Sleep-Wake Disorders — MCQs

Sleep-Wake Disorders Indian Medical PG Practice Questions and MCQs

Question 11: What is a characteristic feature of narcolepsy?

A. Insomnia
B. Daytime hypersomnia (Correct Answer)
C. Bimism
D. Somnambulism

Explanation: **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).

Question 12: Bruxism is characterized by?

A. Increased mobility of the teeth
B. Radiographic widening of the periodontal ligament
C. Morning pain in muscles
D. All the above (Correct Answer)

Explanation: **Explanation:** **Bruxism** is a sleep-related movement disorder characterized by the involuntary grinding or clenching of teeth. In psychiatry, it is often associated with stress, anxiety, and certain psychotropic medications (like SSRIs). **Why "All the above" is correct:** The clinical manifestations of bruxism are a result of repetitive, excessive mechanical force applied to the stomatognathic system: 1. **Increased mobility of the teeth (Option A):** Chronic grinding places excessive occlusal load on the supporting structures. This repetitive trauma can lead to the loosening of teeth within their sockets. 2. **Radiographic widening of the periodontal ligament (Option B):** Under constant pressure, the periodontal ligament (PDL) undergoes compensatory hypertrophy or inflammatory changes to accommodate the stress. On an X-ray, this appears as a characteristic thickening or widening of the radiolucent PDL space. 3. **Morning pain in muscles (Option C):** Since sleep bruxism occurs during the night, patients typically present with "morning symptoms." The masseter and temporalis muscles undergo fatigue and myofascial pain due to prolonged nocturnal contraction. **High-Yield Clinical Pearls for NEET-PG:** * **Sleep Stage:** Bruxism most commonly occurs during **NREM Stage 2** and REM sleep. * **Associated Conditions:** It is frequently linked with Sleep Apnea and Stress/Anxiety disorders. * **Drug-Induced:** SSRIs (e.g., Fluoxetine) are a known cause; **Buspirone** is often used to alleviate SSRI-induced bruxism. * **Management:** Treatment includes occlusal splints (mouth guards), stress management, and occasionally Benzodiazepines or Muscle Relaxants at bedtime. * **Dental Sign:** Look for "flattened occlusal surfaces" or "wear facets" on physical examination.

Question 13: Hallucinations that occur at the onset of sleep are termed as:

A. Hypnagogic hallucinations (Correct Answer)
B. Hypnopompic hallucinations
C. Jactatio nocturna capitis
D. Non-specific hallucination

Explanation: **Explanation:** The correct answer is **Hypnagogic hallucinations**. These are vivid, dream-like sensory perceptions (usually visual or auditory) that occur during the transition from wakefulness to sleep. **1. Why Hypnagogic is correct:** The term is derived from the Greek words *hypnos* (sleep) and *agogos* (leading). These occur at the **onset of sleep**. They are considered physiological but are classically associated with the tetrad of **Narcolepsy**. **2. Analysis of Incorrect Options:** * **Hypnopompic hallucinations:** These occur during the transition from sleep to wakefulness (at the **offset of sleep**). *Mnemonic: "pomp" as in "pomp and circumstance" for an exit/graduation.* * **Jactatio nocturna capitis:** Also known as "rhythmic movement disorder," this involves repetitive head banging or rolling movements during the transition to sleep, commonly seen in infants and young children. * **Non-specific hallucination:** This is not a formal clinical term used to describe sleep-related sensory phenomena. **Clinical Pearls for NEET-PG:** * **Narcolepsy Tetrad:** 1. Excessive Daytime Sleepiness (most common), 2. Cataplexy (most specific), 3. Sleep Paralysis, 4. Hypnagogic/Hypnopompic hallucinations. * **Pathophysiology:** Narcolepsy is caused by the loss of **orexin (hypocretin)** producing neurons in the lateral hypothalamus. * **REM Latency:** In Narcolepsy, there is a characteristic **decreased REM latency** (Sleep Onset REM Periods - SOREMPs). * Hypnagogic and hypnopompic hallucinations are technically **pseudo-hallucinations** because the individual often maintains some insight into their unreality.

Question 14: What is the hypnopompic phenomenon?

A. A sensation experienced while falling asleep
B. A sensation experienced while awakening (Correct Answer)
C. A phenomenon occurring after head trauma
D. A phenomenon occurring after a convulsion

Explanation: **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.

Question 15: Which of the following is a characteristic feature of narcolepsy?

A. Increased sleep time
B. Decreased REM sleep latency (Correct Answer)
C. Increase in muscle tone
D. None of the above

Explanation: **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**.

Question 16: 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?

