A 39-year-old male is rushed to the emergency department after he developed a sudden-onset severe headache with ensuing nausea, vomiting, vision changes, and loss of consciousness. Past medical history is unattainable. He reports that the headache is worse than any he has experienced before. Noncontrast CT of the head is significant for an intracranial hemorrhage. Follow-up cerebral angiography is performed and shows a ruptured anterior communicating artery aneurysm. Which of the following has the strongest association with this patient's current presentation?
Q742
A 54-year-old man is brought to the emergency department because of progressive tingling and weakness in both of his legs for the past two days. The patient reports that his symptoms interfere with his ability to walk. Two weeks ago, he had an upper respiratory tract infection, which resolved spontaneously. His vital signs are within normal limits. Examination shows weakness in the lower extremities with absent deep tendon reflexes. Reflexes are 1+ in the upper extremities. Sensation to pinprick and light touch is intact. Romberg's test is negative. Laboratory studies show a leukocyte count of 12,000/mm3. Cerebrospinal fluid analysis results show:
Opening pressure normal
Protein 200 mg/dL
Glucose 70 mg/dL
White blood cells 4/mm3
This patient is at increased risk for which of the following conditions?
Q743
A 62-year-old Caucasian male presents to your office with hemoptysis and hematuria. On physical exam you note a saddle nose deformity. Laboratory results show an elevated level of cytoplasmic antineutrophil cytoplasmic antibody. Which of the following interventions is most appropriate for this patient?
Q744
A 5-year-old girl with an aortic stenosis correction comes to the office for a follow-up visit for acute lymphoblastic leukemia. She initiated chemotherapy a week before through a peripherally inserted central line. She reports being 'tired all the time' and has been bruising easily. Her vital signs are within normal limits. Physical examination shows several tender, non-blanching petechiae on the pads of the fingers and toes; several dark, non-tender petechiae on her palms and soles; and small, linear hemorrhages under her fingernails. Fundoscopic examination shows various small areas of hemorrhage on the retinae bilaterally. Cardiac examination is notable for a II/VI systolic ejection murmur that seems to have worsened in comparison to the last visit. Which of the following is the most likely cause?
Q745
A 57-year-old man comes to the physician because of a 2-month history of worsening shortness of breath with walking. He has not had any cough, fevers, or recent weight loss. He has hypercholesterolemia, for which he takes simvastatin, but otherwise is healthy. For 35 years he has worked for a demolition company. He has smoked 1 pack of cigarettes daily for the past 33 years. Pulmonary examination shows fine bibasilar end-expiratory crackles. An x-ray of the chest shows diffuse bilateral infiltrates predominantly in the lower lobes and bilateral calcified pleural plaques. The patient is most likely to develop which of the following conditions?
Q746
A 43-year-old woman presents to the physician with the complaint of worsening fatigue over the past several months. She has found that she requires nearly double the amount of coffee consumption each day to stay awake at work and that despite maintaining a balanced, healthy diet, she has experienced significant weight gain. A blood test confirms the presence of anti-thyroid peroxidase antibodies. Which of the following additional findings would be most consistent with the underlying pathophysiology of her condition?
Q747
A 69-year-old man is brought in by his wife with acute onset aphasia for the past 5 hours. The patient's wife says that they were sitting having dinner when suddenly he was not able to speak. They delayed coming to the hospital because he had a similar episode 2 months ago which resolved within an hour. His past medical history is significant for hypercholesterolemia, managed with rosuvastatin, and a myocardial infarction (MI) 2 months ago, status post percutaneous transluminal coronary angioplasty complicated by residual angina. His family history is significant for his father who died of MI at age 60. The patient reports a 15-pack-year smoking history but denies any alcohol or recreational drug use. The vital signs include: temperature 37.0℃ (98.6℉), blood pressure 125/85 mm Hg, pulse 96/min, and respiratory rate 19/min. On physical examination, the patient has expressive aphasia. There is a weakness of the right-sided lower facial muscles. The strength in his upper and lower extremities is 4/5 on the right and 5/5 on the left. There is also a decreased sensation on his right side. A noncontrast computed tomography (CT) scan of the head is unremarkable. CT angiography (CTA) and diffusion-weighted magnetic resonance imaging (MRI) of the brain are acquired, and the findings are shown in the exhibit (see image). Which of the following is the best course of treatment in this patient?
