This topic covers disorders of the spinal cord (injury, compression) and of peripheral and cranial nerves (Guillain-Barré syndrome, peripheral neuropathy, postherpetic neuralgia, trigeminal neuralgia, Bell palsy).

Spinal cord injury (SCI)

• Causes: motor vehicle crashes, falls (especially older adults), violence, sports and diving. Common sites are the cervical (C5–C7) and thoracolumbar (T12–L1) regions.
• Primary injury (the mechanical damage) is followed by secondary injury — edema, ischemia, and inflammation over hours to days — which treatment aims to limit.
• Complete injury: no motor or sensory function below the level, including the lowest sacral segments. Incomplete injury: some function preserved. The ASIA Impairment Scale grades A (complete) to E (normal).

Incomplete cord syndromes

Level and function

• C3–C5 innervate the diaphragm ("C3, 4, 5 keeps the diaphragm alive") — injury at C3 or above usually requires permanent ventilation; C4–C5 injuries often need temporary support.
• Cervical injury → tetraplegia; thoracic or lower → paraplegia.

Spinal shock vs. neurogenic shock

• Spinal shock: temporary loss of all reflexes, flaccid paralysis below the injury; lasts days to weeks; return of reflexes (e.g., bulbocavernosus) marks its end.
• Neurogenic shock: injury at T6 or above disrupts sympathetic outflow → hypotension, bradycardia, warm dry skin (vasodilation), poikilothermia.

Autonomic dysreflexia (AD) — a life-threatening emergency in clients with injury at T6 or above, most often after spinal shock resolves, though it can occur early. A noxious stimulus below the injury (most often bladder distension, then bowel impaction, pressure injuries, tight clothing, ingrown toenail) triggers massive sympathetic discharge below the level. Vasoconstriction causes sudden severe hypertension; the body attempts to compensate with bradycardia, and above the level the client has a pounding headache, flushing, sweating, nasal congestion, and blurred vision. Uncontrolled BP can cause stroke, seizures, or death.

Neurogenic bladder after SCI

• Upper motor neuron (reflex, spastic) bladder: injury above the sacral micturition center (S2–S4) — the bladder empties reflexively and without control → reflex incontinence; often with sphincter dyssynergia and retention.
• Lower motor neuron (flaccid, areflexic) bladder: injury at the conus or cauda equina — bladder does not contract → retention with overflow.

Guillain-Barré syndrome (GBS) — acute immune-mediated inflammatory demyelinating polyneuropathy, often 1–4 weeks after a respiratory or GI infection (e.g., Campylobacter jejuni) or other trigger. Ascending, symmetric weakness that starts in the legs, with absent or reduced reflexes, paresthesias, and pain. It can progress over days to respiratory and bulbar paralysis. Autonomic instability (BP swings, dysrhythmias) is common. Most clients recover over weeks to months.

Peripheral neuropathy — damage to peripheral nerves, most often from diabetes, alcohol, vitamin B12 deficiency, chemotherapy, HIV, or kidney disease. Typically a symmetric "stocking-glove" sensory loss, tingling, burning pain, and distal weakness.

Postherpetic neuralgia — persistent pain after herpes zoster (shingles) in the same dermatome: burning, stabbing or shooting pain along the dermatome, and allodynia (pain from light touch such as clothing).

Trigeminal neuralgia (CN V) — brief, severe, electric shock-like facial pain in one or more branches, usually one side, triggered by light touch, chewing, talking, cold air, or brushing teeth. Often due to vascular compression of the nerve root; in a young adult, consider MS.

Bell palsy (CN VII) — sudden (over hours to 72 hours) one-sided weakness of the entire face, including the forehead; inability to close the eye, drooping mouth, drooling, taste change, hyperacusis. Presumed viral. Most recover within weeks to months.

Spinal cord compression from tumor (often metastatic) or epidural abscess — back pain is usually the first symptom, followed by weakness, a sensory level that rises as compression progresses, and bladder or bowel dysfunction. An oncologic emergency.

SCI: motor and sensory level (dermatomes), respiratory effort and vital capacity, BP and heart rate, bowel and bladder function, priapism, skin.

Autonomic dysreflexia: severe hypertension (systolic 20–40 mmHg or more above baseline — baseline may be as low as 90–110), pounding headache, flushing and sweating above the injury, pale cool skin below, bradycardia, nasal stuffiness, anxiety.

