USMLE USMLE-STEP-2 Online Practice Questions and Exam Preparation

USMLE USMLE-STEP-2 Online Questions & Answers

• Question 1:

  A28-year-old woman with a 7-year history of chronic undifferentiated schizophrenia is hospitalized for an exacerbation of her schizophrenia, with an increase in auditory hallucinations. She has also developed the delusion that she is controlled by aliens from Mars. She has always been very sensitive to the extrapyramidal side effects (EPS) of antipsychotic medications.

  This woman develops cogwheel rigidity and a pill-rolling tremor. Which of the following is the most appropriate treatment choice?

  A. benztropine
  B. propranolol
  C. haldoperidol
  D. dantrolene
  E. fluoxetine
  A. benztropine

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  Explanation

  Typical neuroleptic antipsychotic medications frequently cause unpleasant side effects, which occur at various times during treatment. The extrapyramidal side effect most likely to occur in the first few days of treatment is an acute dystonia, such as a muscle spasm in the neck. A pill-rolling tremor of the hands and masked facies are signs of Parkinsonian EPS, which tend to have their onset several weeks after treatment is begun; whereas severe restlessness of the arms and legs is caused by an unpleasant sensation called "akathisia," which also tends to have its onset several weeks after treatment is begun. Involuntary lip smacking is a sign of tardive dyskinesia, a sometimes irreversible motor syndrome that tends to occur after months or years of treatment with typical antipsychotics. Anticholinergic medications such as benztropine are effective in treating dystonias and pill-rolling tremors. Propranolol is effective in treating akathisia. Haldoperidol would worsen EPS. Dantrolene uncouples muscle contractions and is used occasionally in severe NMS. L-Dopa would decrease the Parkinsonian EPS, but would worsen the psychosis and therefore is not used. Fluoxetine is an SSRI

• Question 2:

  A 33-year-old woman experiences visions of flashing lights followed by throbbing left-sided temporal pain and nausea. Which of the following is the most likely diagnosis?

  This patient is most likely to benefit from acute treatment with which of the following substances?

  A. propranolol
  B. prednisone
  C. sumatriptan
  D. heparin
  E. oxygen
  C. sumatriptan

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  Explanation

  The typical migraine attack consists of a visual aura with flashes, scintillating scotomata (field loss), or fortification spectra followed by a throbbing unilateral temporal headache. There may be associated vestibular, GI, or neurologic symptoms. Attacks are often precipitated by stress, fatigue, or foods that contain tyramine (e.g., cheese, yogurt, nuts) or phenylethylamine (wine, chocolate). Symptoms peak within an hour of onset and persist for hours to days. A positive family history is found in as many as 50% of cases. Tension headaches are more often bilateral and described as band like or vise like and are not usually associated with visual auras. TIAs more typically present as transient monocular blindness without aura or headache. Temporal arteritis may present as painless loss of vision without aura, but is usually in older people.

  Cluster headaches are much more common in men. Sumatriptan and the other triptans work by inhibiting the release of vasoactive peptides, promoting vasoconstriction, and blocking brainstem pain pathways. Sumatriptan comes in oral, injectable, and nasal spray form. Ergotamine tartrate, antiemetics, and analgesics may also be used in the acute treatment of migraine headache. Prophylactic medications such as beta-blockers, tricyclic antidepressants, calcium channel blockers, and anticonvulsants are ineffective for acute attacks. Avoidance of known precipitants and control of stress are also important in prevention.

• Question 3:

  A45-year-old woman, seen by her medical internist, has been experiencing fears that she may have a serious illness. She complains that after eating she experiences "a lot of gas" and abdominal pain, followed by diarrhea on occasion. Her heart at times seems to be beating rapidly, and she feels faint at times, has chest "discomfort," and wonders if she is having a heart attack. Multiple tests have identified only a mild irritable bowel syndrome. The woman's fears are not allayed by this. She makes repeated calls to be seen by her doctors as well as seeking consultation from other specialists. She insists that "there's something there" and believes the doctors are not taking her seriously.

  Which of the following is the most likely diagnosis?

  A. factitious disorder
  B. major depression
  C. reaction psychosis
  D. hypochondriasis
  E. pain disorder
  D. hypochondriasis

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  Explanation

  Hypochondriasis is a somatoform disorder in which misperceptions or distortions of somatic signs and symptoms lead to preoccupation with fears of having a serious illness. In factitious disorders, one deliberately manufactures signs and symptoms to enter the sick role. The preoccupation with fear of serious illness is not part of factitious disorder. Major depression is characterized by symptoms of depression: sleep disturbance, appetite disturbance, and so forth.

  It may be complicated by hypochondriasis. In the case study, no supporting evidence for major depression (for which she would have been evaluated) is provided. This woman's symptoms as described are not of a psychotic level; thus, reactive psychosis would be inappropriate. In pain disorder, pain in a specific body site is the predominant focus, unlike the predominance of fear seen in hypochondriasis. Care of these patients is best managed supportively by developing a therapeutic alliance with them.

