Yasuo Terayama

Prognostic Value of Admission Blood Pressure in Patients With Intracerebral Hemorrhage Keio Cooperative Stroke Study

BACKGROUND AND PURPOSE Patients with acute stroke on admission to the hospital are often found to have high blood pressure. The purpose of the present study was to investigate the prognostic value of admission blood pressure in patients with acute intracerebral hemorrhage, including putaminal, thalamic, subcortical, cerebellar, and pontine hemorrhage. METHODS A total of 1701 patients with intracerebral hemorrhage of the putamen (n = 776; mean +/- SD age, 58 +/- 14 years) thalamus (n = 538; 63 +/- 12 years), subcortex (n = 153; 61 +/- 16 years), cerebellum (n = 110; 64 +/- 11 years), and pons (n = 124; 59 +/- 13 years) were examined. The mean blood pressure on admission in patients with a fatal outcome was compared with that in patients who survived. RESULTS The mean age in each patient group (putaminal, thalamic, subcortical, cerebellar, and pontine hemorrhage) with fatal outcome was older than that with nonfatal outcome, while ANCOVA indicated no correlation between age and blood pressure on admission or age and volume of hematoma. The mean arterial blood pressure on hospital admission was 126.9 +/- 25.8 mm Hg (+/-SD) in cases of putaminal. 127.4 +/- 22.6 mm Hg in thalamic, 116.4 +/- 20.6 mm Hg in subcortical, 123.5 +/- 23.9 mm Hg in cerebellar, and 133.0 +/- 26.0 mm Hg in pontine hemorrhage. The mean blood pressure on admission in patients with a fatal outcome among those with putaminal (136.0 +/- 36.3 mm Hg) and thalamic (133.2 +/- 22.1 mm Hg) hemorrhage was significantly higher than that in those with a nonfatal outcome (123.8 +/- 20.6 mm Hg for putaminal, 101.6 +/- 22.5 mm Hg for thalamic) (P < .01). No correlation between mean blood pressure and outcome was observed in the patients with subcortical (116.5 +/- 22.2 mm Hg for nonfatal, 114.9 +/- 22.0 mm Hg for fatal outcome), cerebellar (125.2 +/- 22.2 mm Hg, 116.9 +/- 28.8 mm Hg), and pontine (129.9 +/- 23.8 mm Hg, 136.0 +/- 27.7 mm Hg) hemorrhage. The volume of hematoma on admission in patients with fatal outcome with putaminal (58.2 +/- 24.4 mL), thalamic (27.0 +/- 13.1 mL), subcortical (32.9 +/- 14.4 mL), and cerebellar (31.4 +/- 28.6 mL) hemorrhage was greater than that in those with nonfatal outcome (20.8 +/- 11.4 mL, 7.1 +/- 4.8 mL, 18.3 +/- 10.6 mL, and 8.1 +/- 4.2 mL, respectively; P < .01), while no correlation between volume of hematoma and outcome was observed in patients with pontine hemorrhage. CONCLUSIONS The above data suggest that an increased mean blood pressure and volume of hematoma on admission in putaminal and thalamic hemorrhage were related to increased mortality, while in patients with subcortical, cerebellar, and pontine hemorrhage, the mean blood pressure was not related to the clinical outcome.

Enhanced erythrocyte aggregability in occlusive cerebrovascular disease.

We measured the rate of erythrocyte aggregation using our whole-blood aggregometer in 80 patients with occlusive cerebrovascular disease during the acute and chronic phases. We compared the data with values for 38 age-matched healthy controls. Mean +/- SD erythrocyte aggregability of the patients during both the acute phase (0.145 +/- 0.21/sec, n = 35) and the chronic phase (0.139 +/- 0.21/sec, n = 45) was higher than that in the controls (0.123 +/- 0.21/sec, n = 38; p less than 0.01). Erythrocyte aggregability was positively correlated with the plasma concentration of globulin and fibrinogen and inversely correlated with the albumin:globulin ratio. However, these correlations did not necessarily exclude the possibility that some unknown substance(s) released from ischemic tissue might enhance erythrocyte aggregability.

Bilateral hemispheric reduction of cerebral blood volume and blood flow immediately after experimental cerebral hemorrhage in cats.

