摘要:

Background and PurposeThe value of carotid endarterectomy (CEA) depends on the safety of the operation. Transcranial Doppler ultrasound (TCD) was used to evaluate the possibilities of hypoperfusion, hyperperfusion, and embolization as causes of stroke and to evaluate the significance of Doppler microembolic signals (DMES).MethodsFive hundred CEAs were monitored with TCD of the ipsilateral middle cerebral artery during various phases of CEA to determine hemodynamic changes and incidence of DMES. Complications were graded according to their severity, and their probable cause was determined from TCD criteria and review of hospital charts.ResultsWe observed 24 cerebrovascular complications (4.8%), including 9 with transient ischemic attacks and 15 (3%) with permanent deficits. Among all cerebrovascular complications, embolism was judged to be responsible in 13 (54%; P<.02 compared with hypoperfusion), hyperperfusion in 7 (29%; P<.14 compared with hypoperfusion), and hypoperfusion in 4 (17%; P<.08 compared with embolism plus hyperperfusion). The surgeons responded to TCD information by several strategies depending on the TCD information. The incidence of permanent deficits diminished from 7% in the first 100 operations to 2% in the last 400 (P<or=to.01). Shunting was more strongly associated with cerebrovascular complications than nonshunting, but this difference was not significant (P=.24). Intraoperative prevalence of DMES was strongly associated with cerebrovascular complications (P=.02).Conclusions Embolism is the principal cause of cerebrovascular complications from CEA; hyperperfusion and hypoperfusion are also important causes. TCD provides information that allows prompt identification and treatment of these three major causes of stroke from this operation. The perioperative stroke rate can be reduced by appropriate measures, taken by the surgeons, based on findings of TCD monitoring. (Stroke. 1997;28:685-691.)

ISSN:0039-2499    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Background and PurposeTo improve reproducibility and reliability in the identification of embolic signals detected with the use of Doppler ultrasound, many studies have used an intensity threshold. However, variable thresholds between 3 and 12 dB have been used, and often the method of measurement of intensity is not stated. Potentially different methods of measurement could result in different intensity measurements for the same embolic signal. We determined the effect of these differences using commercial transcranial Doppler systems.MethodsWe analyzed 81 embolic signals recorded from the middle cerebral arteries of patients with carotid artery disease using three different methods of measuring intensity that had been previously used in research studies. In method 1 individual time frames of the frequency spectra were analyzed, in method 2 a color-coded intensity scale was used, and in method 3 automated software was used.ResultsThere was a highly significant correlation between measurements made by the different techniques (method 1 versus method 2: r=.68, P<.0001; method 1 versus method 3: r=.66, P<.0001; method 2 versus method 3: r=.70, P<.0001). However, the absolute values of intensity for the same embolic signals varied markedly for the different methods. For example, a 4-dB threshold according to method 1 was equivalent to an approximately 7-dB threshold measured by method 2. These differences had major effects on the proportion of embolic signals detected with the use of the same decibel threshold but with intensity measured in the different ways. For example, using a threshold of 7 dB would result in only 4.9% of signals being missed by method 2 but 42.2% and 51.4% being missed by methods 1 and 3, respectively.ConclusionsOur results demonstrate that the intensities of the same embolic signals, recorded with the same parameters, are markedly different when analyzed in the different ways used in previous studies. This has important implications when a decibel threshold is used and emphasizes that criteria developed by one investigator on one machine cannot be used by another investigator without initial reevaluation. This could account for some of the differences in frequencies of embolic signals reported in previous clinical studies. (Stroke. 1997;28:692-695.)

