Parasomnias — MCQs
Which one of the following phenomena is closely associated with slow-wave sleep?
A 78-year-old woman presents with a progressive decline in daily activity. She gives a history of convulsions and visual hallucinations. She does not talk to anyone and keeps looking at the sky. Pathological examination shows the presence of Lewy bodies within the neurons. What is the most probable diagnosis?
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 7-year-old girl is reported by the parents as waking up in the night screaming, and she sits up in bed frightened. She does not respond to questions and after 2 or 3 minutes she goes back to sleep. She has no memory of these events the following morning. Which of the following is the most likely diagnosis?
Drug of choice for night terrors:
Identify the sleep stage in the following Polysomnograph.
A 60-year-old man has resting tremor, pill-rolling movements, rigidity, and bradykinesia. Which of the following is most likely to be decreased in this man?
A 55-year-old man presents with a tremor that occurs when his hands are at rest. He has a slow, shuffling gait and difficulty initiating movement. His symptoms improve with levodopa. What is the most likely diagnosis?
A 45-year-old man presents with a history of frequent falls. He has difficulty in looking down also. What is the most probable diagnosis -
Which human leukocyte antigen (HLA) complex is associated with narcolepsy?
Parasomnias Indian Medical PG Practice Questions and MCQs
Question 1: Which one of the following phenomena is closely associated with slow-wave sleep?
- A. Dreaming
- B. Atonia
- C. Irregular heart rate
- D. Sleepwalking (Correct Answer)
Explanation: ***Sleepwalking*** - **Sleepwalking** (somnambulism) is a **parasomnia** that typically occurs during **slow-wave sleep (SWS)**, particularly in stages N3. - During SWS, the brain waves are slow, and the body's motor systems can still be active, leading to complex behaviors like walking while asleep. *Dreaming* - While dreams can occur in all sleep stages, **vivid and elaborate dreams** are most strongly associated with **REM (rapid eye movement) sleep**. - Dreams in **SWS** tend to be less vivid, more fragmented, and less emotionally charged. *Atonia* - **Atonia**, or muscle paralysis, is a hallmark feature of **REM sleep**, which prevents individuals from acting out their dreams. - In contrast, **muscle tone is typically maintained** during slow-wave sleep. *Irregular heart rate* - An **irregular heart rate** can be a feature of **REM sleep**, where autonomic nervous system activity is highly variable alongside rapid eye movements. - During **slow-wave sleep**, physiological functions such as heart rate tend to be **slowed and regular**, reflecting deep relaxation.
Question 2: A 78-year-old woman presents with a progressive decline in daily activity. She gives a history of convulsions and visual hallucinations. She does not talk to anyone and keeps looking at the sky. Pathological examination shows the presence of Lewy bodies within the neurons. What is the most probable diagnosis?
- A. Prion disease
- B. Huntington's disease
- C. Lewy body dementia (Correct Answer)
- D. Alzheimer's disease
Explanation: ***Lewy body dementia*** - The presence of **progressive cognitive decline**, **visual hallucinations**, and **convulsions** in an elderly patient is highly indicative of Lewy body dementia. - The definitive pathological finding of **Lewy bodies** within neurons confirms the diagnosis. *Prion disease* - Characterized by rapidly progressive dementia, **myoclonus**, and cerebellar ataxia, without typical visual hallucinations or convulsions. - Pathological examination typically shows **spongiform changes** and accumulation of abnormal prion protein, not Lewy bodies. *Huntington's disease* - Presents with a classic triad of **motor dysfunction** (chorea), psychiatric symptoms, and cognitive decline, typically with an earlier onset (30-50 years). - It is an inherited neurodegenerative disorder, and its pathology involves neuronal loss in the striatum, without Lewy bodies. *Alzheimer's disease* - The most common cause of dementia, characterized by **memory impairment** as an early and prominent feature. - Pathological findings include **amyloid plaques** and **neurofibrillary tangles**, not Lewy bodies, and visual hallucinations are less common or occur later in the disease.
