Hypersomnias — MCQs
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?
All of the following criteria are required for diagnosis of obesity hypoventilation syndrome except -
A 9-year-old child is restless. He is hyperactive, and his teacher complains that he does not listen to the teachings, disturbs other students, and shows less interest in playing. The likely diagnosis is?
Narcolepsy is characterized by all of the following except -
Not seen in Narcolepsy:
In narcolepsy, the polysomnographic recording typically shows which of the following patterns?
All of the following are neurologic channelopathies except :
Which human leukocyte antigen (HLA) complex is associated with narcolepsy?
A 49-year-old man presents with a 10-year history of increasing knee and hip pain, exacerbated by end-of-day activity. Over the past year, he has developed increasing drowsiness at work and his wife reports he is a severe snorer. For the last month, he has experienced episodes of sharp, colicky, right upper abdominal pain. His physical examination reveals a temperature of 37°C, pulse of 82/min, respirations of 10/min, and blood pressure of 140/85 mm Hg. He is 175 cm tall and weighs 156 kg (BMI 51). Laboratory findings include glucose of 139 mg/dL, HbA1c of 10%, total cholesterol of 229 mg/dL, and HDL cholesterol of 33 mg/dL. Arterial blood gas measurements show pH 7.35, PCO2 50 mm Hg, and PO2 75 mm Hg. Which of the following additional conditions is most likely present in this man?
Sleep apnoea is defined as a temporary pause in breathing during sleep lasting at least:
Hypersomnias Indian Medical PG Practice Questions and MCQs
Question 1: 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
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.
Question 2: 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 3: A 9-year-old child is restless. He is hyperactive, and his teacher complains that he does not listen to the teachings, disturbs other students, and shows less interest in playing. The likely diagnosis is?
- A. Cerebral palsy
- B. Attention Deficit Hyperactivity Disorder (ADHD) (Correct Answer)
- C. Delirium
- D. Mania
Explanation: ***Attention Deficit Hyperactivity Disorder (ADHD)*** - The symptoms described, such as **restlessness**, **hyperactivity**, **difficulty listening**, and **disturbing others**, are classic indicators of **Attention Deficit Hyperactivity Disorder** in a child. - ADHD is characterized by a persistent pattern of inattention and/or hyperactivity-impulsivity that interferes with functioning or development. - The decreased interest in playing may reflect difficulty with **structured play activities** or **peer interactions** rather than lack of interest in play itself, which can occur in ADHD due to impulsivity and inattention affecting social relationships. *Cerebral palsy* - **Cerebral palsy** is a group of permanent movement disorders that appear in early childhood and primarily affect **muscle coordination and motor control**. - It does not explain the behavioral and attentional issues described in the case, and the focus here is on behavioral problems rather than motor dysfunction. *Delirium* - **Delirium** is an acute, fluctuating disturbance in attention and cognition, often caused by an underlying medical condition, substance intoxication, or withdrawal. - It typically has an **abrupt onset** and waxing-waning course with altered consciousness, which is not consistent with the chronic, stable presentation in this child. *Mania* - **Mania** is a state of elevated, expansive, or irritable mood and increased goal-directed activity or energy, typically seen in **bipolar disorder**. - While it can involve **hyperactivity** and distractibility, mania would present with **elevated/irritable mood**, **decreased need for sleep**, **pressured speech**, and **grandiosity**, which are not described here. The symptom complex is more consistent with the developmental disorder of ADHD.
Question 4: Narcolepsy is characterized by all of the following except -
- A. Sleep paralysis
- B. Snoring (Correct Answer)
- C. Hallucination
- D. Cataplexy
Explanation: ***Snoring*** - **Snoring** is a common symptom of **obstructive sleep apnea**, not a characteristic feature of narcolepsy. - While individuals with narcolepsy can snore, it is not a diagnostic criterion or a primary symptom differentiating it from other sleep disorders. *Sleep paralysis* - **Sleep paralysis**, the inability to move or speak while waking up or falling asleep, is a common symptom in narcolepsy. - It often occurs during the transitions between sleep and wakefulness, a manifestation of REM sleep intrusion into wakefulness. *Hallucination* - **Hypnagogic (at sleep onset) and hypnopompic (at sleep offset) hallucinations** are vivid, dream-like experiences that occur when falling asleep or waking up. - These can be frightening and are another sign of involuntary intrusion of REM sleep phenomena into wakefulness. *Cataplexy* - **Cataplexy** is the sudden, brief loss of voluntary muscle tone, often triggered by strong emotions like laughter or anger. - It is a highly specific symptom of narcolepsy, particularly in type 1, due to a deficiency in **hypocretin** (orexin) in the brain.
