bluuebunny/crossref_metadata_2025 huggingface dataset:
Arm and leg paresis as outcome predictors in stroke rehabilitation.
Authors: Olsen T S
Published: June 2011

I used leg and arm paresis to predict outcome measured as extremity function in a prospective study of 75 consecutive hemiplegic patients admitted to an inpatient stroke rehabilitation unit. In each patient, extremity paresis was quantified according to the five-point scoring system advised by the Medical Research Council, upper extremity function was quantified using the Barthel Index subscore for feeding and dressing the upper body, and lower extremity function was quantified according to a five-point scoring of the ability to walk. Improvement was recorded for upper extremity function in 52% of the patients and for lower extremity function in 89%. Best extremity function was reached a mean +/- SEM of 9 +/- 3 and 10 +/- 4 weeks after stroke for the upper and lower extremities, respectively. In patients experiencing complete recovery, this occurred a mean +/- SEM of 7 +/- 2 weeks (for both upper and lower extremities) after the stroke. Only 8-11% of the patients with paresis scores of less than or equal to 2 regained independent extremity function after rehabilitation. Half of the patients with paresis scores of greater than or equal to 3 regained independent extremity function after rehabilitation, while the other half were able to perform extremity function with only minimal assistance. As predictors of extremity function, the Barthel Index subscore was slightly better (r = 0.64) than paresis score (r = 0.58). However, because evaluation of extremity paresis is easy, it appears to be useful as a preliminary predictor of outcome following stroke.
Cerebral hemodynamic change in the child and the adult with moyamoya disease.
Authors: Kuwabara Y , Ichiya Y , Otsuka M , Tahara T , Gunasekera R , Hasuo K , Masuda K , Matsushima T , Fukui M
Published: June 2011

To clarify the differences in cerebral hemodynamics and metabolism between children and adults with bilateral moyamoya disease, we measured regional cerebral blood flow, regional oxygen extraction fraction, regional metabolic rate for oxygen, regional cerebral blood volume, and regional transit time using positron emission tomography in nine patients (five children and four adults) and compared the values with those in controls (four children with unilateral moyamoya disease and six normal adults). The major differences between pediatric and adult patients were in regional cerebral blood volume and regional oxygen extraction fraction. Regional cerebral blood volume was more markedly increased relative to the control value in the children than in the adults. Also, regional oxygen extraction fraction was greater than control in areas with low blood flow in the children but was never increased in the adults. However, in the adults, only regional transit time was significantly prolonged relative to the control values. The increased regional oxygen extraction fraction relative to the control value observed in children with moyamoya disease may explain why transient ischemic attacks are a common symptom in this group.
Cerebral blood flow and metabolism in normotensive and hypertensive patients with transient neurologic deficits.
Authors: Fujii K , Sadoshima S , Okada Y , Yao H , Kuwabara Y , Ichiya Y , Fujishima M
Published: June 2011

We used positron emission tomography to examine retrospectively the effects of blood pressure on regional cerebral blood flow and oxygen metabolism in seven normotensive and eight hypertensive patients with a history of transient neurologic deficits. In the hypertensive patients, a decrease in regional cerebral blood flow was closely related to blood pressure; these changes were most pronounced in the supratentorial structures, especially the striatum and thalamus. In contrast, the regional cerebral metabolic rate for oxygen was less related to blood pressure. Consequently, the regional oxygen extraction fraction was increased in the hypertensive patients, while regional cerebral blood volume and the regional cerebral blood flow volume ratio were unchanged. Multivariate regression analysis confirmed that hypertension was an independent factor affecting regional cerebral blood flow. The analysis also disclosed that age, sex, hematocrit, smoking, and PaCO2 affected regional cerebral blood flow. These findings suggest that the hemodynamic reserve in hypertensive individuals is reduced, which may predispose them to cerebral ischemia and perhaps stroke, even during small decreases in cerebral perfusion pressure.
Collateral development after carotid artery occlusion in Fischer 344 rats.
Authors: Coyle P , Panzenbeck M J
Published: June 2011

Mortality following permanent occlusion of both common carotid arteries decreases as the time between the first and second occlusions increases in Fischer 344 rats. Our goal was to examine the possibility that collaterals develop after unilateral carotid artery occlusion. During temporary occlusion of both carotid arteries in nine ketamine-anesthetized male rats, mean +/- SEM blood flow in both parietal cortices was 23 +/- 4% of the preocclusion (control) blood flow (120 +/- 7 ml/min/100 g) measured by laser Doppler flowmetry (p less than 0.05). After permanent occlusion of one carotid artery for either 1-2 days (n = 10) or 6 weeks (n = 7), mean +/- SEM blood flow was 16 +/- 2% and 30 +/- 3% of control, respectively, during a temporary test occlusion of the other carotid artery. During the test occlusion, blood flow in the cortex ipsilateral to the 6-week occlusion was 170% that in the contralateral cortex (which was similar to the blood flow immediately after temporary occlusion of both carotid arteries) and twice that after 1-2 days of occlusion. Mean luminal diameter of the basilar-carotid anastomosis ipsilateral to the 6-week occlusion was 186% that of the contralateral anastomosis, which showed only minimal change, and 145% that after 1-2 days of occlusion. We conclude that during 6 weeks of permanent carotid artery occlusion the anastomosis enlarges and its blood flow or reserve increases. Thus, collaterals developed ipsilateral to, but not contralateral to, the 6-week carotid artery occlusion, which suggests the possibility of greater collateral protection on the permanently occluded side.
Arachidonic acid metabolism and pathophysiologic aspects of subarachnoid hemorrhage in rats.
Authors: Gaetani P , Marzatico F , Rodriguez y Baena R , Pacchiarini L , Viganò T , Grignani G , Crivellari M T , Benzi G
Published: June 2011

