Part 35

190) A 42-year-old man comes to the emergency room with the chief complaint that “the men are following me.” He also complains of hearing a voice telling him to hurt others. He tells the examiner that the news anchorman gives him special messages about the state of the world every night through the TV. Which of the following psychiatric findings best describes this last belief of the patient?

191) A 32-year-old woman is seen in an outpatient psychiatric clinic for the chief complaint of a depressed mood for 4 months. During the interview, she gives very long, complicated explanations and many unnecessary details before finally answering the original questions. Which of the following psychiatric findings best describes this style of train of thought?

192) An 18-year-old man is seen by a psychiatrist in the emergency room. During the history, the patient is asked to describe his mood. He answers the following, “My mood is flextitating, I am up and down.” The patient is exhibiting which of the following thought disorders?

193) A 56-year-old man has been hospitalized for a myocardial infarction. Two days after admission, he awakens in the middle of the night and screams that there is a man standing by the window in his room. When the nurse enters the room and turns on a light, the patient is relieved to learn that the “man” was actually a drape by the window. This misperception of reality is best described by which of the following psychiatric terms?

194) A 22-year-old woman is seen by a psychiatrist in the emergency room after she is found walking in the middle of a busy street with no shoes on. During her interview she is asked to count backwards from 100 by 7’s. Which of the following best describes the cognitive functions being tested by this request?

195) A 72-year-old woman is admitted to the burn unit with second- and third-degree burns covering 35% of her body, which she received in a house fire. At 8 pm on the fourth day of her hospital stay, she pulls out her IV and begins screaming that people are trying to hurt her. Several hours later she is found to be difficult to arouse and disoriented. Which of the following is the most likely diagnosis?

196) A psychiatric resident is called to consult on the case of a 75-year-old woman who had undergone a hip replacement 2 days before. On examination, the resident notes that the patient states the date as 1956, and she thinks she is at her son’s house. These impairments best illustrate which aspect of the mental status examination?

197) A 52-year-old man is sent to see a psychiatrist after he is disciplined at his job because he consistently turns in his assignments late. He insists that he is not about to turn in anything until it is “perfect, unlike all of my colleagues.” He has few friends because he annoys them with his demands for “precise timeliness” and because of his lack of emotional warmth. This has been a lifelong pattern for the patient, though he refuses to believe the problems have anything to do with his personal behavior. Which of the following is the most likely diagnosis for this patient?

198) A 23-year-old woman comes to the psychiatrist because she “cannot get out of the shower.” She tells the psychiatrist that she has been unable to go to her job as a secretary for the past 3 weeks because it takes her at least 4 hours to shower. She describes an elaborate ritual in which she must make sure that each part of her body has been scrubbed three times, in exactly the same order each time. She notes that her hands are raw and bloody from all the scrubbing. She states that she hates what she is doing to herself but becomes unbearably anxious each time she tries to stop. She notes that she has always taken long showers, but the problem has been worsening steadily for the past 5 months. She denies problems with friends or at work, other than the problems that currently are keeping her from going to work. Which of the following is the most likely diagnosis?

199) A 23-year-old woman comes to the emergency room with the chief complaint that she has been hearing voices for 7 months. Besides the hallucinations, she has the idea that the radio is giving her special messages. When asked the meaning of the proverb “People in glass houses should not throw stones,” the patient replies, “Because the windows would break.” Which of the following mental status findings does this patient display?

200) A 69-year-old man is brought to see his physician by his wife. She notes that over the past year he has experienced a slow, stepwise decline in his cognitive functioning. One year ago she felt his thinking was “as good as it always had been,” but now he gets lost around the house and can’t remember simple directions. The patient insists that he feels fine, though he is depressed about his loss of memory. He is eating and sleeping well. Which of the following is the most likely diagnosis?

