bluuebunny/crossref_metadata_2025_split huggingface dataset:
Magnetic resonance angiography of cervicocranial dissection.
Authors: Nguyen Bui L , Brant-Zawadzki M , Verghese P , Gillan G 
Published: June 2011

A retrospective study of five patients with the clinical or magnetic resonance-based diagnosis of carotid dissection was done. Clinical data, imaging studies, treatment, and outcome were reviewed. The potential applicability of three-dimensional time-of-flight magnetic resonance angiography in these settings was evaluated.
This modality reliably showed vascular abnormalities and focal, segmental, or aneurysmal dilatation when correlated with conventional angiograms in three patients. Turbulence and magnetic susceptibility at the acute turn of the carotid in the petrous canal led to a false-positive diagnosis on magnetic resonance angiography in one patient (in whom subtle fibromuscular hyperplasia was found with conventional angiography but missed with magnetic resonance angiography).
When combined with appropriate clinical signs, magnetic resonance imaging and magnetic resonance angiography can reliably establish the diagnosis of carotid dissection. Pitfalls of magnetic resonance angiography are discussed.
Different linkage of depression to hypercortisolism early versus late after stroke. A 3-year longitudinal study.
Authors: Aström M , Olsson T , Asplund K 
Published: June 2011

Using the dexamethasone suppression test, we studied the suppressibility of the cortisol axis and its clinical determinants at various time points after stroke. A major aim was to examine the dexamethasone test as a diagnostic tool for the diagnosis of major depression in stroke patients.
The dexamethasone suppression test, major depression, functional ability, and disorientation were assessed in a cohort of 70 patients with acute stroke and after 3 months (n = 63) and 3 years (n = 43).
Early after stroke, 24% of the patients were nonsuppressors, with about the same proportion at 3 months (22%) and 3 years (21%). None of the controls (17 healthy elderly volunteers) were nonsuppressors. High cortisol levels early after stroke were significantly associated with functional impairment (r = 0.35; p = 0.003) and disorientation (r = 0.27; p = 0.03). Three years after stroke, high postdexamethasone cortisol levels were significantly associated with major depression (r = 0.57; p < 0.001). The sensitivity of the dexamethasone test was 70% and the specificity 97%. In a longitudinal analysis of the long-term survivors (n = 42), postdexamethasone cortisol values at 3 months predicted major depression at 3 years.
Hypercortisolism is associated with major depression late (3 years) but not early (0-3 months) after stroke. Patients with hypercortisolism 3 months after stroke are at risk of major depression later in the course and warrant careful follow-up from a psychiatric viewpoint.
Impact of social support on outcome in first stroke.
Authors: Glass T A , Matchar D B , Belyea M , Feussner J R 
Published: June 2011

The purpose of this study is to examine the impact of social support on outcome after first stroke in a prospective cohort study. Although modest evidence exists for the importance of several psychosocial factors, studies have failed to use widely recognized measures of outcome and social support, have failed to control for time since onset, and have not used longitudinal techniques.
Forty-six surviving patients were followed for 6 months after stroke. Recovery was measured using repeated measures of functional status as indicated by the Barthel Index of activities of daily living. Perceived social support was measured at 1, 3, and 6 months after onset. Repeated-measures multivariate analysis of variance was used to analyze changes in functional status.
Significant differences were found across levels of social support in trajectories of functional status (p = 0.002). A significant three-way interaction between stroke severity, social support, and outcome was also found (p = 0.012). Patients with more severe stroke and the largest amount of social support attained an average Barthel Index that was 68 points (65%) higher than the group reporting the least support.
High levels of social support were associated with faster and more extensive recovery of functional status after stroke. Social support may be an important prognostic factor in recovery from stroke. Socially isolated patients may be at particular risk for poor outcome.
Hypoperfusion and vasoreactivity in the thalamus and cerebellum after stroke.
Authors: Sakashita Y , Matsuda H , Kakuda K , Takamori M 
Published: June 2011