We studied the ex vivo production of prostaglandin D2, prostaglandin E2, 6-ketoprostaglandin F1 alpha, and leukotriene C4 in the brain tissue of rats subjected to experimental subarachnoid hemorrhage. The ex vivo method allows the study of arachidonic acid metabolites released from brain slices at different times after subarachnoid hemorrhage induction and reflects the residual capacity for arachidonic acid metabolism after the pathologic event. The rats were sacrificed 30 minutes, 1 and 6 hours, and 2 days after subarachnoid hemorrhage was induced by the injection of 0.30 ml autologous arterial blood into the cisterna magna. Concentration of prostaglandin D2 and 6-ketoprostaglandin F1 alpha was increased significantly relative to control 2 days after induction. The concentration of prostaglandin E2 was increased significantly 6 hours after induction, while ex vivo production of leukotriene C4 was increased significantly at 1 and 6 hours and 2 days. The correlation between these results and the occurrence of vasospasm after subarachnoid hemorrhage is discussed. The results obtained from the ex vivo incubation of brain tissue slices after experimental subarachnoid hemorrhage suggest that after the hemorrhage there is a significant modification of brain eicosanoid metabolism, which could be of great importance in interpreting the pathogenesis of subarachnoid hemorrhage-related neuronal impairment.
Ataxic hemiparesis following thalamic infarction.
Authors: Boiten J , Lodder J
Published: June 2011

We describe a 73-year-old man with ataxic hemiparesis following infarction of the ventrolateral nucleus of the thalamus demonstrated by computed tomography and magnetic resonance imaging. Cerebellar ataxia was most likely due to interruption of the dentatorubrothalamocortical fibers at the level of the injured ventrolateral nucleus. Hemiparesis was probably caused by local edema compressing the corticospinal tract in the adjacent posterior limb of the internal capsule. We believe this to be the first reported case of classic ataxic hemiparesis following thalamic infarction.
Stroke in young adults.
Authors: Bevan H , Sharma K , Bradley W
Published: June 2011

Strokes in young adults are uncommon and often a diagnostic challenge. A retrospective study of strokes due to intracerebral hemorrhage, subarachnoid hemorrhage, or cerebral infarction was undertaken. We reviewed the medical records of 113 young patients aged 15-45 years who were admitted to the Medical Center Hospital of Vermont with a diagnosis of stroke between 1982 and 1987. This group comprised 8.5% of patients of all ages admitted for stroke, 2.3 times the proportion observed in the National Survey of Stroke. Nontraumatic intracerebral hemorrhage was diagnosed in 46 young patients (41%); the main causes included aneurysms, arteriovenous malformations, hypertension, and tumors. Subarachnoid hemorrhage was found in 19 young patients (17%); the majority were due to aneurysms. The remaining 48 young patients (42%) had cerebral infarction, the majority due to cardiogenic emboli and premature atherosclerosis. Mitral valve prolapse, the use of oral contraceptives, alcohol drinking, and migraine were infrequent sole causes of cerebral infarction in the absence of other risk factors. The case-fatality rate for this group of young patients with stroke was 20.4% compared with 23.9% for the National Survey of Stroke. Young adults with stroke deserve an extensive but tailored evaluation, which should include angiography and echocardiography.
Deep cerebral infarcts in the People's Republic of China.
Authors: Davis L E , Xie J G , Zou A H , Wang J Y , Liu Y J , Go T X , Cai Y
Published: June 2011

We reviewed computed tomograms and clinical characteristics for 1,124 consecutive stroke patients from Shanghai, People's Republic of China. While there were many similarities between lacunar syndromes in these patients and patients from Europe and the United States, several differences were noted. Deep cerebral infarcts identified by computed tomography were more common in patients from Shanghai and accounted for 27% of all ischemic infarcts. Small deep infarcts occurred more commonly in women from Shanghai (44%) than in women from the West. Deep cerebral infarcts in patients from Shanghai were larger than those usually seen in patients from the West. The mean infarct volume in patients from Shanghai was 2.4 ml, and 49% were giant lacunes (greater than 15 mm in maximal diameter).
Cerebral venous thrombosis in a child with iron deficiency anemia and thrombocytosis.
Authors: Belman A L , Roque C T , Ancona R , Anand A K , Davis R P
Published: June 2011

We describe a 22-month-old boy with iron deficiency anemia and reactive thrombocytosis who developed vomiting, headache, mental status changes, and seizures. Computed tomography showed infarction of the basal ganglia and thalami. Magnetic resonance imaging revealed cerebral venous thrombosis, delineated the extent of the vascular and associated parenchymal involvement, showed the infarcts to be hemorrhagic (a finding not imaged by computed tomography due to our patient's depressed hemoglobin level), and obviated the need for invasive angiography.
Elevated plasma homocyst(e)ine concentration as a possible independent risk factor for stroke.
Authors: Coull B M , Malinow M R , Beamer N , Sexton G , Nordt F , de Garmo P
Published: June 2011