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)
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.
Question 4: A 7-year-old girl is reported by the parents as waking up in the night screaming, and she sits up in bed frightened. She does not respond to questions and after 2 or 3 minutes she goes back to sleep. She has no memory of these events the following morning. Which of the following is the most likely diagnosis?
- A. Nightmare
- B. Sleep terrors (Correct Answer)
- C. Narcolepsy
- D. Nocturnal seizures
Explanation: ***Sleep terrors*** - **Sleep terrors** are characterized by abrupt awakenings, intense fear and screaming, autonomic arousal, and unresponsiveness, typically occurring during **NREM sleep** in the first third of the night. - The child will have **no memory** of the event the next morning, which is a key diagnostic feature, and they often return to sleep quickly afterward. *Nightmare* - **Nightmares** occur during **REM sleep**, usually in the latter half of the night, and the individual can often recall vivid and frightening details upon waking. - Unlike sleep terrors, individuals experiencing nightmares are typically **responsive to comfort** and fully alert after waking. *Narcolepsy* - **Narcolepsy** is a chronic neurological condition characterized by overwhelming daytime sleepiness and irresistible urges to sleep, often accompanied by **cataplexy**. - It does not involve nocturnal screaming episodes or unresponsiveness followed by a quick return to sleep with no memory. *Nocturnal seizures* - **Nocturnal seizures** can cause nocturnal awakenings with confusion or unusual behaviors, but they often involve **stereotyped movements**, sometimes with motor manifestations or post-ictal confusion that lasts longer than a few minutes. - While there might be no memory of the event, the screaming and frightened demeanor without typical seizure activity make sleep terrors a more likely diagnosis.
Question 5: Drug of choice for night terrors:
- A. Tricyclic antidepressant
- B. Meprobamate
- C. Diazepam
- D. Clonazepam (Correct Answer)
Explanation: ***Clonazepam*** - **Clonazepam**, a benzodiazepine, is the **drug of choice** for night terrors due to its ability to suppress Stage 3 and 4 **slow-wave sleep**, where night terrors occur. - Its sedative and anxiolytic effects help to calm the patient and reduce the frequency and severity of these episodes. *Tricyclic antidepressant* - While some **tricyclic antidepressants** (TCAs) have sedative properties, they are generally not the first-line treatment for night terrors. - Their side effect profile and potential to alter other sleep stages make them less suitable than benzodiazepines for this specific parasomnia. *Meprobamate* - **Meprobamate** is an anxiolytic and sedative drug that is largely historical and has been replaced by safer and more effective alternatives like benzodiazepines. - It has a higher risk of dependence and side effects compared to modern treatments for sleep disorders. *Diazepam* - **Diazepam** is another benzodiazepine, but **clonazepam** is generally preferred for night terrors due to its longer half-life and specific efficacy in suppressing slow-wave sleep. - While diazepam could offer some relief, clonazepam is considered more effective for sustained management of this condition.
Question 6: Identify the sleep stage in the following Polysomnograph.
- A. NREM stage 2 (Correct Answer)
- B. NREM stage 3
- C. REM
- D. NREM stage 1
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.
Question 7: A 60-year-old man has resting tremor, pill-rolling movements, rigidity, and bradykinesia. Which of the following is most likely to be decreased in this man?
