical response to autonomic nerve injury
Loss of function
-ve symptoms
Disordered Function
+ve symptoms
Autonomic
nerves
↓ Sweating
Hypotension
Urinary retention
Impotence
Vascular color changes
↑ Sweating
Hypertension

20. Most PN
Length-dependent
Sensory > motor
Mild or moderate

21. Length-dependent
(Distal) Sensorimotor PN
• Most prevalent pattern
• Clinically symmetric:
Stocking, glove sensory loss
• Proprioception generally preserved
unless severe
• Weakness distal > proximal
• DTRs reduced distally > proximally

22. Peripheral Neuropathy –
Clinical Wise
• It will present by the 3 following
manifestations in difference combinations:
Motor
Sensory
Autonomic

23. Regardless of the cause of the
polyneuropathy, the clinical picture is
essentially the same; variations
depend on whether the motor,
sensory or autonomic features
predominate

24. Prominent motor or sensory neuropathy
Motor neuropathy Sensory Neuropathy
GBS Alcoholic neuropathy
Lead poisoning Arsenic neuropathy
Diphtheric neuropathy Leprotic neuropathy
Porphyria Diabetic neuropathy
Vitamin Deficiency

25. Sensory system in PN
1. History: pain and paresthesia in the limbs, specially distally.
2. Examination:
- Superficial sensory impairment of the stock and glove
nature.
- Deep sensory loss specially distally with absence of deep
reflexes

26. Sensory affection
Superficial Sensation Deep Sensation
Component Pain
Touch
Temperature
Muscles
Irritation Pain, paresthesia Tender muscle
Destruction Lost superficial sensation Lost deep reflexes
Sensory ataxia

27. Sensory
system
examination

28. What to examine?
Superficial Sensation
Deep Sensation
Cortical Sensation

29. Examination of the sensory system includes

30. 1- Superficial
sensation
• Pain using a pin
• Touch using cotton
• Temperature: test tube with
cold or warm water

31. How to…
1. Compare side by side
2. Compare above and below in same side
3. Compare distal and proximal in same limb
4. Circumferential comparison

32. Compare Side by side
• Compare both sides of body between right
& left side; starting with healthy side
At the level of: Head, trunk (chest), UL
(arm), LL (Leg)
Value: Hemi-anesthesia (hemiplegia)

33. Compare above and below in same side
• Compare between Head, trunk (chest, abdomen), UL
(arm), LL (Leg) of same side and after finishing do the
opposite side:
Better UL (arm) & upper trunk (chest), less in
lower trunk (abdomen) & LL (Leg)= extra-
medullary lesion- sensory level of paraplegia
(detect the level)
Better in LL (Leg) & lower trunk (abdomen) less in
upper trunk (chest) & UL (arm)= intramedullary
lesion (jacket sensory loss)

34. Compare distal and proximal in
same limb
• Compare distal with proximal part of the
same limb, after finishing do the opposite
side:
Value: detect the level of stocking &
glove hypoesthesia in peripheral
neuropath

35. Circumferential
comparison
• Circumferential comparison
between lateral, medial, posterior
aspects of the limb, after
finishing do the opposite side:
If sensation is defective in one
dermatome: radicular sensory
loss in that dermatome as in
cauda equina

36. If the 4 above screening
tests were normal =
intact superficial
sensation

37. Dermatomal distribution
C2 Angle of jaw, lateral neck.
C3,4 Shoulder, down manubrium.
C5 Lateral aspect of arm.
C6 Lateral aspect of the forearm, thenar eminence & thumb.
C7 Middle aspect of the forearm, middle of the palm, middle 3 fingers.
C8 Medial aspect of forearm, hypothenar eminence & little finger.
T1 Medial aspect of arm.
T2 → T7 Thorax (T4 = nipple).
T8 → T12 Abdomen (T10= umbilicus), (T6= costal margin), (T12= inguinal ligament).

