首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 28 毫秒
1.
We developed and characterized a model of global forebrain ischaemia in rats, permitting control of CBF at any desired ischaemic level with minimum surgery and without anticoagulation. Both common carotid arteries are occluded temporarily and systemic arterial pressure is lowered by pooling venous blood by lower body negative pressure with a cheap suction device. By measuring rCBF continuously (laser-Doppler-flowmetry) and regulating systemic arterial pressure, the model was used to automatically control cortical rCBF at predetermined ischaemic levels at 50, 30, 15, and 5% of normal rCBF (n = 5). When both common carotid arteries were occluded and systemic arterial pressure was lowered to 55 mmHg with hypobaric hypotension (n = 5), cortical CBF always fell to less than 5% of normal rCBF (n = 5). Prompt recirculation was achieved after reopening of the carotid arteries and return to normobaric body pressure. Hypobaric hypotension with bilateral common carotid occlusion requires only carotid surgery and measurement of systemic arterial pressure; it produces global forebrain ischaemia without anticoagulation as a true step function type insult. If rCBF is measured continuously, the model can be used to control ischaemic CBF to predetermined values.  相似文献   

2.
Little is known about how ischemia affects hemodynamic responses to neural activation in the brain. We compare the effects of a motor activation task and a cerebral vasodilating agent, acetazolamide (ACZ), on regional cerebral blood flow (rCBF) in primary sensorimotor cortex (PSM) in six patients with major cerebral artery steno-occlusive lesions without paresis of the upper extremities. Quantitative rCBF was measured in all patients using H2(15)O autoradiographic method and positron emission tomography. The CBF was determined at rest, during a bimanual motor activation task, and 10 minutes after ACZ administration. With bimanual motor activation, rCBF increased significantly in both PSM compared with at rest (P < 0.01 on lesion side, and P < 0.02 on contralateral side). However, rCBF did not increase after ACZ injection in the PSM on the lesion side, whereas rCBF increased significantly in the contralateral PSM after ACZ injection compared with the level at rest. This result suggests that despite a decreased hemodynamic reserve, there is a nearly normal flow response to neural activation, indicating that the mechanism of vasodilation responsible for perfusion change is different for acetazolamide and neural activation. The relations among neural activation, hemodynamic status, and cerebral metabolism in the ischemic stroke patients are discussed.  相似文献   

3.
Effects of N-methyl-D-aspartate (NMDA) and potassium on 5-day-old rat's brain were examined. We measured extracellular striatal monoamines such as dopamine (DA), 3,4 dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), and 5-hydroxyindole-3-acetic acid (5-HIAA) using intracerebral microdialysis. After 3 h stabilization, pups received varying concentrations of NMDA (1-3 mM) and potassium (200-800 mM) by intrastriatal perfusion for 32 minutes. Increasing the concentration of NMDA and potassium induced a dose related DA increase (p < 0.001), whereas DOPAC, HVA, and 5-HIAA decreased significantly. Five days later the same animals were sacrificed and the weight reduction of their cerebral hemispheres was measured. The weight of the drug perfused side was significantly reduced compared with that of the contralateral one. We examined next the relationship between the level of maximum DA and the relative hemisphere weight reduction. The DA peak was highly correlated with the hemisphere weight reduction (r = 0.70, n = 52, p < 0.001 in the NMDA group, r = 0.83, n = 30, p < 0.001 in the potassium group, respectively). These data show that each treatment alter striatal monoamine metabolism in immature rat brain and that the extracellular DA peak is a potential early indicator to estimate brain injury.  相似文献   

