Sleep in Medical Disorders — MCQs
A 56-year-old woman with diabetes, hypertension, and hyperlipidemia is found to have an A1C of 11 despite her best attempts at diet and faithfully taking her metformin and glyburide. She reports severe fatigue and sleepiness in the daytime, which has limited her ability to exercise. On examination, she is obese, has a full appearing posterior pharynx, clear lungs, a normal heart examination, and trace bilateral edema. Her TSH is 2.0 m/L (normal). Before adding another oral agent or switching to insulin, what is the best next step?
All are causes of pulmonary hypertension except which of the following?
A 40-year-old man presents with daytime sleepiness and impaired concentration and memory. On examination his BMI is 41 kg/m2, BP is 160/100 mm Hg. His awake ABG analysis is given: PaO2=66 mm Hg, PaCO2=50 mm Hg, HCO3=28 mEq/L. What is the most likely diagnosis?
Narcolepsy is due to abnormality in ?
Which condition is associated with periodic discharges on EEG at 4-second intervals?
Which of the following statements regarding prolactin levels is true?
Muller's manoeuvre is used to
Patient with obstructive sleep apnea-hypopnea syndrome is unlikely to have which of the following?
A 42-year-old obese male presented with disturbed sleep and daytime somnolence. All of the following are correct except?
What is the minimum number of apnea episodes required for the diagnosis of obstructive sleep apnea?
Sleep in Medical Disorders Indian Medical PG Practice Questions and MCQs
Question 1: A 56-year-old woman with diabetes, hypertension, and hyperlipidemia is found to have an A1C of 11 despite her best attempts at diet and faithfully taking her metformin and glyburide. She reports severe fatigue and sleepiness in the daytime, which has limited her ability to exercise. On examination, she is obese, has a full appearing posterior pharynx, clear lungs, a normal heart examination, and trace bilateral edema. Her TSH is 2.0 m/L (normal). Before adding another oral agent or switching to insulin, what is the best next step?
- A. Arrange for a sleep study to check the patient for obstructive sleep apnea. (Correct Answer)
- B. Consider prescribing a sleep aid to help her sleep better and increase her energy to exercise during the day.
- C. Assess for possible depression as a contributor to her fatigue.
- D. Educate the patient on sleep hygiene as a supportive measure to improve her overall well-being.
Explanation: A 56-year-old woman with diabetes, hypertension, and hyperlipidemia is found to have an A1C of 11 despite her best attempts at diet and faithfully taking her metformin and glyburide. She reports severe fatigue and sleepiness in the daytime, which has limited her ability to exercise. On examination, she is obese, has a full appearing posterior pharynx, clear lungs, a normal heart examination, and trace bilateral edema. Her TSH is 2.0 m/L (normal). Before adding another oral agent or switching to insulin, what is the best next step? ***Arrange for a sleep study to check the patient for obstructive sleep apnea.*** - The patient's presentation with **severe fatigue**, **daytime sleepiness**, **obesity**, and a **full-appearing posterior pharynx** are highly suggestive of **obstructive sleep apnea (OSA)** [1]. - OSA can lead to **insulin resistance** and worsen glycemic control, making it a critical factor to address before escalating diabetes medications. *Consider prescribing a sleep aid to help her sleep better and increase her energy to exercise during the day.* - Prescribing a sleep aid without investigating the cause of her sleep disturbances could mask a serious underlying condition like **OSA**, which requires specific treatment [1]. - While improved sleep might transiently boost energy, it would not address the **pathophysiology of OSA** or its impact on diabetes. *Assess for possible depression as a contributor to her fatigue.* - While **depression** can cause fatigue and impact exercise, her physical findings (obesity, full pharynx) and the specific symptom of **daytime sleepiness** point more strongly towards a primary sleep disorder like OSA [1]. - A definitive diagnosis of OSA would better explain the combination of her symptoms and poor glycemic control. *Educate the patient on sleep hygiene as a supportive measure to improve her overall well-being.* - **Sleep hygiene** is important for overall health, but it is unlikely to resolve severe daytime sleepiness and fatigue caused by a mechanical obstruction like in **OSA** [1]. - This intervention would be insufficient to address the potential link between her sleep disorder and uncontrolled diabetes.
Question 2: All are causes of pulmonary hypertension except which of the following?
