Sleep-Wake Disorders Practice Questions

Q: Bruxism most commonly occurs during which phase of sleep?

NREM Stage II. **Explanation:** **Sleep Bruxism** is a sleep-related movement disorder characterized by the involuntary grinding or clenching of teeth. **Why NREM Stage II is correct:** While bruxism can occur in any stage of sleep, it is most frequently observed during **NREM Stage II (Light Sleep)**. Statistically, about 80% of bruxism episodes occur during NREM sleep, with the vast majority clustered in Stage II. These episodes are often associated with "micro-arousals"—brief shifts in sleep depth where the sympathetic nervous system activity increases, leading to rhythmic masticatory muscle activity (RMMA). **Analysis of Incorrect Options:** * **REM Sleep (A):** Although bruxism can occur during REM, it is less common. REM-related bruxism is often associated with more severe clinical symptoms and may be linked to obstructive sleep apnea. * **NREM Stage I (B):** This is a transitional phase of very light sleep. While grinding can occur here, the frequency is significantly lower than in Stage II. * **NREM Stage III (D):** Also known as Slow Wave Sleep (SWS) or deep sleep. Parasomnias like sleepwalking (somnambulism) and night terrors typically occur here, but bruxism is less frequent in this stage compared to Stage II. **High-Yield Clinical Pearls for NEET-PG:** * **Treatment of Choice:** The first-line management is usually **stress reduction** and **dental guards (occlusal splints)** to prevent tooth wear. * **Pharmacotherapy:** If severe, **Benzodiazepines** (like Clonazepam) or muscle relaxants may be used short-term. * **Association:** Bruxism is frequently associated with stress, anxiety, and other sleep disorders like Obstructive Sleep Apnea (OSA). * **Key Distinction:** Do not confuse bruxism (Stage II) with **Sleep Terrors/Somnambulism**, which are classic **Stage III (N3)** phenomena.

Q: Kleine-Levin syndrome is characterized by which of the following?

Hypersomnia. **Explanation:** **Kleine-Levin Syndrome (KLS)**, often referred to as "Sleeping Beauty Syndrome," is a rare, relapsing-remitting neurological disorder primarily affecting adolescent males. 1. **Why Hypersomnia is Correct:** The hallmark of KLS is **recurrent episodes of severe hypersomnia**, where patients may sleep for 15 to 21 hours a day. During these episodes, patients are difficult to arouse and exhibit cognitive disturbances (like derealization), irritability, and compulsive behaviors. 2. **Why Other Options are Incorrect:** * **Insomnia:** This is the inability to sleep. KLS is characterized by the polar opposite—excessive sleep duration. * **Depression & Anxiety:** While patients may experience mood changes or "flat affect" during an episode, these are secondary symptoms or part of the post-episode recovery phase. They are not the defining diagnostic criteria for the syndrome itself. 3. **Clinical Pearls for NEET-PG:** * **The Classic Triad:** Hypersomnia, Hyperphagia (compulsive overeating), and Hypersexuality (disinhibition). * **Demographics:** Most common in adolescent males (Male:Female ratio is approx. 3:1). * **Course:** Episodes typically last days to weeks and recur several times a year. Between episodes, patients usually have normal sleep and mood. * **Management:** * *Acute episodes:* Supportive care. * *Prophylaxis:* **Lithium** is the most effective treatment for reducing the frequency and severity of episodes. Carbamazepine or Valproate are second-line options. * **Differential Diagnosis:** Must be distinguished from Kluver-Bucy Syndrome (which involves temporal lobe damage and lacks the periodic sleep episodes).

Q: Narcolepsy is characterized by excessive daytime sleepiness?

Excessive daytime sleepiness. **Explanation:** **Narcolepsy** is a chronic neurological disorder caused by the loss of orexin (hypocretin)-producing neurons in the hypothalamus, leading to an inability to regulate sleep-wake cycles. 1. **Why Option B is Correct:** **Excessive Daytime Sleepiness (EDS)** is the hallmark and usually the first symptom of narcolepsy. Patients experience "sleep attacks" where they fall asleep irresistibly during the day, regardless of the amount of sleep they had the previous night. 2. **Why Other Options are Incorrect:** * **Option A:** In narcolepsy, there is **decreased REM sleep latency**. Patients often enter REM sleep within 15 minutes of falling asleep (Sleep Onset REM Periods - SOREMPs), whereas normal REM latency is about 90 minutes. * **Option C:** While patients have EDS, their **total 24-hour sleep time** is usually normal or only slightly increased. Their sleep is fragmented and inefficient, rather than prolonged. * **Option D:** The **sleep architecture is highly abnormal**, characterized by sleep fragmentation and the intrusion of REM sleep components into wakefulness (e.g., cataplexy, sleep paralysis). **High-Yield Clinical Pearls for NEET-PG:** * **The Tetrad of Narcolepsy:** 1. Excessive Daytime Sleepiness, 2. Cataplexy (sudden loss of muscle tone triggered by emotions), 3. Sleep Paralysis, 4. Hypnagogic/Hypnopompic hallucinations. * **Pathophysiology:** Deficiency of **Hypocretin (Orexin)** in the CSF. * **Diagnosis:** Multiple Sleep Latency Test (MSLT) showing mean sleep latency <8 minutes and ≥2 SOREMPs. * **Treatment:** Modafinil/Armodafinil (first-line for EDS); Sodium Oxybate (for cataplexy and sleep fragmentation).

