Stroke in the elderly
Risk factors for ischemic stroke are dividable in nonmodifiable (age, sex, race/ethnicity and family history) and modifiable (AHT, diabetes mellitus, hyperlipidemia, cardiac disease (coronary artery disease, acute myocardial infarction, atrial fibrillation, valvular disease), peripheral artery disease, elevated homocysteine, smoking, excessive alcohol use, cancer (nonbacterial thrombotic endocarditis) and physical inactivity). AHT the leading risk factor increases with age and is found in over 50% of people older than 65 years. Treatment of isolated systolic hypertension reduces the risk of stroke by more than 30%. Atrial fibrillation increases the risk of stroke fivefold, warfarin cuts the risk by 2/3. Statins reduce the risk of stroke from hyperlipidemia by about 30% among patients with coronary artery disease. Endarterectomy is generally not justified for asymptomatic carotid stenosis, follow the lumen by ultrasound at 6 months interval. If lumen reduces in size and becomes <1.5 mm surgery is considered. There is strong support for anticoagulation for nonvalvular atrial fibrillation, rheumatic heart disease, prosthetic valves, dilated cardiomyopathy and after acute myocardial infarction. Other conditions (e.g. mitral valve prolapse) carry low risk.
During a 3-month period about 10% of patients with TIAs will develop a stroke, with 50% of them occurring in the first 2 days. MRA or Doppler ultrasonography have each a sensitivity of about 85% for a stenosis of >70%. Angiography with catherization is reserved for the confirmation of noninvasive findings.
Aspirin combined with dipyridamole (75 mg tid) reduces the long-term risk of stroke and cardiovascular events after stroke or a TIA with an overall relative reduction in risk of over 22%. Clopidogrel is slightly more effective than aspirin. Anticoagulation in the absence of atrial fibrillation carries a risk and is no better than placebo. Carotid endarterectomy is beneficial in patients with internal carotid artery stenosis of >70% who have had stroke or TIA. The timing of the arterectomy is debatable. Statins reduce the risk of stroke and cardiovascular events (with about 30%) in patients with coronary artery disease even when dyslipidemia is absent. Admission after TIA is anyhow advisable.
Atherosclerosis: Intra-arterial atheromatous ulceration develops in patients suffering from diabetes, hyperlipidemia and chronic hypertension. Recent angiogram can be the cause of cholesterol emboli.
Cerebral amyloid angiopathy (CAA): Although more commonly associated with recurrent lobar (frontal and parietal) hemorrhage in the elderly, CAA may also present with cerebral infarction.
Cardiogenic stroke: About 15-30% of ischemic strokes are cardioembolic caused most frequently by atrial fibrillation and valvular disease. Cardiac emboli often result in multifocal lesions, and cause infarction typically found at the junction of the gray and white matter. As in atrial fibrillation, stroke in cardiac failure is predominantly cardioembolic and, in the case of multiple emboli may lead to dementia. Systolic hypotension is selectively associated with cognitive impairment in older patients with heart failure. Mural thrombus, focal ventricular akinesis after myocardial infarction, dilated cardiomyopathy, and valvular disease are other causes of cardioembolism to be considered.
Trousseau syndrome: Small strokes due to hypercoagulability or nonbacterial thrombotic endocarditis develop early in the course of cancer and need to be differentiated from vasculitis.
Anemia
Intracerebral hemorrhage (ICH) represents about 10-20% of all vascular events in the brain. Lobar intracerebral hemorrhages account for 30% of the non-traumatic hemorrhages, and may be associated with aneurysms, AVM, CAA, hypertension, and tumors. Bleeding diatheses, including hemorrhages associated with warfarin account for 30-40% of all lobar ICH and often occur in association with hypertension. The prognosis of ICH is generally poor with a 30-40% 30-day mortality rate. Systolic values of < 160 mm Hg are the aim for modest reductions in blood pressure. The intravenous antihypertensive agents labetalol and nicardipine are preferred for titrating blood pressures; nitroprusside may cause increased cerebral pressure and is therefore not commonly used. The neurological status must be monitored closely for signs of deterioration that might indicate possible hematoma expansion. In comatose patients in whom neurological status is severely impaired at baseline (GCS score < 9), ICP monitoring may be considered. Other ICP reduction strategies include head-of-bed elevation at 30°; minimizing the patient's agitation (including the use of sedatives as needed); hyperventilation (which reduces cerebral blood flow, but should only be used as a temporary measure); hyperosmolar therapies (including mannitol and hypertonic saline, to reduce intracranial water content); and, rarely, barbiturate-induced comas. The administration of steroids in patients with ICH remains controversial. Significant consideration for surgical intervention is given in young patients (<60 years of age) with superficial hemorrhages (particularly in the non-dominant hemisphere) in whom neurological status deteriorates after an initially good presentation.
Hypertension: In 40-60% of cases hemorrhagic stroke is due to hypertension. Typical locations of the hypertensive ICH are “deep”: internal capsule, basal ganglia, thalamus, cerebellum and pons.
Cerebral amyloid angiopathy (CAA): This disorder accounts for 5-20% of hemorrhagic strokes in the elderly. The diagnosis should particularly be considered in patients who are normotensive and elderly. It is the most common cause of recurrent lobar (frontal and parietal) hemorrhage in the elderly. Clinical conditions associated with CAA are sporadic and familial recurrent hemorrhages, AD, Down syndrome, CNS vasculitis, leukoencephalopathy, late postradiotherapy, CJD, AVM and LBD. CAA may be associated with hypertension and dementia in 30% and 40% of cases, respectively. MRI may show hemosiderin depositis as evidence of prior bleeds. CAA requires histopathologic confirmation. Increased apolipoprotein E e4 allele, apolipoprotein E e2 allele may be associated with increased risk for ICH in patients with CAA.
Iatrogenic hemorrhages: Anticoagulation or thrombolytic therapy account for 5-10% of hemorrhagic strokes.
Cerebral neoplasms: Brain tumors account for 5-10% of hemorrhagic strokes. Glioblastoma and metastasis (melanoma, ovarian and renal cell carcinomas).
Aneurysms, hemangiomas and AVM
Dural venous sinus thrombosis