The following cases and commentary, which address stroke, are excerpted from ACP's Medical Knowledge Self-Assessment Program (MKSAP 15).
Case 1: Ischemic stroke transfer
A 79-year-old woman is to be transferred from the emergency department to a hospital ward for ongoing care. She awoke at home 5 hours ago with slurred speech, difficulty swallowing food and drink, and left hemiparesis. A right hemispheric ischemic stroke was diagnosed in the emergency department after a CT scan of the head confirmed a right hemispheric infarction. Because the time of stroke onset could not be determined, no recombinant tissue plasminogen activator was administered. The patient has no other medical problems and takes no medications.
On physical examination, blood pressure is 168/86 mm Hg, pulse rate is 80 beats/min, and respiration rate is 18 breaths/min. Neurologic assessment reveals dysarthria, dysphagia, left facial droop, and left hemiparesis. Laboratory studies show a plasma LDL cholesterol level of 158 mg/dL (4.09 mmol/L) but no other abnormalities.
Which of the following is the most appropriate first step in management after transfer is completed?
A. Bedside screening for dysphagia
B. Oral administration of an angiotensin-converting enzyme inhibitor
C. Oral administration of a statin
D. Physical therapy and rehabilitation consultation
Case 2: Severe left hemispheric ischemic stroke and hypertension
A 74-year-old woman is admitted to the hospital after sustaining a severe left hemispheric ischemic stroke while alone at home. Her son found her collapsed in the living room when he went to visit her. The patient has hypertension for which she takes enalapril but no history of ischemic heart disease or heart failure.
On physical examination, blood pressure is 190/105 mm Hg, pulse rate is 80 beats/min, and respiration rate is 16 breaths/min. The patient has right hemiparesis, right facial droop, aphasia, and dysarthria. The remainder of the physical examination, including the cardiovascular examination, is normal.
Results of laboratory studies, including serum creatinine level, are normal. A CT scan shows frank ischemic changes that occupy most of the left middle cerebral artery territory. An electro cardiogram and chest radiograph show normal findings.
Which of the following is the most appropriate treatment of her hypertension at this time?
A. Intravenous labetalol
B. Intravenous nicardipine
C. Oral nifedipine
D. Withholding of all antihypertensive medications
Case 3: Mild left hemiplegia
A 45-year-old woman is admitted to the hospital with mild left hemiplegia, left hemineglect, and dysarthria. A CT scan of the head reveals a large right hemispheric infarction due to an occluded right middle cerebral artery. She has a history of anti phospholipid antibody syndrome diagnosed 3 years ago after an episode of iliofemoral venous thrombosis. She was treated for 18 months with warfarin but elected to discontinue treatment. There is no relevant family history. Her only medication is aspirin.
Forty-eight hours later, a progressive deterioration of her mental status is noted. The patient had previously stated that she wants everything possible done to prolong her life (“full code”).
Examination now shows that she has severe left hemiplegia and that her head and eyes are deviated to the right. A repeat CT scan of the head reveals a large hypodense region occupying the entire right middle cerebral artery territory, a local mass effect, and a 7-mm midline shift from right to left.
Which of the following is the most appropriate therapy at this time?
A. Decompressive hemicraniectomy
B. Intra-arterial thrombolysis
C. Intravenous heparin
D. Use of an endovascular mechanical clot-retrieval device
Answers and commentary
Correct answer: A. Bedside screening for dysphagia.
On admission to a hospital ward, a patient with stroke should be given nothing by mouth (kept NPO) until a swallowing assessment is conducted. Dysphagia screening is especially appropriate for this patient, who had difficulty swallowing when she first awoke with stroke symptoms. Dysphagia occurs in 45% of all hospitalized patients with stroke and can lead to poor outcomes, including aspiration pneumonia and death. Bedside screening of swallowing ability should thus be completed before oral intake of any medication or food; if the screening results are abnormal, a complete examination of swallowing ability is recommended. The American Heart Association/American Stroke Association recommends a water swallow test performed at the bedside by a trained observer as the best bedside predictor of aspiration. A prospective study of the water swallow test demonstrated a significantly decreased risk of aspiration pneumonia of 2.4% versus 5.4% in patients who were not screened.