- A. High altitude
- B. Fenfluramine
- C. Morbid obesity
- D. Hyperventilation (Correct Answer)
Explanation: ***Hyperventilation*** - **Hyperventilation** leads to a decrease in arterial carbon dioxide (PaCO2), causing **respiratory alkalosis** [1]. - This alkalosis induces **pulmonary vasodilation**, which tends to decrease rather than increase pulmonary arterial pressure. *Morbid obesity* - **Morbid obesity** often leads to **obesity hypoventilation syndrome (OHS)**, characterized by chronic hypoxemia and hypercapnia. - The resulting **chronic hypoxemia** causes sustained pulmonary vasoconstriction, leading to pulmonary hypertension. *High altitude* - Living at **high altitude** exposes individuals to **chronic hypoxia** due to lower atmospheric partial pressure of oxygen [3]. - This triggers **hypoxic pulmonary vasoconstriction** as a physiological response, which over time can remodel the pulmonary vasculature and lead to pulmonary hypertension [2]. *Fenfluramine* - **Fenfluramine** is an appetite suppressant that was historically linked to the development of pulmonary hypertension. - It causes an increase in pulmonary vascular resistance through various mechanisms, including enhancing the release and inhibiting the reuptake of **serotonin**, a potent pulmonary vasoconstrictor.
Question 3: A 40-year-old man presents with daytime sleepiness and impaired concentration and memory. On examination his BMI is 41 kg/m2, BP is 160/100 mm Hg. His awake ABG analysis is given: PaO2=66 mm Hg, PaCO2=50 mm Hg, HCO3=28 mEq/L. What is the most likely diagnosis?
- A. Obstructive sleep apnea (Correct Answer)
- B. Narcolepsy
- C. Obesity hypoventilation syndrome
- D. Central sleep apnea
Explanation: ***Obstructive Sleep Apnea (Correct Answer)*** - Classic triad: **morbid obesity (BMI 41 kg/m²)**, **excessive daytime somnolence**, and **systemic hypertension (160/100 mmHg)** — hallmarks of OSA - **ABG findings** (PaO2=66 mmHg, PaCO2=50 mmHg, HCO3=28 mEq/L) indicate **chronic nocturnal hypoxemia and hypercapnia** with compensatory **metabolic alkalosis** from repeated apneic episodes - **Cognitive impairment** (impaired concentration and memory) results from **sleep fragmentation** and intermittent nocturnal hypoxia - Obesity promotes **pharyngeal fat deposition** → upper airway narrowing and collapse during sleep → recurrent obstructive events *Narcolepsy* - Causes excessive daytime sleepiness but is **not associated with obesity, hypertension, or ABG abnormalities** - Hallmarks include **cataplexy**, sleep paralysis, and hypnagogic/hypnopompic hallucinations — none present here - Caused by **orexin (hypocretin) deficiency**; associated with **HLA-DQB1*06:02**; ABG is normal *Obesity Hypoventilation Syndrome (OHS / Pickwickian Syndrome)* - Defined as **awake PaCO2 >45 mmHg + BMI >30 kg/m²** with exclusion of other causes of hypoventilation - OHS frequently coexists as an **overlap with and consequence of severe OSA** rather than being the primary diagnosis - In this setting, **OSA is the most prevalent and primary diagnosis**; OHS is specifically considered when awake hypoventilation persists despite adequate OSA treatment *Central Sleep Apnea* - Results from **failure of central respiratory drive** (brainstem), not upper airway obstruction - Associated with **congestive heart failure, opioid use, high-altitude exposure, or neurological disease** — none present here - Not characteristically associated with morbid obesity; clinical and ABG picture here favors an **obstructive** rather than central pattern
Question 4: Narcolepsy is due to abnormality in ?
- A. Hypothalamus (Correct Answer)
- B. Neocortex
- C. Cerebellum
- D. Medulla oblongata
Explanation: **Hypothalamus** - Narcolepsy is primarily caused by the loss of **orexin (hypocretin)** producing neurons in the **hypothalamus**, which are crucial for maintaining wakefulness. - This deficiency leads to dysregulation of **sleep-wake cycles**, causing excessive daytime sleepiness and other narcolepsy symptoms. *Neocortex* - The neocortex is involved in higher-level cognitive functions, sensory perception, and voluntary movement, but it is not the primary site of pathology in narcolepsy. - While sleep stages involve cortical activity, the core deficit in narcolepsy does not originate here. *Cerebellum* - The cerebellum is mainly responsible for motor control, coordination, and balance. - Its dysfunction is associated with ataxic gait and coordination problems, not the sleep disturbances characteristic of narcolepsy. *Medulla oblongata* - The medulla oblongata controls vital autonomic functions like breathing, heart rate, and blood pressure. - While involved in sleep regulation pathways, it is not the primary anatomical location affected in narcolepsy.
