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Biomedical subjects

D B Hier

Publications and source records attributed to D B Hier.

At least 19 recordsLinked to original sources
PubMed1992

Thalamic stroke. Presentation and prognosis of infarcts and hemorrhages.

Thalamic strokes in 62 patients selected from the Stroke Data Bank were studied to determine differences among 18 infarctions (INF), 23 localized hemorrhages (ICH), and 21 hematomas with ventricular extension (IVH). Stupor or coma at onset occurred more frequently in the IVH (62%) than in the INF (6%) or ICH (13%) groups and was reflected in significantly lower median Glasgow Coma Scores in the IVH group (7) than in the INF (15) and ICH (14) groups. Although ocular movements were more frequently abnormal in the IVH group compared with the ICH and INF groups, no significant differences were found in the frequency of motor or sensory deficits. Among the 62 strokes, 32 had restricted lesions of the posterolateral (n = 9), anterior (n = 3), paramedian (n = 7), and dorsal (n = 13) portions of the thalamus. Differences in consciousness and in motor, sensory, and oculomotor deficits were found among the topographic subgroups. Stroke-related deaths occurred in 52% of IVH cases, 13% of ICH cases, and no cases of INF. Median lesion volume as detected with computed tomography was greater in hemorrhages (INF, 2 cm3; ICH, 10 cm3; IVH, 16 cm3), with mortality related to increasing hematoma size. Coma, Glasgow Coma Score lower than 9, weakness score greater than 15 of a possible 30, abnormal ocular movements, and fixed pupils were also associated with stroke-related mortality. We conclude that the initial neurologic syndrome does not discriminate infarcts from intrathalamic hemorrhages. Ventricular extension, however, causes significantly more severe deficits and higher mortality.

Cerebral Hemorrhage↗
PubMed1992

Circadian rhythmicity of stroke onset. Intracerebral and subarachnoid hemorrhage.

BACKGROUND AND PURPOSE: Our purpose was to describe and further understand the determinants of the time of onset of parenchymatous intracerebral hemorrhage and subarachnoid hemorrhage in patients enrolled in the Stroke Data Bank. METHODS: We analyzed the observed times of onset of intracerebral hemorrhage (n = 237 patients) and subarachnoid hemorrhage (n = 243 patients) compared with expected times of onset if the probability of onset was constant across all time intervals. We also analyzed the role of clinical features (if any) in explaining the findings. RESULTS: For intracerebral hemorrhage, 52.5% of patients reported onset times between 0600 hours and 1400 hours, with peak onset between 1000 and 1200 hours (chi 2 = 62.94, df = 11, p less than 0.001). Patients with subarachnoid hemorrhage were more likely to lack a history of hypertension compared with patients who had intracerebral hemorrhage (chi 2 = 23.3, df = 1, p less than 0.001). Patients with subarachnoid hemorrhage were more likely to have more uniform onset time throughout the day (chi 2 = 12.92, df = 7, p = 0.074). However, subarachnoid hemorrhage patients with a history of hypertension were more likely to have peak onset times in mid-to-late morning compared with patients without such a history (chi 2 = 35.25, df = 10, p less than 0.001). The nonuniformity of onset times for intracerebral hemorrhage persisted even if patients with unknown onset times were treated as through their onset times were randomly distributed between 0000 and 0800 hours. Seasonal periodicity and the relation between initial systolic or diastolic blood pressure and time of onset for either type of hemorrhage were not observed. CONCLUSIONS: Our data suggest that the time of onset for both intracerebral hemorrhage and subarachnoid hemorrhage patients with a history of hypertension is similar to the diurnal variation in blood pressure.

Adolescent↗
PubMed1992

Features on initial computed tomography scan of infarcts with a cardiac source of embolism in the NINDS Stroke Data Bank.