Q748
A 48-year-old woman comes to the physician because of a 6-month history of muscle stiffness, myalgia, and a 7-kg (15-lb) weight gain. Her last menstrual period was 4 months ago. Physical examination shows cold, dry skin, and proximal muscle weakness. Deep tendon reflexes are 2+ bilaterally, with delayed relaxation. The creatine kinase level is 2,940 U/L. Which of the following is the most appropriate next step in diagnosis?
Q749
A 9-year-old girl is admitted to the hospital with a one-day history of acute abdominal pain and vomiting. She also has a two-day history of fever, headache, and neck pain. Her immunizations are up-to-date. She is confused and oriented only to place and person. Her temperature is 39.7°C (103.5°F), pulse is 148/min, blood pressure is 90/50 mm Hg, and respiratory rate is 28/min. Cervical range of motion is limited by pain. The remainder of the neurologic examination shows no abnormalities. Laboratory studies show:
Hemoglobin 10.9 g/dL
Leukocyte count 44,000/mm3
Serum
pH 7.33
Na+ 130 mEq/L
Cl- 108 mEq/L
K+ 6.1 mEq/L
HCO3- 20 mEq/L
Urea nitrogen 34 mg/dL
Glucose 180 mg/dL
Creatinine 2.4 mg/dL
Urine ketones negative
A CT scan of the head shows enhancement of the arachnoid and pia mater. Cerebrospinal fluid analysis shows a leukocyte count of 3,400/μL (90% neutrophils), a glucose concentration of 50 mg/dL, protein concentration of 81 mg/dL, and no erythrocytes. Gram stain of the CSF shows gram-negative diplococci. This patient is at increased risk for which of the following complications?
Q750
A 69-year-old woman is rushed to the emergency room by her daughter after she found her unconscious. Bruises are visible on the patient’s torso and limbs, and it is evident that she has epistaxis. Her daughter says that the patient was diagnosed with immune thrombocytopenic purpura at 61 years of age and has not had a normal thrombocyte count since the time of diagnosis. She was treated with corticosteroids, which were discontinued several weeks ago. Her current platelet count is 4,000/mm3. Which of the following is the best next step in the treatment of this patient?
Cardiology US Medical PG Practice Questions and MCQs
Question 741: A 39-year-old male is rushed to the emergency department after he developed a sudden-onset severe headache with ensuing nausea, vomiting, vision changes, and loss of consciousness. Past medical history is unattainable. He reports that the headache is worse than any he has experienced before. Noncontrast CT of the head is significant for an intracranial hemorrhage. Follow-up cerebral angiography is performed and shows a ruptured anterior communicating artery aneurysm. Which of the following has the strongest association with this patient's current presentation?
A. Abdominal CT suggestive of renal cell carcinoma
B. Kidney ultrasound showing numerous bilateral renal cysts (Correct Answer)
C. Brain MRI showing a butterfly glioma with a central necrotic core
D. History of renal transplantation at 8 years of age
E. History of multiple hemangioblastomas of the retina and spine as well as pheochromocytoma
Explanation: ***Kidney ultrasound showing numerous bilateral renal cysts***
- This finding is highly suggestive of **Autosomal Dominant Polycystic Kidney Disease (ADPKD)**, which is strongly associated with an increased risk of **intracranial aneurysms**.
- Ruptured intracranial aneurysms, like the one described in the patient, are a major cause of morbidity and mortality in individuals with ADPKD.
*Abdominal CT suggestive of renal cell carcinoma*
- While renal cell carcinoma can be associated with certain genetic syndromes (e.g., von Hippel-Lindau disease), it does not have a direct strong association with **intracranial aneurysms** causing a sudden-onset severe headache in the manner described.
- The primary presentation here is a ruptured cerebral aneurysm, making other associations less likely.
*Brain MRI showing a butterfly glioma with a central necrotic core*
- A **butterfly glioma with a central necrotic core** is characteristic of **glioblastoma multiforme**, a primary brain tumor.
- While brain tumors can cause headaches, they typically lead to a more gradual onset of symptoms and do not directly predispose to the formation and rupture of **intracranial aneurysms**.
*History of renal transplantation at 8 years of age*
- A history of renal transplantation suggests prior **end-stage renal disease**, which can have various underlying causes.