Angiotensin-converting enzyme inhibitors, statins, and aspirin are appropriate treatments for secondary stroke prevention in some patients, but they should not be orally administered before ruling out the risk of aspiration.
Like most patients with stroke, this patient will undoubtedly require physical therapy and rehabilitation during her recovery. However, consulting with the department(s) responsible for such care is not an immediate concern and should not be the first step taken when the patient arrives in the hospital ward.
- In a patient with stroke, dysphagia screening should be performed before food, oral medication, or liquids are administered.
Correct answer: D. Withholding of all antihypertensive medications.
For uncomplicated ischemic strokes in patients without concurrent acute coronary artery disease or heart failure, consensus exists that antihypertensive medications, such as intravenous labetalol or nicardipine, should be withheld if the systolic blood pressure is less than 220 mm Hg or the diastolic blood pressure is less than 120 mm Hg, unless there are other manifestations of end-organ damage. This patient's systolic and diastolic blood pressure levels are below these limits. Many such patients have spontaneous declines in blood pressure during the first 24 hours after stroke onset.
Oral nifedipine is an inappropriate treatment for this patient not only because of its antihypertensive qualities, but also because of its route of administration. Given the severity of her stroke deficits, in particular the dysarthria, she should receive nothing by mouth until a swallowing evaluation is carried out because of the high risk of aspiration.
Notably, the patient is not eligible for recombinant tissue plasminogen activator therapy because the time interval between now and her previous symptom-free state is unknown.
Aspirin (160 to 325 mg/d) administered within 48 hours of stroke onset results in a small but significant reduction in the risk for recurrent stroke during the first 2 weeks after the stroke and improves outcome at 6 months. Therefore, aspirin is recommended as initial therapy for most patients with acute stroke. However, aspirin should not be administered for at least 24 hours after administration of thrombolytics.
- For uncomplicated ischemic strokes in patients without concurrent acute coronary artery disease or heart failure, antihypertensive medications should be withheld if the systolic blood pressure is less than 220 mm Hg or the diastolic blood pressure is less than 120 mm Hg, unless there are other manifestations of end-organ damage.
Correct answer: A. Decompressive hemicraniectomy.
This patient has malignant brain edema as a result of her ischemic stroke and should be treated with decompressive hemicraniectomy. Young patients with major infarctions affecting the cerebral hemisphere or cerebellum have a heightened risk of brain edema and increased intracranial pressure. Reducing any edema and close monitoring for signs of neurologic worsening, particularly during the first 3 to 5 days after the stroke when the edema maximizes, are recommended. Meta-analyses of randomized, controlled trials have shown that decompressive hemicraniectomy for malignant stroke reduces morbidity and mortality.
Intra-arterial thrombolysis is an option for the treatment of selected patients who have had a major stroke within the past 6 hours due to occlusion of a major intracranial artery. Although this patient's stroke was caused by an occluded right middle cerebral artery, she is long past the time window for this acute stroke therapy. Delay is associated with an increased risk of hemorrhagic conversion and reduced symptomatic benefit.
Long-term anticoagulation may play a role in the prevention of recurrent ischemic stroke in a patient with anti- phospholipid antibody syndrome. However, acute intravenous administration of heparin in this patient who has a large acute cerebral infarction is more likely to accelerate the possibility of hemorrhagic conversion of the infarction and thus to worsen her current clinical state.
The endovascular mechanical clot-retrieval device has been used to extract thrombi from occluded intracranial arteries. However, guidelines recommend that such a device must be used within 8 hours of a stroke. This patient is now beyond that 8-hour time window.
- Decompressive surgery can be a life-saving intervention in a patient who develops malignant brain edema after a hemispheric stroke.