ISSN:0039-2499    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Background and PurposeEarly diagnosis of cerebral transverse sinus venous thrombosis (TSVT) is difficult because of nonspecific and variable clinical presentations. Therefore, we evaluated the diagnostic value of transcranial color-coded duplex sonography (TCCS) after administration of an echocontrast-enhancing agent (cTCCS) in clinically suspected TSVT.MethodsWe examined 14 patients (6 men, 8 women; mean age, 48 years; range, 18 to 70 years) with signs and symptoms suggestive of cerebral TSVT. Color-coded signals from the contralateral transverse sinus were displayed transtemporally before and after injections of an echocontrast agent by TCCS. Sonographic findings were correlated with MRI and MR venography (MRV).ResultsBefore echocontrast enhancement, TCCS displayed color Doppler signals in 7 of 28 transverse sinus. Echocontrast TCCS obtained sufficient color signals in 27 of 28 transverse sinus. Thus, diagnostic confidence was achieved in all but 1 patient. In 13 patients, cTCCS identified 3 cases with symmetrical blood flow in the transverse sinus, which was confirmed by MRV. Accordingly, asymmetry of venous blood flow was correctly assessed by cTCCS in the other 10 patients. In 6 of these 10 patients, cTCCS demonstrated residual color flow signals, which on MRI/MRV corresponded to partial TSVT (4 cases) and to hypoplasia (1 case) of the transverse sinus. One case of complete thrombotic occlusion of the transverse sinus was missed by cTCCS because of color Doppler signals originating from an adjacent dural fistula. Echocontrast TCCS diagnosis of occlusion of a transverse sinus was confirmed by MRI/MRV in all cases (aplasia of transverse sinus, n=1; complete TSVT, n=3). Systolic peak flow velocities were significantly decreased in hypoplastic or partially occluded transverse sinus (9.4 +/- 4.0 cm/s) and significantly increased contralaterally (28.4 +/- 6.5 cm/s) with respect to patients with symmetrical appearance of the transverse sinus (17.5 +/- 1.9 cm/s) (P<.05).ConclusionsTCCS examination of the cerebral venous system is difficult without contrast media application and almost useless for the study of TSVT. However, cTCCS is of practical value in the initial workup of patients with clinically suspected TSVT and may provide further insight for follow-up studies in view of monitoring the recanalization. (Stroke. 1997;28:696-700.)

ISSN:0039-2499    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Background and PurposeWe have previously reported that cerebral blood flow decreased and oxygen extraction fraction and cerebral blood volume increased in pediatric patients with moyamoya disease, whereas these values did not change significantly in adult patients. In this study, we measured the cerebrovascular response to hypercapnia using15O H2O positron emission tomography (PET) in each group of patients. These data were also compared with the oxygen extraction fraction and transit time (cerebral blood volume/cerebral blood flow) measured by15O PET.MethodsThe subjects consisted of 20 patients with moyamoya disease (7 pediatric and 13 adult patients). Cerebral blood flow was measured by the15O H2O bolus injection method at the resting state and during the inhalation of 5% CO sub 2. Cerebrovascular CO2response was estimated as the percentage change of cerebral blood flow per 1 mm Hg change of PaCO2. Oxygen extraction fraction and transit time were measured by the15O steady-state method.ResultsCerebrovascular response to hypercapnia severely decreased over the cerebral cortices in both pediatric and adult patients with moyamoya disease when compared with those of normal control subjects, and there was no significant difference between pediatric and adult patients. A significant correlation was observed between the CO2response and transit time, whereas no significant correlation was seen between the CO2response and oxygen extraction fraction.ConclusionsOur study revealed that the cerebral hemodynamic reserve capacity decreased to an equal degree in both pediatric and adult patients with moyamoya disease. This finding may thus help to explain the occurrence of transient ischemic attack in adult patients. (Stroke. 1997;28:701-707.)

ISSN:0039-2499    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Background and PurposeHigh levels of glutamate in plasma and cerebrospinal fluid (CSF) have been demonstrated in patients with acute ischemic stroke. The duration of this excitatory amino acid release has not been studied, and therefore the window of opportunity of treatment with glutamate antagonists is unknown. The aim of this investigation was to study the duration of the glutamate increase in patients with stable and progressing ischemic stroke.MethodsGlutamate in CSF was measured by high-performance liquid chromatography in 184 patients with an acute cerebral infarction of less than 24 hours' duration and in 43 control subjects.ResultsAmong the 120 patients with stable ischemic stroke, median glutamate levels were significantly lower-and within the reference range of control subjects-in those patients studied 6 to 24 hours from onset of symptoms than in patients studied in the first 6 hours (3 [range, 2 to 10] versus 5 micro mol/L [range, 2 to 17]; P<.0001). In 64 patients with progressing ischemic stroke, glutamate concentrations measured at any time interval during the first 24 hours from onset were significantly higher than in the stable stroke and control groups.ConclusionsThe presence of glutamate increase in the CSF cannot be documented for greater than 6 hours in stable ischemic stroke. The sustained elevation of glutamate observed in progressing stroke suggests that the window to prevent neurological deterioration may be wider. (Stroke. 1997;28:708-710.)