Homocyst(e)ine refers to the sulfur-containing amino acids homocysteine, homocystine, and homocysteine-cysteine mixed disulfide, which normally exist in plasma in both the free and protein-bound forms. Marked hyperhomocyst(e)inemia is associated with well-recognized complications of occlusive thrombotic events and a characteristic syndrome. It is less clear whether mild to moderate elevations in plasma homocyst(e)ine concentrations (i.e., 1.5-5-fold increases) also represent a risk factor for stroke and, if so, whether it is independent of other recognized risk factors. To examine these questions we compared the plasma homocyst(e)ine levels in 41 patients with acute strokes, 27 patients with transient ischemic attacks, 31 patients with recognized risk factors for but no recent symptoms of cerebrovascular disease, and 31 normal volunteers (controls). Plasma homocyst(e)ine concentration was moderately but significantly higher in the patients than in the controls (p less than 0.0001). Approximately 30% of the patients had homocyst(e)ine levels higher than the controls. No relation was found between homocyst(e)ine concentration and other recognized stroke risk factors or stroke type; however, a positive correlation was found between serum uric acid and plasma homocyst(e)ine levels. These data suggest that a moderately elevated plasma homocyst(e)ine concentration may be an independent risk factor for cerebrovascular disease.
Chronic cerebral blood flow changes following experimental subarachnoid hemorrhage in rats.
Authors: Kader A , Krauss W E , Onesti S T , Elliott J P , Solomon R A
Published: June 2011

Experimental subarachnoid hemorrhage was induced in 52 adult male Wistar rats by microsurgical transclival basilar artery puncture. Telencephalic blood flow measured in 24 rats with subarachnoid hemorrhage was compared with that in 23 sham-operated rats and 10 unoperated control rats using the [14C]butanol indicator fractionation technique. Telencephalic blood flow was significantly less in the rats with subarachnoid hemorrhage than in the sham-operated rats 3 (78.7 +/- 6.9 [n = 7] and 112.0 +/- 8.5 [n = 8] ml/100 g/min, respectively; p less than 0.01), 7 (74.9 +/- 5.1 [n = 9] and 112.6 +/- 4.6 [n = 8] ml/100 g/min, p less than 0.001), and 14 (81.9 +/- 6.0 [n = 8] and 104.1 +/- 5.4 [n = 7] ml/100 g/min, p less than 0.01) days after surgery. Telencephalic blood flow in unoperated controls (114.7 +/- 4.9 ml/100 g/min) did not differ significantly from sham-operated rats. Clinically, the 52 rats with subarachnoid hemorrhage were indistinguishable from 32 sham-operated rats. Postmortem examinations in 10 rats used in a preliminary investigation demonstrated significant blood clot in the basal cisterns 2 hours after basilar artery puncture. Intracranial pressure was slightly elevated (2.3 mm Hg over baseline) 30 minutes after the hemorrhage (n = 7), but when measured 3 (n = 3) or 7 (n = 3) days after surgery it had returned to baseline. Histologic examination of the brains from 10 rats subjected to subarachnoid hemorrhage 7 (n = 5) or 14 (n = 5) days before sacrifice revealed no evidence of cerebral ischemia or vasculopathic changes in the cerebral arteries.(ABSTRACT TRUNCATED AT 250 WORDS)
High-dose intravenous naloxone for the treatment of acute ischemic stroke.
Authors: Olinger C P , Adams H P , Brott T G , Biller J , Barsan W G , Toffol G J , Eberle R W , Marler J R
Published: June 2011

To evaluate the safety and possible efficacy of high-dose naloxone for the treatment of acute cerebral ischemia, 38 patients received a loading dose of 160 mg/m2 over 15 minutes followed by a 24-hour infusion at the rate of 80 mg/m2/hr. Nausea and/or vomiting were common side effects. Naloxone was discontinued in seven patients (because of hypotension in one, bradycardia and hypotension in two, myoclonus in one, focal seizures in two, and hypertension in one); all seven patients responded to treatment and no permanent sequelae to naloxone were noted. Twelve of the 38 patients showed early neurologic improvement (by completion of the naloxone loading dose). However, there was no correlation between such a loading dose response and clinical outcome at 3 months. Our experience suggests that naloxone is safe at the dose used, but data for efficacy are inconclusive.
Intracerebral hematomas during anticoagulant treatment.
Authors: Franke C L , de Jonge J , van Swieten J C , Op de Coul A A , van Gijn J
Published: June 2011

We retrospectively studied 79 patients from three centers who suffered an intracerebral hemorrhage during treatment with anticoagulants and compared them with 84 patients from one center who suffered a spontaneous intracerebral hemorrhage without anticoagulant treatment. Mortality after 30 days was slightly higher in patients with anticoagulant treatment (67%) than in those without (55%), and the proportion of patients who attained moderate or complete recovery was slightly smaller in the treated group (22% and 36%, respectively); neither difference was statistically significant. Volume of the supratentorial hematoma was measured from computed tomograms in 70% of the patients in both groups and was significantly greater in the 55 patients treated with anticoagulants than in the 59 patients not so treated. Volume was not related to the degree of anticoagulation. Based on the total number of patients treated with anticoagulants in the Heerlen region, we conclude that for patients older than 50 years of age the risk of intracerebral hemorrhage during anticoagulant treatment is increased approximately eightfold but is unrelated to the degree of anticoagulation. Our results suggest that intracerebral hemorrhage is more frequent and more extensive in patients treated with anticoagulants but that once it has occurred in such patients intracerebral hemorrhage is not significantly more serious than in untreated patients.
Duplex Doppler and spectral flow analysis of racial differences in cerebrovascular atherosclerosis.
Authors: Gil-Peralta A , Alter M , Lai S M , Friday G , Otero A , Katz M , Comerota A J
Published: June 2011