Cerebellar hypoperfusion in the contralateral hemisphere after stroke is well studied and termed crossed cerebellar diaschisis. However, studies of hypoperfusion in the ipsilateral thalamus have been few. The purpose of this study was to investigate the prevalence of hypoperfusion and vasoreactivity to acetazolamide in the thalamus and cerebellum after stroke.
We studied cerebral blood perfusion in the thalamus and cerebellum of 14 patients with unilateral cerebral infarction using [123I]isopropyliodoamphetamine single-photon emission computed tomography (123I-IMP SPECT). We also administered acetazolamide-stressed 123I-IMP SPECT to determine vasodilator capacity in these two areas. Regions of interest were drawn over the bilateral thalami and bilateral cerebellar cortices, and asymmetry indexes were obtained.
We found ipsilateral thalamic hypoperfusion in 12 (85.7%) and contralateral cerebellar hypoperfusion in 11 (78.6%) of 14 patients. Hypoperfusion was improved (p < 0.01 by the Wilcoxon signed rank test) in 11 (91.7%) of the 12 patients with ipsilateral thalamic hypoperfusion and in seven (63.6%) of the 11 patients with contralateral cerebellar hypoperfusion.
Hypoperfusion in the ipsilateral thalamus and contralateral cerebellum is common, and vasoreactivity to acetazolamide is preserved in both the thalamus and the cerebellum with hypoperfusion.
Platelet aggregation in patients with atrial fibrillation taking aspirin or warfarin.
Authors: Helgason C M , Hoff J A , Kondos G T , Brace L D 
Published: June 2011

Although warfarin and perhaps aspirin may be effective in preventing thromboembolism in patients with nonvalvular atrial fibrillation, some patients develop cerebral infarction despite these therapies. The purpose of this study was to determine inhibition of platelet aggregation in patients on aspirin and platelet reactivity in those on warfarin in the Stroke Prevention in Atrial Fibrillation study.
Twenty-four patients in the Stroke Prevention in Atrial Fibrillation study at the University of Illinois at Chicago, 17 on enteric-coated aspirin 325 mg/d and 7 on warfarin to produce an International Normalized Ratio of 2.0 to 4.5, had platelet aggregation studies performed during a 10-month period and interpreted by an investigator blinded to therapy. Epinephrine, adenosine diphosphate, collagen, and arachidonic acid were used as aggregating agents. Compliance was determined by pill count for those patients on aspirin.
Seven patients taking aspirin had partial and 10 had complete inhibition of platelet aggregation. Three of seven patients on warfarin had hyperaggregable platelets. Compliance was 80% or greater for those patients taking aspirin. One patient on warfarin had partial inhibition of platelet aggregation.
Some patients in the Stroke Prevention in Atrial Fibrillation trial on aspirin 325 mg/d did not achieve complete inhibition of platelet aggregation. Others had hyperaggregable platelets. These findings suggest platelet-dependent mechanisms for aspirin and warfarin failure to prevent stroke in these patients.
Risk factors of stroke incidence and mortality. A 12-year follow-up of the Oslo Study.
Authors: Håheim L L , Holme I , Hjermann I , Leren P 
Published: June 2011

The objective of this study was to determine the risk factors of stroke incidence and mortality.
Our data are based on a prospective cohort study of men aged 40 to 49 years after 12 years of follow-up.
In age-adjusted Cox proportional-hazards regression analysis of 14,403 healthy men, diastolic blood pressure was a stronger predictor for stroke incidence and mortality than systolic blood pressure. Smoking was a stronger predictor of mortality than of incidence. However, there was no dose-response relation among smokers by increased cigarette consumption. Total serum cholesterol was a significant (P < .05) risk factor for stroke mortality and of borderline significance (P = .08) for stroke incidence. Increased physical activity at leisure was associated with reduced stroke incidence but not mortality. The myocardial infarction risk score comprising systolic blood pressure, total serum cholesterol, and daily cigarette smoking was a strong predictor of mortality and incidence. Body mass index, triglycerides, blood glucose, and physical activity at work were not found to be risk factors for stroke.
Reduction of blood pressure, cessation of smoking, lowered cholesterol, and increased physical activity at leisure are individual measures to reduce the risk of stroke.
Altered cerebral hemodynamics and metabolism in Takayasu's arteritis with neurological deficits.
Authors: Takano K , Sadoshima S , Ibayashi S , Ichiya Y , Fujishima M 
Published: June 2011