  Anticipating their needs by establishing regular office visits and physical examinations with them will help allay fears as well as reassure them of one's concern for them, and that if an occult condition becomes evident it will be diagnosed early. Certainly, regular consultation with other specialists is in order to manage these patients. Although the course of hypochondriasis tends to be chronic, there are indications that factor in for a good outcome. One of these is the absence of secondary gain. This disorder is seen equally in both men and women. The prevalence in a general medical practice is approximately 46%. There is no relationship between hypochondriasis and increased ESR.

• Question 4:

  Match the antidepressant with the side effect or characteristic of an SSRI with a half-life of 46 days

  A. phenelzine
  B. venlafaxine
  C. trazodone
  D. fluoxetine
  E. mirtazapine
  F. nortriptyline
  G. escitalopram
  D. fluoxetine

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  Explanation

  Fluoxetine has the longest half-life of the current SSRIs (escitalopram's half-life is shorter--less than 24 hours), phenelzine is an MAOI and foods rich in tyramine can induce a hypertensive crisis. Venlafaxine can induce hypertension, especially at higher doses. Trazodone can rarely induce priapism (a painful sustained erection). Nortriptyline is a tricyclic antidepressant, and at high doses, it can cause arrhythmias.

• Question 5:

  A 42-year-old married woman reports being raped in an elevator 1 year ago. Her arms were fractured in the assault but have healed nicely. Still she reports difficulty sleeping, having nightmares of the attack several times per week ever since the assault. She avoids using the elevator and does not want to talk about the incident with anyone. She has been unable to return to work. Her husband feels she has been hypervigilant and irritable, and has been resistive to going out socially. She has a depressed mood. Her husband is encouraging her to seek disability. Which of the following is the most likely diagnosis?

  A. major depression
  B. adjustment disorder with anxious and depressed features
  C. acute stress disorder
  D. malingering
  E. PTSD
  E. PTSD

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  Explanation

  The lifetime prevalence of PTSD is approximately 8%. For PTSD to be diagnosed, the trauma has to be where serious injury or death were threatened or involved, and the traumatized individual experienced a sense of helplessness, fear, or horror, and has at least one reliving symptom (nightmares of the trauma, recurrent intrusive thoughts of the event, intense psychological stress or physiologic reactivity to internal or external cues that symbolize or resemble an aspect of the trauma, or flashbacks), two or more symptoms of increased arousal (difficulty falling to or staying asleep, irritability, difficulty concentrating, hypervigilance, and exaggerated startle response), and three or more avoidance symptoms (efforts to avoid thoughts, feelings, or conversations about the trauma, efforts to avoid people, things or places that remind one of the trauma, inability to remember an important aspect of the trauma, diminished participation in activities, feeling detached or estranged from others, restricted range of affect, and/or sense of foreshortened future). The symptoms have to be recurring for at least a month.

• Question 6:

  A54-year-old woman is brought to the ER with palpitations and dizziness. She has a history of arrhythmia. Adenosine is given and the patient converts to a sinus rhythm. With which of the following rhythms did this patient most likely present to the ER?

  A. ventricular tachycardia
  B. atrial fibrillation
  C. atrial flutter
  D. paroxysmal supraventricular tachycardia
  E. ventricular fibrillation
  D. paroxysmal supraventricular tachycardia

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  Explanation

  The majority of paroxysmal supraventricular tachycardias respond to adenosine, because they involve a re- entrant circuit including the atrioventricular node. Adenosine is ineffective in the termination of the majority of other atrial or ventricular tachycardias that do not involve the AV node, although it may slow the ventricular response to an atrial tachycardia

• Question 7:

  A 4-year-old child presents to your office in July with a history of a low-grade fever (38.1°C) and "s ores" in his mouth for 2 days. He has been refusing to eat but has been drinking an adequate amount of liquids. On examination, he is afebrile and seems well hydrated. He has ulcers on his tongue and posterior pharynx, which are 4 mm in diameter. You also note a few vesicles on his hands and feet, which are 34 mm in size and mildly tender.

  Which of the following is the most likely diagnosis?

  A. herpes simplex virus (HSV)
  B. coxsackie virus
  C. aphthous ulcers
  D. Behcet syndrome
  E. traumatic ulcers
  B. coxsackie virus

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  Explanation

  Coxsackie A16 is the major cause of hand, foot, and mouth disease. This is a summer enteroviral illness presenting with classic lesions of the hand, feet, and mouth. Herpetic gingivostomatitis is the most common cause of stomatitis in children aged 13 years. There is often a high fever, fetor oris, refusal to eat, and irritability. The lesions are initially vesicular, and soon form ulcers ranging from 2 to 10 mm in diameter. The tongue, cheek, and gums are usually involved, and there may be submaxillary lymphadenitis. Aphthous ulcerations (canker sores) are painful ulcerations, which present as erythematous, indurated papules that erode to form circumscribed necrotic ulcers with gray fibrinous exudates and erythematous halo. They are 210 mm in diameter, heal spontaneously, and often recur. Behcet syndrome is a multisystem disorder characterized by recurrent oral and genital ulceration, iritis or uveitis, as well as other cutaneous, arthritic, neurologic, vascular, and gastrointestinal (GI) manifestations. It is rare in children. Traumatic oral ulcers may be seen in chronic cheek biters but do not involve extremities.