We compared carotid artery disease in 99 black and 106 white patients using duplex ultrasonography (B-mode imaging and Doppler spectral analysis). Blacks had significantly less stenosis of the extracranial internal carotid artery than whites. Among the risk factors investigated, hypertension alone, ischemic heart disease, diabetes mellitus, and smoking failed to explain the racial difference. Although carotid stenosis of greater than or equal to 40% correlated significantly with age in both races (p = 0.001 in whites and p = 0.005 in blacks), blacks had significantly less carotid stenosis of any degree even when age was taken into account. Multivariate analysis showed that race is a significant and independent risk factor for carotid stenosis (p less than 0.0001). Hypertension interacting with race was also significant. Our results require verification in population-based studies. Carotid duplex ultrasonography offers a noninvasive method for carrying out such studies.
Study of the elastic skeleton of intracranial arteries in animal and human vessels by scanning electron microscopy.
Authors: Yamazoe N , Hashimoto N , Kikuchi H , Kang Y , Nakatani H , Hazama F
Published: June 2011

We studied the elastic skeleton of major cerebral arteries in rats, monkeys, and one human using scanning electron microscopy after hot formic acid extraction followed by freeze-drying. For comparison, we also examined the thoracic aorta and femoral artery of rats. The cerebral arteries of rats had one distinct internal elastic lamina connected to the thin adventitia with sponge-like medial elastic tissue. This internal elastic lamina had fenestrations, which we found to be less frequent in cerebral arteries than in extracranial arteries, and fold-like protrusions into the lumen. This finding has not been recognized before. Such protrusions were more prominent in cerebral arteries than in extracerebral arteries. At the apical intimal pad, the internal elastic lamina appeared to be continuous, making a honeycomb-like structure. The folds and fenestrations were numerous at the apex. There were no essential differences among species. Our study shows that the internal elastic lamina is not a simple sheet but part of the complicated architecture of the elastic tissue of the vessel wall. These differences in the elastic skeleton, including fenestrations and fold-like structures, in various sites of different arteries may explain the development of various localized vascular diseases.
Calcium antagonist, adenosine A1, and muscarinic bindings in rat hippocampus after transient ischemia.
Authors: Onodera H , Kogure K
Published: June 2011

The protective roles of Ca2+ channel blockers against ischemic hippocampal damage are still debated. We used autoradiography to study postischemic L-type Ca2+ channels (1,4-dihydropyridine Ca2+ channel blocker binding), adenosine A1 receptors, and muscarinic cholinergic receptors in the rat hippocampus using [3H]PN200-110 (PN), [3H]cyclohexyladenosine (CHA), and [3H]quinuclidinyl benzilate (QNB), respectively, in 49 rats subjected to 20 minutes of forebrain ischemia. The rats were decapitated after 1 (n = 7), 3 (n = 7), 6 (n = 8), 12 (n = 7), 24 (n = 6), 48 (n = 6), or 168 (n = 8) hours of recirculation; eight control rats were sham-operated but experienced no cerebral ischemia. Reduced receptor binding preceding the delayed death of CA1 pyramidal cells was first observed in the stratum oriens of the CA1 subfield. Significant reductions in [3H]PN, [3H]CHA, and [3H]QNB bindings of this stratum compared with control were noticed after 3 (35%, p less than 0.01), 12 (31%, p less than 0.01), and 1 (10%, p less than 0.05) hours of recirculation, respectively. By 168 hours after ischemia (when the populations of CA1 pyramidal cells were depleted) all strata in the CA1 subfield had lost most of their receptor sites, and [3H]PN, [3H]CHA, and [3H]QNB bindings in the stratum oriens were decreased to 23%, 30%, and 63% of control (p less than 0.01). Although [3H]PN binding in the CA3 subfield did not change significantly during 168 hours after ischemia, the histologically intact dentate gyrus exhibited a 31% loss of binding sites compared with control (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
Cerebral sinus thrombosis as a potential hazard of antifibrinolytic treatment in menorrhagia.
Authors: Achiron A , Gornish M , Melamed E
Published: June 2011

We describe a 42-year-old woman who developed superior sagittal and left transverse sinus thrombosis associated with prolonged epsilon-aminocaproic acid therapy for menorrhagia. This antifibrinolytic agent has been used in women with menorrhagia to promote clotting and reduce blood loss. Although increased risk of thromboembolic disease has been reported during treatment with epsilon-aminocaproic acid, cerebral sinus thrombosis has not been previously described. Careful use of epsilon-aminocaproic acid therapy is recommended.
Prognosis of transient ischemic attacks in the Oxfordshire Community Stroke Project.
Authors: Dennis M , Bamford J , Sandercock P , Warlow C
Published: June 2011