Question 5: Which condition is associated with periodic discharges on EEG at 4-second intervals?
- A. SSPE (Correct Answer)
- B. Absence Seizure
- C. REM sleep disorder
- D. Focal epilepsy
Explanation: ***SSPE*** - **Subacute sclerosing panencephalitis (SSPE)** is a rare, fatal, progressive brain disorder characterized by inflammation and degeneration of the brain. - The distinctive EEG pattern consists of **periodic high-amplitude, slow-wave complexes** that recur every 4-15 seconds, often every 4-8 seconds, making 4-second intervals a key indicator. *Absence Seizure* - Absence seizures typically manifest as **brief staring spells** with impaired consciousness, lasting only a few seconds. - The EEG in absence seizures shows characteristic **generalized 3-Hz spike-and-wave discharges**, not 4-second interval periodic discharges. *REM sleep disorder* - **REM sleep behavior disorder** involves the acting out of vivid dreams due to the absence of normal muscle atonia during REM sleep [1]. - EEG in REM sleep behavior disorder shows normal sleep architecture but may include evidence of **muscle activity (EMG)** during REM sleep, not periodic discharges [1]. *Focal epilepsy* - **Focal epilepsy** originates in a specific area of the brain, causing seizures with symptoms dependent on the affected region [2]. - EEG findings in focal epilepsy typically show **interictal spikes or sharp waves** localized to the region of seizure onset, which are distinct from generalized periodic discharges [2].
Question 6: Which of the following statements regarding prolactin levels is true?
- A. Hyperthyroidism - Increased prolactin
- B. Sleep - Increased prolactin (Correct Answer)
- C. Organic seizure - normal prolactin
- D. Psychogenic seizure - Normal prolactin
Explanation: ***Sleep - Increased prolactin*** - Prolactin secretion is **pulsatile** and highest during **nocturnal sleep**, peaking around 4-5 AM. - This physiological increase occurs regardless of sleep onset and is a normal diurnal rhythm. *Hyperthyroidism - Increased prolactin* - **Hyperthyroidism** typically causes **decreased prolactin levels** due to altered dopaminergic tone and thyroid hormone effects on pituitary lactotrophs. - Conversely, **hypothyroidism**, particularly primary hypothyroidism, can lead to **increased prolactin** due to elevated TRH stimulating prolactin secretion. *Organic seizure - normal prolactin* - An **organic seizure** (e.g., tonic-clonic seizure) usually causes an **acute, significant elevation in prolactin** levels postictally. - This transient rise in prolactin can be a valuable diagnostic marker to differentiate epileptic seizures from non-epileptic events. *Psychogenic seizure - Decreased prolactin* - **Psychogenic non-epileptic seizures (PNES)** typically result in **normal or slightly decreased prolactin** levels after the event. - This is a key diagnostic differentiator from true epileptic seizures, which show postictal prolactin elevation.
Question 7: Muller's manoeuvre is used to
- A. To remove foreign body from ear
- B. To find degree of obstruction in sleep disordered breathing (Correct Answer)
- C. To remove laryngeal foreign body
- D. To find out opening of mouth
Explanation: ***To find degree of obstruction in sleep disordered breathing*** - **Muller's manoeuvre** is a diagnostic technique where the patient attempts to inspire forcefully against a **closed mouth and nostrils** while an endoscope observes the upper airway. - This maneuver helps to simulate the negative intraluminal pressure that occurs during sleep, making it useful in identifying the **site and severity of airway obstruction** in patients with sleep-disordered breathing. *To remove foreign body from ear* - Removing foreign bodies from the ear typically involves **irrigation**, specialized instruments (e.g., alligator forceps), or suction, not a breathing maneuver. - This option is unrelated to the physiological assessment of airway obstruction. *To remove laryngeal foreign body* - The primary methods for removing laryngeal foreign bodies are the **Heimlich maneuver** (abdominal thrusts) or direct laryngoscopy and removal. - Muller's manoeuvre is a diagnostic procedure, not a therapeutic one for foreign body extraction. *To find out opening of mouth* - Measuring the **opening of the mouth** is typically done with a ruler or specific instruments to assess jaw mobility (e.g., for temporomandibular joint disorders or trismus). - This is a simple measurement and does not involve the complex physiological assessment of the upper airway that Muller's manoeuvre provides.
Question 8: Patient with obstructive sleep apnea-hypopnea syndrome is unlikely to have which of the following?