Takayasu's arteritis is a nonspecific arteritis involving major cerebral arteries. The aim of our study is to examine cerebral hemodynamics and metabolism in Takayasu's arteritis with neurologic symptoms.
We measured cerebral blood flow and metabolism using positron emission tomography in seven patients (14 to 59 years of age) with Takayasu's arteritis who developed transient ischemic attacks (2 patients), ischemic stroke (4) or putaminal hemorrhage with multiple brain infarction (1).
All patients had severe stenosis or occlusion of one or more major cerebral arteries. There were no significant differences in the values of cerebral blood flow, oxygen extraction fraction, and cerebral blood volume in the infarcted and noninfarcted hemisphere. By contrast, the value of cerebral metabolic rate for oxygen in the infarcted hemisphere was markedly reduced (1.87 mL/100 mL per minute, P < .01) compared with controls. Mean transit time in the infarcted hemisphere was significantly greater than in the noninfarcted one, both in patients and controls (P < .01 and P < .05, respectively).
Collateral blood flow to the hemisphere without brain damage may be relatively well developed in Takayasu's arteritis, although hemodynamic reserve as well as oxygen metabolism were impaired in the infarcted hemisphere with ischemic lesions.
Paraplegia following thoracic aortic cross-clamping in dogs. No difference in neurological outcome with a barbiturate versus isoflurane.
Authors: Mutch W A , Graham M R , Halliday W C , Teskey J M , Thomson I R 
Published: June 2011

We compared the incidence and severity of paraplegia following thoracic aortic cross-clamping in dogs for two anesthetic regimens. Animals were randomly assigned to receive methohexital (group M; n = 9) or isoflurane (group I; n = 9). We expected a better neurological outcome in animals administered methohexital because of superior neuronal protection and greater spinal cord perfusion pressure (mean arterial pressure below the cross-clamp site minus mean cerebrospinal fluid pressure).
After surgical preparation and a 30-minute stabilization period, dogs in group M received 14 +/- 6 mg.kg-1 i.v. methohexital to induce an isoelectric electroencephalogram followed by a continuous infusion of methohexital at 20 mg.kg-1 x h-1. Dogs in group I received 1.4 +/- 0.2% end-tidal isoflurane (1 minimum alveolar concentration). The thoracic aorta was then occluded 2.5 cm distal to the left subclavian artery for 30 minutes and then released. Hemodynamics and cerebrospinal fluid pressure were measured at (1) baseline, (2) 2 minutes after aortic cross-clamping, (3) 20 minutes after aortic cross-clamping, (4) 5 minutes after aortic unclamping, and (5) 30 minutes after resuscitation. At 24 hours a neurological assessment was performed. After the clinical assessment the dogs were killed and the spinal cord removed immediately for histopathologic study.
There were no differences in nasopharyngeal temperature, PaCO2, pH, or hemoglobin at any time between groups. With cross-clamping, the spinal cord perfusion pressure decreased precipitously. However, there was no difference in spinal cord perfusion pressure between groups at any time (P = .5555). The neurological outcome, assessed at 24 hours after thoracic aortic cross-clamping by a veterinarian unaware of the anesthetic protocol, was not different between groups (P > .5, two-tailed Mann-Whitney rank-sums test). When anesthetized with methohexital 5 of 9 dogs were paraplegic; with isoflurane 7 of 9 dogs were paraplegic. By Spearman's rank test, a strong inverse correlation between the Tarlov score and the ratio of dead to total lumbar anterior spinal cord neurons was seen (Spearman's correlation coefficient = -.8358; P = .0001).
We conclude that no advantage was offered by the choice of anesthesia to neurological outcome after 30 minutes of thoracic aortic cross-clamping in this canine model.
Apathy following cerebrovascular lesions.
Authors: Starkstein S E , Fedoroff J P , Price T R , Leiguarda R , Robinson R G 
Published: June 2011