In a community-based study of approximately 105,000 people, 184 presented with a transient ischemic attack during the 5 years between 1981 and 1986; we believe these persons represent almost all new cases of transient ischemic attack going to a doctor during that period. During a mean follow-up of 3.7 years 49 patients died, 45 had a first-ever stroke, and 17 had a myocardial infarction. Cardiac disease accounted for 17 (35%) deaths, while stroke was the cause of death in 15 patients (31%). The average actuarial risk of death was approximately 6.3%/yr, slightly greater than that expected for similar people without transient ischemic attacks (risk ratio [observed divided by expected] = 1.4). The actuarial risk of stroke was 11.6% during the first year after a transient ischemic attack and approximately 5.9%/yr over the first 5 years. Patients who suffered a transient ischemic attack had a 13-fold excess risk of stroke during the first year and a sevenfold excess risk over the first 7 years compared with people without transient ischemic attacks. The actuarial risk of death, stroke, or myocardial infarction over the first 5 years after a transient ischemic attack was approximately 8.4%/yr. The prognosis in this community-based cohort was better than that in previous reports. The high early risk of stroke means that investigation and treatment of new cases should commence as soon as possible.
Dementia in stroke survivors in the Stroke Data Bank cohort. Prevalence, incidence, risk factors, and computed tomographic findings.
Authors: Tatemichi T K , Foulkes M A , Mohr J P , Hewitt J R , Hier D B , Price T R , Wolf P A
Published: June 2011

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.
Relation of leukoaraiosis to lesion type in stroke patients.
Authors: Hijdra A , Verbeeten B , Verhulst J A
Published: June 2011

Nonspecific periventricular white matter lucencies on computed tomograms (leukoaraiosis) were found in 141 (38%) of 367 patients with ischemic or hemorrhagic strokes. Patients with leukoaraiosis were significantly older than those without it and were significantly more likely to have hypertension, diabetes mellitus, general vascular disease, and lacunar infarcts on computed tomograms but were less likely to have cortical infarcts. Because many of these variables may be mutually dependent, we performed a logistic regression analysis examining all clinical and computed tomographic variables. The analysis demonstrated that increasing age, lacunar infarcts, and hemorrhages were significant determinants of leukoaraiosis; cortical infarcts were also significantly, but negatively, correlated with leukoaraiosis. In patients with hemorrhages, leukoaraiosis occurred significantly more often when aneurysms or arteriovenous malformations were not demonstrated. These findings suggest that in patients with cerebrovascular disorders leukoaraiosis is associated with small-vessel disease.
Consistency of cerebral blood flow and evoked potential alterations with reversible focal ischemia in cats.
Authors: Matsumiya N , Koehler R C , Traystman R J
Published: June 2011

To enhance the consistency of the ischemic insult caused by reversible transorbital middle cerebral artery occlusion, we investigated the variability of somatosensory evoked potential amplitudes and regional cerebral blood flow in 26 anesthetized cats using four procedures to induce transient ischemia. These procedures included 60 minutes of left middle cerebral artery occlusion with or without left common carotid artery occlusion and 120 minutes of left middle cerebral artery occlusion with or without bilateral common carotid artery occlusion. Blood flow in the left middle cerebral artery territory was markedly and consistently reduced to less than 20 ml/min/100 g with simultaneous occlusion of the left middle cerebral artery and both common carotid arteries. The standard deviation of blood flow with this procedure (5.4) was less than that with the other three procedures (13-25). The amplitudes of ipsilateral somatosensory evoked potentials were decreased to approximately 20% of control during ischemia with all four procedures. During reperfusion, amplitudes recovered more slowly, to half of control, after both procedures involving 120 minutes of ischemia. After 120 minutes of reperfusion, the range of amplitudes was smallest in the group exposed to middle cerebral artery occlusion with bilateral common carotid artery occlusion. The degree of recovery of the somatosensory evoked potentials correlated with residual blood flow in both the ipsilateral middle cerebral artery territory and in the white matter during ischemia. We conclude that the most consistent model of focal ischemia and reperfusion in cats in which there is partial recovery of somatosensory evoked potentials is occlusion of one middle cerebral artery and both common carotid arteries for 120 minutes.
Mixed transcortical aphasia without anatomic isolation of the speech area.
Authors: Rapcsak S Z , Krupp L B , Rubens A B , Reim J
Published: June 2011

We report two patients with mixed transcortical aphasia following left frontal lobe infarctions. Although there was no evidence of anatomic isolation of the speech area on computed tomograms or magnetic resonance imaging scans, single-photon emission computed tomography in one case demonstrated diminished blood flow over the left parietal convexity suggestive of "functional isolation" of the posterior perisylvian language zone.
Predisposing factors of recurrent embolization in cardiogenic cerebral embolism.
Authors: Yasaka M , Yamaguchi T , Miyashita T , Park Y D , Sawada T , Omae T
Published: June 2011

