Sleep Medicine

Sleep Medicine Indian Medical PG Question 1: Which of the following is false about narcolepsy?

• A. Sudden loss of muscle tone (cataplexy)
• B. Cataplexy is a common symptom
• C. Typically occurs only during nighttime sleep (Correct Answer)
• D. Typical onset in the second decade of life

Sleep Medicine Explanation: ***Typically occurs only during nighttime sleep*** - Narcolepsy is characterized by **excessive daytime sleepiness** and sudden, uncontrollable urges to sleep during the day, not exclusively nighttime sleep. - Patients with narcolepsy often experience disrupted nocturnal sleep, including **frequent awakenings** and vivid dreams. *Sudden loss of muscle tone (cataplexy)* - This statement accurately describes **cataplexy**, a hallmark symptom of narcolepsy, which is a sudden, brief loss of **muscle tone** triggered by strong emotions. - Cataplexy is a key diagnostic feature, though not all individuals with narcolepsy experience it. *Cataplexy is a common symptom* - **Cataplexy is indeed common** in narcolepsy, particularly in Narcolepsy Type 1, where it is caused by a deficiency in **hypocretin (orexin)**. - It is a defining characteristic for diagnosing narcolepsy with cataplexy. *Typical onset in the second decade of life* - The onset of narcolepsy symptoms, including excessive daytime sleepiness and cataplexy, often occurs during **adolescence or early adulthood**, typically between the ages of 10 and 25. - This timing can significantly impact education and social development.

Sleep Medicine Indian Medical PG Question 2: A 32-year-old man comes to the physician complaining of excessive sleepiness for the past several months. He reports falling asleep while dealing with customers and had a near accident when he fell asleep while driving. The patient reports that he occasionally hears voices while falling asleep and finds himself "temporarily frozen" and unable to move upon awakening. Which of the following is the most appropriate treatment for this patient?

• A. Melatonin
• B. Modafinil (Correct Answer)
• C. Clonazepam
• D. Continuous positive airway pressure

Sleep Medicine Explanation: ***Modafinil*** - The patient's symptoms of **excessive daytime sleepiness** (EDS), **hypnagogic hallucinations** (hearing voices while falling asleep), and **sleep paralysis** are classic signs of **narcolepsy**. - **Modafinil** is a **non-amphetamine stimulant** that promotes wakefulness and is a first-line treatment for narcolepsy, improving alertness and reducing EDS. *Melatonin* - **Melatonin** is a hormone involved in regulating the **sleep-wake cycle** and is primarily used for **insomnia**, **jet lag**, or **circadian rhythm disorders**. - It is not effective for treating the hallmark symptoms of narcolepsy, such as cataplexy or excessive daytime sleepiness. *Clonazepam* - **Clonazepam** is a **benzodiazepine** that acts as a central nervous system depressant, primarily used for **anxiety disorders**, seizures, and some sleep disorders like **REM sleep behavior disorder**. - While it can help with some parasomnias, it would worsen daytime sleepiness in a patient with narcolepsy and is not a primary treatment for its core symptoms. *Continuous positive airway pressure* - **Continuous positive airway pressure (CPAP)** is the standard treatment for **obstructive sleep apnea (OSA)**, a condition characterized by recurrent upper airway collapse during sleep. - Although OSA can cause excessive daytime sleepiness, the patient's additional symptoms of hypnagogic hallucinations and sleep paralysis are not typical of OSA, making narcolepsy and its specific treatments more appropriate.

Sleep Medicine Indian Medical PG Question 3: A 42-year-old female executive is referred to the sleep clinic with jaw pain. She complains that after she arrives home at night around 10 pm she frequently drinks 3-4 gin and tonics to help quiet her mind.’ She wakes up the next morning around 3am to read the international stock market news, at which point she states her teeth ache an unbearable amount. A study is performed on the patient and it is noted that she grinds her teeth and mutters during roughly half of her sleep. Which of the following would you expect to see on her EEG and at which stage of sleep would you expect her jaw pain to be caused?

