Higher Risk Of Cerebrovascular Disease Research Articles

Strokes after cardiac surgery: mostly right hemispheric ischemic with mild residual damage

Since cardiac surgery is now performed on patients with high risk for cerebrovascular disease, we studied the clinical findings and medium term outcome of patients with acute stroke/transient ischemic attack (TIA) after cardiac surgery. All consecutive patients with acute stroke/TIA after cardiac surgery were prospectively observed during a 19 month period. Follow-up was between 3 months and 21 months. Risk factors, type of stroke, anatomic localization, initial neurological deficit and followup outcome were evaluated, using standard assessment scores. Among 406 patients operated (mean age 64.3 +/- 12.7 years, 284 males), 18 developed stroke and 2 TIAs (mean age 65.7 years, 13 males). There were no cases of intracerebral hemorrhage. Most of the strokes happened shortly after valve surgery (mean 1.3 days post operatively) and were right hemispheric (right = 11, left = 3; p = 0.034). Vertebrobasilar stroke appearance was delayed (mean: 8.25 days post operatively); they were attributed mostly to cardiac arrhythmias. Stroke/TIA patients did not have a higher preoperative risk than those without, but their cardiac functional score was worse (p = 0.01), and the average cardiopulmonary bypass time during surgery was longer (p = 0.009). Two patients died in hospital, both with vertebrobasilar stroke. Most of the hemispheric stroke patients became functionally independent (mean modified Rankin Scale < 2), even those with initial severe deficit. Strokes after cardiac surgery are mostly right hemispheric and exclusively ischemic. Outcome is relatively fair. We suggest an embolic injury to the right hemisphere, procedure related, as a possible mechanism.

Cerebrovascular reactivity over time course in healthy subjects

Introduction Cerebrovascular reactivity (CVR) reflects the compensatory dilatory capacity of cerebral arterioles to a dilatory stimulus and is an important mechanism for maintaining constant cerebral blood flow. Many pathological conditions are associated with an impaired CVR thus contributing to a higher risk of cerebrovascular disease. Since an impaired CVR might contribute to a cerebrovascular disease if it lasts for a longer period of time, it is of importance to know what the time-course of CVR might be under healthy conditions. Methods We investigated CVR in 33 healthy subjects on baseline and on follow-up after 1 to 3 years. CVR was determined by calculating the difference between maximal blood flow velocity after stimulation with acetazolamide and during rest. Blood flow velocities were measured by transcranial Doppler ultrasound. Results CVR did not differ significantly in a group of healthy persons when reevaluated after 1 to 3 years. Possible influencing factors like age, gender, interval between testing, and smoking did not show a significant influence. Discussion This is the first study to investigate within-subject-differences in healthy subjects. CVR seems to remain constant under healthy conditions. Even this short period of life-span is of importance because an altered CVR can improve under treatment within weeks. Nevertheless further studies should follow-up longer periods of time.

Hypoadiponectinemia Is Associated With Ischemic Cerebrovascular Disease

Adiponectin, an adipocyte-derived peptide with antiinflammatory and antiatherogenic effects, is known to protect against the initiation and progression of atherosclerosis. In this study, we investigate whether hypoadiponectinemia is present in patients with ischemic cerebrovascular disease (CVD). In this case-control study, plasma adiponectin concentration was measured by an enzyme-linked immunosorbent assay in type 2 diabetic and nondiabetic subjects with or without ischemic CVD. A total of 534 subjects were studied. The mean plasma level of adiponectin of the 228 patients with ischemic CVD was significantly lower than that of 306 subjects without CVD. When the analysis was stratified according to diabetes status, plasma levels of adiponectin in CVD subjects with or without type 2 diabetes were significantly lower than those of their counterparts. Decreasing concentrations of adiponectin were independently and significantly associated with a higher risk of CVD when concentrations were analyzed by quartile and as a continuous variable. When patients with CVD were subgrouped according to the comorbidity with or without type 2 diabetes, the same trend of association between plasma adiponectin and risk of CVD was observed in each group. These data show that there are significantly lower levels of plasma adiponectin in patients with ischemic CVD.

Community study of dementia in the older Korean rural population.

