1. Peripheral Nerve Diseases
Prof. Dr. Ece AYDOĞ
Physical Medicine and Rehabilitation

2. Learning objectives:
be able to define parts of peripheral nervous system
be able to describe injuries in the peripheral nervous system (neuropraxia, aksonotmezis, nörotmezis,)
be able to describe clinical signs of peripheral neuropathy (somatic and autonomic)
be able to classify peripheral neuropathy according to the causes
5.5 be able to describe diagnosis, pharmacological and nonpharmacological treatment approaches for peripheral neuropathy.

3. Peripheral Nervous System (PNS)
The function of the PNS is to carry impulses to and from to central nervous system
These impulses regulate motor, sensory and automotic activities
The peripheral nervous system is comprised of structures which lie outside the pial membrane of the brainstem and spinal cord and can be divided into cranial, spinal and autonomic componenets.

4. The structure of the NERVE CELL and AXON

5. Peripheral Nervous System

6. Structure of a Peripheral Nerve
􀁻 Endoneurium – loose connective tissue that surrounds axons
􀁺 Perineurium – coarse connective tissue that bundles fibers into fascicles
􀁺 Epineurium – tough fibrous sheath around a nerve

7. PNS in the Nervous System

8. Receptor Classification by Stimulus Type
􀁻 Mechanoreceptors – respond to touch, pressure, vibration, stretch, and itch
􀁻 Thermoreceptors – sensitive to changes in temperature
􀁻 Photoreceptors – respond to light energy (e.g., retina)
􀁻 Chemoreceptors – respond to chemicals (e.g., smell, taste, changes in blood chemistry)
􀁻 Nociceptors – sensitive to pain causing stimuli 8

9. The somatic system consists of 12 pairs of cranial nerves
31 pairs of spinal nerves:
8 cervical (C1-C8)
12 thoracic (T1-T12)
5 Lumbar (L1-L5)
5 Sacral (S1-S5)
1 Coccygeal (C0)

10. Spinal Nerves: Roots
􀁻 Each spinal nerve connects to the spinal cord via two medial roots
􀁻 Ventral roots arise from the anterior horn and contain motor (efferent) fibers
􀁻 Dorsal roots arise from sensory neurons in the dorsal root ganglion and contain sensory (afferent) fibers

12. Nerve Plexuses
All ventral rami except T2-T12 form interlacing nerve networks called plexuses
Plexuses are found in the cervical,
brachial, lumbar, and sacral regions
Each resulting branch of a plexus
contains fibers from several spinal nerves
Each muscle receives a nerve supply from more than one spinal nerve
Damage to one spinal segment cannot completely paralyze a muscle

13. Brachial Plexus
Formed by C5-C8 and T1 (C4 and T2 may also contribute to this plexus)
It gives rise to the nerves that innervate the upper limb

14. Lumbar Plexus
Arises from L1-L4 and innervates the thigh, abdominal wall, and psoas muscle
The major nerves are the
Femoral nerves for anterior thigh muscles
Obturator nerves for adductors muscles

15. Sacral Plexus
Arises from L4-S4 and serves the buttock, lower limb, pelvic structures, and the perineum (pudendal nerve)
The major nerve is the sciatic, the longest and thickest nerve of the body
tibial
common fibular (peroneal)

16. Dermatomes
A dermatome is the area of skin innervated by the cutaneous branches of a single spinal nerve
All spinal nerves except C1 participate in dermatomes

17. Pathologies of peripheral nerves
Nerves (Seddon and Sunderland Classification)
Neurapraxia
Axonotmesis
Neurotmesis

18. Total conduction failure (neurapraxia)
No function
Recovers spontaneously over days or weeks (when the cause is resolved)
Results of spontaneous recovery are almost always good 18

19. Neurapraxia 19

20. Interruption of axons (axonotmesis)
No function
New axon grows from cell body (spontaneously) 20

21. Axonotmesis
Nerve may regenerate from injured location away from the cell body
Regeneration: 1 mm per day (approx. 1 inch per month)
Results of spontaneous recovery are good to moderate depending on distance 21

22. Axonotmesis
Type 2
Neurotmesis
Type 3
Type 4
Type 5

23. Interruption of nerve trunk (neurotmesis)
No function
Does not regenerate spontaneously
Irreversible, grafting is required

24. Axonotmesis
Type 2
Neurotmesis
Type 3
Type 4
Type 5 24

25. Peripheral Neuropathy Mode of Onset
Acute
Subacute
Chronic

26. Peripheral Neuropathy
Acute: (A few days-4 weeks)
Guillain-Barre Syndrome (GBS)
Traumatic
Vasculitis
Herpes Zoster
Diphtheria
Porphyria
Toxic (Thallium)

27. Peripheral Neuropathy
Sub-acute: (Devolop over weeks)
Symmetric..Sensory-motor
Toxic
Nutritional (Alcohol)
Paraneoplastic (Sensory neuronopathy)
Asymmetric...Motor-sensory
Vasculitis
Diabetic amyotrophy

28. Peripheral Neuropathy
Chronic:(Devolop over months, years)
1-Acquired
Diabetic distal sensory neuropathy
Leprosy
Autoimmune neuropathies
Para-Neoplastic
Others ( uremia….)

