Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Localized 1H magnetic resonance spectroscopy was performed in a 45-year-old woman with migraine. She developed throbbing headache attacks without aura since thirteen years ago and the attack was accompanied with right hemiplegia since seven years ago. Brain MRI showed no abnormalities and 123I-IMP SPECT revealed mild frontal dominant decrease of cerebral blood flow. It seemed that her condition was positioned between migraine with prolonged aura and migrainous infarction of complicated migraine in the classification of International Headache Society. Spectra obtained from bilateral frontal lobe interictally showed elevation of lactate at left side. Choline, creatine, and N-acetyl-aspartate were almost equal on both side. The above results suggest that slight ischemia which is not detected by MRI is present or there is a disturbance of oxidative glycolysis, which is induced by mitochondrial dysfunction.
 ...
PMID:[Elevation of cerebral lactate detected by localized 1H magnetic resonance spectroscopy in a patient with migraine]. 792 68

Exercise electrocardiography is still the primary method used in the non-invasive assessment of coronary artery disease. Stress echocardiography is now being increasingly used as a more sensitive adjunct technique to assess ischemia. Ischemia provoked by stress can induce reversible wall motion abnormalities which are disclosed by cross-sectional 2-dimensional echocardiography and standard projections. The types of stress used are physical exercise (bicycle, treadmill), atrial pacing or pharmacologic stimulation. In the latter, the catecholamine dobutamine has emerged as preferable to the vasodilators dipyridamole and adenosine. The diagnostic accuracy of dobutamine stress echocardiography is comparable to that of bicycle or treadmill exercise echocardiography, but dobutamine stress echocardiography is technically simpler and can be performed in patients unable to exercise. Its sensitivity in diagnosing ischemic or viable myocardium is comparable to that of nuclear methods, MRI or PET. In contrast to nuclear methods, stress echocardiography is however free of radiation. In the assessment of patients with coronary artery disease, stress echocardiography has been shown to be valuable for diagnosis, preoperative risk stratification and determination of prognosis. Furthermore, low dose dobutamine echocardiography can be used to detect viable myocardium. Despite these very promising aspects of the method, there are recognized disadvantages and limitations: stress echocardiography is very time-consuming and operator-dependent; its sensitivity correlates strongly with the number of studies performed; analysis of wall motion is performed qualitatively on a purely subjective level, and hence lacks the objectivity of a quantitative approach. These factors emphasize the need for intensive research to render stress echocardiographic analysis more objective. Automatic boundary detection of left ventricular endocardium, color-Doppler-based tissue imaging and three-dimensional reconstruction offer interesting perspectives in rendering the subjective more objective.
 ...
PMID:[Stress echocardiography: development and significance]. 793 13

We reported a patient with bilateral cerebellar peduncle infarcts who had an abrupt onset of bilateral hearing loss. A hypertensive 56-year-old man suddenly experienced bilateral hearing loss without other accompanying neurological deficits. He was hospitalized and treated for "idiopathic deafness". In addition, dysarthria and ataxic gait appeared two days later and he was transferred to our hospital. On neurological examination, the patient presented with diplopia, neurosensory hearing loss (approximately 70 dB) ataxic dysarthria, bilateral cerebellar ataxia and bilateral Babinski's signs. Auditory brain stem evoked response demonstrated prolonged delay of interpeak latency between waves III-IV. CT and MRI revealed fresh ischemic lesions symmetrically located at the middle cerebellar peduncles and cerebellar medullary body. Cerebral angiography showed total occlusion of the left vertebral artery and a stenotic right vertebral artery at the ostium of the posterior inferior cerebellar artery. We postulated that hearing impairment in this patient resulted from transient ischemia of the bilateral auditory tract in the brain stem or the peripheral cochlear system, but the definitive cause of the transient hearing loss remains undetermined. Concomitant appearance of a symmetrical infarction at the cerebellar peduncles is rare. We suggest that a circulation defect involving a multivascular system, which resulted in "border zone infarction" occurred at these regions.
 ...
PMID:[A case of bilateral cerebellar peduncle infarction with bilateral hearing impairment of a sudden onset]. 795 15

This article provides a brief summary of concepts describing the formation and resolution of traumatic brain edema. Recent laboratory and clinical data are reviewed targeted toward resolving the contribution of edema to the swelling process. These data, indicate that blood volume is reduced in areas of ischemia following traumatic injury and edema volume is increased. Thus, edema is the major contributor to the swelling process in diffuse injury. As clinical MRI studies have not revealed barrier compromise in the presence of swelling, it is considered that other forms of edema, primarily ischemic and neurotoxic, make a substantial contribution to the edema volume.
 ...
PMID:Traumatic brain edema: an overview. 797 7

