peripheral nervous system disorders for nursing

1. PNS Disorders
Dr BALAJI B S
ASSOCIATE CONSULTANT NEUROLOGY

2. 01-09-2020 2

3. 01-09-2020 3

4. 01-09-2020 4

5. What is the Peripheral Nervous System?
• CNS is confined to brain and spinal cord
• PNS includes (in anatomical order)
– Anterior horn cell (located within spinal cord)
– Spinal nerve roots (radicles)
– Plexi (brachial and lumbosacral)
– Named peripheral nerves (e.g. median, peroneal)
– Tiny nerve endings (sensory fibers and tiny branches of lower motor
axons at the neuromuscular junction)
– Neuromuscular junction
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6. Neuromuscular junction and muscle
Ulnar nerve
Brachial
plexus
C8 spinal nerve root
Anterior horn
cells (LMN)
The PNS
(Emphasizing Motor Structures)

7. Symptoms of PNS Disease
• Single focal lesions: weakness/numbness/ pain in
one limb, often defined to one part of the limb
• Multiple or diffuse lesions: weakness/
numbness/pain in more than one limb, usually
bilateral and distal
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8. Signs of PNS Disease
• Lower motor neuron signs (atrophy, fasciculations)
• Hyporeflexia or areflexia
• Patch of sensory loss, or stocking-glove sensory
loss
• Not UMN signs (spasticity, hyperreflexia, upgoing
toe) or “brain” signs (impaired consciousness,
cognition, or language)
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9. Reflexes… repeated
• Hyperreflexia and spasticity occur with upper
motor neuron lesions (CNS)
• Hyporeflexia, fasciculations, atrophy with
lower motor neuron lesions (PNS)
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10. Workup
• Serologies, especially for treatable causes
• EMG helps localize and characterize lesions of
PNS
• Imaging for some focal lesions, or to exclude CNS
mimics (such as cord lesion or stroke)
• CSF analysis in demyelinating neuropathies, or
polyradiculopathy
• Nerve biopsy
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11. Anterior Horn Cell
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12. Amyotrophic lateral sclerosis
• Anterior horn cells (lower motor neurons) and
upper motor neurons degenerate
• Mix of UMN and LMN signs/symptoms
• Weakness, spasticity, multifocal muscle atrophy
• No sensory loss from ALS!
• Loss of speech, swallow, respiration Death in
2-5 years
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13. Manifestations
• Initial: spastic, weak muscles with increased
DTRs; muscle flaccidity, paresis, paralysis,
atrophy; clients note muscle weakness and
fasciculations; muscles weaken, atrophy; client
complains of progressive fatigue; usually involves
hands, shoulders, upper arms, and then legs
• Atrophy of tongue and facial muscles result in
dysphagia and dysarthria; emotional lability and
loss of control occur
• 50% of clients die within 2 – 5 years of diagnosis,
often from respiratory failure or aspiration
pneumonia

14. Diagnostic Test
• Testing rules out other conditions that
may mimic early ALS such as
hyperthyroidism, compression of spinal
cord, infections, neoplasms
• EMG to differentiate neuropathy from
myopathy
• Muscle biopsy shows atrophy and loss of
muscle fiber
• Serum creatine kinase if elevated (non-
specific)
• Pulmonary function tests: to determine

15. Therapeutic Interventions
 Muscle Relaxants : Central
 Riluzole
 PT/ OT/ ST
 Pain Control
 Tube Feedings
 Prevention of Infection

16. Neuromuscular junction and muscle
Ulnar nerve
Brachial
plexus
C8 spinal nerve root
Radiculopathy

17. Spinal Nerve Root Disorders
• Most common: monoradiculopathy (cervical or lumbosacral)
• Radiating pain, +/- weakness, +/- sensory loss. Reduced reflex
for that root level
• Commonest causes: disk herniation, minor trauma,
degenerative change
• Usually self-limited
• Image if severe, worsening, or concern for cancer, infection
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18. 18

19. G u illa in -B a r r é S y n d r o m e
(G B S )
Acute autoimmune
inflammatory demyelinating
disorder of peripheral
nervous system
characterized by acute
onset of ascending motor
paralysis

20. M a n if e s t a t io n s
• Most clients have symmetric weakness beginning in
lower extremities
• Ascends body to include upper extremities, torso, and
cranial nerves
• Sensory involvement causes severe pain, paresthesia and
numbness
• Paralysis of intercostals and diaphragmatic muscle
• Autonomic nervous system involvement: blood pressure
fluctuations, cardiac dysrhythmias, paralytic ileus,
urinary retention
• Weakness usually plateaus or starts to improve in the
fourth week with slow return of muscle strength

21. Diagnostic Tests
• diagnosis made thorough history
and clinical examination; there is
no specific test
• CSF analysis: increased protein
• EMG: decrease nerve conduction
• Pulmonary function test reflect
degree of respiratory involvement

