Brown, Robert D.

Much of the available data on stroke occurrence, service use, and cost of care originated with hospital discharge abstracts. This article uses the unique resources of the Rochester Epidemiology Project to estimate the sensitivity and positive predictive value of hospital discharge abstracts for incident stroke. The Rochester Stroke Registry was used to identify all confirmed first strokes (hospitalized and nonhospitalized) among Rochester residents for 1970, 1980, 1984, and 1989 (n = 364). The sensitivity of discharge abstracts was estimated by following these individuals for 12 months after stroke to determine the proportion assigned a discharge diagnosis of cerebrovascular disease (International Classification of Diseases [ICD] codes 430 through 438.9). The positive predictive value of discharge abstracts was assessed by identifying all hospitalizations of Rochester residents with an ICD code of 430-438.9 in 1970, 1980, and 1989 (n = 377). Events were categorized as incident stroke, recurrent stroke, stroke sequelae, or nonstroke after review of the complete community-based medical record by a neurologist. Only 86% (n = 313) of all first-stroke patients in 1970, 1980, 1984, and 1989 were hospitalized. Of hospitalized patients, only 76% were assigned a principal discharge diagnosis code of 430-438.9. Fatal strokes and those occurring during a hospitalization were less likely to be identified. Among all hospitalizations of Rochester residents in 1970, 1980, and 1989, there were 377 with a principal diagnosis code of 430-438.9. Less than half (n = 177) were determined by the neurologist to be incident stroke; only 60% (n = 225) were either incident or recurrent stroke. Comparison of alternative approaches showed the validity of discharge abstracts was enhanced by increasing the number of diagnoses and excluding codes with poor positive predictive value. This study provides previously unavailable estimates of the sensitivity of stroke-coded hospitalizations for a US community. A model for improving the sensitivity and positive predictive value of discharge abstracts is presented.

Although repetitive involuntary movements are a well-recognized manifestation of carotid occlusive disease, similar movements have not been reported with a lacunar infarction outside of the basal ganglia or subthalamic nucleus. We describe a man with tonic spasms associated with a lacunar infarction in the right ventral pons. Involuntary tonic spasms of a paretic limb developed acutely in a 69-year-old hypertensive man with a clinical presentation of pure motor hemiparesis. Magnetic resonance imaging demonstrated a lacunar infarction of the ventral pons. There was no evidence for carotid occlusive disease. An electroencephalogram recorded during the movements showed no abnormality. The abnormal movements responded well to treatment with oral diazepam. A brain stem lacunar infarction may be associated with involuntary tonic limb spasms clinically similar to those reported as paroxysmal symptoms of multiple sclerosis.

Background and Purpose —There is scant population-based information on incidence and risk factors for ischemic stroke subtypes. Methods —We identified all 454 residents of Rochester, Minn, with a first ischemic stroke between 1985 and 1989 from the Rochester Epidemiology Project medical records linkage system. We used Stroke Data Bank criteria to assign infarct subtypes after reviewing medical records and brain imaging. We adjusted average annual incidence rates by age and sex to the US 1990 population and compared the age-adjusted frequency of stroke risk factors across ischemic stroke subtypes. Results —Age- and sex-adjusted incidence rates (per 100 000 population) were as follows: large-vessel cervical or intracranial atherosclerosis with >50% stenosis, 27; cardioembolic, 40; lacuna, 25; uncertain cause, 52; other or uncommon cause, 4. Sex differences in incidence rates were detected only for atherosclerosis with stenosis (47 [95% CI, 34 to 61] for men; 12 [95% CI, 7 to 17] for women). There was no difference in prior transient ischemic attack and hypertension among subtypes, and diabetes was not more common among patients with lacunar infarction than other common subtypes. Conclusions —The age-adjusted incidence rate of stroke due to stenosis of the large cervicocephalic vessels is nearly 4 times higher for men than for women. There is no association between preceding transient ischemic attack and stroke mechanism. Diabetes and hypertension are not more common among patients with lacunae. Age- and sex-adjusted incidence rates for ischemic stroke subtypes in this population can be compared with similarly determined rates from other populations.

