RESUMO
PURPOSE: To evaluate stable xenon-enhanced CT cerebral blood flow with balloon test occlusion as a predictor of stroke risk in internal carotid artery sacrifice. METHODS: Abrupt internal carotid artery occlusion was performed by surgical or endovascular means below the origin of the ophthalmic artery in 31 normotensive patients who were assessed preoperatively by a 15-minute clinical balloon test occlusion followed by an internal carotid artery-occluded xenon CT cerebral blood flow study. RESULTS: One patient, who passed the clinical test occlusion but exhibited regions of cerebral blood flow less than 30 mL/100 g per minute on the occlusion xenon CT cerebral blood flow study went on to have a fatal stroke corresponding exactly to the region of reduced blood flow. Thirty patients passed both components of the preoperative stroke-risk assessment. Neuroimaging demonstrated possible flow-related infarctions, which subsequently developed in three patients. Two patients were asymptomatic, and one patient was left with a mild residual hemiparesis. CONCLUSIONS: Our protocol provided a statistically significant reduction in subsequent infarction rate and infarction-related death rate when compared with a control group of normotensive abrupt internal carotid artery occlusion patients who did not undergo any preoperative stroke-risk assessment (reported in the literature). The estimated false-negative rate for our preoperative assessment protocol ranged from 3.3% to 10% depending on the assessment of the cause of the three potentially flow-related infarctions. Although life-threatening major vascular territory infarctions have been avoided, our protocol is less sensitive to changes predicting smaller, often minimally symptomatic, vascular border zone infarctions and does not predict postoperative thromboembolic strokes.
Assuntos
Encéfalo/irrigação sanguínea , Doenças das Artérias Carótidas/diagnóstico por imagem , Artéria Carótida Interna/diagnóstico por imagem , Cateterismo , Seio Cavernoso/diagnóstico por imagem , Infarto Cerebral/diagnóstico por imagem , Meios de Contraste , Neoplasias de Cabeça e Pescoço/diagnóstico por imagem , Aneurisma Intracraniano/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Xenônio , Adolescente , Adulto , Idoso , Aneurisma Roto/diagnóstico por imagem , Aneurisma Roto/cirurgia , Velocidade do Fluxo Sanguíneo/fisiologia , Mapeamento Encefálico , Doenças das Artérias Carótidas/cirurgia , Artéria Carótida Interna/cirurgia , Seio Cavernoso/cirurgia , Infarto Cerebral/prevenção & controle , Dominância Cerebral/fisiologia , Feminino , Seguimentos , Neoplasias de Cabeça e Pescoço/cirurgia , Humanos , Aneurisma Intracraniano/cirurgia , Masculino , Pessoa de Meia-Idade , Exame Neurológico , Complicações Pós-Operatórias/diagnóstico por imagem , Fluxo Sanguíneo Regional/fisiologia , Estudos Retrospectivos , Fatores de RiscoRESUMO
The long-term roles of dietary sodium and potassium on the renal end-organ damage of hypertension were investigated in Wistar-Kyoto (WKY) and in spontaneously hypertensive (SHR) rats. Eight rats from each strain were maintained since 1 month of age on one of four dietary combinations of either low (0.4%) or high (6.0%) NaCl and low (0.51%) or high (7.6%) KCl providing sodium/potassium molar ratios of 1:1, 1:15, 15:1, and 15:15, respectively. Urinary sodium/potassium excretion ratios confirmed the proportion of salts consumed. Systolic blood pressures (SBP) were similar at 5 months of age and at the completion of the study at 9.5 months; SBP was significantly higher in SHR than in WKY rats and was not attenuated by dietary potassium supplementation of a magnitude that raised plasma potassium concentrations. Albumin excretion rate (AER) was also higher in SHR than in WKY rats (P less than 0.0001). In SHR, AER rose further with high sodium intake (P less than 0.035) but, contrary to SBP, was ameliorated by an equimolar addition of potassium (P less than 0.01). Morphologic lesions were generally absent in WKY rats and were more common in SHR as a group (P less than 0.001). In all four SHR groups, the graded histopathologic injury correlated well with measured AER but a major improvement in hypertensive renal lesions occurred largely in the KCl-supplemented, salt-loaded SHR group. These results show a disassociation between the effects of dietary monovalent cations on the level of SBP and their effect on renal injury. Sodium aggravates renal injury and potassium protects against this renal effect of sodium independent of SBP effect.