Q: All of the following are NREM sleep disorders except?

Nightmares. ### Explanation The correct answer is **Nightmares**. Sleep disorders are primarily classified based on the stage of sleep in which they occur: **NREM (Non-Rapid Eye Movement)** or **REM (Rapid Eye Movement)**. **1. Why Nightmares are the Correct Answer:** Nightmares are a **REM sleep parasomnia**. They typically occur during the later half of the night when REM periods are longer and more intense. Characteristics include vivid, frightening dreams from which the individual awakens fully alert with detailed recall of the dream content. Because muscle atonia is present during REM, there is usually no physical movement or screaming. **2. Analysis of NREM Disorders (Incorrect Options):** * **Somnambulism (Sleepwalking):** Occurs during Stage N3 (Deep/Slow-wave sleep). The individual is difficult to arouse and has no memory of the event. * **Pavor Nocturnus (Sleep Terrors):** Occurs during Stage N3. Characterized by sudden arousal, intense fear, autonomic hyperactivity (tachycardia, sweating), and screaming. Unlike nightmares, there is **no recall** of a dream. * **Somniloquy (Sleep Talking):** Can occur in both NREM and REM, but it is classically associated with NREM stages. **3. NEET-PG High-Yield Pearls:** * **Stage of Occurrence:** NREM parasomnias (Sleepwalking/Terrors) occur in the **first third** of the night (Stage N3). REM parasomnias (Nightmares) occur in the **last third**. * **Memory:** NREM disorders are characterized by **amnesia** for the episode; REM disorders (Nightmares) have **vivid recall**. * **Treatment:** For severe Sleepwalking or Sleep Terrors, **Benzodiazepines** (like Diazepam) are used because they suppress Stage N3 sleep. * **REM Sleep Behavior Disorder (RBD):** A condition where the normal muscle atonia of REM is lost, leading to "acting out" dreams; it is a strong predictor of future neurodegenerative diseases like Parkinson’s.

Q: Which of the following is NOT typically seen in narcolepsy?

Catalepsy. **Explanation:** The correct answer is **C. Catalepsy**. This is a common point of confusion in psychiatry exams. Narcolepsy is characterized by **Cataplexy**, not Catalepsy. 1. **Why Catalepsy is the correct answer (The "Not" factor):** * **Catalepsy** is a state of muscular rigidity and fixed posture regardless of external stimuli, commonly associated with **Catatonic Schizophrenia** or organic brain syndromes. * **Cataplexy** (seen in Narcolepsy) is the sudden, transient loss of muscle tone triggered by strong emotions (laughter, anger). Patients remain conscious during cataplexy, unlike in catalepsy. 2. **Analysis of Incorrect Options:** * **A. Sleep Paralysis:** A classic symptom of Narcolepsy. It is the temporary inability to move or speak while falling asleep (hypnagogic) or waking up (hypnopompic). * **B. Ataxia:** While not a primary diagnostic symptom, "pseudo-ataxia" or motor incoordination can occur during partial cataplectic attacks or periods of extreme daytime sleepiness. In the context of this specific question, Catalepsy is the definitive "wrong" term. * **D. Abnormal REM sleep:** Narcolepsy is fundamentally a disorder of REM sleep regulation. Patients exhibit **SOREMPs** (Sleep Onset REM Periods), where they enter REM sleep within 15 minutes of sleep onset. **High-Yield Clinical Pearls for NEET-PG:** * **The Narcoleptic Tetrad:** 1. Excessive Daytime Sleepiness (earliest symptom), 2. Cataplexy (most specific), 3. Sleep Paralysis, 4. Hypnagogic/Hypnopompic hallucinations. * **Pathophysiology:** Deficiency of **Hypocretin (Orexin)** in the lateral hypothalamus. * **Diagnosis:** Gold standard is the **Multiple Sleep Latency Test (MSLT)** showing mean sleep latency <8 minutes and ≥2 SOREMPs. * **Treatment:** Modafinil (first-line for sleepiness); Sodium Oxybate (drug of choice for cataplexy).

Q: What is a characteristic feature of narcolepsy?