29. Peripheral Neuropathy
2-Hereditary
HMSN ( Charcot-Marie-Tooth )
Refsum’s disease
Hypertrophic polyneuropathy (Dejerine-Sottas disease)

30. Causes
1. Nutritional, metabolic and toxic neuropathies; the most common causes are diabetes mellitus and alcoholism
Vitamin deficiencies,
Renal failure,
Chronic liver disease,
Drugs (e.g. vincristine),
Heavy metals,
Toxins (e.g. diptheria),
Chemicals (e.g. Hexane, glue)
Diabetes - distal symmetric, autonomic and focal or multifocal asymmetric presentations

31. 2-Inflammatory neuropathies
Infectious - shingles (VZV), leprosy
Vasculitic - polyarteritis, SLE
Guillain-Barré
Chronic inflammatory demyelinating polyradiculopathy

32. 3. Hereditary neuropathies
Hereditary sensory, motor and autonomic neuropathies
Leukodystrophies
Porphyria

33. 4. Miscellaneous neuropathies
Amyloid
Paraneoplastic
Compression

35. Mononeuropathies Median nerve- Carpal tunnel Syndrome
Ulnar nerve-Cubital tunnel syndrome
Radial nerve- Spiral oluk tuzak
Posterior interosseous neuropathy
Toracicus longus nerve-Serratus anterior
Winging scapula
Common Peroneal nerve-Fibula head
Lateral femoral cutaneous nerve-Meralgia paresthetica
Tibial nerve-Tarsal tunnel syndrome

36. Plexopathies
Brachial plexus-Erb palsy, Klumpke palsy, Personage-Turner syndrome (idiopathic brachial neuritis)
Lumbosacral plexus

37. Polyneuropathies Diabetic neuropathies
Polyneuropathy (Sensory loss and distal weakness)
Autonomic neuropathy (Postural hypotension, impotence, nocturnal diarrhoea)
Mononeuropathy (Diabetic amytrophy)

38. Polyneuropathies Guillain-Barre Syndrome (GBS):
Acute inflammatory demyelination polyradiculopathy

39. Peripheral Neuropathy Symptomatology-Motor
Weakness:
Lower motor-neuron type
hypotonia & hyporeflexia
fasiculation
wasting (chronic)
distal distribution

40. Peripheral Neuropathy Symptomatology-Motor
Wasting & Deformities:
Chronic > 3 months duration
Kypho-scoliosis
Pes cavus – Clawing of hands & feet
Hereditary Motor-Sensory Neuropathy 40

41. Peripheral Neuropathy Symptomatology-Sensory
Sensory Changes:
Hyposthesia
Parastheasia
Dysthesia
Allodynia
Hyperalgesia 41

42. Peripheral Neuropathy Symptomatology-Sensory
Distribution of sensory changes:
gloves & stocking
root or nerve distribution 42

43. Peripheral Neuropathy Symptomatology-Autonomic
Autonomic manifestations:
Anhydrosis
Postural Hypotension
Bladder Atonia…incontinence
Gut Atonia….diarrhea
Sexual dysfunction

44. History Time course (acute, subacute, chronic, episodic)
Negative: numbness
Postive: tingling, pain
Weakness and loss of function
Balance
Postural dizziness DM
Medication
Social, toxins, diet
Family history

45. Examination/Evaluation
Observation of skin color, integrity, temperature
Presence of pressure points or ulceration
Strength testing
ROM/flexibility testing
Neurological testing
Reflexes
Sensation
Proprioception
Balance/coordination
Foot wear assessment

46. Diagnosis
A strong clinical suspicion will suffice to make a clinical diagnosis. To support the diagnosis some investigatios are necessary these include:
Electromyography
Nerve biopsy
Nerve conduction studies
Magnetic resonance imaging
Computed tomography

47. Special Investigation Nerve conduction studies
Motor conduction velocity
Sensory conduction velocity
Demyelination:
Marked slowing of conduction velocity (30% at least reduced) with progressive reduction of amplitude.
Axonal change:
Reduced amplitude or absence of response to stimulation with mild slowing of conduction velocity
Localized compression of nerve:
Slowing conduction in region of block e.g. Over the elbow when ulnar nerve is compressed there.

48. Special Investigation Electromyography (EMG)
A fine needle is inserted into the muscle and the recorded activity displayed on an oscilloscope.
Primarily of value in muscle disease but can also give indirect evidence of a neropathic process.
If chronic denervation has occured, re-innervation may be present with long duration high amplitude motor unit potentials.

49. Special Investigation Nerve biopsy
In neuropathies of uncertain cause, light and electron microscopy examination occasionally help diagnosis.
The sural nerve is usually chosen for biopsy.

50. Treatment Non pharmacological Patient education
Maintaining optional weight
Avoiding exposure to toxins
Eating a balanced diet
Correcting nutritional deficiencies
Avoiding alchohol consumption
Exercise
Quitting smoking

51. Pharmacological First line treatments Second-line treatments
Antidepressants (i.e., tricyclic antidepressants and dual reuptake inhibitors of both serotonin and norepinephrine)
Calcium channel α2-δ ligands (i.e., gabapentin and pregabalin)
Topical lidocaine
Second-line treatments
- Opioid analgesics and tramadol
Third-line treatments
-Antiepileptic and antidepressant medications, mexiletine, N-methyl-d-aspartate receptor antagonists, and topical capsaicin

52. Physical Therapy and Rehabilitation
 Aerobic conditioning
 Progressive flexibility/stretching exercises
 Progressive strengthening exercises
 Balance/coordination
 Gait training
 Alternative
Monochromatic infrared
Vibrating insoles
Tai chi

53. Aerobic Conditioning

54. Flexibility Exercises
Assessment from trunk to feet
Goal is to normalize muscle length to allow for normal mechanics with movement

55. Strengthening Exercises
Initial focus is on core, hip, knee, and ankle strengthening
Progress into functional activities

56. Balance Exercises

57. Adaptive Devices • Prophylactic measures (eg. pressure sores)
• Orthotics
• Assistive devices
• Walking aids
• Wheelchairs
• Environmental modifications

58. Surgical Options • Tendon transfers, releases
• Procedures for pain relief (eg. ablation, implants)
• Joint stabilization
• Nerve repair, grafts