- A. Absence of snoring
- B. Bradycardia during sleep episodes (Correct Answer)
- C. Normal oxygen saturation throughout sleep
- D. Decreased neck circumference
Explanation: ***Bradycardia during sleep episodes*** - While patients with **obstructive sleep apnea (OSA)** commonly experience various cardiovascular complications, **bradycardia** during apneic episodes is *less typical* than **tachycardia**. - The body's initial response to apnea and **hypoxia** usually involves a sympathetic surge leading to tachycardia upon arousal, followed by bradycardia if the apnea is prolonged. However, the dominant pattern is often elevated heart rate variability. *Normal oxygen saturation throughout sleep* - Patients with OSA frequently experience intermittent **hypoxemia** due to repeated apneas and hypopneas, leading to significant drops in **oxygen saturation** [1]. - A *normal oxygen saturation throughout sleep* would effectively rule out significant OSA, as desaturation is a hallmark of the condition [1]. *Absence of snoring* - **Snoring** is a classic and highly prevalent symptom of OSA, caused by the vibration of upper airway tissues as air struggles to pass through an obstructed pharynx. - While not all snorers have OSA, the *absence of snoring* makes OSA less likely, although it can occur in some subsets of patients, particularly those with central sleep apnea or certain anatomical variations. *Decreased neck circumference* - A **large neck circumference** is a well-established anatomical risk factor for OSA, indicating increased soft tissue in the neck that can contribute to upper airway collapse. - A *decreased neck circumference* would generally be protective against OSA, making it less likely for an individual to have the condition.
Question 9: A 42-year-old obese male presented with disturbed sleep and daytime somnolence. All of the following are correct except?
- A. Apnea with fall in saturation
- B. Apnea with awakening
- C. Pharyngeal muscle contraction increases OSA
- D. Apnea with hypercapnia (Correct Answer)
Explanation: ***Apnea with hypercapnia*** - While hypercapnia can occur in severe cases of **obstructive sleep apnea (OSA)**, a direct correlation of hypercapnia with every apnea event is not a defining characteristic for diagnosis in the provided patient. [1] - OSA is primarily defined by **recurrent episodes of upper airway collapse during sleep**, leading to cessation of airflow despite ongoing respiratory effort, which causes hypoxemia and sleep fragmentation, not necessarily hypercapnia with each event. [1] *Apnea with fall in saturation* - **Apnea events** in OSA frequently lead to a significant **fall in oxygen saturation** as the oxygen in the blood is consumed without replenishment due to the blocked airway. [1] - This desaturation is a key diagnostic criterion and a major contributor to the cardiovascular complications associated with OSA. *Apnea with awakening* - Apnea episodes typically end with a brief **arousal or awakening** from sleep, often not consciously remembered by the patient, as the brain signals to resume breathing. [1] - These awakenings disrupt the sleep architecture, leading to the characteristic **daytime somnolence** and disturbed sleep seen in OSA patients. [1] *Pharyngeal muscle contraction increases OSA* - **Relaxation or decreased tone of pharyngeal muscles** during sleep is a primary cause of upper airway collapse and **obstructive sleep apnea (OSA)**. [1] - Increased pharyngeal muscle contraction would typically help keep the airway open, thus *decreasing* the likelihood of OSA, not increasing it.
Question 10: What is the minimum number of apnea episodes required for the diagnosis of obstructive sleep apnea?
- A. AHI ≥ 10 events/hour
- B. AHI ≥ 2 events/hour
- C. AHI ≥ 5 events/hour (Correct Answer)
- D. AHI ≥ 4 events/hour
Explanation: ***AHI ≥ 5 events/hour*** - An **apnea-hypopnea index (AHI)** of 5 or more events per hour of sleep, accompanied by symptoms such as **daytime sleepiness**, snoring, or witnessed apneas, is the diagnostic criterion for obstructive sleep apnea (OSA) [1]. - This threshold signifies a clinically significant frequency of **breathing disturbances** during sleep [1]. *AHI ≥ 2 events/hour* - An AHI of 2 events/hour is generally considered within the **normal range** or indicates very mild, non-pathological sleep disordered breathing. - It is **insufficient** to diagnose OSA in adults, even with associated symptoms. *AHI ≥ 10 events/hour* - An AHI of 10 events/hour would indicate at least **mild to moderate OSA**, well above the minimum diagnostic threshold. - While diagnostic, it is not the *minimum* number required for initial diagnosis. *AHI ≥ 4 events/hour* - An AHI of 4 events/hour is close to the diagnostic threshold but still **below the minimum** required for a formal diagnosis of OSA. - It would typically be considered **mild sleep-disordered breathing** that may not meet diagnostic criteria without other significant factors.
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