A. Night terrors
B. Nightmares (Correct Answer)
C. Learned behavior
D. Obstructive sleep apnea

Explanation: ### 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 17: All of the following are true about Narcolepsy, except:

A. Strong association with HLA class II
B. Sudden loss of voluntary muscle tone
C. NREM abnormality (Correct Answer)
D. Irresistible desire to sleep

Explanation: **Explanation:** Narcolepsy is a chronic neurological disorder characterized by the brain's inability to regulate sleep-wake cycles normally. **Why Option C is the correct answer (The "Except"):** Narcolepsy is fundamentally an **REM sleep abnormality**, not an NREM abnormality. In healthy individuals, sleep begins with NREM stages; however, narcoleptic patients transition almost immediately into REM sleep (Sleep Onset REM Periods or **SOREMPs**). The classic tetrad of symptoms—cataplexy, sleep paralysis, and hypnagogic hallucinations—are essentially REM phenomena intruding into wakefulness. **Analysis of Incorrect Options:** * **Option A (HLA Association):** There is a very strong association (over 90% of cases with cataplexy) with **HLA-DQB1*0602**. This suggests an autoimmune destruction of hypocretin-producing neurons in the hypothalamus. * **Option B (Loss of muscle tone):** This refers to **Cataplexy**, a pathognomonic feature of Narcolepsy Type 1. It is a sudden, bilateral loss of muscle tone triggered by strong emotions (e.g., laughter, surprise) while consciousness remains preserved. * **Option D (Irresistible desire):** **Excessive Daytime Sleepiness (EDS)** is the most common and often the first symptom. Patients experience "sleep attacks" that can occur at inappropriate times. **High-Yield Clinical Pearls for NEET-PG:** * **Pathophysiology:** Deficiency of **Hypocretin (Orexin)** in the cerebrospinal fluid. * **The Tetrad:** 1. EDS, 2. Cataplexy, 3. Sleep Paralysis, 4. Hypnagogic/Hypnopompic Hallucinations. * **Diagnosis:** Gold standard is **Polysomnography** followed by **Multiple Sleep Latency Test (MSLT)** showing mean sleep latency <8 minutes and ≥2 SOREMPs. * **Treatment:** **Modafinil** (first-line for EDS); **Sodium Oxybate** (effective for cataplexy and sleep fragmentation).

Question 18: Relaxis pad is used in which of the following conditions?

A. Nocturnal enuresis
B. Restless leg syndrome (Correct Answer)
C. Narcolepsy
D. Panic disorder

Explanation: **Explanation:** **Restless Leg Syndrome (RLS)**, also known as Willis-Ekbom Disease, is a neurological sensory disorder characterized by an irresistible urge to move the legs, usually accompanied by uncomfortable sensations. These symptoms worsen at rest and during the evening/night. The **Relaxis pad** is an FDA-cleared, non-pharmacological medical device specifically designed to improve sleep quality in patients with primary RLS. It works on the principle of **counter-stimulation**. The pad is placed under the legs and delivers physical vibrations at varying intensities. These vibrations provide sensory input that "competes" with and overrides the unpleasant sensations of RLS, allowing the patient to fall and stay asleep without the need for constant movement. **Analysis of Incorrect Options:** * **Nocturnal Enuresis:** Managed primarily with behavioral therapy (bell-and-pad alarms) or pharmacotherapy (Desmopressin/Imipramine). * **Narcolepsy:** A disorder of sleep-wake control treated with stimulants (Modafinil) and REM-suppressing drugs (Sodium Oxybate). * **Panic Disorder:** An anxiety disorder treated with SSRIs and Cognitive Behavioral Therapy (CBT). **High-Yield Clinical Pearls for NEET-PG:** * **Etiology:** Often associated with **Iron deficiency** (check serum ferritin levels). * **Drug of Choice:** Dopamine agonists like **Pramipexole** or Ropinirole. Gabapentin enacarbil is also first-line. * **Secondary Causes:** Pregnancy, End-stage renal disease (ESRD), and Vitamin B12 deficiency. * **Key Feature:** Symptoms follow a **circadian rhythm**, peaking between 10 PM and 4 AM.

Question 19: What is true in narcolepsy?