• Question 8:

  A22-year-old G3P1102 is admitted to the Labor and Delivery ward at 28 weeks' gestation complaining of watery vaginal discharge. You confirm the diagnosis of preterm premature rupture of amniotic membranes (PPROM). Fetal monitoring demonstrates reassuring fetal heart tones and no contractions are noted. The patient is understandably concerned and asks you why this happened and what this means for her pregnancy. Which of the following should you tell her? Which of the following is the most appropriate therapy for this woman?

  A. begin antibiotic therapy to prolong the latency period until labor begins
  B. immediate cesarean delivery to prevent umbilical cord prolapse
  C. induction of labor to prevent intraamniotic infection
  D. amniocentesis to determine fetal lung maturity status
  E. placement of a cervical cerclage to prevent preterm delivery
  A. begin antibiotic therapy to prolong the latency period until labor begins

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  Explanation

  Multiple randomized-controlled trials have now demonstrated the benefit of administering antibiotics to women with PPROM at less than 32 weeks' gestation. Most importantly, these drugs prolong the latent period until labor begins, but reductions have also been noted inmaternal infection, fetal infection, fetal respiratory distress syndrome, and fetal intraventricular hemorrhage. Commonly used antibiotics are ampicillin and erythromycin, but efficacy has been noted with many different regimens. Cesarean delivery at this point is not indicated, but might need to be performed in case of nonreassuring fetal status or malpresentation (e.g., breech). Induction of labor generally takes place between 32 and 34 weeks if the patient's status remains stable, or sooner in the event of amniotic infection or other concerns. Amniocentesis may be performed to look for evidence of amniotic infection, but the likelihood of fetal lung maturity at this point is remote. Patients with previously placed cervical cerclages may be candidates for expectant management with the cerclage in place, but it would be inappropriate to place a cerclage after PPROM.

• Question 9:

  A 49-year-old woman presents to her physician with dysphagia, regurgitation of undigested food eaten hours earlier, and coughing over the last 6 months. She was hospitalized 1 month ago for aspiration pneumonia and successfully treated with antibiotics. Examination reveals a thin-appearing woman with normal vital signs and unremarkable chest, heart, and abdominal examination. A UGI contrast study is performed and reveals a pharyngoesophageal (Zenker's) diverticulum. Which of the following statements is true regarding Zenker's diverticula?

  A. Cervical dysphagia is related to the size of the diverticulum.
  B. Pharyngoesophageal diverticula are of the pulsion type.
  C. Pharyngoesophageal diverticula are true diverticula.
  D. Pharyngoesophageal diverticula are congenital in origin.
  E. Upper esophageal sphincter function is usually normal.
  B. Pharyngoesophageal diverticula are of the pulsion type.

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  Explanation

  Pharyngoesophageal (Zenker's) diverticulum is the most common esophageal diverticulum and typically occurs in the 3050 age group and, therefore, is believed to be acquired. Its symptoms include cervical dysphagia, regurgitation of undigested food, and recurrent aspiration. It is categorized as a pulsion type, creating protrusion of mucosa, resulting in a false diverticulum. An underlying neuromotor abnormality exists, which is responsible for increased pharyngeal pressure. The most important aspect of treatment is a cricopharyngeal muscle myotomy, which can be combined with resection or diverticulopexy.

• Question 10:

  A 26-year-old previously healthy man was pinned under a crane at a construction site. After a prolonged extrication, he was brought to the emergency department, immobilized on a back board and receiving 100% oxygen by mask. He is alert and complaining of chest pain with respiratory effort. On examination, he is found to have an oxygen saturation of 90% by pulse oximetry, shallow respirations at a respiratory rate of 35/min, heart rate of 120 beats/min, and a blood pressure of 85/60 mmHg. The trachea is deviated to the right. There is tenderness and crepitation over the left chest wall, asymmetric chest wall movement, and decreased air entry over the left lung field. Which of the following is the most appropriate next step in the initial evaluation and management of this patient?

  A. fluid resuscitation with 2 L of isotonic crystalloid
  B. needle decompression of the left chest, followed by insertion of a chest tube
  C. portable chest x-ray
  D. immediate intubation and assisted ventilation
  E. emergency department thoracotomy
  B. needle decompression of the left chest, followed by insertion of a chest tube

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  Explanation

  This patient has a left tension pneumothorax, a diagnosis established based on symptoms and clinical examination. The patient is hypoxic, with respiratory distress, and demonstrates deviation of the mediastinum to the contralateral side. Hypotension is from the mediastinal shift that compromises venous return and not from hypovolemia. Therefore, aggressive fluid resuscitation is not indicated. A chest x-ray is unnecessary and will delay definitive life-saving intervention. The patient requires urgent decompression with a largebore needle in the second intercostal space anteriorly, followed by insertion of a chest tube. Although assisted ventilation can improve oxygenation, positive pressure may increase the pneumothorax if initiated before adequate decompression.