Daytime hypersomnia. **Explanation:** **Narcolepsy** is a chronic neurological disorder characterized by the brain's inability to regulate sleep-wake cycles normally. The hallmark feature is **Daytime Hypersomnia** (Option B), which manifests as excessive daytime sleepiness (EDS) and "sleep attacks" where the patient falls asleep irresistibly during daily activities. This occurs due to the deficiency of **orexin (hypocretin)** producing neurons in the lateral hypothalamus. **Analysis of Options:** * **Option A (Insomnia):** While narcoleptics have fragmented nighttime sleep, the defining diagnostic feature is the inability to stay awake during the day, not the inability to fall asleep. * **Option C (Bimism):** This is not a recognized medical term in sleep medicine. It may be a distractor for "Bruxism" (teeth grinding), which is a sleep-related movement disorder. * **Option D (Somnambulism):** Also known as sleepwalking, this is a NREM parasomnia occurring during Stage N3 sleep. Narcolepsy, conversely, is characterized by **REM sleep intrusion** into wakefulness. **High-Yield Clinical Pearls for NEET-PG:** * **The Tetrad of Narcolepsy:** 1. **Excessive Daytime Sleepiness:** The most common and usually the first symptom. 2. **Cataplexy:** Sudden loss of muscle tone triggered by strong emotions (pathognomonic). 3. **Sleep Paralysis:** Inability to move upon waking or falling asleep. 4. **Hypnagogic/Hypnopompic Hallucinations:** Vivid dreams while falling asleep or waking up. * **Diagnosis:** Gold standard is the **Multiple Sleep Latency Test (MSLT)** showing a mean sleep latency <8 minutes and ≥2 Sleep Onset REM Periods (SOREMPs). * **Treatment:** Modafinil (first-line for EDS); Sodium Oxybate (for cataplexy).

Q: What is the hypnopompic phenomenon?

A sensation experienced while awakening. **Explanation:** The **hypnopompic phenomenon** refers to hallucinations or sensory experiences (visual, auditory, or tactile) that occur during the transition from sleep to wakefulness. **1. Why the Correct Answer is Right:** The term is derived from the Greek words *hypnos* (sleep) and *pompe* (sending away). It occurs as the brain transitions out of REM sleep. During this phase, elements of dream imagery can "bleed" into wakefulness, often accompanied by sleep paralysis. This makes **Option B** the correct answer. **2. Why Other Options are Incorrect:** * **Option A:** Sensations experienced while falling asleep are termed **hypnagogic** hallucinations (*gogos* = leading to). A common mnemonic to distinguish them is: **"Go"** to sleep = Hypna**go**gic; **"Po"**st-sleep = Hypno**po**mpic. * **Option C:** Phenomena after head trauma are usually referred to as post-concussive symptoms or post-traumatic amnesia. * **Option D:** Phenomena following a convulsion are termed **post-ictal** states (e.g., post-ictal confusion or Todd’s paralysis). **3. NEET-PG High-Yield Pearls:** * **Narcolepsy Tetrad:** Hypnagogic/hypnopompic hallucinations are part of the classic tetrad, which also includes excessive daytime sleepiness, cataplexy, and sleep paralysis. * **Physiological Occurrence:** These hallucinations can occur in 10-15% of the healthy population and are not always indicative of pathology. * **REM Association:** Both hypnagogic and hypnopompic hallucinations are considered "REM-intrusion" phenomena, where REM sleep components occur during wakefulness.

Q: Which of the following is a characteristic feature of narcolepsy?

Decreased REM sleep latency. **Explanation:** Narcolepsy is a chronic neurological disorder characterized by the brain's inability to regulate sleep-wake cycles, primarily due to the loss of **orexin (hypocretin)-producing neurons** in the lateral hypothalamus. **Why Option B is correct:** In normal sleep, REM (Rapid Eye Movement) sleep typically occurs about 90 minutes after falling asleep. In narcolepsy, patients experience **Sleep-Onset REM Periods (SOREMPs)**. This means they transition directly from wakefulness into REM sleep, resulting in a **decreased REM sleep latency** (often <15 minutes). This rapid entry into REM explains symptoms like hypnagogic hallucinations and sleep paralysis. **Why the other options are incorrect:** * **Option A:** While narcoleptics suffer from excessive daytime sleepiness (EDS) and "sleep attacks," their total 24-hour sleep time is usually **normal** or only slightly increased. Their sleep is fragmented rather than prolonged. * **Option C:** Narcolepsy is associated with **cataplexy** (sudden loss of muscle tone triggered by strong emotions) and sleep paralysis. Therefore, there is a **decrease** or absence of muscle tone, not an increase. **High-Yield Clinical Pearls for NEET-PG:** * **The Tetrad of Narcolepsy:** 1. Excessive Daytime Sleepiness (most common), 2. Cataplexy (most specific), 3. Hypnagogic/Hypnopompic hallucinations, 4. Sleep paralysis. * **Diagnosis:** Gold standard is the **Multiple Sleep Latency Test (MSLT)** showing a mean sleep latency <8 minutes and ≥2 SOREMPs. * **Treatment:** **Modafinil** is the first-line treatment for daytime sleepiness; **Sodium Oxybate** is effective for cataplexy. * **CSF Finding:** Low levels of **Hypocretin-1**.