• A. Alpha waves, N2
• B. Beta waves, N3
• C. Delta waves, N3
• D. Sleep spindles, N2 (Correct Answer)

Sleep Medicine Explanation: ***Sleep spindles, N2*** - The patient's presentation of teeth grinding (**bruxism**) and muttering during sleep, along with jaw pain, is characteristic of **parasomnias**, which often occur during **stage N2 sleep**. - **Sleep spindles** and **K-complexes** are defining EEG features of **N2 sleep**, indicating that the sleep study would likely show these patterns. *Alpha waves, N2* - **Alpha waves** are characteristic of a **relaxed, awake state** or the early stages of falling asleep (N1), not N2 sleep. - While the patient has jaw pain, its cause is linked to sleep behaviors occurring in more advanced sleep stages than N1. *Beta waves, N3* - **Beta waves** are typically seen during **active wakefulness** and **REM sleep**, not deep N3 sleep. - **N3 sleep** (slow-wave sleep) is characterized by **delta waves**, not beta waves. *Delta waves, N3* - Although **delta waves** are indeed characteristic of **N3 sleep** (deep sleep), the patient's symptoms of teeth grinding and muttering are more commonly associated with **N2 sleep** or arousal disorders, not typically the deepest stage of sleep. - Bruxism and muttering are generally not prominent features of undisturbed N3 sleep.

Sleep Medicine Indian Medical PG Question 4: The sleep apnea syndrome is defined as -

• A. Apnea-Hypopnea Index (AHI) ≥ 5/hour (Correct Answer)
• B. Apnea-Hypopnea Index (AHI) ≥ 10/hour
• C. Apnea-Hypopnea Index (AHI) ≥ 30/hour
• D. Apnea-Hypopnea Index (AHI) ≥ 15/hour

Sleep Medicine Explanation: ***Apnea-Hypopnea Index (AHI) ≥ 5/hour*** - The definition of **sleep apnea syndrome** generally requires an **AHI of 5 or more events per hour**, often accompanied by symptoms like excessive daytime sleepiness or cardiovascular complications [1]. - This threshold identifies individuals with clinically significant sleep-disordered breathing that warrants further evaluation and potential treatment [1]. *Apnea-Hypopnea Index (AHI) ≥ 10/hour* - While an AHI of 10/hour indicates sleep apnea, it is a higher severity criterion and does not represent the **minimum threshold** for defining the syndrome [1]. - Patients with an AHI between 5 and 10 also have sleep apnea and can experience significant symptoms. *Apnea-Hypopnea Index (AHI) ≥ 30/hour* - An AHI of 30/hour or more signifies **severe sleep apnea**, which requires aggressive management. - This is far above the **general diagnostic threshold** for sleep apnea syndrome. *Apnea-Hypopnea Index (AHI) ≥ 15/hour* - An AHI of 15/hour is typically classified as **moderate sleep apnea**. - This value is higher than the **lowest AHI threshold** used to define the presence of sleep apnea syndrome.

Sleep Medicine Indian Medical PG Question 5: Hormonal secretions are tightly controlled by the time of day due to an inbuilt biological clock in human body. This rhythmic secretion is controlled by:

• A. Ventrolateral nucleus
• B. Supraoptic nucleus
• C. Suprachiasmatic nucleus (Correct Answer)
• D. Posterolateral nucleus

Sleep Medicine Explanation: ***Suprachiasmatic nucleus*** - The **suprachiasmatic nucleus (SCN)**, located in the hypothalamus, is the primary pacemaker of the body's **circadian rhythms**, controlling the timing of hormonal secretions, sleep-wake cycles, and other daily oscillations. - It receives direct input from the **retina** about light-dark cycles, allowing it to synchronize the body's internal clock with the external environment. *Ventrolateral nucleus* - The **ventrolateral preoptic nucleus (VLPO)** is involved in **sleep regulation** and promoting non-REM sleep, but it does not act as the primary circadian pacemaker. - It receives input from the SCN and collaborates in regulating sleep, but its role is primarily inhibitory to wakefulness. *Supraoptic nucleus* - The **supraoptic nucleus** is primarily involved in the production and secretion of **vasopressin (ADH)** and **oxytocin**, which are neurohormones regulating fluid balance and social bonding, respectively. - It does not directly control the rhythmic aspect of general hormonal secretions or act as the central circadian clock. *Posterolateral nucleus* - This term is less commonly used in the context of circadian rhythm control; however, if referring to a thalamic nucleus, the **posterolateral nucleus** is generally associated with sensory processing, particularly somatosensory information. - It has no known role as a central pacemaker for hormonal secretions or circadian rhythms.