201) A psychiatrist is seeing a patient in his outpatient practice. The patient treats the psychiatrist as if he were unreliable and punitive, though he had not been either. The patient’s father was an alcoholic who often did not show up to pick her up from school and frequently hit her. The psychiatrist begins to feel as if he must overprotect the patient and treat her gingerly. Which of the following psychological mechanisms best describes the psychiatrist’s behavior?

202) A patient is able to appreciate subtle nuances in thinking and can use metaphors and understand them. This patient’s thinking can be best defined by which of the following terms?

203) A 65-year-old man, who had been hospitalized for an acute pneumonia 3 days previously, begins screaming for his nurse, stating that “there are people in the room out to get me.” He then gets out of bed and begins pulling out his IV line. On examination, he alternates between agitation and somnolence. He is not oriented to time or place. His vital signs are as follows: pulse, 126 beats per minute; respiration, 32 breaths per minute; blood pressure (BP), 80/58; temperature, 39.2°C (102.5°F). Which of the following diagnoses best fits this patient’s clinical picture?

204) A 59-year-old man goes to a psychiatrist for a 3-month history of panic attacks. He notes for the past 3 months he has experienced “out of the blue,” extreme episodes of fearfulness that last about 20 minutes. During that time he experiences palpitations, sweating, shortness of breath, and trembling. He denies any substance abuse, and has never had symptoms like this before these past 3 months. Which of the following signs or symptoms would likely lead the physicians to expect a diagnosis of anxiety secondary to a general medical condition in this case?

205) A 19-year-old woman presents to the emergency room with the chief complaint of a depressed mood for 2 weeks. She notes that since her therapist went on vacation she has experienced suicidal ideation, crying spells, and an increased appetite. She states that she has left 40 messages on the therapist’s answering machine telling him that she is going to kill herself and that it would serve him right for leaving her. Physical examination reveals multiple well-healed scars and cigarette burns on the anterior aspect of both forearms. Which of the following diagnoses best fits this patient’s clinical presentation?

206) A 29-year-old man is brought to the emergency room by his wife after he woke up with paralysis of his right arm. The patient reports that the day before, he had gotten into a verbal altercation with his mother over her intrusiveness in his life. The patient notes that he has always had mixed feelings about his mother, but that people should always respect their mothers above all else. Which of the following diagnoses best fits this patient’s clinical picture?

207) A 28-year-old business executive sees her physician because she is having difficulty in her new position, as it requires her to do frequent public speaking. She states that she is terrified she will do or say something that will cause her extreme embarrassment. The patient says that when she must speak in public, she becomes extremely anxious and her heart beats uncontrollably. Based on this clinical picture, which of the following is the most likely diagnosis?

208) A 56-year-old man is brought to the physician’s office by his wife because she has noted a personality change during the past 3 months. While the patient is being interviewed, he answers every question with the same three words. Which of the following symptoms best fits this patient’s behavior?

209) A 32-year-old patient is being interviewed in his physician’s office. He eventually answers each question, but he gives long answers with a great deal of tedious and unnecessary detail before doing so. Which of the following symptoms best describes this patient’s presentation?

210) An 18-year-old man is brought to the emergency room by the police after he is found walking along the edge of a high building. In the emergency room, he mumbles to himself and appears to be responding to internal stimuli. When asked open-ended questions, he suddenly stops his answer in the middle of a sentence, as if he has forgotten what to say. Which of the following symptoms best describes this last behavior?

211) A 26-year-old woman with panic disorder notes that during the middle of one of her attacks she feels as if she is disconnected from the world, as though it were unreal or distant. Which of the following terms best describes this symptom?

212) A patient with a chronic psychotic disorder is convinced that she has caused a recent earthquake because she was bored and wishing for something exciting to occur. Which of the following symptoms most closely describes this patient’s thoughts?

213) A 45-year-old man with a chronic psychotic disorder is interviewed after being admitted to a psychiatric unit. He mimics the examiner’s body posture and movements during the interview. Which of the following terms best characterizes this patient’s symptom?