This study aims to estimate the prevalence of all dementias, including Alzheimer's disease (AD) and vascular dementia (VaD) in a population of Korean elderly and to identify possible risk factors which correlated with specific types of dementia. A two-phase survey, based on a door-to-door survey, was conducted. Initially, the Korean version of the Psychogeriatric Assessment Scale (PAS-K) was administered to all 1037 participants aged 65 years and older. Three hundred and seventy people sampled from the case groups (n = 320) of PAS-K subscales and the non-case group (n = 50) entered the second phase for clinical evaluation. Dementia was defined using the DSM-III-R, NINCDS-ADRDA and NINDS-AIREN criteria. Among 1037 elderly people aged 65-94 years who completed the interview, 74 cases of dementia were detected, giving an overall age-standardized prevalence (95% CI) of 6.8% (6.1-7.5) (male 6.3%[5.3-7.4]; female 7.1%[6.1-8.0]). The prevalence (95% CI) of AD was 4.2% (3.6-4.7) (male 2.4%[2.0-2.8]; female 5.3%[4.5-6.1]), and it increased with age. The prevalence (95% CI) of VaD was 2.4% (2.0-2.8) (male 3.5%[2.7-4.3]; female 1.6%[1.2-2.1]). Smoking for longer than 30 pack-years significantly increased the risk of VaD (OR = 11.5 [2.8-44,6]). Long-term smoking, much more prevalent in men, may be closely related to higher risk of cerebrovascular disease that leads to vascular dementia.

THE DIAGNOSTIC APPROACH TO THE DIZZY PATIENT

BACKGROUND Dizziness is one of the most common medical complaints by patients older than 50 years of age. Symptoms subsumed under the term dizziness include vertigo, light-headedness, imbalance, and visual disorientation. REVIEW SUMMARY The evaluation of the dizzy patient is complicated by the frequent vagueness of patient complaints, the number of sensory systems involved in balance, and the poor availability of specific diagnostic tests for vestibular disease. Refinements of the history regarding types of dizziness, duration of symptoms, and associated symptoms dramatically increase diagnostic yield. In the domain of the neurological examination, there are many valuable but underused maneuvers that shed light on vestibular function. Audiometry, vestibular testing, and imaging have limited but well defined roles in diagnosing patients. When used in the right order to answer specific questions, these testing procedures can be cost-effective means of achieving a specific diagnosis. Diagnostic algorithms are presented for both the acute and chronic presentations of vertigo. CONCLUSIONS If abnormalities that suggest CNS disease or invasive otologic disease are detected during an examination, imaging should be performed. In cases of acute vertigo, if the patient is at high risk of cerebrovascular disease, imaging is warranted. If the patient does not fall into one of these categories, e.g., the patient is dizzy but has no abnormalities on careful examination, we recommend a hearing evaluation with pure tone audiometry and speech reception thresholds. If progression of asymmetric hearing loss is not documented, we do not believe that imaging is warranted. Progressive hearing loss with abnormal speech reception thresholds probably warrants magnetic resonance imaging of the internal auditory canals.

The diagnostic value of imaging the patient with dizziness. A Bayesian approach.

Imaging studies are routinely used in the evaluation of patients with dizziness. A principal concern of the ordering physician is to rule out a cerebellopontine angle (CPA) mass. The incidence of such masses in patients presenting with dizziness is quite low, however, raising the question of the value of imaging this population. To calculate the probability, using Bayes theorem, that a given patient with dizziness has a CPA mass. Meta-analysis of epidemiological data on CPA masses and of studies reporting the incidence of otologic symptoms in patients with these masses. We also conducted a study of consecutive patients with dizziness to determine the frequency of asymmetric hearing loss in this population. These data were combined in applications of Bayes theorem to calculate disease probabilities. The probability that a patient with dizziness has a CPA mass is 0.0004, indicating that 2500 imaging studies would have to be performed to identify 1 CPA mass. If patients with subjectively normal hearing are investigated (ie, those with isolated dizziness), the probability is 0.000107, indicating that 9307 scans would have to be performed to identify 1 CPA mass. If the search is restricted to those patients with dizziness and asymmetric hearing loss (the patients usually felt to be high risk), the probability is 0.00156, indicating that 638 scans would have to be performed to identify 1 CPA mass. Even when studying patients with dizziness and asymmetric hearing loss, the probability of identifying a CPA mass is sufficiently low that we do not feel imaging is generally warranted. When faced with a patient with dizziness, we recommend a careful neurologic and otologic examination. If abnormalities are detected on examination that suggest central nervous system disease or invasive otologic disease, imaging should be pursued as appropriate. In cases of acute vertigo, if the patient is at high risk for cerebrovascular disease by virtue of age and additional risk factors, imaging should probably be pursued. For the remainder of patients, if progression of hearing loss is not documented, we do not believe imaging is warranted. Progressive hearing loss with abnormal speech reception thresholds probably warrants a magnetic resonance imaging scan of the internal auditory canals.