ISSN:0039-2499    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Background and PurposeIntubation and mechanical ventilation are sometimes necessary during treatment of acute stroke. Indications include neurological deterioration, pulmonary complications, and elective intubation for procedures and surgery. Prognosis in severe stroke patients requiring mechanical ventilation has often been reported to be poor. This study was performed to prospectively assess the prognosis of stroke patients who require ventilation in a neurological intensive care unit and to determine factors that may influence outcome.MethodsAnalysis was made of 124 consecutive stroke patients who required mechanical ventilation over a 2-year period. We determined the survival rate at 1 year after admission. Initial clinical data, history of previous diseases, and indication for intubation were analyzed for prognostic significance by univariate and multiple logistic regression analysis.ResultsThe 1-year survival rate was 33.1% (n=41). Sixty-five patients (52%) died in the neurological intensive care unit. Among 17 variables analyzed, seven were found to significantly influence 2-month fatality in the univariate analysis: age greater than 65 years, atrial fibrillation, bilateral absence of pupillary light reflex, bilateral absence of corneal reflex, bilateral Babinski's sign, infratentorial stroke, and Glasgow Coma Scale (GCS) score less than 10. Independent predictors of death at 2 months were age greater than 65 years (P=.03), GCS score less than 10 (P=.01), and intubation performed because of coma or acute respiratory failure (P=.04).ConclusionsOverall prognosis of ventilated patients with severe stroke is better than previously reported. Older patients comatose on admission who need to be intubated because of neurological or respiratory deterioration have the poorest prognosis. We conclude that intubation and mechanical ventilation of severe stroke patients should be performed in a timely manner, before irreversible damage occurs. (Stroke. 1997;28:711-715.)

ISSN:0039-2499    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Background and PurposeThe identification of stroke patients who are prone to falls is essential to the development of prevention strategies. This study aimed at developing an easily administered fall risk index for patients in stroke rehabilitation.MethodsA consecutive series of 135 patients in geriatric stroke rehabilitation was studied. Patient characteristics viewed as potential fall predictor variables were assessed at admission. Univariate and multiple Cox regression analyses of these variables were used in the development of a fall prediction index.ResultsThe final index included the following items: male sex, poor performance of activities of daily living, urinary incontinence, impaired postural stability, bilateral motor impairment, presence of bilateral cortical or white matter lesions, visuospatial hemineglect, and use of diuretics, antidepressants, or sedatives. The index score correlated significantly with the fall risk (odds ratio, 1.46; 95% confidence interval, 1.26 to 1.69). The score was also used to classify individuals into low-, intermediate-, and high-risk groups, among which the fall rates differed significantly (log rank statistics, 29.86; P<.001).ConclusionsAn easily administered fall risk index is suggested, which might serve as a basis for prevention strategies among patients in stroke rehabilitation. (Stroke. 1997;28:716-721.)

ISSN:0039-2499    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Background and PurposeAfter stroke, the ability to balance in sitting is critical to independence. Although impairments in sitting balance are common, little is known about the effectiveness of rehabilitation strategies designed to improve it. The purpose of this randomized placebo-controlled study was to evaluate the effect of a 2-week task-related training program aimed at increasing distance reached and the contribution of the affected lower leg to support and balance.MethodsTwenty subjects at least 1 year after stroke were randomized into an experimental or control group. The experimental group participated in a standardized training program involving practice of reaching beyond arm's length. The control group received sham training involving completion of cognitive-manipulative tasks within arm's length. Performance of reaching in sitting was measured before and after training using electromyography, videotaping, and two force plates. Variables tested were movement time, distance reached, vertical ground reaction forces through the feet, and muscle activity. Subjects were also tested on sit-to-stand, walking, and cognitive tasks. Nineteen subjects completed the study.ResultsAfter training, experimental subjects were able to reach faster and further, increase load through the affected foot, and increase activation of affected leg muscles compared with the control group (P<.01). The experimental group also improved in sit-to-stand. The control group did not improve in reaching or sit-to-stand. Neither group improved in walking.ConclusionsThis study provides strong evidence of the efficacy of task-related motor training in improving the ability to balance during seated reaching activities after stroke. (Stroke. 1997;28:722-728.)