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Hipertensão Renal/etiologia , Rim/lesões , Potássio/administração & dosagem , Albuminúria/etiologia , Animais , Pressão Sanguínea/efeitos dos fármacos , Hipertensão Renal/patologia , Hipertensão Renal/fisiopatologia , Rim/patologia , Rim/fisiopatologia , Masculino , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , Sódio na Dieta/administração & dosagemRESUMO
This longitudinal study describes the growth of syntactic abilities and vocabulary size in nine children with unilateral antepartum or perinatal brain injury. Five children with left hemisphere damage (LHD) and four with right hemisphere damage (RHD), ages 15 to 48 months, were evaluated on three or more occasions. Language samples generated from parent-child interaction were transcribed, coded, and analyzed using the Child Language Data Exchange System. Individual growth trajectories were constructed by graphing three dependent variables--MLU, scores on the Index of Productive Syntax (IPSYN), and number of different words--as a function of the child's age. One subject remained in a prelinguistic stage throughout the study. Simple linear functions best described the growth of MLU, IPSYN scores, and vocabulary in the other eight children. The slopes of the individual growth trajectories, the graphic representations of rates of progress, were comparable in the eight children. Seven children showed developmental delays in initial word use and five in the onset of multiword utterances. However, by age 24 months, four children with LHD and two children with RHD had syntactic capabilities comparable to those of children without brain injuries. The developmental patterns suggested that both cerebral hemispheres may play critical roles in the very earliest stages of language acquisition. Some unilateral lesions caused little discernible effect on language outcome in the toddler-preschool years after the initial developmental delays.
Assuntos
Dano Encefálico Crônico/congênito , Dominância Cerebral/fisiologia , Transtornos do Desenvolvimento da Linguagem/diagnóstico , Dano Encefálico Crônico/complicações , Pré-Escolar , Feminino , Humanos , Testes de Linguagem , Masculino , Exame Neurológico , Aprendizagem Verbal/fisiologia , VocabulárioRESUMO
The effect of administration of estradiol (E2) alone or combined with progesterone upon the circadian rhythm of oxytocin concentrations in cerebrospinal fluid (CSF) was examined in adult ovariectomized rhesus monkeys bearing temporary subarachnoid catheters and maintained in a constant photoperiod (lights on 06.00-18.00 h). Animals were subcutaneously implanted with silastic capsules containing 17 beta-E2 for 6 days and progesterone for the last 3 days of E2 administration. Hourly samples of CSF were collected before, during and after gonadal steroid administration and measured for oxytocin by RIA and reverse-phase high-performance liquid chromatography (RP-HPLC). A significant increase in the serum concentration of E2 and the plasma concentration of oxytocin neurophysin, but not the plasma concentration of oxytocin, was found during gonadal steroid administration. Each animal displayed a dirunal pattern of secretion of oxytocin in CSF with peak and trough levels during light and dark hours, respectively. No significant differences were found across experimental conditions in the following CSF oxytocin parameters: mean level of oxytocin in CSF during the light, dark, or light and dark hours combined; the daily phase or amplitude of the CSF oxytocin rhythm; the peak or nadir concentration of oxytocin in CSF; or the total amount of oxytocin secreted into the CSF as expressed as the area under the curve (multivariate repeated measures ANOVA). The CSF oxytocin parameters in the animals that were restudied using empty silastic implants were not significantly different across time (multivariate repeated measures ANOVA).(ABSTRACT TRUNCATED AT 250 WORDS)