All questions
Question 1
A 24-year-old law student presents with difficulty completing his coursework. He reports a lifelong pattern of being easily distracted, procrastinating on assignments, and losing his belongings. His childhood report cards frequently noted that he was 'inattentive' but 'very bright.' These symptoms are now jeopardizing his ability to graduate. He has no history of substance use or other psychiatric conditions.
Which of the following is the most appropriate initial pharmacologic treatment?
- Sertraline
- Methylphenidate (correct answer)
- Lorazepam
- Risperidone
Explanation: This patient's symptoms are consistent with adult attention-deficit/hyperactivity disorder (ADHD), characterized by a persistent pattern of inattention and/or hyperactivity-impulsivity that interferes with functioning. First-line pharmacologic treatment for ADHD in adults is a stimulant medication, such as methylphenidate or amphetamine. Sertraline is an SSRI for depression/anxiety, lorazepam is a benzodiazepine for anxiety, and risperidone is an antipsychotic.
Question 2
A 62-year-old woman presents with a 2-year history of a progressive language disturbance. Her speech has become slow and effortful, and she often struggles to find the right words. Her husband notes that her personality and memory for daily events have remained largely unchanged. Neurologic examination reveals no motor weakness or sensory loss.
This clinical presentation is most characteristic of which of the following neurodegenerative syndromes?
- Behavioral-variant frontotemporal dementia
- Primary progressive aphasia (correct answer)
- Corticobasal degeneration
- Typical Alzheimer disease
Explanation: Primary progressive aphasia (PPA) is a clinical dementia syndrome characterized by the gradual and prominent decline in language abilities, while other cognitive domains like memory and executive function are relatively spared early in the disease course. PPA is considered a form of frontotemporal lobar degeneration. This contrasts with typical Alzheimer disease (early memory loss) and behavioral-variant FTD (early personality and behavioral changes).
Question 3
An 85-year-old man with a history of mild cognitive impairment is evaluated for worsening confusion. His son reports that his father's memory has been slowly declining for years. However, over the past week, his condition has varied dramatically; he is lucid in the morning but becomes extremely disoriented and agitated in the evening, often not recognizing his own son.
Which of the following features most specifically suggests a diagnosis of delirium superimposed on a neurocognitive disorder?
- Memory impairment
- Impaired executive functioning
- Acute onset and fluctuating course (correct answer)
- Language difficulties
Explanation: While cognitive deficits like memory impairment and executive dysfunction are present in both dementia and delirium, the hallmark features that distinguish delirium are its acute onset (hours to days) and a fluctuating course of symptoms, with variations in attention and arousal level throughout the day. The slow, progressive decline is characteristic of the underlying neurocognitive disorder (dementia), while the recent, rapid change with fluctuations points to delirium.
Question 4
A 28-year-old man is diagnosed with attention-deficit/hyperactivity disorder. He has a history of opioid use disorder and is currently maintained on methadone. He is motivated to treat his ADHD symptoms to maintain employment. He has a history of diverting prescribed stimulants in the past.
Which of the following is the most appropriate first-line treatment for his ADHD?
- Amphetamine-dextroamphetamine
- Modafinil
- Atomoxetine (correct answer)
- Clonidine
Explanation: In patients with ADHD and a co-occurring substance use disorder, particularly with a history of diversion, non-stimulant medications are preferred. Atomoxetine, a norepinephrine reuptake inhibitor, is an effective and FDA-approved non-stimulant treatment for ADHD and lacks abuse potential. Stimulants like amphetamine-dextroamphetamine would be a poor choice due to the high risk of abuse and diversion.
Question 5
A 75-year-old woman is brought to the clinic by her son due to a 2-year history of progressive memory loss. He states she frequently misplaces items, has difficulty managing her finances, and recently got lost while driving in her own neighborhood. She is pleasant and cooperative but has limited insight into her deficits. Her medical history is significant for hypertension, which is well-controlled. On neurologic examination, there are no focal deficits. Her Mini-Mental State Examination score is 22/30, with deficits primarily in recall and orientation.
What is the most likely diagnosis?
- Alzheimer disease (correct answer)
- Vascular dementia
- Lewy body dementia
- Frontotemporal dementia
Explanation: This patient presents with an insidious onset and gradual progression of cognitive decline, primarily affecting recent memory (amnestic presentation) and executive function. This clinical picture in an elderly individual is classic for Alzheimer disease, the most common cause of dementia. The absence of stepwise decline, parkinsonism, hallucinations, or prominent early personality changes makes other dementia subtypes less likely.