4.
To understand the relationship of caudate, thalamic, and anterior cingulate perfusion to pain states, we investigated familial restless legs syndrome in a father and daughter during the state of pain induced by immobility using semiquantitative regional cerebral blood flow (rCBF) brain single photon emission computed tomography (SPECT). The father underwent 4 brain SPECT scans using the rCBF tracer 99mTc-HMPAO several weeks apart, at different pain levels and after treatment with L-dopa. Caudate, thalamic, and anterior cingulate rCBF indices were measured. The caudate nuclei showed a 13% reduction in rCBF with increasing pain. The thalami and anterior cingulate showed a 7 and 6.6% increase in rCBF, respectively, with increasing pain. Compared to normal controls at rest, there was a decrease in caudate rCBF by 13% and an increase in thalamic rCBF by 3%. Linear regression for the caudate nuclei revealed a significant reduction in rCBF (p < 0.05), as pain increased. The daughter underwent an identical rCBF brain SPECT scan procedure at a high pain level induced by immobilization. Her scan showed a 12% reduction in caudate rCBF and a 1.2% increase in the anterior cingulate rCBF compared to healthy controls. The study supports the association between pain and decreased regional cerebral blood flow to the caudate nucleus as reported in fibromyalgia syndrome. There is increase in anterior cingulate rCBF with increasing pain. Our findings also corroborate that there is increased thalamic rCBF with pain stimulation.  相似文献   

5.
M Soehle  A Heimann  O Kempski 《Canadian Metallurgical Quarterly》1998,29(6):1240-6; discussion 1246-7
BACKGROUND AND PURPOSE: The lipid peroxidation inhibitor U-101033E was examined for effects on cerebral blood flow (CBF), cortical tissue hemoglobin oxygen saturation (HbSo2), and neuronal damage. METHODS: Fifteen minutes of global cerebral ischemia was induced by two-vessel occlusion and hypobaric hypotension. Wistar rats (n = 25) were randomized to receive vehicle (n = 9) or 40 mg/kg U-101033E (n = 9) intraperitoneally during 2 hours of reperfusion. A sham group (n = 7) had neither ischemia nor therapy. Histology was evaluated 7 days after ischemia. RESULTS: During late hyperperfusion (at 17 minutes), vehicle-treated animals had a higher (P = 0.044) cortical tissue HbSo2 (72.0 +/- 1.4%) than did U-101033E-treated animals (65.8 +/- 2.5%). Neuronal counts in the superficial cortex layer found after 7 days correlated negatively with rCBF (r = -0.76; P < 0.001) or cortical tissue HbSo2 (r = -0.56; P = 0.028) assessed during the late hyperperfusion phase. U-101033E reduced neuronal damage in hippocampal CA1 from 64.3 +/- 9.2% to 31.2 +/- 8.4% (P = 0.020), as well as in the superficial cortical layer from 53.5 +/- 14.6% to 12.8 +/- 11.7% (P = 0.046). While animals in the vehicle group had reduced counts in all four examined cortex layers (P < 0.05 versus sham group), there was significant cortical neuron loss in the U-101033E group in only one of four areas. U-101033E had no effect on resting CBF or CO2 reactivity. CONCLUSIONS: Postischemic application of U-101033E protects hippocampal CA1 and cortical neurons after 15 minutes of global cerebral ischemia. The results indicate that free radical-induced lipid peroxidation contributes to reperfusion injury, a process that can be inhibited by antioxidants such as U-101033E.  相似文献   

6.
A useful correlation between maximum thyroid uptake and radioiodine urine levels at different times after exposure was developed in order to determine when the intervention with an adequate blocking agent might still be effective. In an animal model (dog), six different doses were administered in the range of 100-600 kBq. The best correlation was found between the 125I uptake after 48 h (T-48) and urine radioactivity 4-6 h (U-4, U-5, U-6) after exposure. For the case of U-4, the equation Y(T-48) = 0.790 X(U-4) + 2.973 (r = 0.974 with a level of significance of p < 0.001) was obtained. An analogous study, carried out in humans (n = 20) to whom 1311 was administered, showed a similar correlation and level of significance: Y(T-24) = 1.162 X(U-4)+3.263 (r = 0.926; p < 0.001). The validity of this correlation was confirmed in four volunteers who received small doses of 125I(25-100 kBq), with good agreement between measured and extrapolated thyroid uptake and a mean difference of less than 10% (CV = 16.2%). Three different blocking agents were then tested in the same dog: potassium iodide, potassium perchlorate, and a thionamide (Tapazole). The blocking action of the first two compounds was about 90%, as opposed to only 48% for the third compound. Potassium iodide was chosen for its limited side effects and more universal utilization. The final study, carried out with four different doses, indicated that 25 mg of KI is the ideal amount to be administered to the dog. This corresponds to approximately 100 mg for a 70 kg human being (i.e., 1.4 mg kg(-1)). This dose, when administered to a volunteer 4 h after exposure, provided a thyroid blocking of 68%.  相似文献   