Background and Purpose— To evaluate the periprocedural outcome after carotid artery stenting with embolic brain protection (EBP+) versus without embolic brain protection (EBP−). Methods— We retrospectively reviewed data from a prospective nonrandomized database of 357 patients who underwent carotid artery stenting in the neuroradiology division of our institution from 1999 to 2009. One hundred five patients underwent angioplasty and stenting without distal protection, whereas 252 were treated with distal protection. Patients were analyzed according to their EBP status (+ or −) for the primary end points of perioperative stroke, death, or myocardial infarction. Results— Unprotected stenting was mostly performed in the early years of this study and this is reflected in significant baseline differences between the two groups. In our earlier experience, carotid artery stenting was used in patients with more significant comorbidities. Diabetes mellitus ( P =0.04), previous coronary artery disease ( P =0.02) and myocardial infarction ( P =0.04), and symptomatic lesion ( P =0.01) were significantly more common in the EBP− cohort. Despite these baseline differences, there were no significant differences in the primary end points (2% in the EBP+ group and 4.8% in the EBP−, P =0.15). The incidence of ipsilateral stroke in the EBP− and in the EBP+ group was 3.8% versus 0.8%, respectively ( P =0.6). There were 2 perioperative deaths (1 in each group) and 4 myocardial infarctions (3 in the EBP+ arm and 1 in the EBP− arm, all non-Q infarcts; P =nonsignificant). Conclusions— In accordance with recent literature, this series cast doubts as to the real effectiveness of distal embolic protection devices in reducing periprocedural complications.

Background and Purpose— Coronary artery disease is the leading cause of death after TIA. Reliable estimates of the risk of MI after TIA, however, are lacking. Methods— Our purpose was to determine the incidence of and risk factors for MI after TIA. We cross-referenced preexisting incidence cohorts from the Rochester Epidemiology Project for TIA (1985–1994) and MI (1979–2006) to identify all community residents with incident MI after incident TIA. Incidence of MI after TIA was determined using Kaplan–Meier life-table methods. This was compared to the age-, sex-, and period-specific MI incidences in the general population. Proportional hazards regression analysis was used to examine associations between clinical variables and the occurrence of MI after TIA. Results— Average annual incidence of MI after TIA was 0.95%. Relative risk for incident MI in the TIA cohort compared to the general population was 2.09 (95% CI, 1.52–2.81). This was highest in patients younger than 60 years old (relative risk, 15.1; 95% CI, 4.11–38.6). Increasing age (hazard ratio, 1.51 per 10 years; 95% CI, 1.14–2.01), male sex (hazard ratio, 2.19; 95% CI, 1.18–4.06), and the use of lipid-lowering therapy at the time of TIA (hazard ratio, 3.10; 95% CI, 1.20–8.00) were independent risk factors for MI after TIA. Conclusions— Average annual incidence of MI after TIA is ≈1%, approximately double that of the general population. The relative risk increase is especially high in patients younger than 60 years old. These data are useful for identifying subgroups of patients with TIA at highest risk for subsequent MI.

Background and Purpose— Analyze the relationship between the location and extent of sinus thrombosis and presence and severity of brain lesions. Methods— Retrospective chart and neuroimaging review of patients with documented CVST. A CVST score was devised to quantify the extent of cerebral venous sinus thrombosis. Results— Nineteen of 56 (34%) patients had brain lesions. The extent of sinus thrombus was associated with increased risk of brain lesions (CVST score 1.9 among patients without brain lesions versus 3.1 in those with lesions; P =0.006). Age, sex, and acquired or hereditary thrombophilias were not associated with the risk of parenchymal lesions. Functional outcomes were favorable even in patients with extensive CVST and parenchymal lesions at presentation. Conclusions— The extent of the sinus involvement correlates with the risk of brain lesions in patients with CVST, but additional factors might also contribute to their occurrence.

Background and Purpose — Contrast-enhanced magnetic resonance angiography (CEMRA) permits acquisition of high-spatial-resolution, venous-suppressed, 3D MR angiograms of the cervical carotid and vertebral arteries. In this study, an elliptic centric-view ordering with either MR fluoroscopic triggering or test bolus timing was used. The use of CEMRA of the cervical vessels has changed our clinical practice and is replacing conventional angiography for the evaluation of most carotid and vertebral artery diseases. Methods — We retrospectively reviewed our experience with the use of CEMRA performed in 422 patients from January through December 1999. Results — CEMRA was performed to evaluate transient ischemic attack and ischemic stroke in 239 patients, asymptomatic carotid bruit in 88 patients, and other neurological symptoms in 95 patients. Carotid endarterectomies were performed in 97 patients (103 procedures), and conventional angiography was performed in 12 of these patients. CEMRA was used to evaluate for the presence of an arterial dissection in 85 of the 239 patients with transient ischemic attack and ischemic stroke. Of this group, 32 patients had cervical arterial dissection, and pseudoaneurysm was detected in 11 of these patients. Compared with ultrasonography of the cervical vessels, CEMRA provided additional information in 43 of 422 patients and led to changes in the decision as to whether to perform carotid endarterectomy in 5 patients. Conclusions — Use of CEMRA permits noninvasive evaluation of patients suspected of having carotid or vertebral disease and avoids the potential complications of conventional angiography.