BACKGROUND AND PURPOSE: The lack of valid criteria for the clinical diagnosis of cardiogenic embolism is a major problem in both patient care and research. The aim of this study was to identify features on the initial computed tomogram of the brain that discriminate between patient groups with and without a cardiac source of embolism. To gain insight into the neuroradiological features relevant to the diagnosis of cardiac embolic stroke, we studied the initial computed tomogram of the 1,267 patients with ischemic stroke and such a scan in the National Institute of Neurological Disorders and Stroke (NINDS) Stroke Data Bank. METHODS: We analyzed the initial computed tomographic data from 1,267 patients with ischemic stroke in the NINDS Stroke Data Bank. Based solely on the presence of cardiac sources of embolism, we defined groups with high (n = 244), medium (n = 165), and low (n = 858) risk for cardiogenic embolism and compared the features on the initial computed tomogram among these three groups. RESULTS: Patients in the high-risk group were significantly more likely (p < 0.001) to have infarcts involving one half lobe or larger or infarcts involving both superficial and deep structures than patients in the medium- or low-risk groups. In contrast, deep small infarcts had a negative association (p = 0.004) with the presence of a cardiac source of embolism. There was no significant trend across risk groups in the percent with hemorrhagic infarction, regardless of whether patients with anticoagulant use at the time of the stroke were excluded. CONCLUSION: Although some features of the initial computed tomogram had highly significant associations with the presence of a cardiac source of embolism, the predictive value of these features for an embolic source was low.

Cerebral Infarction↗
PubMed1992

Early clinical differentiation of cerebral infarction from severe atherosclerotic stenosis and cardioembolism.

BACKGROUND AND PURPOSE: Hyperacute cerebral infarction trials require early differentiation of infarction subtype. Our aim was to determine clinical factors predictive of infarction subtype from data collected in the early hours of admission. METHODS: Using the 1,273 patients enrolled in the Stroke Data Bank, stroke risk factors and demographic, clinical, and radiological features were compared between the 246 cardioembolic and 113 large-vessel atherosclerotic cerebral infarcts. RESULTS: Stroke Data Bank definitions ensured more transient ischemic attacks in atherosclerotic infarcts and more cardiac disease in cardioembolic infarcts, but the diagnosis was distinguished further using a logistic regression model. Fractional arm weakness (shoulder different from hand) (odds ratio 3.1, 95% confidence interval [CI] 1.6-5.8), hypertension (odds ratio 2.8, CI 1.4-5.3), diabetes (odds ratio 2.5, CI 1.2-5.1) and male gender (odds ratio = 2.2, CI 1.2-4.1) occurred more frequently in patients with atherosclerotic than cardioembolic infarcts. Reduced consciousness (odds ratio = 3.2, CI 1.4-7.3) was more frequent in cardioembolism. For a male patient with hypertension, diabetes, and fractional arm weakness, the estimated odds of an atherosclerotic infarction were 47-fold that of a cardioembolic infarction. Patients with atherosclerotic infarcts were more likely to have a fractional arm weakness regardless of infarct size, whereas, for those with cardioembolic infarctions, fractional weakness was more frequent in infarcts less than 20 cc in volume. CONCLUSIONS: Clinical features that are observed at stroke onset can help distinguish cerebral infarction subtypes and may allow for early stratification in therapeutic trials.

Aged↗
PubMed1992

Infarcts with a cardiac source of embolism in the NINDS Stroke Data Bank: neurologic examination.

To gain insight into neurologic signs relevant to the diagnosis of cardiogenic embolism, we analyzed data from 1,290 patients with cerebral infarcts in the NINDS Stroke Data Bank. Based solely on the presence of potential cardiac sources of embolism, we divided patients into groups of high (N = 250), medium (N = 167), and low (N = 873) risk of a cardiogenic mechanism for their stroke. Diminished level of consciousness was highly associated with the presence of a cardiac source of embolism. Of the four primarily cortical deficits assessed, three (visual field abnormalities, neglect, and aphasia) showed a highly significant graded relationship to the cardiac risk groups. For the fourth cortical deficit (other nonlanguage cognitive functions), this relationship did not attain statistical significance. Conversely, hemiparesis without sensory or cortical deficits had a strong inverse association to the presence of a cardiac source of embolism. This inverse association was weaker for sensorimotor strokes and nonexistent for pure sensory strokes. Although some neurologic findings had highly significant associations with the presence of a cardiac source of embolism, their predictive value for an embolic source was low.

