Sleep Medicine — 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?

Q35

Patient with obstructive sleep apnea-hypopnea syndrome is unlikely to have which of the following?

Q36

All of the following criteria are required for diagnosis of obesity hypoventilation syndrome except -

Q37

What is the minimum number of apnea episodes required for the diagnosis of obstructive sleep apnea?

Sleep Medicine Indian Medical PG Practice Questions and MCQs

Question 31: Which of the following statements about obstructive sleep apnea is true?

A. Nocturnal asphyxia
B. Alcoholism is a cofactor
C. Prone to hypertension (Correct Answer)
D. Overnight oximetry alone is sufficient for diagnosing obstructive sleep apnea.

Explanation: ***Prone to hypertension*** - Obstructive sleep apnea (OSA) is strongly associated with **hypertension** due to recurrent episodes of hypoxemia, hypercapnia, and increased sympathetic activity. - The repeated arousals and stress responses during sleep cause a persistent elevation in blood pressure. [1] *Nocturnal asphyxia* - While OSA involves episodes of **apnea** and **hypopnea** (reduced breathing), the term **asphyxia** implies complete cessation of breathing leading to severe oxygen deprivation and CO2 retention, which is generally not the typical presentation of OSA as patients usually eventually gasp for air. [1] - OSA is characterized by partial or complete **upper airway obstruction** during sleep, leading to reduced airflow and oxygen desaturation, but not usually full asphyxia. [1] *Alcoholism is a cofactor* - **Alcohol consumption**, particularly before bedtime, acts as an **exacerbating factor** for OSA by causing muscle relaxation in the upper airway, but it is not typically considered a primary cofactor in the development of the condition itself. - While alcohol can worsen OSA symptoms and severity, it is not a direct underlying cause in the way obesity or anatomical abnormalities are. *Overnight oximetry alone is sufficient for diagnosing obstructive sleep apnea.* - **Overnight oximetry** can detect oxygen desaturations but is **not sufficient** for a definitive diagnosis of OSA, as it does not measure airflow, respiratory effort, or sleep stages. - A definitive diagnosis requires a **polysomnography (PSG)**, which records multiple physiological parameters including airflow, respiratory effort, oxygen saturation, heart rate, and brain activity.

Question 32: What is the minimum duration of apnea defined in obstructive sleep apnea?

A. >=10 sec (Correct Answer)
B. 20 sec
C. 15 sec
D. 5 sec

Explanation: ***>=10 sec*** - An **apnea event** in obstructive sleep apnea (OSA) is defined as a cessation of airflow for at least **10 seconds** [1] during sleep. - This duration is crucial for distinguishing between normal respiratory pauses and clinically significant apneas. *5 sec* - A 5-second period of no airflow is generally considered a **normal physiological variation** or a brief pause, not meeting the criteria for apnea in OSA. - Such brief pauses typically do not lead to significant **oxygen desaturation** [1] or arousal from sleep. *15 sec* - While 15 seconds would certainly qualify as an apnea event, the **minimum threshold** for definition is 10 seconds [1]. - Longer durations of apnea are indicative of more **severe airflow obstruction**, but the 10-second mark is the standard lower limit. *20 sec* - Similarly, 20 seconds represents a **prolonged apnea event**, but it is not the **minimum duration** for diagnosis. - Apneas lasting 20 seconds or more are associated with greater **physiological stress** and more noticeable clinical symptoms.

Question 33: What is the most reliable diagnostic tool to differentiate between psychological and organic erectile dysfunction?

A. Nocturnal penile tumescence (Correct Answer)
B. PIPE therapy
C. Sildenafil induced erection
D. Squeeze technique

Explanation: ***Nocturnal penile tumescence*** - This diagnostic tool assesses whether a man experiences erections during sleep, which are naturally occurring physiological events. The presence of normal nocturnal erections indicates intact **neurovascular pathways** necessary for erection, suggesting that any daytime erectile dysfunction is likely due to **psychological factors** [2]. - Conversely, the absence of nocturnal erections points towards an **organic cause** for erectile dysfunction, as the physiological mechanism itself is impaired [1]. *Squeeze technique* - The squeeze technique is a behavioral therapy used to treat **premature ejaculation**, not erectile dysfunction. It involves stopping stimulation at the point of impending ejaculation and applying pressure to the glans to reduce arousal. - This technique does not provide any diagnostic information regarding the underlying cause (psychological vs. organic) of erectile dysfunction. *Sildenafil induced erection* - While sildenafil (Viagra) can induce an erection in many men with erectile dysfunction, its response does not reliably differentiate between psychological and organic causes. Sildenafil works by enhancing the effects of **nitric oxide**, leading to increased blood flow to the penis. - Both men with psychological erectile dysfunction and some with organic causes (e.g., mild vascular compromise) may respond to sildenafil, so a positive response does not rule out an **organic etiology**. *PIPE therapy* - "PIPE therapy" is not a recognized medical or diagnostic term for erectile dysfunction. It may be a typo or a misnomer. - Therefore, it does not serve as a diagnostic tool for differentiating between psychological and organic causes of erectile dysfunction.

Question 34: 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 35: 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 36: All of the following criteria are required for diagnosis of obesity hypoventilation syndrome except -

A. PaCO2 > 45 mmHg
B. BMI 30 kg/m2
C. Hypertension (Correct Answer)
D. Sleep disorder breathing

Explanation: ***Hypertension*** - While **hypertension** is a common comorbidity in patients with **obesity hypoventilation syndrome (OHS)**, it is _not_ a diagnostic criterion. - OHS is defined by specific respiratory and obesity-related parameters, not the presence of associated cardiovascular conditions. *BMI $\geq$ 30 kg/m$^2$* - A **body mass index (BMI)** of **30 kg/m$^2$** or greater is a fundamental criterion for diagnosing OHS, as the syndrome is directly linked to obesity. - Severe obesity leads to mechanical compression of the lungs and chest wall, contributing to hypoventilation. *PaCO$_{2}$ > 45 mmHg* - A **daytime arterial partial pressure of carbon dioxide (PaCO$_{2}$)** greater than **45 mmHg** is a key diagnostic criterion, indicating chronic alveolar hypoventilation. - This persistent hypercapnia is present even when other causes like obstructive lung disease have been excluded. *Sleep-disordered breathing* - **Sleep-disordered breathing**, most commonly **obstructive sleep apnea (OSA)**, is almost universally present in OHS patients and is a required diagnostic criterion [1]. - The combination of severe obesity and OSA often leads to the development of chronic hypoventilation [1].

Question 37: 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.

Practice by Chapter

Normal Sleep Physiology

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Sleep-Disordered Breathing

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Insomnia

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Hypersomnias

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Circadian Rhythm Disorders

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Parasomnias

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Sleep-Related Movement Disorders

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Sleep in Medical Disorders

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Sleep in Psychiatric Disorders

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Sleep Diagnostics

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Pharmacologic Management of Sleep Disorders

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Non-pharmacologic Sleep Interventions

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