- While some causes of kidney disease (like ADPKD) are linked to aneurysms, transplantation itself is not a direct risk factor for aneurysm rupture; rather, it's the *underlying cause* of kidney disease that might be relevant.
*History of multiple hemangioblastomas of the retina and spine as well as pheochromocytoma*
- This constellation of symptoms is indicative of **von Hippel-Lindau disease**, which is associated with various tumors, including **hemangioblastomas** of the central nervous system.
- While von Hippel-Lindau disease is linked to CNS lesions, it is **not primarily associated with an increased risk of intracranial saccular aneurysms** leading to subarachnoid hemorrhage.
Question 742: A 54-year-old man is brought to the emergency department because of progressive tingling and weakness in both of his legs for the past two days. The patient reports that his symptoms interfere with his ability to walk. Two weeks ago, he had an upper respiratory tract infection, which resolved spontaneously. His vital signs are within normal limits. Examination shows weakness in the lower extremities with absent deep tendon reflexes. Reflexes are 1+ in the upper extremities. Sensation to pinprick and light touch is intact. Romberg's test is negative. Laboratory studies show a leukocyte count of 12,000/mm3. Cerebrospinal fluid analysis results show:
Opening pressure normal
Protein 200 mg/dL
Glucose 70 mg/dL
White blood cells 4/mm3
This patient is at increased risk for which of the following conditions?
A. Respiratory failure (Correct Answer)
B. Dementia
C. Hypertrophic cardiomyopathy
D. Thymoma
E. Urinary incontinence
Explanation: ***Respiratory failure***
- The patient's presentation is consistent with **Guillain-Barré Syndrome (GBS)**, characterized by **ascending paralysis**, areflexia, and a history of preceding infection.
- As the paralysis ascends, it can affect the **respiratory muscles** (diaphragm and intercostal muscles), leading to life-threatening respiratory failure requiring mechanical ventilation.
*Dementia*
- **Dementia** is a chronic neurodegenerative condition characterized by progressive cognitive decline, memory impairment, and functional deficits.
- It does not present with acute, rapidly progressing **motor weakness** and **areflexia** as seen in this patient.
*Hypertrophic cardiomyopathy*
- **Hypertrophic cardiomyopathy** is a genetic heart condition causing thickening of the heart muscle, leading to impaired diastolic filling and potential arrhythmias.
- It does not explain the patient's neurological symptoms of **progressive weakness**, **areflexia**, or the characteristic CSF findings.
*Thymoma*
- A **thymoma** is a tumor of the thymus gland, most commonly associated with **myasthenia gravis**, an autoimmune disorder causing fluctuating muscle weakness that worsens with activity.
- The patient's symptoms of progressive, ascending paralysis with absent reflexes are **inconsistent with myasthenia gravis**.
*Urinary incontinence*
- While urinary symptoms can be seen in some neurological conditions, **urinary incontinence** is not a primary or hallmark feature of **Guillain-Barré Syndrome** in its acute phase unless severe autonomic dysfunction or profound flaccid paralysis affecting the bladder occurs.
- The most immediate and life-threatening complication in GBS is respiratory compromise due to ascending paralysis.
Question 743: A 62-year-old Caucasian male presents to your office with hemoptysis and hematuria. On physical exam you note a saddle nose deformity. Laboratory results show an elevated level of cytoplasmic antineutrophil cytoplasmic antibody. Which of the following interventions is most appropriate for this patient?
A. Smoking cessation
B. Corticosteroids (Correct Answer)
C. IV immunoglobulin
D. Discontinuation of ibuprofen
E. Isoniazid
Explanation: ***Corticosteroids***
- The patient's presentation with **hemoptysis**, **hematuria**, and **saddle nose deformity**, coupled with a **positive c-ANCA**, is highly suggestive of **granulomatosis with polyangiitis (GPA)**, a severe vasculitis.
- **Corticosteroids** are a cornerstone of treatment for GPA, especially during acute flares, to suppress the inflammatory response and prevent organ damage.
*Smoking cessation*
- While **smoking cessation** is important for overall health, particularly in cases of hemoptysis, it does not directly treat the underlying autoimmune vasculitis in GPA.
- It would be a supportive measure, but not the primary or most appropriate intervention for the acute, life-threatening aspects of GPA.
*IV immunoglobulin*
- **Intravenous immunoglobulin (IVIG)** may be used in certain autoimmune conditions, but it is **not the primary treatment for GPA**.