Sickle Cell Disease and Stroke

The increased risk of stroke in sickle cell disease has been recognized for over 50 years. Recent reports have increased our understanding by better describing the clinical characteristics and presentation of sickle cell disease patients with stroke and provided relatively consistent estimates of prevalence applicable to younger cohorts. The experience from established clinics in Los Angeles,1 1 Philadelphia,2 and Kingston, Jamaica,3 indicate that clinically evident cerebrovascular disease has a prevalence of about 7% to 8% in cohorts followed for the first 2 decades of life. Less is known about stroke in older patients, but the Cooperative Study of Sickle Cell Disease4 is developing estimates of stroke incidence and prevalence data from adults as well as children with sickle cell disease. Studies using magnetic resonance imaging (MRI) or computed tomography (CT) have shown that the prevalence of cerebral infarction is higher than that of stroke. This is consistent with the definition that stroke is a clinical syndrome, and cerebral infarction is a pathologic entity detected with high sensitivity and specificity by MRI and, to a lesser extent, CT. The study by Glauser and colleagues5 supports prior observations that not all sickle cell disease patients with abnormal MRIs have a history or neurologic findings that go with the lesion(s). Their systematic study provides an estimate of silent infarction from their sample of 30 patients of 24% based on history and examination alone. This is higher than the 11% reported from a 55patient series from Columbia-Presbyterian Hospital6 and from the Cooperative Study of Sickle Cell Disease, in which 16% of 172 patients had abnormal MRI without a stroke history This suggests that only about half of the sickle cell disease patients with brain infarction report or develop symptoms sufficient to prompt recognition, at least early in life. Clinical surveillance alone misses a sizable number of patients with brain lesions. The rate of silent infarction in sickle cell disease is comparable to that reported in other groups at high risk for cerebrovascular disease. The Asymptomatic Carotid Atherosclerosis Study, which compared carotid endarterectomy with medical treatment in patients with 60% or greater cervical carotid stenosis, reported that 126 (15%) of 848 patients with no history of transient ischemic attacks or stroke had one or more CT lesions, primarily small, deep infarcts, at entry into the study.8 Ten percent of Framingham patients presenting with first-time stroke already had CT-evident lesions.9 In the presence of chronic atrial fibrillation, the reported prevalence of silent cerebral infarction has ranged from 11% to 48%.8 S

Brain MRI hyperintense lesions and cerebrovascular risk factors in the elderly

It is known that asymptomatic MRI lesions of the brain are found in elderly subjects, but the significance of the lesions has not been determined. In previous reports, the prevalence of MRI lesions varied from 11% to 59%, but many of the authors indicated a close relationship with cerebrovascular risk factors. We evaluated 76 elderly subjects (over 60 years old, average age +/- SD was 66.7 +/- 4.5) without a history of cerebrovascular disease and dementia, and determined the prevalence of periventricular (PVH), white matter (WMH) and pontine (PH) hyperintensity and risk factors. The severity of MRI lesion was evaluated in T2-weighted images by Fazekas' scoring method of MRI hyperintense lesions. PVH, WMH and PH were graded visually from 0 to 3 by the author and these points are added to the MRI score. In T1-weighted images, we also measured the diameter of the third ventricle, frontal horn and body of the lateral ventricle. Our results were that 62% of subjects had PVH, 64% had WMH and 8% had PH. In regard to risk factors, 38% of subjects had hypertension, 17% had diabetes mellitus, 8% had ischemic heart disease. The PVH (+) group was significantly older (p<0.01) and had larger lateral ventricles (p<0.05) than the PVH (-) group. The WMH (+) group was significantly older (p<0.05) and had higher risk of cerebrovascular disease (p<0.05) than the WMH (-) group. The MRI score was related, but not significantly, to a history of hypertension, diabetes mellitus and ischemic heart disease.(ABSTRACT TRUNCATED AT 250 WORDS)