TIA Group Research Articles

もやもや病の統計学的脳血流ＳＰＥＣＴ画像解析

To investigate pathophysiology of moyamoya disease, we analyzed brain single photon emission tomography (SPECT) images of patients with this disease by using interface software for a 3-dimensional (3D) data extraction format. Presenting symptoms were TIA in 21 patients and hemorrhage in 6 patients. All the patients underwent brain SPECT scan of 123I-IMP at rest and after acetazolamide challenge (17 mg/kg iv, 2-day method). Cerebral blood flow (CBF) was quantitatively measured using arterial blood sampling and an autoradiography model. The group of the patients who presented with TIAs showed decreased CBF in the frontal lobe at rest compared to that of patients with hemorrhage, but Z-score ((mean—patient data)/SD) did not reach statistical significance. Significant CBF decrease after acetazolamide challenge was observed in a wider cerebral cortical area in the TIA group than in the hemorrhagic group. The brain region of hemodynamic ischemia (stage II) correlated well with the responsible cortical area for clinical symptoms of TIA. A hemodynamic ischemia stage image clearly represented recovery of reserve capacity after bypass surgery. Statistical evaluation of SPECT may be useful to understand and clarify the pathophysiology of this disease.

Proteína C reactiva en la fase aguda del ictus

We aimed to assess the prognostic importance of C-reactive protein (CRP) in the acute phase of ischemic stroke in-patients.One hundred and seventeen patients within 48 h after index ischemic stroke were included. CRP levels and blood samples were obtained at this time, and a brain computerized tomography or magnetic resonance imaging were performed. Neurological and functional disability were evaluated and patients were divided according to the outcome into the following categories: transient ischemic attack, favorable stroke, and non-favorable stroke.32 in-patients were classified as transient ischemic attack, 31 as favourable stroke, and 54 as non-favorable stroke. There was a worsening in neurological (p < 0.0001) and functional (p < 0.005) disabilities from the TIA group to non-favorable stroke. The CRP mean, by category, was 1.7, 1.07 and 3.6 mg/dl, respectively (p < 0.0001).We found increased levels of CRP in the non-favorable stroke category, that was related with neurological and functional disabilities, and with radiological findings, mainly when levels were greater than 3.6 (0.49) mg/dl.

Asymmetric dimethylarginine (ADMA) as a risk marker for stroke and TIA in a Swedish population

Asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase, has been shown to be involved in the pathogenesis of atherosclerosis. The present study was initiated to investigate the role of ADMA as a risk marker of acute cerebrovascular disease (CVD). We examined 363 CVD patients and 48 controls. The ADMA concentration (mean ± S.D., μmol/L) in controls was 0.50 ± 0.06. Compared to controls, increased concentrations of ADMA were observed in cardio-embolic infarction (0.55 ± 0.08; p < 0.001; n = 71), and TIA (0.54 ± 0.05; p < 0.001; n = 31), but not in non-cardio-embolic infarction (0.51 ± 0.07; p = 0.56; n = 239) and haemorrhagic stroke (0.51 ± 0.11; p = 0.77; n = 22). In multivariate logistic regression models, CVD increased across quartiles of ADMA in all subgroups, but this association was only significant in the TIA group (odds ratio for highest versus lowest quartile 13.1; 95% CI: 2.9–58.6; p trend 0.001) A decreased arginine/ADMA ratio was significantly associated with CVD in the entire study population ( p < 0.01). Our results indicate that ADMA is a weak independent marker for acute stroke and a strong marker for TIA and that relative arginine deficiency, measured as the l-arginine/ADMA ratio, is present in acute CVD.

Retracted:Dynamics of cytochromecoxidase activity in acute ischemic stroke

We have investigated the dynamics of cytochrome c oxidase (COX) activity in the cerebrospinal fluid (CSF) and the erythrocyte haemolysate (EH) in 85 patients suffering from brain infarction (BI), reversible (RIA), or transient (TIA) ischemic attack from the perspective of mitochondrial affection in ischemia. In all patients, the COX activity was decreased in the CSF, especially within the first two days, indicating an acute inactivation or modification of mitochondrial proteins, probably mediated by free radicals. The gradual elevation of COX activity until the seventh day suggested that these changes may be reversible. The increase in the COX activity was established in the EH, with the highest values found in the BI, somewhat lower in the RIA, and the lowest in the TIA group, respectively. This could indicate a systemic compensatory response to an acute ischemia. Thus, COX activity in the CSF and EH in acute ischemia could be an indicator of brain metabolic dysfunction.