214) A 54-year-old man with a chronic mental illness seems to be constantly chewing. He does not wear dentures. His tongue darts in and out of his mouth, and he occasionally smacks his lips. He also grimaces, frowns, and blinks excessively. Which of the following disorders is most likely in this patient?

215) A 58-year-old woman with a chronic mental disorder comes to the physician with irregular choreoathetoid movements of her hands and trunk. She states that the movements get worse under stressful conditions. Which of the following medications is most likely to have caused this disorder?

216) A 24-year-old woman comes to the emergency room with the chief complaint that “my stomach is rotting out from the inside.” She states that for the last 6 months she has been crying on a daily basis and that she has decreased concentration, energy, and interest in her usual hobbies. She has lost 25 lb during that time. She cannot get to sleep, and when she does, she wakes up early in the morning. For the past 3 weeks, she has become convinced that she is dying of cancer and is rotting on the inside of her body. Also, in the past 2 weeks she has been hearing a voice calling her name when no one is around. Which of the following is the most likely diagnosis?

217) A 19-year-old man is brought to the physician by his parents after he called them from college, terrified that the Mafia was after him. He reports that he has eaten nothing for the past 6 weeks other than canned beans because “they are into everything––I can’t be too careful.” He is convinced that the Mafia has put cameras in his dormitory room and that they are watching his every move. He occasionally hears the voices of two men talking about him when no one is around. His roommate states that for the past 2 months the patient has been increasingly withdrawn and suspicious. Which of the following is the most likely diagnosis?

218) A 36-year-old woman is brought to the psychiatrist by her husband because for the past 8 months she has refused to go out of the house, believing that the neighbors are trying to harm her. She is afraid that if they see her they will hurt her, and she finds many small bits of evidence to support this. This evidence includes the neighbors’ leaving their garbage cans out on the street to try to trip her, parking their cars in their driveways so they can hide behind them and spy on her, and walking by her house to try to get a look into where she is hiding. She states that her mood is fine and would be “better if they would leave me alone.” She denies hearing the neighbors or anyone else talks to her, but is sure that they are out to “cause her death and mayhem.” Which of the following is the most likely diagnosis?

219) A 35-year-old woman has lived in a state psychiatric hospital for the past 10 years. She spends most of her day rocking, muttering softly to herself, or looking at her reflection in a small mirror. She needs help with dressing and showering, and she often giggles and laughs for no apparent reason. Which of the following is the most likely diagnosis?

220) A 20-year-old woman is brought to the emergency room by her family because they have been unable to get her to eat or drink anything for the past 2 days. The patient, although awake, is completely unresponsive both vocally and nonverbally. She actively resists any attempt to be moved. Her family reports that during the previous 7 months she became increasingly withdrawn, socially isolated, and bizarre; often speaking to people no one else could see. Which of the following is the most likely diagnosis?

221) A 21-year-old man is brought to the emergency room by his parents because he has not slept, bathed, or eaten in the past 3 days. The parents report that for the past 6 months their son has been acting strangely and “not himself.” They state that he has been locking himself in his room, talking to himself, and writing on the walls. Six weeks prior to the emergency room visit, their son became convinced that a fellow student was stealing his thoughts and making him unable to learn his school material. In the past 2 weeks, they have noticed that their son has become depressed and has stopped taking care of himself, including bathing, eating, and getting dressed. On examination, the patient is dirty, disheveled, and crying. He complains of not being able to concentrate, a low energy level, and feeling suicidal. Which of the following is the most likely diagnosis for this patient?

222) A 47-year-old woman is brought to the emergency room after she jumped off an overpass in a suicide attempt. In the emergency room she states that she wanted to kill herself because the devil had been tormenting her for many years. After stabilization of her fractures, she is admitted to the psychiatric unit, where she is treated with risperidone and sertraline. After 2 weeks she is no longer suicidal and her mood is euthymic. However, she still believes that the devil is recruiting people to try to persecute her. In the past 10 years, the patient has had three similar episodes prior to this one. Throughout this time, she has never stopped believing that the devil is persecuting her. Which of the following is the most appropriate diagnosis for this patient?