Cerebral Infarction↗
PubMed1991

Intracerebral hemorrhage: external validation and extension of a model for prediction of 30-day survival.

We report validation of a previously reported logistic regression model for predicting 30-day survival after supratentorial intracerebral hemorrhage using independent, prospectively collected data. The original model, using initial Glasgow Coma Scale score, hemorrhage size, and pulse pressure, accounted for mortality or survival at 30 days in 92% of patients in the Pilot Stroke Data Bank with a sensitivity of 0.84 and a specificity of 0.96. For external validation, the model was used to predict 30-day status for each patient in the Main Phase Stroke Data Bank for whom complete risk factor information was available. Overall, 90% of patients' outcomes were correctly predicted with a sensitivity of 0.85 and a specificity of 0.92. Two factors not collected in the Pilot Stroke Data Bank, hyperglycemia and intraventricular hemorrhage extension, were assessed to determine if they provided additional predictive information on 30-day mortality. Intraventricular hemorrhage extension contributed significant predictive information in a logistic regression, whereas hyperglycemia did not. The resulting four-factor model with an interaction term (intraventricular hemorrhage extension and Glasgow Coma Scale score) correctly classified the survival status of 94% of patients at 30 days. A more general outcome, death or failure to achieve a "good" Activities of Daily Living Score by one year, was analyzed with respect to the same four factors. The resulting model correctly classified 95% of the patients in the cohort.

Blood Glucose↗
PubMed1991

Deriving clinical prediction rules from stroke outcome research.

BACKGROUND AND PURPOSE: Our purpose was to determine whether clinical prediction rules could be derived from current stroke outcome research. SUMMARY OF REPORT: We reviewed 92 articles on stroke outcome research to determine their suitability for implementation as a clinical prediction rule. Methodological problems in many of these studies made implementation of their results as a clinical prediction rule difficult. CONCLUSIONS: Implementation of stroke outcome research as clinical prediction rules would be facilitated by description of patient population demographics; precise definitions of predictor and outcome measures; stratification of patients by stroke mechanism; use of adequate patient sample sizes; and description of the mathematical methods used, including coding schemes, cutpoints, beta coefficients, constant terms, and a priori probabilities.

Cerebrovascular Disorders↗
PubMed1991

Stroke recurrence within 2 years after ischemic infarction.

We prospectively studied stroke recurrence in 1,273 patients with ischemic stroke who were entered into the Stroke Data Bank. Median follow-up was 13 months. The 2-year cumulative recurrence rate among these patients was 14.1%. Age, sex, race, history of hypertension, atrial fibrillation, or transient ischemic attacks, and stroke location were not associated with a higher risk of stroke recurrence. Patients with an elevated blood pressure, an abnormal initial computed tomogram, or a history of diabetes mellitus were at a higher risk of stroke recurrence. In contrast, patients with an infarct of unknown cause were at a lower risk of stroke recurrence than patients with a defined stroke mechanism, such as lacune, embolism, or atherosclerosis. A multivariate model suggests that patients at the lowest risk for stroke recurrence have a low diastolic blood pressure, no history of stroke, no history of diabetes mellitus, and an infarct of unknown cause.

Cerebral Infarction↗
PubMed1991

Clinical-computed tomographic correlations of lacunar infarction in the Stroke Data Bank.

Lacunar stroke was diagnosed in 337 (26%) of the 1,273 patients with cerebral infarction among the 1,805 total in the Stroke Data Bank. We analyzed the 316 patients with classic lacunar syndromes. Among these, 181 (57%) had pure motor hemiparesis, 63 (20%) sensorimotor syndrome, 33 (10%) ataxic hemiparesis, 21 (7%) pure sensory syndrome, and 18 (6%) dysarthria-clumsy hand syndrome. No striking differences were found among the risk factors for the lacunar subtypes, but differences were found between lacunar stroke as a group and other types of infarcts. Compared to 113 patients with large-vessel atherosclerotic infarction, those with lacunar stroke had fewer previous transient ischemic attacks and strokes. Compared to 246 with cardioembolic infarction, patients with lacunar stroke more frequently had hypertension and diabetes and less frequently had cardiac disease. We found a lesion in 35% of the lacunar stroke patients' computed tomograms, with most lesions located in the internal capsule and corona radiata. The mean infarct volume was greater in patients with pure motor hemiparesis or sensorimotor syndrome than in those with the other lacunar stroke subtypes. In patients with pure motor hemiparesis and infarcts in the posterior limb of the internal capsule, there was a correlation between lesion volume and hemiparesis severity except for the few whose infarct involved the lowest portion of the internal capsule; in these patients severe deficits occurred regardless of lesion volume. Taken together, the computed tomographic correlations with the syndromes of hemiparesis showed only slight support for the classical view of a homunculus in the internal capsule.