Question 5: Not seen in Narcolepsy:
- A. Sleep attack
- B. Cataplexy
- C. Catalepsy (Correct Answer)
- D. Sleep paralysis
Explanation: ***Catalepsy*** - **Catalepsy** is a trancelike state with **muscle rigidity** and **waxy flexibility**, often seen in conditions like **catatonic schizophrenia** or **epilepsy**. - It is **NOT a feature of narcolepsy** and is distinct from cataplexy, which involves sudden muscle weakness (not sustained rigidity). *Sleep attack* - **Sleep attacks ARE seen in narcolepsy** - they are a primary symptom characterized by **sudden, irresistible bouts of sleepiness** during waking hours. - These attacks can occur without warning and are a defining feature of the disorder. *Cataplexy* - **Cataplexy IS seen in narcolepsy** - it is a hallmark symptom of **narcolepsy type 1**, involving sudden, **brief episodes of muscle weakness** triggered by strong emotions like laughter or anger. - Despite muscle weakness, the individual remains conscious throughout the episode. *Sleep paralysis* - **Sleep paralysis IS seen in narcolepsy** - characterized by a **temporary inability to move or speak** when waking up or falling asleep. - This occurs due to a dissociation of REM sleep features into wakefulness.
Question 6: In narcolepsy, the polysomnographic recording typically shows which of the following patterns?
- A. REM intrusion during inappropriate periods (Correct Answer)
- B. An absence of REM sleep in midcycle
- C. Extreme muscular relaxation
- D. Spike-and-wave EEG recording
Explanation: ***REM intrusion during inappropriate periods*** - In narcolepsy, the hallmark polysomnographic finding is **sleep-onset REM periods (SOREMPs)** - the occurrence of REM sleep within 15 minutes of sleep onset. - The **Multiple Sleep Latency Test (MSLT)** in narcolepsy typically shows **≥2 SOREMPs** along with a mean sleep latency of ≤8 minutes. - Clinically, this **REM sleep intrusion** manifests as **sudden, irresistible sleep attacks** during the day, **cataplexy** (sudden muscle weakness triggered by strong emotions), **sleep paralysis**, and **hypnagogic/hypnopompic hallucinations**. - These represent features of REM sleep (muscle atonia, dreams) occurring at inappropriate times. *An absence of REM sleep in midcycle* - This statement is incorrect as narcolepsy is characterized by an **abnormal presence and early onset of REM sleep**, not its absence. - Individuals with narcolepsy enter REM sleep much faster than normal (often within minutes rather than the typical 90 minutes). *Extreme muscular relaxation* - While **cataplexy** (present in Type 1 narcolepsy) involves sudden loss of muscle tone due to REM-related atonia during wakefulness, this is a clinical symptom rather than a continuous polysomnographic finding. - Polysomnography focuses on **sleep architecture** and the timing of **REM sleep onset**, not general muscle relaxation patterns. *Spike-and-wave EEG recording* - **Spike-and-wave patterns** on EEG are characteristic of **absence seizures** (a form of epilepsy), not narcolepsy. - Narcolepsy is a primary **sleep disorder** with distinct polysomnographic features related to **REM sleep dysregulation**, not epileptiform activity.