223) A 40-year-old woman is arrested by the police after she is found crawling through the window of a movie star’s home. She states that the movie star invited her into his home because the two are secretly married and “it just wouldn’t be good for his career if everyone knew.” The movie star denies the two have ever met, but notes that the woman has sent him hundreds of letters over the past 2 years. The woman has never been in trouble before and lives an otherwise isolated and unremarkable life. Which of the following is the most likely diagnosis?

224) A 26-year-old woman is brought to the emergency room by her husband after she begins screaming that her children are calling to her and becomes hysterical. The husband states that 2 weeks previously, the couple’s two children were killed in a car accident, and since that time the patient has been agitated, disorganized, and incoherent. He states that she will not eat because she believes he has been poisoning her food, and she has not slept for the past 2 days. The patient believes that the nurses in the emergency room are going to cause her harm as well. The patient is sedated and later sent home. One week later, all her symptoms remit spontaneously. Which of the following is the most likely diagnosis for this patient?

225) A 25-year-old woman is diagnosed with schizophrenia when, after the sudden death of her mother, she begins complaining about hearing the voice of the devil and is suddenly afraid that other people are out to hurt her. Her history indicates that she has also experienced a 3-year period of slowly worsening social withdrawal, apathy, and bizarre behavior. Her family history includes major depression in her father. Which of the following details of her history leads the physician to suspect that her outcome may be poor?

226) A 22-year-old man is brought to the emergency room after he became exceedingly anxious in his college dormitory room, stating that he was sure the college administration was sending a “hit squad” to kill him. He also notes that he can see “visions” of men dressed in black who are carrying guns and stalking him. His thought process is relatively intact, without thought blocking or loose associations. His urine toxicology screen is positive for one of the following drugs. Which drug is the most likely cause of these symptoms?

227) A 72-year-old woman is brought to the emergency room by her daughter after she found her mother rummaging in the garbage cans outside her home. The daughter states that the patient has never had any behavior like this previously. On interview, the patient states she sees “martians hiding around her home, and on occasion, hears them too.” She also demonstrates a constructional apraxia, with difficulty drawing a clock and intersecting pentagons. All of these symptoms point to a medical cause for this patient’s behavior except one. Which symptom is common in patients with a psychiatric cause for their behavior (ie, not a medical cause)?

228) A 62-year-old man with chronic schizophrenia is brought to the emergency room after he is found wandering around his halfway house, confused and disoriented. His serum sodium concentration is 123 meq/L and urine sodium concentration is 5 meq/L. The patient has been treated with risperidone 4 mg/day for the past 3 years with good symptom control. His roommate reports that the patient often complains of feeling thirsty. Which of the following is the most likely cause of this patient’s symptoms?

229) A 75-year-old man is being cared for in a hospice setting. He has widely spread prostatic carcinoma and is considered terminal. Which of the following psychiatric symptoms are seen in 90% of all terminal patients?

230) A 52-year-old man is seen by a psychiatrist in the emergency room because he is complaining about hearing and seeing miniature people who tell him to kill everyone in sight. He states that these symptoms developed suddenly during the past 48 hours, but that he has had them “on and off” for years. He states that he has never previously sought treatment for the symptoms, but that this episode is particularly bad. He denies the use of any illicit substances. The patient is alert and oriented to person, place, and time. His mental status examination is normal except for his auditory and visual hallucinations. His thought process is normal. His drug toxicology screen is positive for marijuana. He is quite insistent that he needs to be “put away” in the hospital for the symptoms he is experiencing. Which of the following is the most likely diagnosis?