Aged↗
PubMed1991

Quantitative measurement of delta activity in Alzheimer's disease.

Quantitative measurements of delta activity were made in 10 healthy elderly controls and 31 subjects with Alzheimer's disease. Delta activity did not discriminate between the healthy elderly controls and the early mild Alzheimer's disease subjects. However, delta activity was a significantly greater percentage of total EEG power in the moderate-to-advanced Alzheimer's subjects when compared to either the healthy controls or mild Alzheimer subjects. In the T3 and T4 electrodes, delta activity in the moderate-to-advanced Alzheimer subjects was 78.3% and 47.6% higher, respectively, than in control subjects. Furthermore, delta activity was an excellent predictor of dementia severity within the 31 subjects with Alzheimer's disease.

Aged↗
PubMed1991

Clinical discriminators of lobar and deep hemorrhages: the Stroke Data Bank.

Of the 1,805 patients with acute stroke enrolled in the Stroke Data Bank, 237 had parenchymatous hemorrhage. After excluding 34 secondary intracerebral and 31 infratentorial hemorrhage patients, a logistic regression analysis of the 172 patients with primary supratentorial intracerebral hemorrhage (ICH) elucidated clinical factors that distinguished the 65 patients with lobar hemorrhage (LH) from the 107 patients with deep hemorrhage (DH) located in the basal ganglia and thalamus. In LH, severe headache was more common than in DH, while hypertension and motor deficit were significantly less common. Patients with either LH or DH had a similar prognosis and mean Glasgow Coma Scale (GCS) scores, despite the hematoma volume measured on the initial CT being significantly greater for LH than DH. The presence of intraventricular extension (IVH) was more frequent in DH. The frequency of IVH increased with hematoma volume in LH, but remained constant for DH. Two CT variables (IVH and hematoma volume) that differed in these two hemorrhage groups were important predictors of coma (GCS less than or equal to 8) in a logistic regression model. Differences in the frequency of IVH may help explain why the degree of impairment in consciousness was similar in the two groups. Among patients with supratentorial ICH, location of the hematoma is related to both volume and IVH, which are important determinants of the level of consciousness.

Aged↗
PubMed1990

Caudate infarcts.

Eighteen patients had caudate nucleus infarcts (10 left-sided; 8 right-sided). Infarcts extended into the anterior limb of the internal capsule in 9 patients, and also the anterior putamen in 5 patients. Thirteen patients had motor signs, most often a slight transient hemiparesis. Dysarthria was common (11 patients). Cognitive and behavioral abnormalities were frequent, and included abulia (10 patients), agitation and hyperactivity (7 patients), contralateral neglect (3 patients, all right caudate), and language abnormalities (2 patients, both left caudate). The majority of patients had risk factors for penetrating artery disease. Branch occlusion of Heubner's artery, or perforators from the proximal anterior or middle cerebral arteries were the posited mechanism of infarction.

Adult↗
PubMed1990

Dementia in stroke survivors in the Stroke Data Bank cohort. Prevalence, incidence, risk factors, and computed tomographic findings.