- While it can modulate the immune system, its role in GPA is generally limited to cases refractory to conventional therapy or in specific situations like severe neurologic involvement, which is not indicated here.
*Discontinuation of ibuprofen*
- **Ibuprofen**, an NSAID, might contribute to renal dysfunction or gastrointestinal bleeding, but discontinuing it alone would **not address the systemic autoimmune vasculitis**.
- It would be a symptomatic management, potentially alleviating some non-specific inflammation or pain, but would not halt the progression of GPA.
*Isoniazid*
- **Isoniazid** is an antibiotic primarily used for the treatment and prophylaxis of **tuberculosis**.
- There is no indication of tuberculosis in this patient's presentation, and isoniazid has no role in the treatment of systemic vasculitis like GPA.
Question 744: A 5-year-old girl with an aortic stenosis correction comes to the office for a follow-up visit for acute lymphoblastic leukemia. She initiated chemotherapy a week before through a peripherally inserted central line. She reports being 'tired all the time' and has been bruising easily. Her vital signs are within normal limits. Physical examination shows several tender, non-blanching petechiae on the pads of the fingers and toes; several dark, non-tender petechiae on her palms and soles; and small, linear hemorrhages under her fingernails. Fundoscopic examination shows various small areas of hemorrhage on the retinae bilaterally. Cardiac examination is notable for a II/VI systolic ejection murmur that seems to have worsened in comparison to the last visit. Which of the following is the most likely cause?
A. Dilated cardiomyopathy
B. Acute rheumatic fever
C. Infective endocarditis (Correct Answer)
D. Hypertrophic cardiomyopathy
E. Bleeding diathesis secondary to thrombocytopenia
Explanation: ***Infective endocarditis***
- The patient's history of **aortic stenosis correction** and a recently placed **PICC line** are significant risk factors for **infective endocarditis**.
- The presence of **petechiae on fingers/toes/palms/soles**, **splinter hemorrhages** (under fingernails), and **retinal hemorrhages** (Roth spots) are classic peripheral stigmata of infective endocarditis. The worsening systolic ejection murmur suggests new or worsening valvular dysfunction.
*Dilated cardiomyopathy*
- While it can cause fatigue and a murmur, **dilated cardiomyopathy** does not typically present with the specific peripheral dermatological and ophthalmological findings seen in this patient (petechiae, splinter hemorrhages, Roth spots).
- It is often associated with a dilated ventricle and reduced ejection fraction, which is not suggested by the classic signs in the question.
*Acute rheumatic fever*
- **Acute rheumatic fever** typically occurs after a Group A Streptococcus infection and presents with migratory polyarthritis, carditis, chorea, erythema marginatum, and subcutaneous nodules according to the **Jones criteria**.
- The presence of petechiae and splinter hemorrhages is not characteristic of acute rheumatic fever.
*Hypertrophic cardiomyopathy*
- **Hypertrophic cardiomyopathy** is characterized by left ventricular hypertrophy and can cause systolic murmurs, but it does not explain the widespread petechiae, splinter hemorrhages, or retinal hemorrhages observed.
- Its symptoms often include dyspnea, palpitations, chest pain, and syncope, which are distinct from the current presentation.
*Bleeding diathesis secondary to thrombocytopenia*
- **Thrombocytopenia** could explain easy bruising and petechiae due to platelet deficiency, which is possible in a patient undergoing chemotherapy for ALL. However, thrombocytopenia alone would not cause the specific signs of **splinter hemorrhages** or **retinal hemorrhages (Roth spots)** particularly with a worsening cardiac murmur.
- The combination of peripheral embolic phenomena and cardiac involvement strongly points away from a simple bleeding diathesis and towards an infectious cardiac source.
Question 745: A 57-year-old man comes to the physician because of a 2-month history of worsening shortness of breath with walking. He has not had any cough, fevers, or recent weight loss. He has hypercholesterolemia, for which he takes simvastatin, but otherwise is healthy. For 35 years he has worked for a demolition company. He has smoked 1 pack of cigarettes daily for the past 33 years. Pulmonary examination shows fine bibasilar end-expiratory crackles. An x-ray of the chest shows diffuse bilateral infiltrates predominantly in the lower lobes and bilateral calcified pleural plaques. The patient is most likely to develop which of the following conditions?
