Which nerve's electrical stimulation could address the underlying pathophysiology of his symptoms?

Author

Dr. Shoaib Ahmad Baig
December 10, 2024

Question

A 57-year-old man presents with unrefreshing sleep, daytime fatigue, and occasional napping during lunch. His wife reports loud snoring and gasping for breath at night. He has severe claustrophobia, a history of hypertension, and a BMI of 32 kg/m². Examination reveals a bulky tongue and a crowded oropharynx. Blood pressure is 156/94 mm Hg.

Which nerve's electrical stimulation could address the underlying pathophysiology of his symptoms?

  • Hypoglossal

  • Lingual

  • Maxillary

  • Phrenic

  • Recurrent laryngeal

Correct Answer: Hypoglossal Nerve

🧠 Step 1: Understanding the Scenario

  • Patient Clues:

    • 💤 Loud snoring, gasping, and unrefreshing sleep → Think OSA!

      (Obstructive Sleep Apnea)

    • 🔍 BMI ↑ (30 kg/m²) + bulky tongue + narrow oropharynx → Obstructive cause likely

    • 🔍 Hypertension + daytime fatigue → Consequence of fragmented sleep

    • ⚖️ Severe claustrophobia → CPAP intolerance, alternative treatments needed.

🧠 Underlying Cause
⬇
Obesity (BMI ↑)
⬇
Bulky tongue & crowded oropharynx
⬇
Narrowed upper airway

Airway Patency During Sleep ⬇
⬇
↓ Muscle tone in upper airway (sleep-induced relaxation)
⬇
Upper airway collapse
⬇
Obstruction to airflow

⬇

Ventilation
⬇
Hypoxia (↓ O₂) + Hypercapnia (↑ CO₂)
⬇
Recurrent arousals (to restore airway patency)
⬇
Sleep fragmentation

⬇

Consequences
⬇
Daytime fatigue & unrefreshing sleep
⬇
Loud snoring & gasping during sleep
⬇
↑ Sympathetic activation
⬇
Hypertension (BP: 156/94 mmHg)

🔍 Why symptoms occur?
→ Gasping & loud snoring: Turbulent airflow during partial obstruction.
→ Daytime fatigue: Poor sleep quality due to arousals (↓ REM/NREM cycles).
→ Hypertension: Sympathetic overdrive during apneic episodes.

🔍 What resolves the problem?
→ Keep airway open → Prevent collapse → Hypoglossal nerve stimulation is key!


⚙️ Mechanism:

  • Hypoglossal nerve 🧠 → Activates genioglossus muscle ⚙️ → Tongue moves forward → Airway patency ↑ → Stops obstruction

Explanation of Other Answers ⚖️

Option

Mechanism ⚙️

Role in OSA

Lingual nerve

Sensory to tongue 🧠

🚫 No effect on airway tone.

Maxillary nerve

Sensory to midface 🧠

🚫 Unrelated to airway obstruction.

Phrenic nerve

Controls diaphragm movement ⚙️

🚫 Helps with central apnea, not OSA.

Recurrent laryngeal nerve

Vocal cord innervation 🧠

🚫 Vocal cords don’t cause airway collapse in OSA.

Flashcards

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Dr. Shoaib Ahmad