The definition of blood-brain barrier (BBB) damage in cerebral ischemia using contrast-enhanced MRI has not been clearly correlated to the spread of edema or other histological measures of barrier disruption. In this study, we used a rabbit model of focal cerebral ischemia to compare GdDTPA-enhanced MRI with spin-echo images of brain injury and immunocytochemical detection of BBB damage and vasogenic edema. After 4 h of transient ischemia followed by 6 h of reperfusion, in vivo T2W and T1W images were obtained in a 1.5 T magnet using a 3-inch surface coil. After MRI, the animals were sacrificed and anti-serum protein (IgG) monoclonal antibodies were used to detect regions of increased BBB permeability to serum proteins. Ischemic neuronal damage was confirmed with cresyl-violet histology. T2W scans showed focal regions of increased signal intensity in the ischemic hemisphere (17.0 +/- 4.1%) that primarily involved the cortex and striatum. T1W scans showed corresponding regions of hypointensity but demonstrated, in general, smaller lesion sizes (10.1 +/- 2.9%). GdDTPA-enhanced images showed variable areas of BBB disruption that included regions of intense leakage as well as lesions that only showed subtle enhancement along the periphery of damaged tissue. It appeared that large and more severe lesions corresponded to peripheral enhancement whereas smaller lesions showed central parenchymal enhancement. The extent of MR contrast enhancement did not correlate well with immunocytochemical images of serum protein leakage. Anti-IgG stains demonstrated widespread regions of BBB damage corresponding with areas of damaged neurons that appeared pyknotic on cresyl-violet sections.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Blood-brain barrier disruption in experimental focal ischemia: comparison between in vivo MRI and immunocytochemistry. 800 69

The authors present a case of basilar artery migraine in a 33-year-old woman who was initially misdiagnosed as having a cerebrovascular or mental disorder and subjected to MRI and cerebral angiography, which, however, did not show any pathologic findings. During admission to the university hospital, she lost consciousness. An emergency Tc-99m HMPAO brain SPECT showed a significant decrease of regional cerebral blood flow in the right temporal and occipital cortices, and right cerebellar hemisphere, where regional cerebral blood flow was decreased by 10-24% as compared to the left side. The second brain SPECT during a symptom-free phase showed the reversion of regional cerebral blood flow to normal in these areas. Basilar artery migraine was diagnosed by the finding of reversible ischemia in the territory of the right basilar artery on brain SPECT images and the clinical picture.
 ...
PMID:Basilar artery migraine. Reversible ischemia demonstrated by Tc-99m HMPAO brain SPECT. 803 71

The reduction of the apparent diffusion coefficient (ADC) of water shortly after a focal ischemic insult is thought to reflect intracellular water accumulation (cytotoxic edema) related to high-energy metabolism failure and loss of ion homeostasis. We attempted to clarify whether varying ranges of ADC measurements in ischemic brain tissue can be used to differentiate between reversible and irreversible ischemic lesions before reperfusion in a temporary ischemia model. We induced 45 minutes of temporary ischemia in 12 rats using the middle cerebral artery suture occlusion method. Regional changes of ADC values were serially measured in seven regions of interest in each hemisphere and evaluated by delta ADC, defined as the difference between ADC value in an ischemic region and that in a contralateral homologous region. We acquired dynamic contrast-enhanced perfusion images 2 minutes before and after reperfusion to document reduced perfusion and its restoration. We confirmed the infarct area by 2,3,5-triphenyltetrazolium chloride staining 24 hours after occlusion and correlated this with the MRI studies. Recovery of initially reduced ADC values occurred only in ischemic regions where delta ADC values were not below -0.25 x 10(-5) cm2/sec. Although the extent of infarction at postmortem examination varied in regions with moderately decreased prereperfusion ADC values, more than 70% of regions of interest with slight declines of prereperfusion ADC values exhibited no infarction. ADC values progressively decreased after reperfusion in regions that initially had severely decreased prereperfusion ADC values, and postmortem examination always demonstrated infarction in such regions.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:MRI diffusion mapping of reversible and irreversible ischemic injury in focal brain ischemia. 805 54