A. Tuberculosis
B. Thyroid carcinoma
C. Sarcoidosis
D. Mesothelioma (Correct Answer)
E. Bronchogenic carcinoma
Explanation: ***Mesothelioma***
- The patient has **asbestosis** (interstitial lung disease from asbestos exposure causing bilateral lower lobe infiltrates and bibasilar crackles) due to 35 years working in **demolition** with asbestos exposure.
- **Calcified pleural plaques** are pathognomonic for asbestos exposure and indicate significant cumulative exposure.
- Patients with asbestosis and pleural plaques have markedly increased risk of **malignant mesothelioma**, a highly specific asbestos-related malignancy of the pleura.
- While bronchogenic carcinoma is statistically more common, **mesothelioma is virtually pathognomonic** for asbestos exposure and is the classic malignancy tested in this clinical context.
*Tuberculosis*
- TB typically presents with **cough, fevers, night sweats, and weight loss**, which are absent in this patient.
- Chest x-ray in TB shows **upper lobe cavitations or consolidation**, not bilateral lower lobe interstitial infiltrates with pleural plaques.
- No epidemiologic risk factors for TB are present.
*Thyroid carcinoma*
- Thyroid cancer presents with a **thyroid nodule or mass**, not pulmonary symptoms.
- No association with asbestos exposure or the clinical findings described.
*Sarcoidosis*
- Sarcoidosis typically shows **bilateral hilar lymphadenopathy** and upper/middle lobe involvement on chest x-ray.
- Not associated with asbestos exposure or calcified pleural plaques.
- Occurs more commonly in younger patients (20-40 years old).
*Bronchogenic carcinoma*
- While this patient's **smoking history** increases lung cancer risk, and asbestos exposure synergistically increases this risk further, bronchogenic carcinoma would present with a **focal mass or nodule**, not diffuse bilateral infiltrates.
- The **calcified pleural plaques** and diffuse interstitial pattern point more specifically toward asbestos-related pathology (asbestosis now, mesothelioma risk in future).
- Mesothelioma is more specific to asbestos exposure in this clinical scenario.
Question 746: A 43-year-old woman presents to the physician with the complaint of worsening fatigue over the past several months. She has found that she requires nearly double the amount of coffee consumption each day to stay awake at work and that despite maintaining a balanced, healthy diet, she has experienced significant weight gain. A blood test confirms the presence of anti-thyroid peroxidase antibodies. Which of the following additional findings would be most consistent with the underlying pathophysiology of her condition?
A. Galactorrhea (Correct Answer)
B. Constipation
C. Brisk deep tendon reflexes
D. Diarrhea
E. Heat intolerance
Explanation: ***Galactorrhea***
- This patient has **Hashimoto's thyroiditis**, an autoimmune hypothyroidism, given the fatigue, weight gain, and positive **anti-thyroid peroxidase antibodies**.
- **Hypothyroidism** can lead to **hyperprolactinemia** due to increased **TRH** (thyrotropin-releasing hormone), which stimulates both TSH and prolactin release from the anterior pituitary.
- Elevated prolactin can manifest as **galactorrhea**, representing a less commonly recognized endocrine consequence of primary hypothyroidism.
*Constipation*
- **Constipation** is a common symptom of **hypothyroidism** due to decreased gastrointestinal motility.
- While consistent with hypothyroidism, it is a direct consequence of reduced metabolic activity rather than a secondary endocrine effect.
- This is a well-known, expected finding rather than an additional pathophysiologic manifestation.
*Brisk deep tendon reflexes*
- **Hypothyroidism** typically causes **delayed relaxation of deep tendon reflexes** (hung-up reflexes), not brisk reflexes.
- **Brisk reflexes** are characteristic of **hyperthyroidism** due to increased neuromuscular excitability.
*Diarrhea*
- **Diarrhea** is typically associated with **hyperthyroidism** due to increased gastrointestinal motility from elevated metabolic rate.
- **Hypothyroidism** more commonly causes **constipation** due to decreased GI motility.
*Heat intolerance*
- **Heat intolerance** is a classic symptom of **hyperthyroidism** due to an elevated metabolic rate and increased thermogenesis.
- Patients with **hypothyroidism** usually experience **cold intolerance** due to decreased metabolic heat production.