231) A 25-year-old man is brought to the physician after complaining about a visual hallucination of a transparent phantom of his own body. Which of the following specific syndromes is this patient most likely to be displaying?

232) A 26-year-old man comes to the physician with the chief complaint of a depressed mood for the past 5 weeks. He has been feeling down, with decreased concentration, energy, and interest in his usual hobbies. Six weeks prior to this office visit, he had been to the emergency room for an acute asthma attack and was started on prednisone. Which of the following is the most likely diagnosis?

233) A 24-year-old woman, 5 days after delivery of a normal, full-term infant, is brought to the obstetrician because she is so tearful. She states that her mood is quite labile, often changing within minutes. She has trouble sleeping, both falling asleep and awakening early. She notes anhedonia, stating she doesn’t enjoy “much of anything” right now. Which of this patient’s symptoms point preferentially to a postpartum depression?

234) A 28-year-old woman sees her physician with the chief complaint of a depressed mood. She also notes that she is sleeping more than usual––up to 14 hours per night––but does not feel rested and that she feels tired and fatigued all the time. She has gained 14 lb in the last month, something that she is very unhappy about, but she says that she seems to have such a craving for sweets that the weight gain seemed inevitable. Which of the following is the most likely diagnosis?

235) A 27-year-old woman has been feeling blue for the past 2 weeks. She has little energy and has trouble concentrating. She states that 6 weeks ago she had been feeling very good, with lots of energy and no need for sleep. She says that this pattern has been occurring for at least the past 3 years, though the episodes have never been so severe that she couldn’t work. Which of the following is the most likely diagnosis?

236) A 19-year-old woman comes to the psychiatrist for a history of anger and irritability, which occurs on monthly on an average. During this time the patient also reports feeling anxious and “about to explode,” which alternates rapidly with crying spells and angry outbursts. The patient notes during this time she can’t concentrate and sleeps much more than she usually needs to do. During the several days these symptoms last, the patient must skip most of her classes because she cannot function. Which of the following is the most likely diagnosis?

237) A 64-year-old man is admitted to the psychiatric unit after an unsuccessful suicide attempt. Following admission, he attempts to cut his wrists three times in the next 24 hours and refuses to eat or drink anything. He is scheduled to have electroconvulsive therapy (ECT) because he is so severely depressed that an antidepressant is deemed too slow acting. Which of the following side effects should the patient be informed is most common after ECT?

238) A 14-year-old boy is brought to the psychiatrist because for the past 15 months he has been irritable and depressed almost constantly. The boy notes that he has difficulty concentrating, and he has lost 5 lb during that time period without trying. He states that he feels as if he has always been depressed, and he feels hopeless about ever feeling better. He denies suicidal ideation or hallucinations. He is sleeping well and doing well in school, though his teachers have noticed that he does not seem to be able to concentrate as well as he had previously. Which of the following is the most likely diagnosis?

239) A 45-year-old woman comes to her physician for help with her insomnia. She states “ever since my husband died, I just can’t sleep.” The patient states her 57-year-old husband died suddenly of a heart attack 9 weeks ago. Since that time, the patient has had a very depressed mood, had been crying, has lost interest in activities, is fatigued, and has insomnia. Which of the following symptoms, if present, should make the physician think this patient has a major depression instead of bereavement?

240) A 32-year-old man is being treated for a severe major depression. Which of the following symptoms, if present, is one of the most accurate indicators of long-term suicidal risk?

241) A 44-year-old white male presents with a long history of joint pains in several joints. He has seen a physician before but no diagnosis was made. He has been taking ibuprofen with partial relief. He has now developed fever, diarrhea and weight loss. He denies any genitourinary or eye symptoms. He does not use tobacco, alcohol or drugs. He is a farmer. On examination, he has generalized lymphadenopathy and non-deforming arthritis. Small intestinal biopsy reveals periodic Acid-Schiff (PAS)-positive macrophages. Which of the following is the most likely diagnosis?