22. Medical management
• IVIG OR
• Plasmapheresis
• Enteral feeding
• Tracheostomy

23. Neuromuscular junction and muscle
Ulnar nerve
Brachial
plexus
C8 spinal nerve root
Plexopathy

24. Plexopathy
• PNS syndrome in one limb not explained by a single spinal
root, or by a single “named” peripheral nerve
• Causes: trauma or stretch, compression by tumor or
hematoma, radiation, diabetic
• EMG confirms plexopathy
• Image if compressive lesion suspected
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25. Brachial Plexus
behind clavicle, in upper thorax
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26. Lumbosacral
Plexus: Pelvic,
Retroperitoneal
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27. Neuromuscular junction and muscle
Ulnar nerve
Brachial
plexus
C8 spinal nerve root
Mononeuropathy

28. Mononeuropathy
• Weakness, numbness, pain, paresthesias
confined to the distribution of
– UE: median nerve, radial n., ulnar n.
– LE: femoral n., sciatic n., peroneal n.
• Most common causes: entrapment, trauma,
prolonged limb immobility (e.g., surgery)
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29. Important Mononeuropathies
• Median mononeuropathy at the wrist (carpal
tunnel syndrome)
• Ulnar mononeuropathy at the elbow (cubital
tunnel syndrome)
• Radial mononeuropathy (“Saturday night
palsy”) wrist and finger drop
• Peroneal mononeuropathy (e.g., from leg
crossing) one cause of footdrop
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30. Median n.
Ulnar n.
Peroneal n.
Named peripheral nerves have well-defined
sensory territories (and muscle targets)
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31. 31

32. “Peripheral Neuropathy”
• Distal symmetric polyneuropathy
• Affects longest sensory/ motor/ autonomic
nerves
• Nerves are “dying back”
• Length dependent (“stocking glove”)
• Symmetric loss of pain/ temp / vibration/
proprioception; distal reflex loss
• Usually chronic. Many possible causes!
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33. Peripheral polyneuropathy symptoms
• Initially, feet numb with paresthesia/ pain
• Symptoms ascend:  legs fingertips
• Distal weakness (feet, or fingers/grip), atrophy,
• Severe sensory loss can cause “steppage gait”,
“sensory ataxia”, imbalance, falls
• Feet prone to injuries, ulcers, deformation
(e.g., “Charcot foot”)
• Autonomic: orthostasis, bladder and erectile
dysfunction
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34. Causes of peripheral polyneuropathy
• Usually toxic or metabolic
• #1 cause: diabetes & impaired glucose tolerance
• B12 defeciency
• Hematologic (e.g., multiple myeloma) or other immunoglobulin disorders (check
SPEP)
• Drugs: Li, chemotherapy
• Alcoholic neuropathy
• Liver or kidney disease
• HIV and neurosyphilis
• Inflammatory causes: connective tissue disease
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35. Workup for peripheral neuropathy?
• For typical distal symmetric sensory > motor
neuropathy: glucose / Hba1c, B12, SPEP
• Need EMG and more if rapid or severe,
prominent weakness, asymmetry, young
patient

37. Manifestations
Seen in the muscles that are affected:
• Ptosis (drooping of eyelids), diplopia
(double vision)
• Weakness in mouth muscles resulting in
dysarthria and dysplagia
• Weak voice, smile appears as snarl
• Head juts forward
• Muscles are weak but DTRs are normal
• Weakness and fatigue exacerbated by
stress, fever, overexertion, exposure to

38. Diagnostic Tests
• Physical examination and history
• Tensilon Test: edrophonium chloride (Tensilon)
administered and client with myasthenia will
show significant improvement lasting 5 minutes
• SFEMG: senstive
• Antiacetylcholine receptor antibody serum
levels: increased in 80% MG clients; used to
follow course of treatment
• Serum assay of circulating acetylcholine
receptor antibodies: if increased, is diagnostic
of MG

39. Therapeutic Interventions
 Thymectomy- < production of actecycholine antibodies
 Cholinergic Agents- pyridostigmine,
 Steroids- predisone
 Plasmapheresis- remove antibodies from the blood

40. Trigeminal Neuralgia
 Pathophysiology
 Irritation of the trigeminal nerve (5th cranial nerve), affects sensory portion of
nerve
 Etiology
 Irritation or Chronic Compression
 Dx: H&P, CT, MRI

41. Trigeminal Innervation

42. Signs & Symptoms
 Intense Pain on One Side of Face
 Forehead, Cheek, Nose, Jaw
 Triggered by Touch, Talking, Other Stimulation

43. Therapeutic Interventions
 Anticonvulsants
 Nerve Blocks
 Surgery to Block Pain Signals

44. Bell’s Palsy
 Pathophysiology/Etiology
 Inflammation and Edema of Facial Nerve
 Loss of Motor Control
 Etiology Unknown
 Dx: H&P, EMG, rule out stroke

45. Signs & Symptoms
 One Sided Facial
 Pain
 Weakness
 Speech Difficulty
 Drooling
 Tearing of Eye
 Inability to Blink

46. Therapeutic Interventions
 Prednisone
 Antiviral Medication
 Facial physio, facial nerve stimulation
 Eye drops

47. Thank you