7.
The role of changes in preload in maintaining stable hemodynamics during coronary obstruction was assessed in the presence of myocardial ischemia due to occlusions of the left anterior descending (LAD) and left circumflex (LCX) coronary arteries. Changes in preload (mean left atrial pressure) to maintain a constant stroke volume after coronary occlusion were examined in 18 anesthetized dogs (LAD occlusion in 9 dogs, LCX occlusion in 9 dogs). The level of ischemia was assessed sonomicrometrically. Ventricular function curves relating left atrial pressure to stroke volume were assessed during a control state and after 1 min of coronary occlusion. The extent of preload reserve after coronary occlusion was examined on the ventricular function curves and was defined as the change in mean left atrial pressure required to maintain stroke volume at the level of the control state under conditions of regional ischemia. Ischemic size was determined by a stereo-angiogram after the animals were sacrificed. The extent of preload reserve (X) was linearly related to the ischemic size (Y) in both LAD (Y = 0.90 + 0.16X, r = 0.76, p < 0.001) and LCX (Y = -1.79 + 0.19X, r = 0.79, p < 0.001) occlusions. The slopes of the regression lines in LAD and LCX occlusions were the same. The X intercepts of these lines were -5.6% and 9.4% of the left ventricular weight in LAD and LCX ischemia (p < 0.001), respectively. Thus, the presence of systolic wall motion abnormalities due to coronary occlusion can be compensated for hemodynamically by changes in the preload reserve.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

8.
PURPOSE: Our goal was to elucidate the temporal profile of cerebral circulation and its relationship to prognosis in patients with diffuse brain injury by using single-photon emission CT (SPECT) and 123I-iodoamphetamine (IMP). METHODS: A total of 67 assessments were made in 26 patients with diffuse brain injury (Glasgow Coma Scale score < or = 8). The microsphere method was used for quantifying cerebral blood flow (CBF). The hemispheric CBF was defined as a mean regional CBF (rCBF), and the total cerebral hemispheric CBF (tCBF) as a mean of the bilateral hemispheric CBF. The relationship between patient outcome and tCBF was investigated. RESULTS: The rCBF in patients with diffuse brain injury showed dynamic and global changes with little regional differences. The tCBF values increased in 1 to 3 days, and they were higher in the poor-outcome group than in the good-outcome group. During the period of 14 to 42 days, the tCBF values stayed within normal range in the good-outcome group, whereas they were below normal range in the poor-outcome group. CONCLUSION: Our results revealed a good correlation between patient outcome and CBF values. Quantitative and sequential CBF studies with IMP SPECT are promising for helping to determine the prognosis for patients with diffuse brain injury.  相似文献   