GBS: symmetric ascending weakness and areflexia — for example, weak ankle and toe extension, sensory loss in both legs, absent leg reflexes with arm reflexes still present early on; facial weakness; dysphagia; declining vital capacity; labile BP and heart rate.

Peripheral neuropathy: loss of protective sensation (monofilament test), unnoticed foot injuries, balance problems.

Bell palsy: whole-face weakness on one side (forehead included — distinguishes it from stroke); dry eye.

Acute SCI

• Spinal immobilization until injury is ruled out; log-roll; rigid cervical collar; surgical decompression and stabilization, ideally early (within 24 hours).
• Maintain perfusion: current guidance suggests keeping MAP at least 75–80 mmHg and no higher than 90–95 mmHg for 3–7 days after acute SCI, with fluids and vasopressors (e.g., norepinephrine). Older protocols used 85–90 mmHg — follow the ordered target.
• Bradycardia from neurogenic shock: atropine; pacing if severe.
• Methylprednisolone is not routinely given; if used, only within 8 hours and per institutional policy, because of infection and GI bleeding risk.
• VTE prophylaxis (low-molecular-weight heparin once bleeding risk allows, compression devices) — SCI carries very high VTE risk.

Autonomic dysreflexia (emergency sequence)

1. Sit the client upright and lower the legs (orthostatic drop lowers BP).
2. Loosen tight clothing, abdominal binders, and leg bags.
3. Monitor BP every 2–5 minutes.
4. Check the bladder first: if an indwelling catheter is present, check for kinks and unblock or irrigate; if none, catheterize using lidocaine gel.
5. If systolic BP remains at or above about 150 mmHg after the bladder is managed, give the ordered fast-acting, short-duration antihypertensive before checking the bowel (e.g., nitroglycerin paste above the injury level — not within 24–48 hours of a PDE-5 inhibitor such as sildenafil; or immediate-release nifedipine or captopril per protocol), because rectal stimulation can worsen the crisis.
6. Then check the bowel for impaction (with lidocaine gel), then skin (pressure, ingrown toenail, tight shoes). Monitor BP for at least 2 hours after resolution and watch for hypotension once the trigger is removed.

GBS

• IV immunoglobulin (IVIG) or plasma exchange — equally effective; start early. (Corticosteroids are not effective.) IVIG: headache, thrombosis, kidney injury, anaphylaxis in IgA deficiency. Plasma exchange: hypotension, bleeding, hypocalcemia, line complications.
• Intubation for falling vital capacity (e.g., below about 20 mL/kg), NIF weaker than about −30 cm H₂O, or bulbar weakness.
• Cardiac monitoring for autonomic instability; VTE prophylaxis; pain control (gabapentin, carbamazepine, or opioids).

Neuropathic pain (peripheral neuropathy, postherpetic neuralgia)

• First-line: tricyclic antidepressants (amitriptyline, nortriptyline), gabapentinoids (gabapentin, pregabalin), and SNRIs (duloxetine). NSAIDs are largely ineffective for neuropathic pain.
  • TCAs: anticholinergic effects (dry mouth, constipation, urinary retention), orthostatic hypotension, sedation, cardiac conduction effects (avoid after recent MI or with dysrhythmias; caution in older adults), overdose lethality.
  • Gabapentinoids: dizziness, sedation, edema; reduce dose in kidney impairment; respiratory depression when combined with opioids; taper to stop.
  • Duloxetine: nausea, hepatotoxicity, serotonin syndrome with other serotonergic drugs; avoid in severe liver disease.
• Topical lidocaine patches or capsaicin for localized pain (postherpetic neuralgia).
• Prevention: recombinant zoster vaccine for adults 50 and older (and immunocompromised adults 19 and older); early antivirals for acute zoster.

Trigeminal neuralgia: carbamazepine (first-line) or oxcarbazepine — monitor sodium, CBC, and rash (HLA-B*1502 screening in at-risk Asian ancestry). Refractory cases: microvascular decompression, radiofrequency or radiosurgery procedures (which may leave numbness — protect the cornea and mouth).