Question 747: A 69-year-old man is brought in by his wife with acute onset aphasia for the past 5 hours. The patient's wife says that they were sitting having dinner when suddenly he was not able to speak. They delayed coming to the hospital because he had a similar episode 2 months ago which resolved within an hour. His past medical history is significant for hypercholesterolemia, managed with rosuvastatin, and a myocardial infarction (MI) 2 months ago, status post percutaneous transluminal coronary angioplasty complicated by residual angina. His family history is significant for his father who died of MI at age 60. The patient reports a 15-pack-year smoking history but denies any alcohol or recreational drug use. The vital signs include: temperature 37.0℃ (98.6℉), blood pressure 125/85 mm Hg, pulse 96/min, and respiratory rate 19/min. On physical examination, the patient has expressive aphasia. There is a weakness of the right-sided lower facial muscles. The strength in his upper and lower extremities is 4/5 on the right and 5/5 on the left. There is also a decreased sensation on his right side. A noncontrast computed tomography (CT) scan of the head is unremarkable. CT angiography (CTA) and diffusion-weighted magnetic resonance imaging (MRI) of the brain are acquired, and the findings are shown in the exhibit (see image). Which of the following is the best course of treatment in this patient?
A. Aspirin
B. Mannitol
C. Mechanical thrombectomy (Correct Answer)
D. IV tPA
E. Low molecular weight heparin
Explanation: ***Mechanical thrombectomy***
- The patient presents with **acute ischemic stroke** symptoms (aphasia, right-sided weakness, sensory deficits) at **5 hours from symptom onset**. Imaging (CTA showing large vessel occlusion and MRI confirming diffusion restriction) demonstrates a **large vessel occlusion**, making him a candidate for **mechanical thrombectomy**.
- Since the patient is **beyond the 4.5-hour window for IV tPA**, mechanical thrombectomy is the **primary reperfusion therapy** indicated for large vessel occlusion strokes up to **24 hours** (with appropriate imaging showing salvageable tissue).
- Mechanical thrombectomy offers the best chance for complete recanalization and improved neurological outcomes in large vessel occlusion strokes, particularly when IV tPA is not an option.
*Aspirin*
- While **aspirin** is crucial for **secondary stroke prevention**, it is not the primary acute treatment for a large vessel occlusion stroke due to its limited ability to achieve rapid and complete recanalization.
- Aspirin (or other antiplatelet therapy) is typically initiated **within 24-48 hours after stroke onset**, but only after excluding hemorrhagic transformation and after acute reperfusion therapies have been considered or completed.
*Mannitol*
- **Mannitol** is an osmotic diuretic used to reduce **intracranial pressure (ICP)** in cases of severe cerebral edema, which can be a complication of large ischemic strokes.
- It is not a primary treatment for the acute ischemic event itself, but rather a supportive measure used to manage life-threatening complications if **cerebral edema** develops and causes significant mass effect or herniation risk.
*IV tPA*
- **Intravenous tissue plasminogen activator (IV tPA)** is the first-line pharmacologic treatment for acute ischemic stroke if administered **within 4.5 hours of symptom onset** in eligible patients.
- This patient presents at **5 hours**, which is **beyond the approved time window** for IV tPA administration, making him **ineligible** for thrombolytic therapy.
- Even if within the time window, patients with large vessel occlusion often require mechanical thrombectomy in addition to or instead of IV tPA for optimal outcomes.
*Low molecular weight heparin*
- **Low molecular weight heparin (LMWH)** is primarily used for **deep vein thrombosis (DVT)** prophylaxis in immobilized patients or for the treatment of established DVT/pulmonary embolism.
- It is generally **not recommended for acute ischemic stroke treatment** due to an increased risk of hemorrhagic transformation without proven benefit in recanalization or clinical outcomes.
Question 748: A 48-year-old woman comes to the physician because of a 6-month history of muscle stiffness, myalgia, and a 7-kg (15-lb) weight gain. Her last menstrual period was 4 months ago. Physical examination shows cold, dry skin, and proximal muscle weakness. Deep tendon reflexes are 2+ bilaterally, with delayed relaxation. The creatine kinase level is 2,940 U/L. Which of the following is the most appropriate next step in diagnosis?