To elucidate the pathophysiology of intracardiac thrombus formation, serial two-dimensional echocardiographic examinations were performed on 30 consecutive patients with acute cardiogenic cerebral embolism in parallel with measurement of hematocrit and plasma levels of antithrombin III. The data from groups of patients with and without newly formed or enlarged thrombi were compared. Intracardiac thrombi were detected in eight of the 30 patients (27%), four at admission and four after admission. Enlargement of the thrombus was observed in four, and systemic embolization recurred in three of the eight. Antithrombin III levels already were low at admission in patients who later developed thrombi or had enlarged thrombi on serial examinations. When the development or enlargement of an intracardiac thrombus was detected by echocardiography, the diameter of the inferior vena cava was found to be reduced. At the same time, a decrease in antithrombin III and an increase in hematocrit were demonstrated. Intracardiac thrombi are frequently detected by repeated echocardiographic examination in patients with cerebral embolism. Dehydration seems to accelerate thrombus formation that is reflected by a decrease in antithrombin III. A low antithrombin III level at admission and/or a decrease in antithrombin III after admission may indicate the possible recurrence of embolism.
Social and family integration of hemiplegic elderly patients 1 year after stroke.
Authors: Santus G , Ranzenigo A , Caregnato R , Inzoli M R
Published: June 2011

We interviewed 120 elderly hemiplegic patients 1 year after their acute stroke to assess cognitive impairment using the Mini-Mental State Examination, functional autonomy using the Barthel Index, mood disorders using the Hamilton Rating Depression Scale, and social integration using the Social Functioning Exam. Of the 76 patients admitted to this study, eight (12.1% of those testable) had significant cognitive impairment, 41 (53.9%) were functionally self-sufficient, 27 (35.5%) showed depressive symptoms, and 44 (57.9%) had problems in social and family integration. We suggest that a complete rehabilitation program aimed at producing a good quality of life for elderly hemiplegic patients should take into account all these aspects of human existence.
Regional cerebral blood flow and distribution of [99mTc]ethyl cysteinate dimer in nonhuman primates.
Authors: Orlandi C , Crane P D , Platts S H , Walovitch R C
Published: June 2011

Increases in regional cerebral blood flow have been described in a variety of cerebral pathologic states, including stroke and seizure disorders. The usefulness of technetium-99m-labeled cysteinate dimer as a marker in the measurement of regional cerebral blood flow was tested in five cynomolgus monkeys. To expand the range of blood flow to beyond the normal limits, 40 mg/kg i.v. of the carbonic anhydrase inhibitor acetazolamide was administered. Regional cerebral blood flow in all five monkeys was measured using radiolabeled microspheres (before and after acetazolamide) and the marker (after acetazolamide) in 60-70 samples from 12 brain regions. Acetazolamide significantly increased the mean +/- SEM regional cerebral blood flow measured using microspheres from 0.56 +/- 0.21 to 1.71 +/- 0.9 ml/min/g (p less than 0.01 for each region). A significant positive correlation was found between regional cerebral blood flow values calculated using microspheres and the marker after normalizing the values to those in the cerebellum (r = 0.773, p less than 0.0001). The mean +/- SEM regional cerebral blood flow determined using the marker in a single monkey (1.21 +/- 0.04 ml/min/g) did not differ significantly from that determined in the same monkey using microspheres (1.13 +/- 0.04 ml/min/g). These data support the potential use of this new brain perfusion imaging agent to assess regional cerebral blood flow over a clinically relevant range of blood flows.
Effect of hemodilution on regional cerebral blood flow during chronic hyperglycemia in rats.
Authors: Duckrow R B
Published: June 2011

Regional cerebral blood flow decreases during chronic hyperglycemia, a condition frequently associated with elevated hematocrit. To test the hypothesis that an elevated hematocrit is responsible for the reduced regional cerebral blood flow during chronic hyperglycemia, I used isovolemic hemodilution to normalize the hematocrit in seven normoglycemic and seven streptozotocin-treated (hyperglycemic) rats. Regional cerebral blood flow was measured in 28 awake, restrained rats (14 normoglycemic and 14 hyperglycemic) using [14C]iodoantipyrine and dissection of 17 brain regions. Hemodilution lowered the hematocrit by 6 units (13%) and increased the average cerebral blood flow by 14%. Chronic hyperglycemia did not elevate the hematocrit, but it decreased the average cerebral blood flow by 12% and that in nine nontelencephalic brain regions by 17%. This effect was independent of changes in hematocrit caused by hemodilution. The reduced regional cerebral blood flow during chronic hyperglycemia is not caused by elevated hematocrit.
Hematologic disorders and ischemic stroke. A selective review.
Authors: Hart R G , Kanter M C
Published: June 2011

More than a dozen primary hematologic disorders have been associated with ischemic stroke. Inherited deficiencies of antithrombin III, protein C, and protein S have been linked with stroke in case reports; optimal screening requires functional as well as antigenic assays. Antiphospholipid antibodies and lupus anticoagulants are the most frequently identified acquired states associated with ischemic stroke. Polycythemia vera, sickle cell anemia, sickle-C disease, and essential thrombocythemia are the major disorders of formed blood elements causing stroke. Special, step-wise screening for occult prothrombotic entities in stroke patients is recommended for young persons with stroke of uncertain cause, for those with prior venous thrombosis, for those with a family history of unusual thrombosis, and for those with no other explanation for recurrent stroke. Acquired, perhaps transient, abnormalities of platelets, coagulation inhibition, and fibrinolysis may contribute importantly to brain ischemia in synergy with other mechanisms, but at present these remain ill-defined. The contribution of prothrombotic diatheses to stroke is probably underrecognized and warrants further investigation.
Grading the amount of blood on computed tomograms after subarachnoid hemorrhage.
Authors: Hijdra A , Brouwers P J , Vermeulen M , van Gijn J
Published: June 2011