Although apathy has been reported to constitute a frequent sequela of stroke lesions, there have been no prospective studies on the frequency and correlates of apathy after stroke lesions. In the present study, we examined the frequency and correlates of apathy in a consecutive series of 80 patients with cerebrovascular lesions.
We included patients within the first 10 days after a stroke lesion. Patients were examined with a comprehensive neuropsychiatric battery that included the Apathy Scale.
Eighteen patients (22.5%) showed apathy, nine of whom were also depressed. On the other hand, 18 patients (22.5%) showed depression in the absence of apathy. Although depression and apathy may exist independent of one another, major depression (but not minor depression) was associated with an increased frequency of apathy. Apathy was also significantly associated with older age, cognitive impairments, and deficits in activities of daily living. Finally, apathy was significantly associated with lesions in the posterior limb of the internal capsule.
These findings demonstrate that apathy is a frequent finding among patients with acute stroke lesions and may coexist with important emotional and cognitive poststroke disturbances.
The impact of cardiac index on cerebral hemodynamics.
Authors: Saha M , Muppala M R , Castaldo J E , Gee W , Reed J F , Morris D L 
Published: June 2011

Current noninvasive testing allows accurate assessment of cerebrovascular hemodynamics. The cardiovascular influence on the noninvasive assessment of cerebrovascular studies has not been defined. This study was designed to determine the effect of cardiac index (CI) on cerebral blood flow velocities, ocular pulse amplitude, ophthalmic systolic pressure, and ocular blood flow (OBF) as currently estimated by noninvasive laboratories.
Based on a retrospective study of 181 patients, we prospectively evaluated 45 patients undergoing right heart catheterization for hemodynamic monitoring to correlate the relation between CI, transcranial Doppler sonography, and ocular pneumoplethysmography. Patients with hemodynamic instability, severe carotid stenoses, massive cerebral infarct, or sepsis were ineligible for the study. Simultaneous recordings of systemic blood pressure, ophthalmic systolic pressure, heart rate, ocular pulse amplitude, middle cerebral artery blood flow velocities, and cardiac output were obtained on all patients. OBF was calculated from the heart rate and ocular pulse amplitude.
The relation between OBF and CI is expressed by the equation CI = 2.36 + 0.61 x OBF (r = .47, P = .0010). The middle cerebral artery peak systolic velocities and CI had a correlation of .36 (P = .0181). The equation, derived from the linear relation between OBF and CI, was then validated on a sample of 15 patients. With the apparent linear relation between OBF and CI, we used the derived equation to predict CI from OBF. The OBF determination predicted CI within 30% in all patients and within 20% in 53.3% of the patients.
We demonstrated that OBF and middle cerebral artery systolic velocity decrease with diminishing CI. Our findings suggest that CI may be potentially estimated in selected patients by noninvasive assessment of OBF using ocular pneumoplethysmography.
Cerebral hypoperfusion in stroke prognosis and brain recovery.
Authors: Davis S M , Chua M G , Lichtenstein M , Rossiter S C , Binns D , Hopper J L 
Published: June 2011

The value of acute cerebral blood flow measurements in stroke prognosis is controversial. No previous study has determined whether acute perfusion deficits independently add to a validated clinical prognostic score. We aimed to compare the value of acute hypoperfusion deficits with a quantitative clinical score in stroke prognosis and to correlate the changes in perfusion with brain recovery.
Volumetric analysis of regional hypoperfusion was performed in 38 patients with middle cerebral infarction within 72 hours of onset by use of single photon emission computed tomography and 99mTc hexamethylpropylene amine oxime. Stroke severity was assessed by the Canadian Neurological Score and Barthel Index. Allen's prognostic score was determined acutely in all patients. Clinical outcome was evaluated in 36 of 38 patients, of whom 18 had repeat blood flow studies.
Acute hypoperfusion correlated with both the outcome Barthel Index (P < .001, r = -.61) and Canadian Neurological Score (P < .001, r = -.64). Allen's score correlated better with both the outcome Barthel Index (P < .001, r = .80) and Canadian Neurological Score (P < .001, r = .81). Acute hypoperfusion deficits, after allowing for Allen's score, independently predicted neurological but not functional outcome. Despite overall neurological improvement, mean hypoperfusion increased on the repeat blood flow studies (P < .05).
Volumetric analysis of acute regional hypoperfusion within 72 hours of onset predicts stroke outcome after 3 months, but Allen's score is a better prognostic method. Neurological recovery is not associated with chronic infarct reperfusion.
Neuroprotection by excitatory amino acid antagonist augments the benefit of thrombolysis in embolic stroke in rats.
Authors: Sereghy T , Overgaard K , Boysen G 
Published: June 2011