9.
OBJECTIVE: To determine cerebral blood flow (CBF) and metabolism in the acute phase after severe head injury by a new dynamic SPECT device using 133Xenon and to evaluate a possible role of CBF and metabolism in the determination of prognosis. DESIGN: Prospective study. SETTING: General intensive care unit in a universitary teaching hospital. SUBJECTS: 23 severely head injured patients having CT scan and CBF determination, intracranial pressure (ICP) and jugular bulb oxygen saturation monitoring in the first 48 hours. MEASUREMENTS AND MAIN RESULTS: CBF varied from 18.0 to 60.0 ml/100 g/min. No correlation was found between early CBF and severity of trauma evaluated with the Glasgow Coma Score (GCS) (F = 2.151, p = 0.142) and between CBF and prognosis at 6 months evaluated with Glasgow outcome score (GOS) (F = 0.491, p = 0.622: rs = 0.251, p = 0.246). CMRO2 was depressed in relation to the severity of injury, specifically ranging from 0.9 +/- 0.5 ml/100 g/min in patients with GCS 3 to 1.7 +/- 0.8 ml/100 g/min in patients with GCS 6-7. In no patient with CMRO2 less than 0.8 ml/100 g/min was a good outcome observed. A significant correlation was found between GCS and GOS (rs = 0.699, p = 0.0002), between CMRO2 and GOS (F = 4.303, p = 0.031; rs = 0.525, p = 0.013) and between AJDO2 and GOS (F = 3.602, p = 0.046; rs = 0.491, p = 0.017). Fronto-occipital ratio (F/O) of CBF distribution was significantly lower than normal values (chi 2 = 18.658, p = 0.001) but did not correlate either with prognosis (chi 2 = 1.626, p = 0.443) or with severity (chi 2 = 1.913, p = 0.384). CONCLUSIONS: CBF in the first 48 hours after trauma varies within a large range of values and is not correlated with severity and prognosis. Clinical evaluation with GCS and CMRO2 are much more reliable indicators of severity of head trauma and have a significant role in the determination of prognosis. F/O ration is significantly altered from normal values confirming "post-traumatic hypofrontalism" but does not correlate with severity and prognosis.  相似文献   

10.
OBJECTIVE: To examine the circadian variation in the signal averaged electrocardiogram (saECG) and heart rate variability and investigate their relations in healthy subjects. METHODS: 24 hour ECGs were obtained with a three channel recorder using bipolar X, Y, and Z leads in 20 healthy subjects. The following variables were determined hourly: heart rate, filtered QRS (f-QRS) duration, low and high frequency components of heart rate variability (LF and HF), and the LF/HF ratio. RESULTS: Heart rate, f-QRS duration, HF, and the LF/HF ratio showed significant circadian rhythms, as determined by the single cosinor method. Heart rate and the LF/HF ratio increased during daytime, and f-QRS duration and HF increased at night. f-QRS duration was negatively correlated with heart rate (r = 0.95, p < 0.001) and the LF/HF ratio (r = 0.94, p < 0.001) and positively with HF (r = 0.93, p < 0.001). CONCLUSIONS: f-QRS duration has a significant circadian rhythm in healthy subjects and is closely related to the circadian rhythm of autonomic tone.  相似文献   

11.
OBJECTIVE: Decreased cerebral blood flow (CBF) and cerebral ischemia occurring immediately after subarachnoid hemorrhage (SAH) may be caused by acute microvascular constriction. However, CBF can also be influenced by changes in intracranial pressure (ICP) and cerebral perfusion pressure (CPP). The goal of these experiments was to assess the significance of acute vasoconstriction after SAH and its relationship to changes in CBF, ICP, CPP, and extracellular glutamate concentrations. METHODS: Three experiments were performed using the endovascular filament technique to produce SAH. In the first experiment, CBF, ICP, and CPP were measured for 60 minutes after SAH (n = 21) and were correlated with the 24-hour mortality rate. In the second experiment, rats undergoing SAH (n = 23) or a sham procedure (n = 7) were perfused 60 minutes after SAH for measurement of the circumference and wall thickness of the internal carotid and anterior cerebral arteries and correlation with CBF, ICP, and CPP. In the third experiment (n = 11), extracellular glutamate concentrations determined by hippocampal and cortical microdialysis and high performance liquid chromatography were correlated with physiological changes. RESULTS: CBF reductions to less than 40% of baseline for 60 minutes after SAH predicted 24-hour mortality with 100% accuracy and were used to define "lethal" SAH. In contrast, ICP and CPP 60 minutes after SAH were not correlated with the mortality rate. The vascular circumference was significantly smaller in lethal than in sublethal SAH or sham-operated rats (P < 0.001). Vessel measurements were correlated with both CBF and hemorrhage size (P < 0.01). Extracellular glutamate concentration increased to 600% of baseline after lethal SAH in both hippocampus and cortex and was inversely correlated with CBF (r = 0.9, P < 0.001) but did not increase after sublethal SAH. CONCLUSION: Acute vasoconstriction after SAH occurs independently of changes in ICP and CPP and is associated with decreased CBF, larger hemorrhage size, persistent elevations of extracellular glutamate, and poor outcome. Acute vasoconstriction seems to contribute directly to ischemic brain injury after SAH. Further evaluations of pharmacological agents with the potential to reverse acute vasoconstriction may increase CBF and improve outcome.  相似文献   