Acute cerebral circulatory changes following experimental cerebral hemorrhage were investigated in eight cats. The cerebral hemorrhage was produced in the right basal ganglia by introducing arterial blood via a thin catheter, using the systemic arterial blood pressure of the cat as a driving force. Local cerebral blood volume was measured continuously in the bilateral parietotemporal cortexes employing photoelectric apparatuses. Carbon black dilution curves were recorded from the regions, and the mean transit time of blood was calculated. Local cerebral blood flow was estimated from mean transit time and cerebral blood volume. Intracranial pressure was monitored continuously in the right parietal epidural space. Five minutes after cerebral hemorrhage, intracranial pressure increased by 24.0 +/- 6.1 mm Hg, while mean arterial blood pressure increased by only 2.9 +/- 2.0 mm Hg. Cerebral blood volume decreased by 1.60 +/- 0.24 vol% in the hemorrhagic and 1.14 +/- 0.30 vol% in the nonhemorrhagic hemisphere. Cerebral blood flow decreased by 30.0 +/- 4.5 ml/100 g brain/min in the hemorrhagic (initially 64.5 +/- 13.6) and by 30.3 +/- 7.5 ml/100 g brain/min in the nonhemorrhagic (initially 60.9 +/- 6.9) hemisphere. Increased intracranial pressure appeared to be the main cause of the observed cerebral blood volume/flow reduction shortly after experimental hemorrhage in the basal ganglia. Several other factors and mechanisms involved are discussed.

Development of a Novel, Weighted, Quantifiable Stroke Scale: Japan Stroke Scale

Background and Purpose— Several stroke scales are available for estimation of the severity of stroke, but none of them provides information regarding the relative weights of the observed variables. To define an integrated severity of stroke, we developed a quantifiable stroke scale with weighted variables that apply conjoint analysis to calculate the relative weight of each item. Methods— We selected 10 variables (consciousness, language, neglect, hemianopsia, gaze, pupillary abnormality, facial palsy, plantar reflex, sensation, and weakness) based on the multivariate analysis of the Keio Stroke Patient Database Battery. The variables were categorized and evaluated for their distribution and sensitivity. The categorizations were then modified and rechecked. The procedure was repeated until the appropriate categorization was obtained from 198 patients. A temporary stroke scale without weight was then formulated, and the reliability of the scale was examined and revised with 80 new stroke patients. As a next step, 150 neurologists were asked to rank a set of 27 virtual patients, each with a different combination of variables, according to severity. From these rankings, conjoint analysis was used to derive utility scores (weights) for each factor level. Results— The relative weights of each of the factors were as follows: consciousness 49.8%, language 9.9%, weakness of lower extremity 7.3%, pupillary abnormality 6.8%, gaze palsy 5.6%, weakness of arm 4.3%, weakness of hand 3.7%, neglect 3.7%, facial palsy 2.4%, plantar reflex 2.2%, hemianopsia 2.2%, and sensory impairment 2.1%. The total score for a patient could be calculated from the sum of the scores for each of the variables ranging from −0.38 to 27.86. Scoring of 100 patients with acute stroke was carried out, and the changes in scores were followed for validation. Longitudinal clinical monitoring of the patients correlated well with the scores in each patient. The interrater and intrarater reliabilities of the scale were excellent (weighted &kgr; 0.83; Cronbach’s &agr; 0.998). Conclusions— The Japan Stroke Scale is a parametric stroke scale that provides a quantitative measure of the severity of stroke. Each of the variables of the scale has a relative weight according to the severity of stroke. Reliability and responsiveness were proved to be excellent. The present data revealed a potentiality for the Japan Stroke Scale to be a universally accepted and reliable standardized system from the clinimetrical point of view.

The behavior of99mTc-hexamethylpropyleneamineoxime (99mTc-HMPAO) in blood and brain

Abstract99mTc-hexamethylpropyleneamineoxime (99mTc-HMPAO) is a reagent for scanning cerebral blood flow. We investigated how99mTc-HMPAO changed in the blood and brain. The99mTc-HMPAO, which was prepared by adding of99mTcO-4 to HMPAO and Sn(II), consisted of primary and secondary complexes, reduced hydrolyzed99mTc, and99mTc0pertechnetate. The percentage of the primary complex in99mTc-HMPAO decreased with time after preparation. The primary complex converted to the secondary one very rapidly in the presence of plasma. When99mTc-HMPAO was injected into patients,99mTc activity was immediately partitioned in the plasma fraction, with approximately 60% in whole blood. In plasma,99mTc was found to be associated with proteins such as albumin and globulin.99mTc trapped in red cells was not washed out with either plasma or saline. Biodistribution studies showed that the less lipophilic compounds of99mTc-HMPAO could not pass through the blood brain barrier (BBB), and therefore did not accumulate in the brain. The results of gel chromatography and equilibrium dialysis indicated that no specific99mTc binding protein was present in the brain. Considering the instability of99mTc-HMPAO in vivo, we proposed that the speed at which the primary complex converted to the less lipophilic compounds was important in allowing99mTc-HMPAO to pass through the BBB and to be fixed in the brain.