A. Thyroid function tests (Correct Answer)
B. Repetitive nerve stimulation
C. Serum electrolytes
D. Muscle biopsy
E. Serum assay for muscle specific tyrosine kinase antibody
Explanation: ***Thyroid function tests***
- The patient's symptoms (muscle stiffness, myalgia, weight gain, cold/dry skin, proximal muscle weakness, delayed deep tendon reflex relaxation, and elevated CK) are highly suggestive of **hypothyroidism**.
- Measuring **TSH** and **free T4** is crucial to confirm or rule out this diagnosis and it is the most appropriate next step in the diagnostic workup.
*Repetitive nerve stimulation*
- This test is primarily used to diagnose disorders of the **neuromuscular junction**, such as **myasthenia gravis** or **Lambert-Eaton syndrome**.
- The patient's clinical picture, particularly the delayed deep tendon reflex relaxation and muscle stiffness, is not typical for these conditions.
*Serum electrolytes*
- While electrolytes can be abnormal in various conditions, they are unlikely to directly explain the constellation of symptoms (muscle stiffness, weight gain, cold/dry skin, delayed reflexes) and the high **creatine kinase** level in this patient.
- While a basic metabolic panel is often part of a general workup, it is not the most specific or appropriate *next step* for this clinical presentation.
*Muscle biopsy*
- A muscle biopsy is an **invasive procedure** typically reserved for diagnosing specific **myopathies** (e.g., inflammatory myopathies, muscular dystrophies) when less invasive tests have not yielded a diagnosis.
- Given the strong indicators for hypothyroidism, a muscle biopsy would be premature before evaluating thyroid function.
*Serum assay for muscle specific tyrosine kinase antibody*
- This antibody is a marker for a subtype of **myasthenia gravis** (**MuSK-associated myasthenia gravis**), a disorder of the neuromuscular junction.
- As with repetitive nerve stimulation, the patient's symptoms, especially the delayed deep tendon reflexes and myxedema-like features, do not primarily point towards myasthenia gravis.
Question 749: A 9-year-old girl is admitted to the hospital with a one-day history of acute abdominal pain and vomiting. She also has a two-day history of fever, headache, and neck pain. Her immunizations are up-to-date. She is confused and oriented only to place and person. Her temperature is 39.7°C (103.5°F), pulse is 148/min, blood pressure is 90/50 mm Hg, and respiratory rate is 28/min. Cervical range of motion is limited by pain. The remainder of the neurologic examination shows no abnormalities. Laboratory studies show:
Hemoglobin 10.9 g/dL
Leukocyte count 44,000/mm3
Serum
pH 7.33
Na+ 130 mEq/L
Cl- 108 mEq/L
K+ 6.1 mEq/L
HCO3- 20 mEq/L
Urea nitrogen 34 mg/dL
Glucose 180 mg/dL
Creatinine 2.4 mg/dL
Urine ketones negative
A CT scan of the head shows enhancement of the arachnoid and pia mater. Cerebrospinal fluid analysis shows a leukocyte count of 3,400/μL (90% neutrophils), a glucose concentration of 50 mg/dL, protein concentration of 81 mg/dL, and no erythrocytes. Gram stain of the CSF shows gram-negative diplococci. This patient is at increased risk for which of the following complications?
A. Vesicular skin eruptions
B. Adrenal hemorrhage (Correct Answer)
C. Pancreatitis
D. Temporal lobe inflammation
E. Deep neck abscess
Explanation: **Adrenal hemorrhage**
- The clinical picture of **fever, acute abdominal pain, confusion, hypotension, and a high WBC count (44,000/mm³)**, along with **Gram-negative diplococci in CSF**, indicates **meningococcal meningitis with sepsis**. This rapidly progressive infection by *Neisseria meningitidis* can lead to **Waterhouse-Friderichsen syndrome**, characterized by **adrenal hemorrhage** and profound shock.
- The **elevated potassium (6.1 mEq/L)** and **hyponatremia (130 mEq/L)** are consistent with **adrenal insufficiency** resulting from adrenal hemorrhage.
*Vesicular skin eruptions*
- **Vesicular skin eruptions** are characteristic of viral infections such as **herpes simplex virus (HSV)** or **varicella-zoster virus**, which would present differently (e.g., HSV encephalitis often causes temporal lobe involvement).
- While various infections can cause skin rashes, this specific presentation with extensive meningeal inflammation and septic shock points away from typical vesicular eruptions.