Q: A 4-year-old boy occasionally wakes in the middle of the night crying. When his parents check on him, he seems visibly frightened and tells his parents that Chihuahuas were chasing him. What sleep disturbance is most consistent with this history?

Nightmares. ### Explanation The correct answer is **Nightmares**. **1. Why Nightmares are the correct answer:** Nightmares are frightening dreams that occur during **REM (Rapid Eye Movement) sleep**, typically in the later half of the night. The key diagnostic features present in this clinical scenario are: * **Detailed Recall:** The child can vividly describe the dream content (being chased by Chihuahuas). * **Full Alertness:** Upon waking, the child is quickly oriented and can interact with parents. * **Timing:** They occur during REM sleep, which predominates in the later part of the night. **2. Why other options are incorrect:** * **Night Terrors (Sleep Terrors):** These occur during **NREM Stage N3 (Slow-wave sleep)**, usually in the first third of the night. Unlike nightmares, children with night terrors are difficult to arouse, appear inconsolable, experience autonomic arousal (tachycardia, sweating), and—most importantly—have **amnesia** for the episode the next morning. * **Learned Behavior:** This refers to sleep-onset association disorders where a child requires specific conditions (e.g., rocking) to fall asleep. It does not involve vivid frightening imagery. * **Obstructive Sleep Apnea (OSA):** While OSA can cause nighttime awakenings, it is characterized by snoring, gasping, and daytime somnolence, not specific dream recall. **3. Clinical Pearls for NEET-PG:** * **REM vs. NREM:** Nightmares = REM (Late night); Night Terrors = NREM Stage 3 (Early night). * **Memory:** Nightmares = Good recall; Night Terrors = No recall. * **Management:** For nightmares, reassurance is sufficient. For persistent night terrors, low-dose benzodiazepines (like Diazepam) may be used as they suppress Stage N3 sleep. * **Age:** Both are common in children, but nightmares peak between ages 3–6.

Question 1

Bruxism most commonly occurs during which phase of sleep?

Accepted Answer

NREM Stage II

Answer

REM sleep

Answer

NREM Stage I

Answer

NREM Stage III

Question 2

Kleine-Levin syndrome is characterized by which of the following?

Accepted Answer

Hypersomnia

Answer

Insomnia

Answer

Depression

Answer

Anxiety

Question 3

A person hears voices before falling asleep, with a history of falls and daytime sleep attacks. What is the probable diagnosis?

Accepted Answer

Narcolepsy

Answer

Schizophrenia

Answer

Delusion

Answer

Insomnia

Question 4

Narcolepsy is characterized by excessive daytime sleepiness?

Accepted Answer

Excessive daytime sleepiness

Answer

Increased REM sleep latency

Answer

Increased total sleep time

Answer

Normal sleep architecture

Question 5

All of the following are NREM sleep disorders except?

Accepted Answer

Nightmares

Answer

Somnambulism

Answer

Pavor nocturnus

Answer

Somniloquy

Question 6

Which of the following is NOT typically seen in narcolepsy?

Accepted Answer

Catalepsy

Answer

Sleep paralysis

Answer

Ataxia

Answer

Abnormal REM sleep

Question 7

What is a characteristic feature of narcolepsy?

Accepted Answer

Daytime hypersomnia

Answer

Insomnia

Answer

Bimism

Answer

Somnambulism

Question 8

What is the hypnopompic phenomenon?

Accepted Answer

A sensation experienced while awakening

Answer

A sensation experienced while falling asleep

Answer

A phenomenon occurring after head trauma

Answer

A phenomenon occurring after a convulsion

Question 9

Which of the following is a characteristic feature of narcolepsy?

Accepted Answer

Decreased REM sleep latency

Answer

Increased sleep time

Answer

Increase in muscle tone

Answer

None of the above

Question 10

A 4-year-old boy occasionally wakes in the middle of the night crying. When his parents check on him, he seems visibly frightened and tells his parents that Chihuahuas were chasing him. What sleep disturbance is most consistent with this history?

Accepted Answer

Nightmares

Answer

Night terrors

Answer

Learned behavior

Answer

Obstructive sleep apnea

Sleep-Wake Disorders — MCQs

Sleep-Wake Disorders — MCQs

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