Question 6
A 48-year-old man with a long-standing history of HIV and medication non-adherence presents with a 1-year history of increasing apathy and psychomotor slowing. His family reports that he has become socially withdrawn and has difficulty with multi-step tasks. His most recent CD4 count was 80 cells/mm³. An MRI of the brain shows diffuse cerebral atrophy but no focal lesions.
What is the most likely diagnosis?
- HIV-associated neurocognitive disorder (correct answer)
- Progressive multifocal leukoencephalopathy (PML)
- Primary CNS lymphoma
- Toxoplasmosis
Explanation: HIV-associated neurocognitive disorder (HAND) is a common complication in patients with advanced HIV/AIDS (typically CD4 < 200). It characteristically presents as a subcortical dementia with symptoms of apathy, executive dysfunction, and psychomotor slowing. Other opportunistic infections like PML, CNS lymphoma, and toxoplasmosis typically present more acutely with focal neurological deficits and show characteristic focal lesions on MRI.
Question 7
A 78-year-old man is evaluated for a 1-year history of cognitive decline. His wife reports that his attention and alertness fluctuate significantly throughout the day. He has had several episodes of seeing small children in the house who are not there. On examination, he has a mild resting tremor and bradykinesia. His wife also mentions that he has become violent in his sleep, often shouting and flailing his arms.
What is the most likely diagnosis?
- Alzheimer disease with psychosis
- Parkinson disease dementia
- Dementia with Lewy bodies (correct answer)
- Delirium
Explanation: This patient's presentation includes the core features of dementia with Lewy bodies (LBD): fluctuating cognition, well-formed visual hallucinations, and parkinsonism. The presence of REM sleep behavior disorder (acting out dreams) is also highly suggestive. In LBD, cognitive decline begins before or within one year of the onset of motor symptoms. In Parkinson disease dementia, dementia develops more than one year after the diagnosis of Parkinson disease.
Question 8
A 58-year-old high school principal is brought for evaluation by his wife due to a 2-year history of personality change. She reports he has become socially disinhibited, making inappropriate jokes during faculty meetings, and has developed a striking preference for sweet foods. His memory and navigational skills seem to be intact. He shows little empathy for his wife's concerns during the interview.
This patient's symptoms are most likely caused by degeneration of which of the following brain regions?
- Hippocampus and temporal-parietal cortex
- Frontal and temporal lobes (correct answer)
- Substantia nigra and brainstem
- Basal ganglia and thalamus
Explanation: The clinical picture of early and prominent personality change (disinhibition), apathy, and altered food preferences with relatively preserved memory is characteristic of the behavioral variant of frontotemporal dementia (bvFTD). This condition is caused by focal neurodegeneration in the frontal and temporal lobes.
Question 9
An 82-year-old woman with a history of moderate Alzheimer disease is brought from her nursing home to the emergency department for an acute change in mental status. For the past 2 days, she has been more confused than usual, agitated, and seeing things that are not there. She is unable to focus during the interview. Her temperature is 38.1°C (100.6°F), heart rate is 105/min, and blood pressure is 110/70 mm Hg.
Which of the following is the most appropriate next step in management?
- Administer haloperidol for agitation
- Obtain urinalysis, CBC, and chest x-ray (correct answer)
- Increase her dose of donepezil
- Obtain a non-contrast CT scan of the head
Explanation: This patient has an acute change in mental status superimposed on her chronic dementia, which is highly suggestive of delirium. The most important initial step is to identify and treat the underlying medical cause. In elderly patients, infections such as urinary tract infections or pneumonia are common precipitants. Therefore, an infection workup including urinalysis, CBC, and chest x-ray is the most appropriate next step.
Question 10
A 3-year-old boy is brought for a well-child visit. His parents are concerned about his development. He speaks only a few single words and does not respond when his name is called. He avoids eye contact and does not engage in pretend play. His parents note that he spends hours repeatedly spinning the wheels on his toy trucks. He becomes extremely distressed if his daily routine is changed.
Which of the following is the most likely diagnosis?
- Autism spectrum disorder (correct answer)
- Global developmental delay
- Social (pragmatic) communication disorder
- Hearing impairment
Explanation: This child displays the core features of autism spectrum disorder (ASD): 1) persistent deficits in social communication and social interaction (impaired eye contact, lack of response to name, no pretend play), and 2) restricted, repetitive patterns of behavior, interests, or activities (spinning wheels, insistence on sameness). While he has developmental delay, the specific pattern of deficits points to ASD.