Sleep Medicine Indian Medical PG Question 6: Diurnal variation of ACTH depends on ?

• A. Suprachiasmatic nucleus (Correct Answer)
• B. Supraoptic nucleus
• C. Ventrolateral nucleus
• D. Thalamus

Sleep Medicine Explanation: ***Suprachiasmatic nucleus*** - The **suprachiasmatic nucleus (SCN)** acts as the body's **master circadian clock**, synchronizing various physiological rhythms, including the **diurnal variation of ACTH** secretion. - It receives light input from the **retina** and projects to other brain regions to regulate the timing of hormone release. *Supraoptic nucleus* - The **supraoptic nucleus (SON)** is primarily involved in the production of **vasopressin (ADH)** and **oxytocin**, which are released by the posterior pituitary. - It does not directly control the diurnal rhythm of ACTH. *Ventrolateral nucleus* - The **ventrolateral preoptic area (VLPO)** is a key region for **sleep regulation**, promoting sleep by inhibiting wake-promoting neurotransmitters. - While it contributes to sleep-wake cycles, it is not the primary regulator of ACTH's diurnal variation. *Thalamus* - The **thalamus** is a major relay center for sensory information and plays a role in consciousness, sleep, and alertness. - It does not directly control the **circadian rhythm of ACTH secretion**.

Sleep Medicine Indian Medical PG Question 7: A patient presents to you with an irregularly irregular pulse of 120/minutes and a pulse deficit of 20. Which of the following would be the jugular venous pressure (JVP) finding?

• A. Normal JVP
• B. Absent a wave (Correct Answer)
• C. Cannon a wave
• D. Raised JVP with normal waveform

Sleep Medicine Explanation: ***Absent a wave*** - An **irregularly irregular pulse** with a **pulse deficit** strongly suggests **atrial fibrillation (AF)**. - In AF, the atria quiver chaotically instead of contracting effectively, leading to the **absence of a coordinated atrial contraction** and thus an **absent 'a' wave** in the JVP. *Normal JVP* - A normal JVP would show a regular **'a' wave** corresponding to normal atrial contraction. - This is inconsistent with the **irregularly irregular pulse** and **pulse deficit** seen in the patient, which points to a significant atrial arrhythmia. *Cannon a wave* - A **cannon 'a' wave** results from the right atrium contracting against a closed tricuspid valve, leading to a large, prominent wave in the JVP. - This is typically seen in conditions like **complete heart block** or **ventricular tachycardia with AV dissociation**, not atrial fibrillation. *Raised JVP with normal waveform* - A raised JVP with a normal waveform indicates increased right atrial pressure but preserves the normal sequence of atrial contraction and relaxation. - This could be due to conditions like **right heart failure** or **volume overload**, but would still show the presence of an 'a' wave, which is absent in atrial fibrillation.

Sleep Medicine Indian Medical PG Question 8: Identify the sleep stage in the following Polysomnograph.

• A. NREM stage 2 (Correct Answer)
• B. NREM stage 3
• C. REM
• D. NREM stage 1

Sleep Medicine Explanation: ***NREM stage 2*** - The **EEG** shows prominent **sleep spindles** (bursts of 12-14 Hz waves) and **K-complexes** (high-amplitude biphasic waves), which are characteristic features of NREM stage 2 sleep. - The EOG channels indicate slow eye movements or an absence of rapid eye movements, consistent with NREM sleep, while the **EMG shows moderate muscle tone**, higher than in REM sleep but lower than wakefulness. *NREM stage 3* - This stage is characterized by **delta waves**, which are slow waves with high amplitude (0.5-2 Hz, often >75 μV) on the EEG, comprising 20% or more of the epoch, and are not significantly visible here. - While muscle tone is still present, the EEG would primarily show widespread **slow-wave activity**, distinguishing it from the sleep spindles and K-complexes seen in the image. *REM* - **Rapid eye movements** would be clearly visible on the EOG channels, which are not prevalent in this polysomnograph. - The **EMG would show very low muscle tone** (atonia), which is not the case here, and the EEG would largely consist of low-voltage, mixed-frequency activity, similar to wakefulness. *NREM stage 1* - This stage is typically characterized by a **disappearance of alpha waves** from the EEG and the presence of **theta waves** (4-7 Hz). - While there may be slow eye movements on the EOG, **sleep spindles and K-complexes are absent** in NREM stage 1, making it distinct from the presented polysomnograph.