*Pancreatitis*
- **Pancreatitis** is characterized by severe epigastric pain radiating to the back, often with nausea and vomiting, and elevated lipase/amylase. While **abdominal pain** is present, other symptoms like **neck stiffness, confusion, and CSF findings of bacterial meningitis** are not typical for pancreatitis.
- There is no specific evidence, such as imaging findings or elevated pancreatic enzymes, to suggest pancreatitis in this case.
*Temporal lobe inflammation*
- **Temporal lobe inflammation** is a hallmark of **HSV encephalitis**, which often presents with seizures, bizarre behavior, and specific MRI findings in the temporal lobes. While a CT scan showed arachnoid and pia mater enhancement, this indicates **meningeal inflammation**, not specifically temporal lobe parenchymal inflammation (encephalitis).
- The presence of **Gram-negative diplococci in the CSF** strongly indicates bacterial meningitis, not viral encephalitis, making temporal lobe inflammation less likely.
*Deep neck abscess*
- A **deep neck abscess** would typically cause localized neck pain, swelling, dysphagia, and stridor, potentially with fever, but would not explain the widespread CNS symptoms (confusion, meningeal signs, CSF findings) or systemic signs of shock and coagulopathy seen here.
- While the patient has neck pain, it is due to **meningismus**, not a localized abscess, and there is no mention of local swelling or airway compromise.
Question 750: A 69-year-old woman is rushed to the emergency room by her daughter after she found her unconscious. Bruises are visible on the patient’s torso and limbs, and it is evident that she has epistaxis. Her daughter says that the patient was diagnosed with immune thrombocytopenic purpura at 61 years of age and has not had a normal thrombocyte count since the time of diagnosis. She was treated with corticosteroids, which were discontinued several weeks ago. Her current platelet count is 4,000/mm3. Which of the following is the best next step in the treatment of this patient?
A. Administration of intravenous immunoglobulins (Correct Answer)
B. Splenectomy
C. Platelet transfusion
D. Continuation of corticosteroids
E. Stem cell transplantation
Explanation: ***Administration of intravenous immunoglobulins***
- Given the patient's **severe thrombocytopenia (platelet count 4,000/mm3)**, **active bleeding (epistaxis)**, and unconsciousness indicating a potential severe bleeding event (e.g., intracranial hemorrhage), **IVIG** is the most appropriate first-line treatment to rapidly increase platelet count.
- **IVIG acts quickly** (within 24-48 hours) by blocking macrophage Fc receptors, preventing the destruction of antibody-coated platelets, and is preferred as the primary intervention in acute, life-threatening ITP with bleeding.
- While platelet transfusion may be given concurrently in life-threatening bleeding, **IVIG addresses the underlying immune destruction** and is the definitive acute intervention.
*Splenectomy*
- While **splenectomy** is an effective treatment for chronic ITP unresponsive to corticosteroids or IVIG, it is an **invasive surgical procedure** and not suitable for immediate stabilization in a patient with severe, acute bleeding.
- It takes time to arrange and perform and carries surgical risks, which are heightened in an actively bleeding patient.
- Typically considered for **chronic refractory ITP** after failure of medical management.
*Platelet transfusion*
- **Platelet transfusions** in ITP are **rapidly destroyed by autoantibodies**, making them generally ineffective as monotherapy.
- However, they **may be used as a temporizing measure** in life-threatening bleeding (such as suspected intracranial hemorrhage) while awaiting the effect of IVIG or corticosteroids.
- They do not address the underlying immune-mediated platelet destruction and should be given **in conjunction with** immunosuppressive therapy (IVIG or corticosteroids), not as a standalone intervention.
- **IVIG remains the best answer** as it treats the cause of thrombocytopenia rather than just temporarily supplementing platelet numbers.
*Continuation of corticosteroids*
- The patient has already received corticosteroids, which were discontinued, suggesting either **lack of sustained response** or inability to tolerate long-term use.
- While high-dose corticosteroids may be restarted in acute ITP with bleeding, they have a **slower onset of action** (days to weeks) compared to IVIG (24-48 hours) and are less suitable as the primary intervention for an acute, severe bleeding emergency.
*Stem cell transplantation*
- **Stem cell transplantation** is a highly invasive and high-risk procedure reserved for **severe refractory autoimmune conditions** when multiple other treatments have failed.
- It is not a first-line treatment for acute ITP exacerbations and would not be considered in an emergency setting for immediate management of severe bleeding.