38. Dermatomal distribution (cont.)
L1 Upper 1/3 front of thigh.
L2 Middle 1/3 front of thigh.
L3 Lower 1/3 front thigh.
L4 Anterolateral aspect of thigh, front of knee, anteromedial aspect of leg,medial aspect
of foot & big toe.
L5 Lateral aspect of thigh, lateral aspect of leg, middle 1/3 of dorsum of foot & middle 3
toes.
S1 Posterolateral aspect of thigh & leg, lateral 1/3 of dorsum of foot & little toe.
S2 Posterior aspect of thigh, leg & sole of the foot.
S3,4,5 Anal, perianal & gluteal region (saddle shaped area) in concentric manner.

39. Dermatomal distribution (cont.)

40. Pattern of sensory loss

41. 2- Deep
Sensation
Examination

42. Deep sensation
1. Vibration Sense
2. Position and movement
(joint) sense
3. Nerve
4. Muscle

43. Vibration sense
• Tuning fork 128
• Start on forehead to test thalamus
Upper limbs Lower limbs
• Styloid process of
radius: PN
• Clavicle: posterior
column (PC)
• Forehead: thalamus
Medial malleolus: PN
ASIS: PC
Forehead: thalamus

44. Muscle sense
• Squeeze the calf muscle.
• Loss of muscle sense. Called Abadie's sign
as in neurosyphilis
• Tender calf muscle in:
Diabetic P.N.
Nutritional P.N.
D.V.T.
Myositis
GBS

45. Joint (Position) sense
• First learn the patient: position
and whether finger is moved or
not
• Ask patient to close his eye and
test position and movement
• Caught finger or toe gently

46. Nerve sensation
• By pressing the ulnar nerve
and the lateral popliteal nerve
against the bones.
• Normally, it results in an
electric like sensation.

47. Romberg sign
• Ask the patient to stand with the heels
together, 1st with his eyes open, then with
his eyes closed.
• Note any swaying or loss of balance.
• If present:
With eyes open or closed = cerebellar
ataxia.
Only with closed eyes = sensory
ataxia.

48. Cortical Sensation

49. Cannot be
examined due to
loss of superficial
sensation

50. Cortical sensation
• They are only examined when the superficial and deep sensation are
intact with open and closed eyes.
1. Tactile localization
2. Two-points discrimination
3. Stereognosis
4. Graphesthesia
5. Perceptual rivalry

51. Don’t forget to ask patient to close his eye
They are tested on healthy side

52. Tactile
localization
•Prick and ask where

53. Two-point
discrimination
• Prick 2 places and ask
where

54. Stereognosis
• Recognize familiar objects
within hands

55. Graphesthesia
• Recognize letter or
number on your hand

56. Perceptual
rivalry
• 2 simultaneous pricks in 2
corresponding sites

57. Motor affection in PN
1. Weakness or paralysis of LMN nature (wasting, hypotonia,
hyporeflexia ...).
2. The weakness and wasting are:
- Bilateral and symmetrical.
- Affecting L.L. more than U.L.
- Affecting distal muscles more than proximal muscles.
- Affecting extensors more than flexors, affecting
adductors more than abductors

58. Motor affection in PN (cont.)
3. The weakness in the extensors of the distal group of muscles
leads to bilateral foot drop and wrist drop.
4. The ankle reflex is lost while the knee reflex is preserved.
5. The cranial nerves may be affected specially CN 3, 6, 7 and
10.
6. The gait is high steppage due to the foot drop.

59. Motor
affection

60. Muscle wasting

61. Reflexes in peripheral neuropathy
• It should be differentiated from deep
sensory loss
• In PN: there is loss of distal reflexes and
preserved proximal one
• Example: lost ankle preserved knee
reflex

62. Knee
reflex

63. Ankle
reflex

64. PN= high
steppage
gait

65. Sensory ataxia=
stamping gait

66. Autonomic features of PN
1. Vasomotor: coldness and cyanosis of the
limbs.
2. Cutaneous: loss of hair, brittle nails, trophic
ulcers.

67. Autonomic
dysfunction tests
1. Heart rate variability with deep
breathing
2. Valsalva maneuver and Valsalva ratio
3. Tilt table testing

69. Email: usamaragab@medicine.zu.edu.eg
Slideshare: https://www.slideshare.net/dr4spring/
Mobile: 00201000035863