Sleep Medicine Indian Medical PG Question 9: Which is not seen in heart failure?

• A. Cardiomegaly
• B. Kerley B lines
• C. Kerley A Lines
• D. Oligemia (Correct Answer)

Sleep Medicine Explanation: ***Oligemia*** - **Oligemia** refers to a reduced blood volume or total blood flow to a region, which is typically not observed in **heart failure**. - In **heart failure**, the body often experiences **fluid overload** and **pulmonary congestion**, leading to increased blood volume in the lungs, not reduced [1]. *Cardiomegaly* - **Cardiomegaly**, or an enlarged heart, is a common finding in **heart failure** as the heart muscle remodels and dilates to compensate for impaired pumping function [1], [3]. - This can be seen on a chest X-ray as an **increased cardiothoracic ratio** [1], [2]. *Kerley B lines* - **Kerley B lines** are thin, horizontal lines visible on a chest X-ray, typically found at the lung periphery. - They indicate **interstitial edema** due to increased pulmonary venous pressure, a characteristic sign of **pulmonary congestion** in **heart failure** [1]. *Kerley A Lines* - **Kerley A lines** are longer, less common lines seen radiating from the hila towards the upper lobes. - These lines represent **distended anastomotic channels** between pulmonary and systemic venous systems, also indicative of **pulmonary edema** and **heart failure** [1], [4].

Sleep Medicine Indian Medical PG Question 10: Which type of cardiomyopathy is associated with alcohol abuse?

• A. Hypertrophic cardiomyopathy
• B. Dilated cardiomyopathy (Correct Answer)
• C. Pericarditis
• D. Myocarditis

Sleep Medicine Explanation: ### Dilated cardiomyopathy - Chronic **alcohol abuse** is a well-established cause of **dilated cardiomyopathy**, leading to weakening and enlargement of the ventricles [1]. - This condition results in impaired systolic function and can cause **heart failure** [1]. *Hypertrophic cardiomyopathy* - This condition is primarily characterized by **pathological thickening of the heart muscle**, often genetic, and is not directly caused by alcohol abuse. - It leads to issues with relaxation and filling of the heart, rather than dilation and weakness. *Pericarditis* - **Pericarditis** is the inflammation of the sac surrounding the heart (pericardium), most commonly caused by viral infections, autoimmune diseases, or injury. - It is not directly linked to alcohol abuse as a primary cause. *Myocarditis* - **Myocarditis** is the inflammation of the heart muscle, often triggered by viral infections, autoimmune reactions, or certain medications. - While heavy alcohol use can weaken the heart, myocarditis is primarily an inflammatory process not directly caused by alcohol.

Sleep Medicine Flashcard 1 of 7

Question: Syndrome _____ is characterized by OSA with metabolic syndrome

Answer: Z

Sleep Medicine Flashcard 2 of 7

Question: OSA, causes hypoventilation and resulting _____ hypoxia and hypercapnia

Answer: transient

Sleep Medicine Flashcard 3 of 7

Question: Obstructive sleep apnea is associated with _____, loud snoring with periods of apnea, and daytime sleepiness

Answer: obesity

Sleep Medicine Flashcard 4 of 7

Question: Daytime somnolence, systemic hypertension, and high BMI raise the suspicion for _____ and Obesity hypoventilation syndrome(OHS)

Answer: Obstructive sleep apnoea(OSA)

Sleep Medicine Flashcard 5 of 7

Question: _____ is associated with loss of orexin from lateral hypothalamus.

Answer: Narcolepsy

Sleep Medicine Flashcard 6 of 7

Question: Obstructive sleep apnea may be caused by excess _____ tissue in adults (age group)

Answer: parapharyngeal

Sleep Medicine Flashcard 7 of 7

Question: Obstructive sleep apnea is associated with difficult to manage _____ due to increased sympathetic tone

Answer: systemic hypertension