According to several studies, the amount of subarachnoid blood on the initial computed tomogram of patients with aneurysmal subarachnoid hemorrhage has predictive value with respect to infarction and outcome. Of several methods for assessing the amount of subarachnoid blood, none has been subjected to a study of interobserver agreement. We describe our own method, applied in previous studies, in which the amounts of blood in 10 basal cisterns and fissures and in four ventricles are graded separately. In grading single computed tomograms of 182 consecutive patients with subarachnoid hemorrhage, the agreement between pairs of three observers, studied with kappa statistics, was relatively good for individual cisterns or fissures (kappa between 0.35 and 0.65) and ventricles (kappa between 0.47 and 0.74). The Spearman rank correlation coefficients for the sum of the scores for subarachnoid and intraventricular blood were very high. Summed scores for extravasated blood are suitable as a baseline variable in follow-up studies of patients with subarachnoid hemorrhage.
Cortical activity, ionic homeostasis, and acidosis during rat brain repetitive ischemia.
Authors: Matsumoto T , Obrenovitch T P , Parkinson N A , Symon L
Published: June 2011

Recent data strongly suggest that repetitive ischemic episodes have an adverse cumulative effect on development of edema and tissue damage. We wanted to assess further whether special risks such as exacerbation of extracellular acidification reflecting progressive exhaustion of the capacity to buffer H+ in the extracellular space are associated with repeated short ischemic insults. We monitored spontaneous electrical activity, extracellular direct-current potential, extracellular H+ activity, and tissue PCO2 in the cerebral cortex of rats subjected to four cycles of 3-minute ischemia produced by four-vessel occlusion with 27-minute reperfusion after each insult. Except for electrical activity, which failed to recover fully from the first ischemic insult, all parameters returned to a level close to normal after each reperfusion. Changes during ischemia did not evolve with repetition of the insult. Electrical silence occurred within approximately 20 seconds after the onset of each ischemic episode and always preceded the steep drop of direct-current potential, indicating ischemic depolarization. Each four-vessel occlusion immediately initiated a steep rise of tissue PCO2 and extracellular H+ activity, with extracellular H+ activity reaching a maximum within approximately 145 seconds. Changes in extracellular H+ activity during each recirculation period consistently included an additional and short-lasting increase associated with repolarization, a rapid decrease closely related to that of tissue PCO2, and a slow progressive return to normal. These results suggest that short, repetitive ischemic episodes severe enough to produce cell membrane depolarization and maximum acidosis of the neuronal microenvironment do not have a deleterious cumulative effect on the studied parameters, in particular, on interstitial acidosis.
Seasonal variation in stroke incidence in Hisayama, Japan.
Authors: Shinkawa A , Ueda K , Hasuo Y , Kiyohara Y , Fujishima M
Published: June 2011

We investigated seasonal variation in the incidence of cerebral stroke among the general population aged greater than or equal to 40 years in November of 1961 in Hisayama, Japan. During the 24-year follow-up period, 311 cases of cerebrovascular diseases occurred. The date or month of onset was determined in 308 cases, of which 51 were classified as intracerebral hemorrhage, 223 as cerebral infarction, and 27 as subarachnoid hemorrhage. We observed a significant seasonality in the incidence of all stroke (p less than 0.01), of intracerebral hemorrhage (p less than 0.05), and of cerebral infarction (p less than 0.01), whereas subarachnoid hemorrhage had no significant seasonal pattern. Subjects less than 64 years of age showed a significant seasonal variation in the incidence of both intracerebral hemorrhage (p less than 0.05) and cerebral infarction (p less than 0.01). A significant seasonal pattern for the incidence of intracerebral hemorrhage was also noted among persons with hypertension (p less than 0.05) or a high serum cholesterol level (p less than 0.05), whereas such a pattern for cerebral infarction was documented among normotensive persons (p less than 0.05) and those with a low serum cholesterol level (p less than 0.01). In addition, the incidences of intracerebral hemorrhage and cerebral infarction were negatively correlated with mean ambient temperature (p less than 0.01 and p less than 0.05, respectively), and all stroke and intracerebral hemorrhage in men were significantly related to intradiurnal temperature change (p less than 0.05 and p less than 0.01, respectively). The significance of the seasonal occurrence of stroke is discussed in relation to relevant risk factors.
The principle of parsimony: Glasgow Coma Scale score predicts mortality as well as the APACHE II score for stroke patients.
Authors: Weingarten S , Bolus R , Riedinger M S , Maldonado L , Stein S , Ellrodt A G
Published: June 2011

Although the development and use of severity-of-illness measures has gained widespread enthusiasm, uncertainty remains as to the optimal measure for stroke patients. The Health Care Financing Administration recently derived a severity-of-illness measure based on the APACHE II system to explain differences in Medicare mortality rates among hospitals treating stroke patients. We hypothesized that the Glasgow Coma Scale score provides prognostic information of accuracy comparable to that of the APACHE II score for stroke patients, yet is simpler and cheaper to abstract from the medical record. We therefore studied 246 patients hospitalized with stroke, including 49 oversampled mortalities. The Glasgow Coma Scale score was as accurate as the APACHE II score in predicting stroke mortality both before (r = -0.50 and r = 0.50, respectively) and after (r = -0.40 and r = 0.38, respectively) the oversampled mortalities were excluded. The APACHE II score required abstraction of 16 variables from the medical record compared with three for the Glasgow Coma Scale score and required more than three times the time to abstract from the medical record. Therefore, in the interest of parsimonious data collection, the Glasgow Coma Scale may be a preferable severity-of-illness measure for patients with stroke.
Ipsilateral leg weakness associated with carotid stenosis.
Authors: Chimowitz M I , Lafranchise E F , Furlan A J , Awad I A
Published: June 2011