The effects of delayed thrombolysis with alteplase and neuroprotection with an excitatory amino acid receptor antagonist and their combination were tested in an embolic stroke model.
In 61 rats the carotid artery territory was embolized with arterial-like fibrin-rich clots. Hemispheric cerebral blood flow before and after embolization was measured by intra-arterial 133Xe injection method. The animals were assigned to one of the following treatments: (1) vehicle-treated controls (n = 15); (2) dizocilpine 1 mg/kg i.v. 5 minutes after embolization (n = 16); (3) alteplase 20 mg/kg as an intravenous continuous infusion starting 2 hours after embolization (n = 16); and (4) both agents (n = 14). Carotid angiography displayed the site of occlusion of the cerebral arterial tree immediately after and 3 hours after embolization, and the clinical neurological score was assessed after the rats recovered from anesthesia and before the rats were killed. Brains were fixed after 2 days and evaluated neuropathologically; infarct volume affecting cortical and deep brain structures was measured separately.
Both alteplase and dizocilpine reduced the total infarct volume (P = .05 and P = .04, respectively, Mann-Whitney tests). Dizocilpine reduced the incidence of cortical infarctions by 48% (P < .001, Fisher's test). Only the combined treatment significantly reduced deep brain infarctions (P = .03, Mann-Whitney test). The combined treatment also improved the clinical score by 83% compared with controls, by 75% compared with the group treated by dizocilpine alone, and by 50% compared with the group treated by alteplase alone. Sixty-seven percent of thrombolytic-treated animals recanalized completely compared with 39% of those given no thrombolytics (P = .05, Fisher's test). The clinical outcome correlated with infarct size (P < .01, Spearman test).
Our results document comparable efficacy of delayed thrombolysis and excitatory amino acid receptor antagonism in this model and suggest that combination of these two therapeutic approaches may yield additional benefit in treatment of thromboembolic stroke, particularly in cases where deep brain (end-artery-supplied) structures are affected.
Hemiplegia due to posterior cerebral artery occlusion.
Authors: North K , Kan A , de Silva M , Ouvrier R 
Published: June 2011

Hemiplegia is a rare manifestation of posterior cerebral artery occlusion. The acute clinical picture may be difficult to differentiate from occlusion of the middle cerebral artery. A mechanism for the hemiplegia has not been conclusively determined.
We describe a patient with hemiplegia secondary to posterior cerebral artery occlusion by an embolized fragment of a prosthetic valve. Computed tomographic scan showed the foreign body just distal to the origin of the posterior cerebral artery with infarction of its vascular territory. These findings were later confirmed at autopsy. There was no radiological or autopsy evidence of involvement of the other cerebral arteries or their territories.
The patient provides further evidence that occlusion of the posterior cerebral artery just distal to its junction with the posterior communicating artery may produce contralateral hemiplegia without oculomotor nerve nucleus involvement.
Upper limb somatosensory evoked potentials as a predictor of rehabilitation progress in dominant hemisphere stroke patients.
Authors: Keren O , Ring H , Solzi P , Pratt H , Groswasser Z 
Published: June 2011

The aim of this study was to determine the predictive yield of upper limb short latency somatosensory evoked potential (USEP) in patients with first stroke in the dominant hemisphere.
Nineteen patients (average age, 58 years) were evaluated twice: on arrival at the rehabilitation center, approximately 3 weeks after the stroke, and again approximately 10 weeks later. The clinical assessment included a quantitative evaluation of motor ability, independence in activities of daily living, and communication ability. USEP was recorded during the week of the initial clinical evaluation. Special attention was paid to the relations between USEP parameters and the dynamics of the clinical condition.
The seven patients in whom no cortical potential could be detected showed the worst outcomes; however, the existence of cortical potentials in the remaining 12 patients did not provide a precise prediction of their "rehabilitative capacity" (ie, the extent of their progress). A correlation was established between the amplitude of the potentials recorded over both hemispheres and changes in communication ability. Additional findings included an association between shortened central conduction time over the damaged hemisphere during the first month after stroke and improvement in motor ability.
USEP can serve as an adjuvant tool for predicting the recovery progress of stroke patients.