Question 11
A 76-year-old man presents with a 1-year history of progressive gait difficulty, which he describes as his 'feet being stuck to the floor.' He has also had several falls and has developed urinary incontinence. His wife notes that his memory has declined over the same period. A CT scan of the head shows enlarged ventricles out of proportion to sulcal widening.
In addition to the neuroimaging findings, which of the following procedures is most useful for confirming the diagnosis?
- Electroencephalogram (EEG)
- Serum vitamin B12 and folate levels
- High-volume lumbar puncture (correct answer)
- Neuropsychological testing
Explanation: The clinical triad of gait disturbance ('magnetic' gait), dementia, and urinary incontinence, along with ventriculomegaly on imaging, is classic for Normal Pressure Hydrocephalus (NPH). The most useful diagnostic procedure is a high-volume lumbar puncture (spinal tap), where removal of 30-50 mL of cerebrospinal fluid leads to a temporary improvement in gait, which supports the diagnosis and predicts response to ventriculoperitoneal shunting.
Question 12
A 68-year-old man with a history of poorly controlled hypertension, hyperlipidemia, and a previous lacunar stroke is brought in by his family due to cognitive decline. His wife states that his mental function seems to worsen suddenly, remains stable for a few months, and then worsens again. On examination, he has a left-sided pronator drift and hyperreflexia.
What is the most likely diagnosis?
- Alzheimer disease
- Vascular dementia (correct answer)
- Creutzfeldt-Jakob disease
- Dementia with Lewy bodies
Explanation: This patient's presentation is classic for vascular dementia. Key features include the presence of significant cardiovascular risk factors, a stepwise or fluctuating decline in cognitive function corresponding to new ischemic events, and the presence of focal neurologic deficits on examination. This is in contrast to the insidious, gradual decline seen in Alzheimer disease.
Question 13
A 79-year-old man admitted to the hospital for a hip fracture develops acute confusion and agitation on postoperative day 2. He is pulling at his Foley catheter and yelling that he is being held captive. Environmental modifications and reorientation by staff have been ineffective, and he poses a safety risk to himself. He has no history of alcohol use.
Which of the following is the most appropriate medication to manage this patient's acute agitation?
- Diazepam
- Diphenhydramine
- Haloperidol (correct answer)
- Trazodone
Explanation: This patient is experiencing delirium with severe agitation. When non-pharmacologic interventions fail and the patient is a danger to himself or others, a low-dose antipsychotic is the treatment of choice. Haloperidol is a commonly used agent. Benzodiazepines, like diazepam, can worsen delirium in non-alcohol withdrawal settings. Antihistamines with anticholinergic properties, like diphenhydramine, will also exacerbate delirium.
Question 14
A 4-year-old boy is diagnosed with autism spectrum disorder. He has severe language deficits and exhibits frequent, aggressive outbursts and self-injurious behavior when he becomes frustrated or overstimulated.
Which of the following is the most important initial component of his management plan?
- Pharmacotherapy with an atypical antipsychotic
- Early intensive behavioral and educational intervention (correct answer)
- Enrollment in a specialized gluten- and casein-free diet program
- Family therapy focused on parental coping skills
Explanation: The cornerstone of management for autism spectrum disorder is early, intensive, and comprehensive behavioral and educational interventions, such as Applied Behavior Analysis (ABA). These therapies are the most effective way to improve communication, social skills, and adaptive behaviors. While medications like risperidone may be used for severe irritability and aggression, they are adjunctive to behavioral interventions, not a replacement.
Question 15
A 72-year-old woman is brought by her daughter for evaluation of a 3-month history of memory problems. The patient is very distressed by her cognitive difficulties and frequently answers 'I don't know' during cognitive testing. Her daughter notes that since her husband's death 4 months ago, the patient has had low energy, poor sleep, and a loss of interest in her usual activities. She has also lost 10 pounds unintentionally.
What is the most likely cause of this patient's cognitive complaints?
- Alzheimer disease
- Major depressive disorder (correct answer)
- Vitamin B12 deficiency
- Normal pressure hydrocephalus
Explanation: This patient's cognitive symptoms are occurring in the context of classic neurovegetative symptoms of depression (anhedonia, low energy, poor sleep, weight loss) following a major life stressor. This presentation is consistent with cognitive impairment secondary to major depression (formerly 'pseudodementia'). The patient's significant distress about her deficits and giving 'I don't know' answers are also characteristic, contrasting with the frequent lack of insight in early Alzheimer disease.
Question 16
An 80-year-old man with a diagnosis of Alzheimer disease has been treated with donepezil for the past 18 months. His MMSE score has declined from 20/30 to 14/30. His wife reports he now needs assistance with bathing and dressing, and his memory has worsened significantly.