242) A 33-year-old tennis player comes to you with a complaint of pain in his right shoulder. He says that the pain is absent at rest but present when he lifts his arm over his head. The pain is compromising his play. On examination, active motion at right shoulder is limited due to pain. Pain is most severe on passive internal rotation and flexion at the right shoulder. No atrophy of the shoulder muscle is seen. Which of the following is the most likely diagnosis in this patient?

243) A 75-year-old white male comes to the physician's office for his routine health maintenance examination. He has no symptoms. He has a past medical history significant for hypertension and hyperlipidemia. He takes aspirin, hydrochlorothiazide and simvastatin. He does not smoke and consumes 1-2 beers on weekends. He walks 2 miles every morning and eats a balanced diet. His vital signs are within normal limits. His chest is clear to auscultation, and his abdomen is soft and nontender. Rectal examination shows a diffusely enlarged, firm prostate without nodules. Stool for occult blood is negative. The distal interphalangeal joints are enlarged, and his gait is normal. His labs are as follows: Total bilirubin 1.0 mg/dl, Alkaline phosphatase 420 U/L, Aspartate aminotransferase (SGOT) 20 U/L, Alanine aminotransferase (SGPT) 25 U/L, Serum creatinine 0.8 mg/dl, Calcium 8.8 mg/dl, Serum PSA 2.1 ng/ml. Which of the following is the most likely cause of the elevated alkaline phosphatase in this patient?

244) A 21-year-old Caucasian female presents with a one-week history of low-grade fever and joint pain. She describes symmetric swelling of the small hand joints. Her rheumatoid factor tests positive, and antinuclear antibodies are weakly positive at a 1:40 dilution. She is treated with NSAIDs. Four weeks later, the patient reports not taking the prescribed drugs since she feels no pain. Which of the following is the most likely diagnosis?

245) A 64-year-old male comes to the physician's office because of increasing pain in his right groin for the past several months. The pain increases with activity and is relieved with rest. He also has difficulty moving after a period of rest. He denies any trauma or falls. He has no fever, weight loss or loss of appetite. He has had lumbar disk herniation in the past but denies any current back pain. He has no other active medical problems. His vital signs are within normal limits. He weighs 95 kg (210 lb) and is 168 cm (66 in) tall. Examination shows pain on passive internal rotation of right hip joint. Direct pressure over the groin did not increase the pain. His reflexes are 2+, and there are no sensory deficits. Muscle bulk, tone and power are within normal limits. Pulses are 2+ in both legs. Which of the following is the most likely cause of his hip pain?

246) A 36-year-old female who is currently having regular menstrual periods comes to the emergency room because of malaise and a high-grade fever with chills. She also complains of pain in multiple joints. She always uses highly absorbent tampons during her menses. She uses intravenous heroin and cocaine and works as a prostitute. Her temperature is 39.3°C (103.4°F), pulse is 102/min, blood pressure is 120/80mmHg and respirations are 14/min. Examination shows multiple pustules on the extensor surfaces of her forearms. Joint examination does not show redness, swelling or tenderness. Three sets of blood cultures are negative Based on these findings, which of the following is the most likely diagnosis in this patient?

247) A 54-year-old retired schoolteacher comes to the physician's office because of worsening low back pain. The pain started three weeks ago. It is continuous and is worse at night. He has had little relief with over-the-counter nonsteroidal analgesics. He has no other symptoms. He had a surgical resection of a lung tumor one year ago for non-small cell carcinoma of the lung. Preoperative positron emission tomography (PET) scanning did not reveal any evidence of metastasis. His vital signs are within normal limits. Examination shows local spinal tenderness at the L4-L5 level. What is the most likely cause of his back pain?