Bell palsy: oral corticosteroids (prednisolone or prednisone) started within 72 hours improve recovery; antivirals may be added in severe cases but are not used alone. Monitor glucose on steroids.

Spinal cord compression (tumor): high-dose dexamethasone, urgent MRI, radiation and/or surgical decompression.

Listed in priority order.

1. Airway and breathing
   • High cervical SCI and GBS: monitor respiratory rate, vital capacity, NIF, cough strength, and swallowing — continuous respiratory assessment is the top priority in GBS. Assisted ("quad") cough, incentive spirometry, suction; prepare for intubation.
2. Circulation
   • Neurogenic shock: maintain MAP target, treat bradycardia; suctioning and turning can trigger bradycardia in high SCI.
   • GBS: cardiac monitoring for dysrhythmias and BP swings.
   • Autonomic dysreflexia: act immediately — sit up, loosen clothing, check and empty the bladder (open or change a blocked catheter), then bowel and skin.
3. Spinal stability — maintain alignment, log-roll, collar and halo care (pin site care; keep the wrench to release the vest attached for emergencies).
4. Bladder and bowel
   • Intermittent catheterization schedule or indwelling catheter as ordered; keep bladder volumes low to prevent AD and UTI.
   • Bowel program: scheduled time daily, stool softeners, suppository and digital stimulation (with lidocaine gel for T6 and above).
5. Skin and VTE prevention — turn every 2 hours, pressure-redistributing surfaces, compression devices, anticoagulant as ordered.
6. Peripheral neuropathy — protect insensate feet and hands; check bath water temperature with a bath thermometer (or the elbow).
7. Eye protection (Bell palsy, trigeminal procedures) — artificial tears by day, lubricating ointment and taping the eyelid closed at night, sunglasses; protect from corneal injury.
8. Trigeminal neuralgia comfort — room temperature environment, avoid drafts; lukewarm foods and fluids; chew on the unaffected side; soft toothbrush or mouth rinse if brushing triggers pain.
9. Psychosocial — body image, depression, sexuality, rehabilitation goals.

• SCI and AD: know the signs (pounding headache, flushing, sweating, high BP); sit up and look for a full bladder, blocked catheter, constipation, or tight clothing; carry an AD wallet card; call emergency services if BP stays high.
• Bladder program: clean intermittent self-catheterization technique; adequate fluids; UTI signs.
• Peripheral neuropathy foot care: inspect feet daily, using a mirror for the soles, and feel for injuries; wash and dry between toes; wear well-fitting shoes and socks; never walk barefoot; no heating pads; regular podiatry visits; control blood glucose.
• Postherpetic neuralgia: loose soft clothing; take neuropathic pain medications regularly; get the zoster vaccine.
• Bell palsy: eye care is essential until the eyelid closes; facial exercises; most people recover.
• GBS: recovery can take months; rehabilitation; report any new weakness.
• Neuropathic pain drugs: rise slowly (orthostatic hypotension), avoid alcohol, do not stop gabapentinoids suddenly.

• Autonomic dysreflexia (T6 and above): severe hypertension, headache, bradycardia → sit upright, loosen clothing, check bladder/catheter first; if SBP stays ≥ 150, antihypertensive before the bowel check.
• Neurogenic shock: hypotension + bradycardia; MAP target about 75–80 up to 90–95 mmHg for 3–7 days.
• C3–C5 = diaphragm; high cervical injury → ventilatory support.
• Injury above S2–S4 → reflex (spastic) bladder with reflex incontinence; conus/cauda equina → flaccid bladder with retention.
• Anterior cord syndrome: motor and pain/temperature lost, touch and position preserved; central cord: arms worse than legs.
• GBS: ascending symmetric weakness, areflexia, high CSF protein with normal cells; priority = respiratory monitoring; IVIG or plasma exchange; no steroids.
• Neuropathic pain: TCAs, gabapentinoids, SNRIs — not NSAIDs.
• Postherpetic neuralgia: stabbing/burning pain along the dermatome; zoster vaccine prevents it.
• Trigeminal neuralgia: carbamazepine; avoid triggers; chew on the unaffected side.
• Bell palsy: whole side of face including forehead; steroids within 72 hours; eye protection.
• Spinal cord compression: back pain first, then a rising sensory level — emergency.
• Neuropathy: daily foot inspection with a mirror.