12.
13.
We examined the relation between language dominance and regional cerebral blood flow (rCBF) during the intracarotid amobarbital procedure (IAP). A previous report limited to three patients suggested that dominant rather than nondominant hemisphere IAP may have a differential effect on rCBF. Behavioral assessment during the IAP also suggests that dominant hemisphere injection results in a differential effect on memory and affective symptoms rather than nondominant injection. Thirteen patients were assessed using single-photon emission CT (SPECT) brain imaging during both left and right IAP. The SPECTs were coregistered with the individual's MRI. Changes in rCBF during each IAP were compared with the patient's baseline SPECT. Nine patients had left hemisphere dominance, two were right dominant, and two had bilateral speech representation. In the left dominant subjects, left-hemisphere injection had a consistently greater effect on rCBF than right-hemisphere injection in the anterior (p < 0.005) and posterior (p < 0.01) temporal neocortex. There was also a trend for greater hypoperfusion in the frontal lobe of the left hemisphere. rCBF in the ipsilateral hippocampus was not significantly different after each injection (p > 0.05). In the two patients with right hemisphere speech, the reverse pattern was seen, with greater hypoperfusion after right (dominant) hemisphere injection. There was no consistent asymmetry in the two patients with bilateral speech. Dominant hemisphere IAP results in significantly greater hypoperfusion than does nondominant injection. These data provide a physiologic basis for behavioral differences noted after dominant versus nondominant IAP.  相似文献   

14.
Stroke patients were assessed by brain CT scan, accompanied by demographic and clinical factors to predict the development of dementia following an ischemic episode. Vascular dementia was defined by NINDS-AIREN criteria. From 50 demented and 50 non-demented stroke patients, we analyzed the location of lesion, counted the numbers of lacunae, and semiquantitatively assessed the size of infarction, severity of overall white matter lesions (WML), and degree of brain atrophy. Compared to the non-demented patients, the demented patients: 1) encountered more stroke episodes (p < 0.001); 2) had more lacunae at bilateral basal ganglion (p < 0.001) or thalamus (p < 0.01); and 3) tended to have lesions in left cortex (p < 0.001), particularly a large infarct at the parietal (p < 0.001) or temporal lobe (p < 0.001). Periventricular changes (p < 0.001), subcortical WML (p < 0.001), overall WML (p < 0.001), and brain atrophy (p < 0.05) were also more severe in the demented group. However, no difference existed in demographic factors between the two groups. We concluded that several factors were important in developing dementia following an ischemic stroke, and the order by logistic regression would be: the severity of overall WML, left parietal infarct, and numbers of thalamic lacunae.  相似文献   