- A. GABA neurons in the caudate nucleus and putamen
- B. Serotonin neurons in the raphe nuclei
- C. Acetylcholine neurons in the forebrain
- D. Dopamine neurons in the substantia nigra (Correct Answer)
Explanation: ***Dopamine neurons in the substantia nigra*** - The symptoms described—**resting tremor**, **pill-rolling movements**, **rigidity**, and **bradykinesia**—are classic signs of **Parkinson's disease** [5]. - Parkinson's disease is pathologically characterized by the degeneration of **dopamine-producing (dopaminergic) neurons** in the **substantia nigra pars compacta**, leading to decreased dopamine levels in the **striatum** [1]. *GABA neurons in the caudate nucleus and putamen* - **GABAergic neurons** in the **caudate nucleus and putamen** are primarily affected in conditions like **Huntington's disease**, where their degeneration leads to increased involuntary movements (chorea) [4]. - While there can be secondary changes in these neurons in Parkinson's, the primary deficit is not in GABA but in dopamine. *Serotonin neurons in the raphe nuclei* - **Serotonin neurons** in the **raphe nuclei** are involved in mood regulation, sleep, and appetite, and their dysfunction is primarily linked to conditions like **depression**, anxiety, and certain sleep disorders [3]. - While some serotonergic involvement can occur in Parkinson's, it is not the primary neurological deficit explaining the motor symptoms. *Acetylcholine neurons in the forebrain* - **Acetylcholine neurons** in the **nucleus basalis of Meynert** (part of the forebrain) are primarily implicated in **Alzheimer's disease**, where their degeneration contributes to cognitive decline [2]. - While some cholinergic deficits may be present in advanced Parkinson's, they are not the hallmark pathology or the initial cause of the characteristic motor symptoms.
Question 8: A 55-year-old man presents with a tremor that occurs when his hands are at rest. He has a slow, shuffling gait and difficulty initiating movement. His symptoms improve with levodopa. What is the most likely diagnosis?
- A. Parkinson’s disease (Correct Answer)
- B. Huntington’s disease
- C. Essential tremor
- D. Multiple sclerosis
Explanation: ***Parkinson’s disease*** - The classic triad of symptoms—**resting tremor**, **bradykinesia** (difficulty initiating movement, shuffling gait), and **rigidity**—is highly characteristic of Parkinson's disease [1, 5]. - Significant improvement with **levodopa** is a hallmark of dopaminergic responsiveness seen in Parkinson's disease. *Huntington’s disease* - Characterized by **chorea** (involuntary, jerky movements), cognitive decline, and psychiatric symptoms, which are not described in this patient. - The onset is typically earlier, and the tremor is not primarily a resting tremor. *Essential tremor* - Primarily an **action tremor** [1] that occurs during voluntary movement, unlike the resting tremor described in the patient. - While it can be debilitating, it typically does not present with **bradykinesia** or **shuffling gait**. *Multiple sclerosis* - A demyelinating disease presenting with a wide range of neurological symptoms depending on lesion location, such as sensory disturbances, weakness, visual problems, and **ataxia**. - While tremors can occur (often intention tremors), the clinical presentation of a **resting tremor**, **shuffling gait**, and **bradykinesia** is not typical of MS.
Question 9: A 45-year-old man presents with a history of frequent falls. He has difficulty in looking down also. What is the most probable diagnosis -
- A. Alzheimer's disease
- B. Normal pressure hydro-cephalus
- C. Parkinson's disease
- D. Progressive supranuclear palsy (Correct Answer)
Explanation: ***Progressive supranuclear palsy*** - The combination of **frequent falls** and **difficulty looking down** (supranuclear ophthalmoplegia, especially affecting vertical gaze) is a classic presentation of progressive supranuclear palsy (PSP). - PSP is a **tauopathy** characterized by **postural instability**, early falls, and distinctive ocular motor dysfunction. *Alzheimer's disease* - Primarily presents with **progressive memory loss** and cognitive decline, not typically early or prominent falls or vertical gaze palsy. - While falls can occur in later stages, they are not usually an initial hallmark symptom associated with restricted eye movements. *Normal pressure hydrocephalus* - Characterized by the triad of **gait disturbance** (often described as magnetic gait), **urinary incontinence**, and **dementia** [2]. - While gait disturbance can lead to falls, the specific difficulty in looking down is not a feature of NPH. *Parkinson's disease* - Characterized by **bradykinesia**, **rigidity**, **tremor**, and **postural instability** leading to falls later in the disease [1]. - However, difficulty looking down (vertical gaze palsy) is not a typical feature of Parkinson's disease, and falls tend to occur later in the disease course compared to PSP.
Question 10: 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.
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