865 Hyperthomocysteinemia is associated with the presence of left atrial spontenous echo contrast and or thrombus in stroke patients with nonvalvular atrial fibrillation

72 ± 20%, p<0.001) were significantly different between both groups. There were thrombi/spontaneous echo in 9% vs. 0%, respectively, p=NS).In the stroke group we identified another potential embolic source in 3 patients and none in TIA group. Conclusions: In patients with stroke, the LAA systolic area is bigger and its fractional area shortening is smaller than in patients with TIA. This may represent a worse LAA function and greater predisposition for larger thrombi to develop.

Leukocyte activation detected by increased plasma levels of inflammatory mediators in patients with ischemic cerebrovascular diseases.

Leukocytes have been implicated in the development of ischemic atherosclerotic vascular diseases. In a prospective study we investigated whether the plasma concentrations of inflammatory mediators, ie, proteases and cytokines, as markers for systemic leukocyte activation, are increased in patients with acute ischemic cerebrovascular diseases. Using enzyme-linked immunosorbent assays, we measured the plasma levels of neutrophil gelatinase-associated lipocalin (NGAL), neutrophil proteinase 4 (NP4), tumor necrosis factor-alpha (TNF), and soluble TNF receptor protein-1 p55 (sTNFR-1) in 120 patients with acute ischemic cerebrovascular insult (72 with stroke and 48 with transient ischemic attack [TIA]) and in 35 age- and sex-matched healthy subjects. Compared with the control group, plasma NGAL levels were higher in the stroke group (P < .0001) and the TIA group (P < .01); plasma NP4 levels were higher in the stroke group (P < .0001) and the TIA group (P < .01); and plasma sTNFR-1 levels were higher in the stroke group (P < .04). There was significant correlation between the plasma levels of fibrinogen and those of both sTNFR-1 (r = .32; P = .005) and NGAL (r = .40; P = .0001) and between the erythrocyte sedimentation rate and the plasma levels of both sTNFR-1 (r = .35; P = .001) and NGAL (r = .34; P = .002). Our study demonstrated that markers for systemic leukocyte activation, ie, plasma levels of cytokines and proteases, were higher in patients with acute ischemic cerebrovascular disease than in healthy control subjects. Activated leukocytes and leukocytic mediators may have an important role in acute cerebrovascular ischemia and its consequences.

Response of thoracic interneurons to tactile stimulation in the cockroach, Periplaneta americana

Recent findings indicate that cockroaches escape in response to tactile stimulation as well as they do in response to the classic wind puff stimulus. The thoracic interneurons that receive inputs from ventral giant interneurons also respond to tactile stimulation and, therefore, represent a potential site of convergence between wind and tactile stimulation, as well as other sensory modalities. In this article, we characterize the tactile response of these interneurons, which are referred to as type-A thoracic interneurons (TIAs). In response to tactile stimulation of the body cuticle, TIAs typically respond with a short latency biphasic depolarization which often passes threshold for action potentials. The biphasic response is not typical of responses to wind stimulation nor of tactile stimulation of the antennae. It is also not seen in tactile responses of thoracic interneurons that are not part of the TIA group. The responses of individual TIAs to stimulation of various body locations were mapped. The left-right directional properties of TIAs are consistent with their responses to wind puffs from various different directions. Cells that respond equally well to wind from the left and right side also respond equally well to tactile stimuli on the left and right side of the animal's body. In contrast, cells that are biased to wind on one side are also biased to tactile stimulation on the same side. In general, tactile responses directed at body cuticle are phasic rather than tonic, occurring both when the tactile stimulator is depressed and released. The response reflects stimulus strength and follows repeated stimulation quite well. However, the first phase of the biphasic response is more robust during high-frequency stimulation than the second phase. TIAs also respond to antennal stimulation. However, here the response characteristics are complicated by the fact that movement of either antenna evokes descending activity in both left and right thoracic connectives. The data suggest that the TIAs make up a multimodal site of sensory convergence that is capable of generating an oriented escape turn in response to any one of several sensory cues.