We report 14 patients with so called spontaneous vertebral artery dissection. Dissection site was the atlanto-axial (V3) segment in 12 patients, the intertransverse (V2) in 5 and the intracranial (V4) in 3. Two had additional carotid artery dissection. Typical clinical presentation of symptoms consisted in unilateral, acute, severe neck and occipital head pain (12/14) simultaneously with, or followed by signs of vertebrobasilar ischemia (12/14). The later may be Wallenberg's syndrome (7/14), a cerebellar (5/14) or a vestibular syndrome. When this constellation is present in a young patient and preceded by a "trivial" head or neck trauma dissection should be suspected in cases without vascular risk factors. According to our results, MRI today is the method of choice to confirm diagnosis. Mural hematoma can be shown non invasively (12/13). Angiography is only rarely indicated. Doppler- and duplex sonography of posterior circulation is more difficult and results are less conclusive than with the carotid system. Nevertheless, we found abnormal results in 86% and definite pathologic results in 64% of our patients when combining both methods. Immediate anticoagulation appears to be an adequate treatment when intracranial dissection is excluded. Its effectiveness, however, has not been demonstrated. None of the 12 anticoagulated patients showed deterioration.
 ...
PMID:[Vertebral artery dissection. Clinical aspects, non-invasive diagnosis, therapy--observations in 14 patients]. 807 94

Two cases of vertebral artery injury following mild neck trauma are reported. A 52-year-old man was hospitalized with gait disturbance 7 days after mild traffic accident. Right vertebral angiogram revealed complete occlusion of the rt. vertebral artery (VA) and MR images revealed infarction in the rt. cerebellar hemisphere and rt. dorsolateral part of the medulla oblongata and revealed the thrombus in the rt. VA. He underwent anticoagulation and became asymptomatic. Angiogram 6 months later revealed the vessel to be normal. A 23-year-old man who has a habit of self-manipulation of his neck was hospitalized on the day when he experienced dysesthesia in the left part of his face and left upper and lower extremities and unsteady gait. MR images revealed multiple infarction in bilateral cerebellar hemispheres and thrombus in bilateral VAs. Bilateral vertebral angiogram revealed severe stenoses of bilateral VAs. He underwent anticoagulation and wore soft collar. Angiogram 20 days after onset revealed improvement of bilateral VA stenoses. He was discharged with no neurological deficit. It is said that vertebral artery injuries in association with head and neck trauma are relatively rare, but this condition is possible to be more common than realized, considering that the case of unilateral VA occlusion or the case with well developed collateral circulation is sometimes well tolerated for ischemia and that this condition can occur even after mild head and neck injury. The diagnosis must be established by vertebral angiogram, but MRI and MRA are very useful as ancillary methods. The therapeutic point is to prevent propagation of the thrombus and distal embolism, accordingly wearing a collar and anticoagulation are important.
 ...
PMID:[Vertebral artery injury following mild neck trauma: report of two cases]. 807 1

The regional distribution and temporal evolution of the diffusion coefficient (Dw) of water in rat brain was measured during and after transient middle cerebral artery (MCA) occlusion. Male Wistar rats (n = 14) were subjected to 2 h of middle cerebral artery occlusion, induced by intracarotid insertion of a filament. Diffusion (n = 14) and perfusion (n = 7) weighted magnetic resonance imaging were performed before, and at various time points after MCA occlusion, ranging from 30 min up to 7 days. Our data demonstrate that the temporal profiles of Dw differ between the severely and the least damaged regions of tissue. In the core of the lesion, where the tissue evolved to necrosis, Dw declined significantly (P < 0.001) within 0.5 h after onset of ischemia, and remained depressed until 24 h after withdrawal of the suture. However, no statistically significant decline in Dw was found in the perifocal regions containing morphologically intact cells. Perfusion MRI qualitatively exhibited a hypoperfusion and reperfusion during, and after 2 h MCA occlusion, respectively. A significant (r > or = 0.71, P < 0.01) correlation was found between delta Dw (the difference in Dw between the ipsilateral ischemic and homologous contralateral control regions) obtained immediately before withdrawal of the suture (2 h of ischemia) and at specific early time points after withdrawal of the suture, and the degree of ischemic cell damage. No significant (P > 0.01) correlation was detected at an early time points of ischemia or at other time points after withdrawal of the suture.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Temporal evolution and spatial distribution of the diffusion constant of water in rat brain after transient middle cerebral artery occlusion. 813 99


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>