A. Normal night time sleep
B. Normal REM sleep
C. Hypersomnia (Correct Answer)
D. Increased REM latency

Explanation: **Explanation:** Narcolepsy is a chronic neurological disorder characterized by the brain's inability to regulate sleep-wake cycles normally. It is primarily caused by a deficiency of **hypocretin (orexin)** producing neurons in the hypothalamus. **Why Hypersomnia is Correct:** The hallmark of narcolepsy is **Excessive Daytime Sleepiness (EDS)** or hypersomnia. Patients experience an irresistible urge to sleep, leading to "sleep attacks" that can occur at inappropriate times (e.g., while eating or talking). These episodes are typically brief (10–20 minutes) and the patient feels temporarily refreshed upon awakening. **Analysis of Incorrect Options:** * **A. Normal night time sleep:** Incorrect. Narcoleptics suffer from **fragmented nocturnal sleep**. While they fall asleep quickly, they experience frequent awakenings and poor sleep quality. * **B. Normal REM sleep:** Incorrect. Narcolepsy is characterized by **REM sleep dysregulation**. REM sleep phenomena (like atonia) intrude into wakefulness (cataplexy), and REM sleep occurs much earlier than normal. * **D. Increased REM latency:** Incorrect. In narcolepsy, there is **decreased REM latency**. Patients often enter REM sleep within 15 minutes of falling asleep (Sleep Onset REM Periods - SOREMPs), whereas normal REM latency is approximately 90 minutes. **High-Yield Clinical Pearls for NEET-PG:** 1. **The Tetrad of Narcolepsy:** * Excessive Daytime Sleepiness (Most common/Universal). * **Cataplexy:** Sudden loss of muscle tone triggered by strong emotions (most specific sign). * **Sleep Paralysis:** Inability to move upon waking or falling asleep. * **Hypnagogic/Hypnopompic Hallucinations:** Vivid dreams while falling asleep (gogic) or waking up (pompic). 2. **Diagnosis:** Gold standard is the **Multiple Sleep Latency Test (MSLT)** showing mean sleep latency <8 minutes and ≥2 SOREMPs. 3. **Treatment:** Modafinil (first-line for EDS); Sodium Oxybate (effective for cataplexy and sleep fragmentation).

Question 20: Which of the following statements about narcolepsy is false?

A. Sleep onset REM periods occur
B. It typically presents in the second decade of life (Correct Answer)
C. Cataplexy is a common feature
D. Sudden loss of muscle tone can occur

Explanation: **Explanation:** Narcolepsy is a chronic neurological disorder characterized by the brain's inability to regulate sleep-wake cycles normally, primarily due to the loss of **hypocretin (orexin)** producing neurons in the hypothalamus. **Why Option B is the Correct (False) Statement:** While narcolepsy can occur at any age, its peak onset is bimodal. The first and most significant peak occurs around **age 15 (second decade)**, and a second smaller peak occurs around **age 35 (fourth decade)**. Therefore, stating it "typically presents in the second decade" is considered the least accurate or "false" statement in the context of competitive exams when compared to the definitive physiological hallmarks described in other options. *Note: In some clinical texts, this is debated, but for NEET-PG, the bimodal distribution is the key differentiator.* **Analysis of Other Options:** * **Option A (True):** A hallmark of narcolepsy is **SOREMPs (Sleep Onset REM Periods)**. Unlike normal sleep where REM occurs after ~90 minutes, narcoleptics enter REM sleep within 15 minutes of sleep onset. * **Option C & D (True):** **Cataplexy** is a pathognomonic feature of Narcolepsy Type 1. It is a **sudden loss of muscle tone** (bilateral) triggered by strong emotions (laughter, surprise) while consciousness remains preserved. **High-Yield Clinical Pearls for NEET-PG:** * **The Tetrad of Narcolepsy:** 1. Excessive Daytime Sleepiness (EDS), 2. Cataplexy, 3. Sleep Paralysis, 4. Hypnagogic/Hypnopompic hallucinations. * **Gold Standard Investigation:** Polysomnography followed by **Multiple Sleep Latency Test (MSLT)** showing mean sleep latency <8 minutes and ≥2 SOREMPs. * **CSF Finding:** Low levels of **Hypocretin-1**. * **Treatment:** **Modafinil** (First-line for EDS); **Sodium Oxybate** (Drug of choice for cataplexy).

Practice by Chapter

Normal Sleep Physiology

Practice Questions

Insomnia Disorder

Practice Questions

Hypersomnolence Disorders

Practice Questions

Narcolepsy

Practice Questions

Breathing-Related Sleep Disorders

Practice Questions

Circadian Rhythm Sleep-Wake Disorders

Practice Questions

Parasomnias

Practice Questions

Sleep-Related Movement Disorders

Practice Questions

Sleep Disorders in Psychiatric Conditions

Practice Questions

Pharmacotherapy for Sleep Disorders

Practice Questions

Cognitive-Behavioral Therapy for Insomnia

Practice Questions

Sleep Hygiene and Other Non-pharmacological Approaches

Practice Questions

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