Ipsilateral motor or sensory symptoms associated with carotid occlusive diseases are rare. We report a 52-year-old man who presented with aphasia, right hemiparesis, mild left leg weakness, and bilateral Babinski's signs. During the previous 10 days, he had experienced three episodes of left leg numbness and incoordination that occurred either alone or in association with right arm and leg weakness. Computed tomography showed infarcts in the right frontoparietal (parasagittal), left frontal, and left parietal lobes. Cerebral angiography revealed 60% stenosis of the right internal carotid artery, 80% stenosis of the left internal carotid artery, absence of the A1 segment of the right anterior cerebral artery, filling of the right anterior cerebral artery from the left carotid circulation only, and a normal vertebrobasilar system. This report illustrates that leg weakness may occur ipsilateral to carotid disease if the contralateral anterior cerebral artery is supplied by the ipsilateral carotid artery.
The functional nature of cerebellar diaschisis.
Authors: Di Piero V , Chollet F , Dolan R J , Thomas D J , Frackowiak R
Published: June 2011

We report a patient who presented with transient clumsiness of his right hand due to a small hemorrhage in the left globus pallidus. Ten days later, positron emission tomography performed at rest showed decreased oxygen metabolism and blood flow at the site of the anatomic lesion and in remote areas such as the ipsilateral frontotemporoparietal cortex and the contralateral cerebellar hemisphere. Cerebellar hypometabolism has been ascribed to functional disconnection of the contralateral hemisphere from the cerebral cortex and has been termed crossed cerebellar diaschisis. One month later, positron emission tomography performed during unilateral motor activation (finger opposition) showed increased blood flow in the sensorimotor and supplementary motor areas contralateral to the hand engaged in the motor task. An at-rest study at this time showed resolution of the crossed cerebellar diaschisis observed acutely, but cerebellar asymmetry was demonstrated during performance of the motor task with the normal as well as with the previously paretic hand. Our activation study demonstrated cerebellar asymmetry in the chronic phase during a motor task, even though resting cerebellar blood flow was symmetrical. This observation reveals the dynamic, functional nature of crossed cerebellar diaschisis and may partially explain the lack of any clinical counterpart in functional studies of the cerebellum performed with the patient at rest.
Death and functional outcome after spontaneous intracerebral hemorrhage. A prospective study of 166 cases using multivariate analysis.
Authors: Daverat P , Castel J P , Dartigues J F , Orgogozo J M
Published: June 2011

Using death and functional status as end points, we prospectively analyzed the outcome 6 months after spontaneous intracerebral hemorrhage in 166 patients admitted to an acute-care stroke unit on the first day of their stroke. Seventy-one patients (43%) died, 69 (42%) had a satisfactory outcome, and 26 (16%) had a poor functional outcome. Early (30-day) survival was correlated with morphologic parameters on the initial computed tomogram (hemorrhage size, midline shift, and intraventricular spread of the hemorrhage), while later (6-month) survival was correlated with age. Using logistic regression, we found five independent predictors of satisfactory outcome at 6 months: age, hemorrhage size, intraventricular spread of the hemorrhage, limb paresis, and communication disorders. Of these, age was the most important predictor by far.
Effects of prostaglandin F2 alpha and thromboxane A2 analogue on bovine cerebral arterial tone and calcium fluxes.
Authors: Wendling W W , Harakal C
Published: June 2011

We determined sources of activator calcium for prostanoid-induced cerebrovascular constriction by measuring isometric tension and calcium-45 (45Ca) fluxes in bovine middle cerebral arteries. Constriction induced by prostaglandin F2 alpha or the stable thromboxane A2 analogue SQ-26,655 was near-maximally inhibited in calcium-deficient solutions but only partially inhibited by calcium antagonists (10(-5) M verapamil or 3.3 x 10(-7) M nifedipine). Studies of 45Ca binding at different external Ca2+ concentrations showed that cerebral arteries possess two calcium binding sites, a high-affinity site and a low-affinity site. Each prostanoid significantly increased low-affinity 45Ca uptake (external Ca2+ concentration = 1.2 mmol/l) during 5 minutes of 45Ca loading; for prostaglandin F2 alpha 45Ca uptake increased from 69 to 108 nmol/g and for SQ-26,655, from 78 to 141 nmol/g. The prostanoid-induced increases in low-affinity 45Ca uptake were completely abolished by pretreatment with verapamil or nifedipine. Prostaglandin F2 alpha, SQ-26,655, verapamil, and nifedipine had no effect on high-affinity 45Ca uptake (external Ca2+ concentration = 45 mumol/l) or 45Ca efflux (after 60 minutes' preincubation in calcium-deficient media). Prostaglandin F2 alpha and SQ-26,655 each appear to constrict cerebral arteries by two mechanisms: first, by promoting calcium uptake from low-affinity binding sites through receptor-operated channels sensitive to the calcium antagonists, and second, by releasing calcium from depletable internal stores.