Question 7: All of the following are neurologic channelopathies except :
- A. Episodic ataxia type I
- B. Spinocerebellar ataxia I (Correct Answer)
- C. Hypokalemic periodic paralysis
- D. Familial hemiplegic migraine
Explanation: ***Spinocerebellar ataxia I*** - This is a neurodegenerative disorder caused by a **CAG trinucleotide repeat expansion** in the ATXN1 gene, leading to protein misfolding and neuronal dysfunction, not directly a channelopathy. [1] - SCA1 primarily involves the **cerebellum and brainstem**, resulting in progressive ataxia, dysarthria, and dysphagia due to neuronal degeneration. *Episodic ataxia type I* - This is a **potassium channelopathy** caused by mutations in the KCNA1 gene (encoding Kv1.1 potassium channels). - It leads to brief, recurrent attacks of **ataxia, dysarthria, and myokymia** due to impaired repolarization of neurons. *Hypokalemic periodic paralysis* - This is a muscle **calcium or sodium channelopathy**, often caused by mutations in CACNA1S or SCN4A genes. [2] - It presents with episodes of **muscle weakness or paralysis** due to transient shifts of potassium into cells, affecting muscle excitability. [2] *Familial hemiplegic migraine* - This is a **calcium or sodium channelopathy** of the brain, associated with mutations in CACNA1S, SCN1A, or ATP1A2 genes. - It causes migraine attacks with a temporary **hemiparesis** (weakness on one side of the body), reflecting channel dysfunction in neuronal excitability.
Question 8: Which human leukocyte antigen (HLA) complex is associated with narcolepsy?
- A. DR2 (Correct Answer)
- B. DR3
- C. DR4
- D. B4
Explanation: Narcolepsy, particularly Type 1 (narcolepsy with cataplexy), has one of the strongest known genetic associations in medicine [1]. The correct answer is **HLA-DR2**, specifically the subtype **HLA-DRB1*1501** and its closely linked allele **HLA-DQB1*0602**. 1. **Why HLA-DR2 is correct:** Over 95% of patients with narcolepsy and cataplexy carry the HLA-DR2/DQB1*0602 complex. This association supports the autoimmune theory of the disease, where the immune system selectively destroys **hypocretin (orexin)-producing neurons** in the lateral hypothalamus. Hypocretin is essential for maintaining wakefulness and regulating REM sleep. 2. **Why other options are incorrect:** * **HLA-DR3:** Associated with autoimmune conditions like Type 1 Diabetes Mellitus, SLE, and Graves' disease. * **HLA-DR4:** Classically associated with Rheumatoid Arthritis and Type 1 Diabetes Mellitus. * **HLA-B27 (related to B4):** HLA-B alleles (like B27) are typically associated with seronegative spondyloarthropathies (e.g., Ankylosing Spondylitis), not sleep disorders. **Clinical Pearls for NEET-PG:** * **The Pentad of Narcolepsy:** Excessive daytime sleepiness (earliest symptom), Cataplexy (most specific), Hypnagogic hallucinations, Sleep paralysis, and Fragmented nocturnal sleep. * **Diagnosis:** Gold standard is the **Multiple Sleep Latency Test (MSLT)** showing a mean sleep latency <8 minutes and ≥2 Sleep Onset REM Periods (SOREMPs). * **CSF Findings:** Low or absent **Hypocretin-1 (Orexin-A)** levels in the cerebrospinal fluid are diagnostic for Type 1 Narcolepsy [1]. * **Treatment:** Modafinil is the first-line for daytime sleepiness; Sodium Oxybate is the drug of choice for cataplexy.
Question 9: A 49-year-old man presents with a 10-year history of increasing knee and hip pain, exacerbated by end-of-day activity. Over the past year, he has developed increasing drowsiness at work and his wife reports he is a severe snorer. For the last month, he has experienced episodes of sharp, colicky, right upper abdominal pain. His physical examination reveals a temperature of 37°C, pulse of 82/min, respirations of 10/min, and blood pressure of 140/85 mm Hg. He is 175 cm tall and weighs 156 kg (BMI 51). Laboratory findings include glucose of 139 mg/dL, HbA1c of 10%, total cholesterol of 229 mg/dL, and HDL cholesterol of 33 mg/dL. Arterial blood gas measurements show pH 7.35, PCO2 50 mm Hg, and PO2 75 mm Hg. Which of the following additional conditions is most likely present in this man?