Comparison between the Photoelectric Method and H2 Clearance Method for Measuring Cerebrocortical Blood Flow in Cats

The photoelectric method using carbon black as a nondiffusible tracer of blood was compared with the hydrogen clearance (H2) method in nine anesthetized cats. A photoelectric apparatus and H2 electrode were applied to a small region of the cerebral cortex (left ectosylvian gyrus) for simultaneous measurement of the regional CBF. The values of CBF(H2) and CBF(photoelectric) were 50.7 ± 19.2 and 52.1 ± 14.5 ml − 100 g−1 · min−1, respectively. CBF(H2) and CBF(photoelectric) were found to correlate well (r = 0.588, p < 0.01) when changes in CBF were induced by CO2 inhalation, exsanguination, hyperventilation, and occlusion of the middle cerebral artery. The correlation between CBF(H2) and CBF(photoelectric) was much better in the case of intraindividual comparisons (r = 0.957, p < 0.01). In addition to its merits in common with the H2 clearance method, such as handiness, low cost, and strict regionality, the photoelectric method displayed the following advantages: time-to-time measurements of CBF (<20 s), immediate display of the microcirculatory flow pattern, and simultaneous monitoring of cerebral blood volume. However, measurements from deep structures of the brain are better performed by the H2 method despite the disadvantage of the use of a potentially explosive gas.

RBC Aggregation Is Not a Primary Factor for Microvascular Stasis on Temporary Complete Ischemia of the Feline Brain

Vascular dementia could be triggered by cerebral ischemia, in which micro-circulatory stasis and subsequent impairment of microcirculation may constitute the cardinal events. The possibility that aggregation of red blood cells (RBC) might contribute to the stasis and no-reflow has been suggested for many years, since the viscosity of blood in a sluggish flow or stasis is predicted to increase from the hemorrheological viewpoint. We examined the effect of RBC aggregation in the leptomeningeal vessels and parenchymal microvasculature on reflow after a brief, complete interruption of flow through the brain tissue produced by cardiac arrest.

Diffusion of Oxygen and Hydrogen Gas is Faster Through a Layer of Suspended Cultured C6 Cells than Through the Medium

The gas diffusion in the living cerebral cortex has been reported by Gotoh et al. to be faster than that in the dead cortex (Gotoh, Tazaki and Meyer, 1961). This was attributed by them to a mixing effect due to the vasomotor action of the microvasculature in the tissue, by which gas molecules could be transported to far distant areas. The present study examined whether or not such a facilitated process persisted even in a cell suspension where the microcirculation was deprived.

Cerebral Hemodynamics in Patients with Periventricular White-Matter Lesions on Brain Imaging

Periventricular or deep white-matter lesions on brain imaging, so-called leukoaraiosis [8], have been frequently observed in elderly subjects with or without dementia. They are associated with age, increased systolic blood pressure, motor and reflex deficits, and with deficits in cognitive function [1,19]. Recently these changes have attracted the attention of clinicians and pathologists in relation to Binswanger’s disease [3,6,12,17,18] or senile dementia [15]. The pathological significance of these changes are, however, still in dispute. Hachinski and his coworkers [8,19,20] concluded from their studies that white-matter changes were associated with intellectual impairment and sometimes with vascular disease. On the other hand, Leys et al. [14] reported that periventricular and white-matter hyperintensities on magnetic resonance imaging (MRI) were frequent incidental findings in the elderly and did not significantly differ between patients with Alzheimer’s disease and healthy controls. In order to clarify the underlying pathophysiological mechanism of these changes, we investigated cerebral hemodynamics in patients with periventricular white-matter lesions on brain imaging and correlated the data with severity of white-matter changes, mental function, and other clinical findings.

The Mechanical Filtration Coefficient (Lp) of the Cell Membrane of Cultured Glioma Cells (C6)

The mechanical filtration coefficient (Lp) of the membrane of cultured glioma cells was determined from the rate of swelling of the cells. The swelling was induced by exposing the cells to distilled water. Assuming that cells swell in a symmetrical manner, Lp was 2.2 x 10(-8) cm/s.mmHg, or 1.7 x 10(-4) microns/s.cmH2O when calculated from changes of the cell diameter.