15.
The dorsal hand vein compliance technique was used to study direct vascular effects of human neuropeptide Y in vivo. Human neuropeptide Y is an endogenous vasoconstrictor peptide that is costored with norepinephrine in sympathetic nerve endings and coreleased with the catecholamine under various physiologic and pathologic conditions. Compared with the alpha 1-adrenergic agonist phenylephrine (geometric mean dose-rate that produces the half-maximal response [ED50]: 1.05 nmol/min; maximum venoconstriction [Emax] +/- SEM, expressed as a percentage of baseline compliance: 91% +/- 3%), human neuropeptide Y was nine times more potent (geometric mean ED50: 0.122 nmol/min; p < 0.001) but markedly less efficacious (Emax: 58% +/- 4%; n = 12; p < 0.001). Venoconstrictor effects of human neuropeptide Y lasted several hours and were unchanged by simultaneous administration of alpha-adrenergic antagonists but were readily reversed by nitroglycerin or bradykinin. The high responsiveness of subcutaneous veins to human neuropeptide Y indicates that human neuropeptide Y may regulate venous compliance and filling of the venous subcutaneous capacitance bed in vivo.  相似文献   

16.
We developed a mouse model of embolic focal cerebral ischemia, in which a fibrin-rich clot was placed at the origin of the middle cerebral artery (MCA) in C57BL/6J mice (n = 31) and B6C3 mice (n = 10). An additional three non-embolized C57BL/6J mice were used as a control. Embolus induction, cerebral vascular perfusion deficit, and consequent ischemic cell damage were confirmed by histopathology, immunohistochemistry, laser confocal microscopy, and regional cerebral blood flow (rCBF) measurements. Reduction in rCBF and cerebral infarct were not detected in the control animals. An embolus was found in all C57BL/6J and B6C3 mice at 24 hours after injection of a clot. Regional CBF in the ipsilateral parietal cortex decreased to 23% (P < 0.05) and 17% (P < 0.05) of preembolization levels immediately and persisted for at least 1 hour in C57BL/6J mice (n = 6) and in B6C3 mice (n = 3), respectively. A significant decrease of rCBF was accompanied by a corresponding reduction of plasma perfusion in the ipsilateral MCA territory. Neurons exhibited marked reduction in microtubule-associated protein-2 immunostaining coincident with the area of perfusion deficit. The percent infarct volume was 30.3% +/- 13.4% for C57BL/6J mice (n = 17), and 38.3% +/- 15.3% for B6C3 mice (n = 7) at 24 hours after embolization. This model of embolic ischemia is relevant to thromboembolic stroke in humans and may be useful to investigate embolic cerebral ischemia in the genetically altered mouse and for evaluation of antiembolic therapies.  相似文献   

17.
Technetium-99m-1,1-ethyl cysteinate dimer (ECD) has been proposed as a "chemical microsphere" for SPECT measurement of regional cerebral blood flow (rCBF). However, its distribution has not yet been compared in humans to an established rCBF measure. Therefore, we compared the uptake and distribution of ECD with rCBF measured by 133Xe SPECT in subjects with mild to moderate flow abnormalities and in normal volunteers. Blood and urine chemistries and vital signs were unchanged from pre-ECD values up to seven days postinjection. Profile plots demonstrated pattern agreement between rCBF ratios (133Xe) and ECD count density ratios. A significant correlation of rCBF ratios to ECD count density ratios was observed (r = 0.77), with a slope of 0.64 and intercept of 0.36. To explore whether or not the relationship between rCBF and ECD was dependent on absolute flow, ECD region of interest data were expressed in units of ml/min/100 g by equating global CBF (133Xe) and ECD global count density. A closer correlation (r = 0.88) was found for these data than for the count ratio data. The slope was closer to one (m = 0.83) and the intercept was closer to zero (b = 8.2). Also, a significant correlation was observed between ECD-derived rCBF and 133Xe rCBF in the lesion area (r = 0.92) for patients with well-demarcated rCBF lesions. The slope (0.80) suggested a slight underestimation of lesion flow by ECD. Finally, ECD clearance from cortical gray matter ROIs derived from high-resolution scans from 1 to 4 hr postinjection was slow (2.4%/hr). In summary, ECD is a safe and effective marker of regional cerebral perfusion. The distribution of ECD is linearly related to rCBF measured by 133Xe SPECT, although our data suggest a mild underestimation of flow at the high end of the normal range.  相似文献   