- A. Hashimoto thyroiditis
- B. Hypertrophic cardiomyopathy
- C. Laryngeal papillomatosis
- D. Nonalcoholic fatty liver disease (Correct Answer)
Explanation: ### Explanation **Correct Answer: D. Nonalcoholic fatty liver disease (NAFLD)** **1. Why it is correct:** The patient presents with a classic constellation of **Metabolic Syndrome** and **Obesity Hypoventilation Syndrome (OHS)**. Key findings include morbid obesity (BMI 51), Type 2 Diabetes (HbA1c 10%), dyslipidemia, and daytime hypercapnia ($PCO_2$ 50 mm Hg) [1]. * **NAFLD** is the hepatic manifestation of metabolic syndrome and is highly prevalent in patients with morbid obesity and insulin resistance [2]. * The "sharp, colicky, right upper abdominal pain" suggests **cholelithiasis** (gallstones), which is also strongly associated with obesity and rapid weight fluctuations. * The combination of snoring, daytime somnolence, and hypercapnia in an obese patient confirms OHS (Pickwickian Syndrome), which frequently coexists with NAFLD. **2. Why the other options are incorrect:** * **A. Hashimoto thyroiditis:** While hypothyroidism can cause weight gain, it does not explain the colicky RUQ pain or the specific metabolic profile (diabetes/dyslipidemia) as directly as NAFLD does in this context. * **B. Hypertrophic cardiomyopathy:** This is a genetic structural heart disease. While this patient may develop *congestive* heart failure or *Cor Pulmonale* due to chronic hypoxia, HCM is not etiologically linked to obesity or metabolic syndrome. * **C. Laryngeal papillomatosis:** This is caused by HPV 6 and 11. While it can cause airway obstruction, it is unrelated to the patient's metabolic markers, BMI, or abdominal symptoms. **3. NEET-PG High-Yield Pearls:** * **Obesity Hypoventilation Syndrome (OHS):** Defined as the triad of Obesity (BMI >30), daytime hypercapnia ($PaCO_2 >45$ mmHg), and sleep-disordered breathing, in the absence of other causes of hypercapnia [1]. * **NAFLD Spectrum:** Ranges from simple steatosis to Non-alcoholic Steatohepatitis (NASH), cirrhosis, and hepatocellular carcinoma [3]. It is now the most common cause of chronic liver disease worldwide. * **Metabolic Syndrome Criteria (ATP III):** Abdominal obesity, High TG, Low HDL, Hypertension, and High Fasting Glucose. This patient meets almost all criteria.
Question 10: Sleep apnoea is defined as a temporary pause in breathing during sleep lasting at least:
- A. 40 seconds
- B. 30 seconds
- C. 20 seconds
- D. 10 seconds (Correct Answer)
Explanation: **Explanation:** **Correct Answer: D. 10 seconds** **Understanding the Concept:** In clinical sleep medicine, **Apnoea** is defined as the total or near-total cessation of airflow (at least a 90% reduction) for a duration of **at least 10 seconds**. This threshold is used because pauses shorter than 10 seconds are generally considered physiological and do not typically lead to significant oxygen desaturation or sleep fragmentation [1]. Sleep apnoea is further categorized into: 1. **Obstructive (OSA):** Continued respiratory effort against a collapsed airway (most common) [1]. 2. **Central (CSA):** Lack of respiratory effort due to a failure of the brain's drive to breathe [1]. 3. **Mixed:** A combination of both. **Analysis of Incorrect Options:** * **A, B, and C (40, 30, and 20 seconds):** While an apnoeic event can certainly last this long (and often does in severe cases), these are not the *minimum* diagnostic criteria. **High-Yield Clinical Pearls for NEET-PG:** * **Hypopnoea:** Defined as a reduction in airflow (≥30%) for ≥10 seconds associated with either oxygen desaturation (≥3% or 4%) or an arousal. * **Apnoea-Hypopnoea Index (AHI):** The gold standard for grading severity [2]. It is the number of apnoeas and hypopnoeas per hour of sleep. * *Mild:* 5–15 events/hr * *Moderate:* 15–30 events/hr * *Severe:* >30 events/hr * **Gold Standard Investigation:** Overnight Polysomnography (PSG). * **Treatment of Choice (OSA):** Continuous Positive Airway Pressure (CPAP) [2]. * **Common Association:** Obesity (Pickwickian Syndrome), retrognathia, and hypothyroidism.
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