We determined the prevalence of dementia in 927 patients with acute ischemic stroke aged greater than or equal to 60 years in the Stroke Data Bank cohort based on the examining neurologist's best judgment. Diagnostic agreement among examiners was 68% (kappa = 0.34). Of 726 testable patients, 116 (16%) were demented. Prevalence of dementia was related to age but not to sex, race, handedness, educational level, or employment status before the stroke. Previous stroke and previous myocardial infarction were related to prevalence of dementia although hypertension, diabetes mellitus, atrial fibrillation, and previous use of antithrombotic drugs were not. Prevalence of dementia was most frequent in patients with infarcts due to large-artery atherosclerosis and in those with infarcts of unknown cause. Computed tomographic findings related to prevalence of dementia included infarct number, infarct site, and cortical atrophy. Among 610 patients who were not demented at stroke onset, we used methods of survival analysis to determine the incidence of dementia occurring during the 2-year follow-up. Incidence of dementia was related to age but not sex. Based on logistic regression analysis, the probability of new-onset dementia at 1 year was 5.4% for a patient aged 60 years and 10.4% for a patient aged 90 years. With a multivariate proportional hazards model, the most important predictors of incidence of dementia were a previous stroke and the presence of cortical atrophy at stroke onset.

Aged↗
PubMed1990

Infarcts with a cardiac source of embolism in the NINCDS Stroke Data Bank: historical features.

To gain insight into the historical features relevant to the diagnosis of cardiac embolic strokes, we studied the 1,290 patients with cerebral infarcts in the NINCDS Stroke Data Bank. Based solely on the presence of cardiac sources of embolism, we divided the patients into groups of high (n = 250), medium (n = 166), and low (n = 874) risk of a cardiogenic mechanism for their stroke. There was a highly significant graded relationship between increasing risk of a cardiac source and a history, or presence of, systemic embolism, abrupt onset, and diminished level of consciousness at onset. These clinical features may be useful for assessing the likelihood of a cardiac embolic mechanism in patients with cerebral infarcts.

Cerebral Infarction↗
PubMed1989

Predictors of survival in clinically diagnosed Alzheimer's disease and multi-infarct dementia.

Duration of survival from time of first evaluation was studied in 61 patients with clinically diagnosed Alzheimer's disease (senile dementia of the Alzheimer type [SDAT]) and 34 patients with clinically diagnosed multi-infarct dementia (MID). Duration of survival did not differ significantly between MID and SDAT. However, since MID patients were younger at onset, MID patients had a lower life quotient than SDAT patients. Race, sex, and age at onset were not predictive of survival in SDAT. History of hypertension, elevated systolic blood pressure, lower scores on tests of Block Designs, and Logico-Grammatical Comprehension predicted shorter survival in SDAT. Age at onset and race were not predictive of survival in MID. Male sex, lower educational attainment, as well as low scores on tests of Logico-Grammatical Comprehension, Digit Span, Naming, Verbal Fluency, and receptive vocabulary, predicted shorter survival in MID.

Age Factors↗
PubMed1989

Infarcts of undetermined cause: the NINCDS Stroke Data Bank.

In a prospective study of 1,805 hospitalized patients in the Stroke Data Bank of the National Institute of Neurological and Communicative Disorders and Stroke, the 1,273 with infarction were classified into diagnostic subtypes. Diagnosis was based on the clinical history, examination, and laboratory tests including computed tomography, noninvasive vascular imaging, and where safe and relevant, angiography. Five hundred and eight cases (fully 40%) were labeled as infarcts of undetermined cause (IUC), of which 138 (27%) were evaluated with both computed tomography and angiography. The clinical syndrome and computed tomographic and angiographic findings in 91 (65.9%) of these 138 IUC cases were clearly not attributable to large-artery thrombosis and could permit reclassification of the infarct as due to some form of embolism. Failure to define a source of embolus kept them in the category of IUC. Thirty-one cases (22.5%) could be reclassified as due to stenosis or thrombosis of a large artery, and 16 (11.6%) as lacunar infarction. To determine if those selected for angiography among the IUC patients differed from those with other final diagnoses, a stepwise multiple logistic model was used. The most important characteristics were young age, presence of a superficial infarct, prior transient ischemic attack, low weakness score, and presentation with a nonlacunar syndrome. The results of the model suggest that angiography use was determined by clinical characteristics uniformly across centers and not by final diagnosis. Continued use of the category IUC may help clarify risk factors and stroke subtypes, allow new mechanisms of ischemic stroke to be uncovered, and prevent classification categories of stroke used in clinical trials from becoming too broad.

Cerebral Angiography↗