NMS Q&A Family Medicine

Cerebrovascular Disease 59ventricular dysfunction, history of previous stroke, TIA,or systemic embolism (“very high risk”) have a risk ofstroke of 10% per year. Atrial fibrillation associated withrheumatic or other mitral valve disease carries a 17-foldincrease in the risk of stroke over age- and sex-matchedcontrol subjects.These ostensibly dry statistics should be appreciatedin their rank order (but not memorized specifically)because of the implications for management. Persons oflow and low moderate risk status should be treated withaspirin; those of low moderate risk should be treated witheither aspirin or warfarin anticoagulation therapy, with atarget international normalized ratio of 2 to 3; high moderate,high, and very high risk patients should be treatedwith aspirin, warfarin anticoagulation therapy, or both,with a target international normalized ratio of 2 to 3.8. The answer is E. ALS would have a gradual not anacute onset. There would be motor symptoms only, and,although bulbar paralysis is one of the types of ALS, problemsspeaking involve dysarthria rather than expressiveaphasia. Migraine aura may take the form of focal neurologicsymptoms, from homonymous scotomata to hemiparesisand nearly any temporary focal neurologic lesionin between. Being a transient syndrome, migraine auramay be difficult to differentiate from TIA. The former ismore likely to occur in a younger person than is the latter.Hypoglycemia may present with diplopia along with disturbedconsciousness and may be briefly confused withTIA or stroke. Metastatic cancer to the brain, with hemorrhage,may present as indistinguishable from a completedstroke until an MRI or CT scan with contrast is done.However, metastatic cancer would be expected to presentwith a more gradual onset of more subtle neurologicsymptoms before the acute event associated with thehemorrhage. Seizures may present with focal symptoms,usually with shaking movements.9. The answer is D. In an acute stroke or TIA in the presenceof significant hypertension but with BP 220/120,BP should not be lowered too aggressively. Generally, BPlevel immediately after a completed stroke is lower thanthe previous baseline, sometimes even in the normotensiverange, often not recovering the previous level for upto 2 weeks. For this reason and because cerebral and coronaryarterial circulation may depend on elevated pressures,generally BP should be treated rather gingerlyimmediately after stroke or TIA, allowing for “resetting”of autoregulatory mechanisms in the cerebral circulation.A TIA may even be precipitated by an orthostatic drop inBP. Thus, only when BP 220/120 (or if there is concomitantrenal failure, acute myocardial infarction with leftventricular failure, or hypertensive encephalopathy),should it be aggressively lowered within the first few daysafter stroke or TIA.10. The answer is B. Femoral artery stenosis secondaryto atherosclerosis is a risk factor for stroke, as would beknown coronary or carotid artery disease. African-American race is a risk factor, but neither Caucasian norAsian race is a risk factor. As to sex, maleness is a risk factor.Other risk factors for stroke have been discussed inprevious questions and their answer sections.11. The answer is C. While ticlopidine functions as aninhibitor of platelet aggregation to prevent intravascularthrombus formation, it is not superior to aspirin and, bysome reports, is inferior in that regard. No monitoring ofclotting functions is required. Its best indication is forsubstitution for aspirin in patients who cannot takeaspirin.12. The answer is A. In a 40-year-old normotensivewoman (especially one with no strong family history ofatherosclerotic disease), an ischemic stroke is a definite“outlier.” In other words, this is a person one would normallyplace in a low-risk status for stroke. A workup forvasculitis or antiphospholipid antibodies is normallyreserved for patients who have other features of these disorders(e.g., evidence of systemic lupus), or those who areon medications that are associated with these disorders(such as procainamide), or those who have suffered ischemicstrokes at a young age (age 45 years) with no riskfactors for atherosclerosis and no other explanation (suchas an atrioventricular malformation) for this stroke.13. The answer is A. A noncontrast CT scan of the head.This patient has a classic presentation for subarachnoidhemorrhage (SAH). Ninety percent of SAH cases willshow intraventricular blood on a noncontrast CT. Contrastadds nothing to the sensitivity of this study for SAHand takes more time and is more expensive. Contrast alsorequires assurance that the patient’s renal function showsno elevation of serum creatinine; the latter may not beassumed in people with atherosclerotic vascular disease,which is the most common cause of SAH in the group ofindividuals who are 50 years or older. Cerebrospinal fluidis obtained only if the CT scan is negative in the face ofsuspected SAH and shows no lesions that could causeherniation when the cerebrospinal fluid is withdrawn.Skull x-rays are of no value. A CT scan is more sensitiveand faster than an MRI.14. The answer is C. Headache in the presence of rapidonset of neurologic symptoms is a prominent feature ofhemorrhagic stroke and may be severe. The mechanismfor this is the edema and swelling that develops in responseto the hemorrhage and the resultant increase in intracranialpressure. Vomiting and a clouded sensorium are alsotypical features. Ischemic strokes do not produce thismarked edema and produce either no headache or a very