ISSN:0039-2499    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Background and PurposeThis study compared stroke features and poststroke disability in two age groups of patients with ischemic stroke: younger (55 to 70 years) and older (71 to 85 years). Stroke has an impact on daily living in many areas, but whether risk factors, stroke features, and poststroke disability differ between young and old patients with stroke is not so well established.MethodsA cohort of 486 ischemic stroke patients aged 55 to 85 years admitted consecutively to the Helsinki University Central Hospital (Finland) between December 1, 1993, and March 31, 1995, were examined 3 months after the index stroke. Structured medical, neurological, and radiological (MRI or CT) examinations, mental status, and emotional examination and interview of a close informant were done. Prestroke and poststroke activities of daily living were assessed with five scales: the Index of ADL, Instrumental Activities of Daily Living Scale, Functional Activities Questionnaire, Blessed Functional Activities Scale, and Barthel Index.ResultsHistory of cardiac failure (P<.001), atrial fibrillation (P<.001), and cardioembolic stroke (P=.011) was more frequent in the older age group, whereas stroke due to large-artery atherosclerosis (P=.048) was more common in the younger age group. The older patients more often had major dominant stroke syndrome (P=.018).Comparison of activities of daily living before and after stroke showed that the older age group deteriorated significantly more than the younger age group after adjustment for sex, education, and living conditions (Barthel Index, P=.005; other scales, P<.0001).ConclusionsThe stroke patients in young and old age groups had different risk profiles and stroke features. The older stroke patients were more dependent and disabled beforehand, and after stroke they were relatively even more dependent than the patients in the younger age group. Because older patients already constitute the majority of stroke victims, the importance of early active diagnosis, treatment, rehabilitation, and guidance is stressed. (Stroke. 1997;28:729-735.)

ISSN:0039-2499    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Background and PurposeIt has been demonstrated that bone mass was significantly reduced on the hemiplegic side of stroke patients, which might increase their risk of hip fracture. We evaluated the efficacy of 1 alpha-hydroxyvitamin D3[1 alpha (OH)D3] and supplemental elemental calcium in maintaining bone mass and decreasing the incidence of hip fractures after hemiplegic stroke.MethodsIn a randomized study, 64 patients with hemiplegia after stroke with a mean duration of illness of 4.8 years received either 1 micro g 1 alpha (OH)D3daily (treatment group, n=30) or an inactive placebo (placebo group, n=34) for 6 months and were observed for this duration. Both groups received 300 mg of elemental calcium daily. The bone mineral density (BMD) and metacarpal index (MCI) in the second metacarpals were determined by computed x-ray densitometry. The incidence of hip fractures in these patients was recorded.ResultsBMD on the hemiplegic side decreased by 2.4% in the treatment group and 8.9% in the placebo group (P=.0021), while BMD on the intact side increased by 3.5% and decreased by 6.3% in the treated and placebo groups, respectively (P=.0177). In the treatment group, the difference in BMD between hemiplegic and nonhemiplegic sides decreased significantly compared with that before randomization. This difference increased in the placebo group. We observed a similar improvement in MCI in the treatment group but not in the placebo group. Four patients in the placebo group suffered a hip fracture compared with none in the treatment group (P=.0362).ConclusionsTreatment with 1 alpha (OH)D3and supplemental elemental calcium can reduce the risk of hip fractures and can prevent further decreases in BMD and MCI on the hemiplegic side of patients with a long-standing stroke. Treatment also may improve these indices on the intact side. (Stroke. 1997;28:736-739.)

ISSN:0039-2499    

出版商:OVID    

年代:1997

数据来源: OVID