18.
STUDY OBJECTIVE: To determine the prognostic significance of supraclavicular lymph node (SCLN) involvement in small cell lung cancer. MATERIALS AND METHODS: Patients (1,370) with small cell lung cancer were included in four consecutive clinical trials and classified as having either limited or extensive forms of disease using the Veterans Administration staging system. RESULTS: SCLN was present in 17% of patients (n = 234). Median survival was 258 days for patients with SCLN (n = 234) and 297 days for patients without SCLN (n = 1136) (p = 0.002). SCLN involvement was correlated with the presence of distant metastases at baseline (169 vs 65, p = < 0.001). Median survival was 375 days for patients with limited forms without SCLN (n = 529), 332 days for those with limited forms with SCLN (n = 65) (p = 0.12), 244 days for those with extensive forms without SCLN (n = 604), and 228 days for those with extensive forms with SCLN (n = 169) (p = 0.94). The 2-year survival rates were 17%, 12%, 2%, and 4%, respectively. Cox models confirmed that SCLN did not provide any significant additional prognostic information. CONCLUSION: SCLN is highly correlated with extensive forms explaining its overall prognostic value. In limited disease, SCLN is only a minor poor prognostic factor, not justifying any amendment to the staging system currently used.  相似文献   

19.
OBJECT: The goal of this study was to determine whether regional cerebral blood flow (rCBF) changes that were found contralaterally to a verified unilateral epileptic focus were associated with the spatiotemporal organization of epileptic abnormalities. METHODS: The CBF in both hippocampi was assessed using stable Xe-enhanced computerized tomography in a series of 19 patients with unilateral mesiotemporal epilepsy. Results were compared according to the distribution of interictal spiking and the spatiotemporal organization of the ictal discharges as determined by stereoelectroencephalography. Two groups were defined: in Group 1 (nine patients), the discharge remained unilateral; in Group 2 (10 patients), the discharge spread to contralateral mesiotemporal structures. For Group 1, the rates of ipsi- and contralateral hippocampal blood flow (HBF) were 32.88+/-15.53 and 45.88+/-17.19 ml/100 g/minute, respectively, whereas in Group 2 they were 36.7+/-11.54 and 36.4+/-11.27 ml/100 g/minute (mean+/-standard deviation). A two-way analysis of variance combining type of seizure (Group 1 compared with Group 2) and HBF (ipsi- compared with contralateral absolute values) demonstrated a main effect for HBF (F[1,17] = 5.051; p = 0.0382), a significant interaction between the two factors (F[1,17] = 6.188; p = 0.0235), and no main effect for type of seizure (F[1,17] = 0.258; p = 0.6178). CONCLUSIONS: In unilateral mesiotemporal epilepsy, asymmetrical interictal hippocampal perfusion was correlated with restricted unilateral ictal discharges, whereas bilateral hippocampal hypoperfusion was correlated with ictal discharges spreading to the contralateral mesiotemporal structures. The lack of correlation between the degree of hypoperfusion and the percentage of neuron cell loss indicated that the decrease in rCBF has both functional and lesional origins.  相似文献   

20.
To examine the nature of asthma in the elderly, we compared older (group 1: 65 years or older, n = 50) with younger patients (group 2: <40 years, n = 99) and to determine the influence of long-standing disease, elderly asthmatics with early onset (group A: onset before 40, n = 22) were compared with patients developing symptoms later in their lives (group B: onset after 40, n = 22). Blood eosinophilia and IgE value >/=100 IU/l were more frequent in younger patients. Short symptom-free periods were more frequent among older asthmatics (78.5 vs. 45.4%, p < 0.001). Only 31.2% of older patients had only mild symptoms. Requirement of systemic steroids was higher in the elderly population. The worst FEV1 was lower in older patients (54.4 +/- 17.3 vs. 71.8 +/- 18.5%, p 相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号