248) A 60-year-old man presents to the emergency department after being awoken from sleep by severe pain in his right great toe. He reports that his toe is suddenly swollen and very tender to touch. On review of systems, the patient also describes occasional headaches and pruritus that can be "unbearable" after a hot bath. He does not smoke or drink alcohol. On physical examination, his lungs are normal. The liver span is 10 cm and the spleen is palpable 2 cm below the costal margin. Aspiration of the affected toe joint reveals negatively birefringent crystals. Which of the following is most likely responsible for this patient's symptoms?

249) A 29-year-old woman presents to your office complaining of easy fatigability over the last several months. She tires easily after walking short distances. She also has difficulties combing her hair due to an inability to hold her hands over her head for a long time. She reports a weight loss of two or three pounds over the last two months. She denies fever or loss of appetite. She does not smoke or consume alcohol. On family history, her father died of a stroke when he was 54 years old and her mother has diabetes mellitus. On examination, she is afebrile with a pulse of 105/min. Cardiac exam reveals regular rhythm with no murmur. Her gait is normal but, when asked to sit down slowly, she drops into the chair. A fine finger tremor is evident when she extends her arms. Her muscles are non-tender to palpation. She appears to have decreased muscle mass in her shoulders. Deep tendon reflexes are normal. Which of the following is the most likely cause of this patient's symptoms?

250) A 62-year-old male treated for hypertension and hyperlipidemia complains of nagging right knee pain that is worse in the evening. The pain has been present for several months and it seems to limit his physical activities. His blood pressure is 160/100 mmHg and his heart rate is 70/min. His BMI is 32 kg/m2, and palpation of the knee reveals a cool joint with bony tenderness. His blood cholesterol level is 200 mg/dl and his serum uric acid level is 9.0 mg/dl. Which of the following additional findings is likely on further examination of the right knee?

251) A 34-year-old man complains of back tightness and persistent low back pain. The pain has a dull and aching quality. It is worse during the night and in the morning but improves gradually during the day. He has no significant past medical history. He does not use tobacco, alcohol, or illicit drugs. He is married and lives with his wife. His pulse is 80/min, respirations are 14/min, and blood pressure is 120/76 mmHg. Which of the following most likely accounts for this patient's symptoms?

252) A 34-year-old woman with a skin rash, joint pains, and oral ulcers is diagnosed with systemic lupus erythematosus. She has no renal or central nervous system involvement, and her past medical history and review of systems are otherwise negative. Therapy with hydroxychloroquine is started. Which of the following screening tests is most important in this patient?

253) A 68-year-old man with hypertension, hyperlipidemia, and diabetes is hospitalized for an acute myocardial infarction. It is complicated by pulmonary edema and he undergoes angiography of the left anterior descending artery. On post-operative day 3, he complains of abdominal pain and discoloration of his toes. His vital signs are stable. Examination shows bluish discoloration of his right great toe and of all the toes on his left foot. The skin over the toes is cold and clammy. Bilateral pedal pulses are present and full. His abdomen is soft and mildly tender at the center. Chest auscultation is clear. Laboratory studies show a rise in creatinine to 2.3 g/dl from his baseline of 1.2 g/dl. An EKG shows sinus rhythm and Q waves in anterior leads. Which of the following is the most likely cause of his toe discoloration?

254) A 32-year-old man presents to the clinic with one week of escalating lower back pain. He describes the pain as dull and aching. It increases with motion and it is not completely relieved by rest. He has no significant past medical history. He smokes one pack of cigarettes per day and consumes alcohol occasionally. He admits to being "under a lot of stress" and has recently used injectable drugs. His family history is significant for prostate cancer in his father. His temperature is 36.7°C (98°F), pulse is 90/min, respirations are 16/min, and blood pressure is 120/80 mmHg. Gentle percussion over the lumbar vertebrae elicits pain. A full neurologic exam including straight leg raise is normal. Laboratory results are shown below: Complete blood count: Leukocyte count 6,500/mm3, Hematocrit 46%, Platelets 400,000/mm3. Which of the following is the most likely diagnosis?