Which of the following is the most appropriate medication to add to his current regimen?
- Rivastigmine
- Galantamine
- Memantine (correct answer)
- Sertraline
Explanation: This patient has progressed from mild to moderate/severe Alzheimer disease. Memantine, an NMDA-receptor antagonist, is indicated for the treatment of moderate to severe Alzheimer disease. It is often added to a cholinesterase inhibitor (like donepezil) when the disease progresses. Adding another cholinesterase inhibitor (rivastigmine, galantamine) is not indicated. Sertraline would be used for comorbid depression, which is not described here.
Question 17
A 65-year-old man who has followed a strict vegan diet for 20 years presents with a 6-month history of cognitive slowing, apathy, and tingling sensations in his feet. Neurologic examination is notable for impaired proprioception and vibration sense in the lower extremities and a positive Romberg sign.
A deficiency of which of the following is the most likely cause of his symptoms?
- Thiamine (Vitamin B1)
- Folate (Vitamin B9)
- Cobalamin (Vitamin B12) (correct answer)
- Niacin (Vitamin B3)
Explanation: The combination of neuropsychiatric symptoms (cognitive impairment, apathy) and neurologic findings of subacute combined degeneration of the spinal cord (loss of proprioception and vibratory sense) is classic for vitamin B12 (cobalamin) deficiency. Strict vegans are at high risk because B12 is found almost exclusively in animal products. Thiamine deficiency causes Wernicke-Korsakoff syndrome, folate deficiency typically does not cause neurologic symptoms, and niacin deficiency causes pellagra (dermatitis, diarrhea, dementia).
Question 18
An 88-year-old woman with severe Alzheimer dementia in a long-term care facility has become increasingly agitated and physically aggressive toward staff, especially during bathing. A comprehensive assessment has ruled out underlying medical causes, pain, or environmental triggers. Multiple non-pharmacologic interventions have been tried without success, and she now poses a significant safety risk.
Which of the following is the most appropriate next step in management?
- Start a standing dose of lorazepam
- Initiate a low-dose atypical antipsychotic (correct answer)
- Apply physical restraints during care
- Switch her from donepezil to memantine
Explanation: When non-pharmacologic interventions fail to manage severe agitation or aggression in dementia and the patient poses a danger to self or others, a low-dose atypical antipsychotic (e.g., risperidone, olanzapine, quetiapine) may be indicated. Benzodiazepines like lorazepam should generally be avoided due to the risk of falls, paradoxical disinhibition, and worsening confusion. Restraints are a last resort. Changing dementia medications is unlikely to address acute severe agitation.
Question 19
A 10-year-old boy was started on extended-release methylphenidate for ADHD two months ago. His teacher reports a dramatic improvement in his ability to focus in class. However, his parents are concerned because he has a poor appetite and has lost 2 kg (4.4 lbs). He is otherwise healthy. His height and weight are at the 50th percentile.
What is the most appropriate management recommendation?
- Discontinue methylphenidate immediately
- Switch to atomoxetine
- Administer the medication with or after a calorie-dense breakfast (correct answer)
- Add cyproheptadine to stimulate appetite
Explanation: Decreased appetite and weight loss are common side effects of stimulant medications. Since the medication is effective, the first step is to implement behavioral strategies to mitigate the side effect. Giving the dose with or after a meal, especially a high-calorie breakfast, can help improve overall daily caloric intake. Discontinuing or switching an effective medication is not the first step. Adding another medication to treat a side effect is generally avoided if simpler strategies are available.
Question 20
A 30-year-old computer programmer seeks evaluation for anxiety. He reports lifelong difficulty in social situations, stating he often 'misses the point' of jokes and struggles to interpret nonverbal cues. He has very few friends but is not distressed by this. He has an encyclopedic knowledge of World War II naval battles, an interest that occupies most of his free time. He has excelled in his career. He has no history of psychosis.
Which of the following diagnoses best accounts for this patient's presentation?
- Social anxiety disorder
- Schizoid personality disorder
- Autism spectrum disorder (correct answer)
- Obsessive-compulsive personality disorder
Explanation: This patient's presentation is consistent with autism spectrum disorder (ASD) in an adult with normal intelligence. Key features include persistent deficits in social communication and interaction (difficulty with nonverbal cues, reciprocity) and restricted, circumscribed interests of abnormal intensity. While he may experience social anxiety, ASD is the underlying neurodevelopmental condition that better explains the full range of his symptoms. Schizoid personality is characterized by a pervasive lack of interest in social relationships, whereas this patient's issue is more with the 'how-to' of social interaction.