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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Ten patients with encephalitis disseminata and 10 patients with cerebral ischemia underwent computed tomography and magnetic resonance imaging examinations. The results before and after the application of contrast media were compared. It is shown that T1-weighted MRI images, even after application of gadolinium-DTPA, are of little value for differential diagnosis of these diseases. In contrast, T2-weighted images did support the diagnosis of an acute stage of encephalitis disseminata versus acute ischemia. This was also true for lesions that had not been adequately depicted by computed tomography.
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PMID:Balance of T1-weighted images before and after application of a paramagnetic substance (Gd-DTPA). 345 67

Recently, the brainstem pathways of bilateral late reflexes (R2) of electrically elicited blink reflex have been well established. An afferent delay or block of the late reflexes is closely related to a lesion of the lateral medullary portion. The chronological alteration of blink reflex (BR) was studied to compare with radiological abnormalities on MRI in a patient with lateral medullary infarction on the right side. A diagnosis of Wallenberg syndrome was made clinically and location of the lesion was identified in detail by MRI. The infarcted region which was well demonstrated as an increased intensity area on SE images obtained 52 days after the onset of symptoms was much smaller than that on SE as well as on IR image 21 days after the onset of symptoms. Therefore, it was concluded that more than half of the increased intensity area on the SE images obtained 21 days after the onset of symptoms recovered from the condition of being extremely damaged by ischemia on the right lateral medullary portion in this patient. On the other hand, in the initial BR 26 days after the onset of symptoms, the late reflexes (R2) were consistently absent bilaterally when the affected side (right) was stimulated and normal when the normal side (left) was stimulated. This type of BR abnormality is compatible with an afferent block of late reflexes (R2). The early reflex (R1) was normal on either side. Whereas in the second BR at 55 days after the onset of symptoms, the late reflexes turned to be normal in latency when the right side was stimulated.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Chronological changes in the blink reflex and MRI in a patient with lateral medullary infarction]. 377

As a pilot study, 31-P-spectra of the quadriceps femoris muscle (1.5T) and proton images of the right thigh (.5T) were performed in two cyclists (T) and two untrained (UT) subjects. During ischemia, while MRI did not show any change, phosphocreatine (PCr) concentration decreased and inorganic phosphate (Pi) increased. Recovery occurred within 3 minutes. Ergometric bicycle tests were performed outside the magnet. Submaximal workload (UT 150W/T 260W, 3.5 minutes) caused transient minimal changes in phosphorus metabolites. Supramaximal, partially anaerobic exercise (UT 320W/T 350W, 3.5 minutes) induced similar changes in heart rate, oxygen uptake rate, and plasma lactate in both groups. Decrease of the PCr/Pi ratio, however, was more pronounced in UT subjects and clearly lasted longer. If methodical problems can be resolved, combined MRS and MRI in whole body magnets may become a standard noninvasive modality, adding unique information on morphology (organ volume) and local metabolism to classic mechanical and global physiologic data.
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PMID:Combined use of magnetic resonance imaging (MRI) and spectroscopy (MRS) by whole body magnets in studying skeletal muscle morphology and metabolism. 404 94

A rare case of persistent primitive trigeminal artery variant (PTAV) with cerebellar ischemia is reported. A 23-year-old male complained of sudden dizziness and nausea after playing valley ball. CT scan and MRI on admission revealed no abnormal findings. Left carotid angiography demonstrated a PTAV anastomoting precavernous portion of left internal carotid artery to the left superior cerebellar artery. The 37 cases reported in literature were reviewed to characterise PTAV. Ninety-seven% of the cases arising from precavernous portion of internal carotid artery, and terminated in anterior inferior cerebellar artery in 73%, posterior inferior cerebellar artery in 13.5% and superior cerebellar artery in 13.5%. Approximately 22.2% of patients with PTAV have cerebral aneurysms. The hypotension or mechanical compression of PTAV on playing valley ball with poor vascular supply to the part of cerebellum possibly caused cerebellar ischemia in this case.
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PMID:[Persistent carotid-superior cerebellar artery anastomosis presenting with cerebellar ischemic attack: a case of persistent trigeminal artery variant]. 749 18

MRI findings and risk factors for vascular dementia were evaluated with multi-variate analysis in 96 multi-infarct patients without dementia and 40 multi-infarct patients with dementia (MID). Only subjects with small infarcts in the territory of the perforator artery or deep white matter were studied. The diagnosis of MID was diagnosed according to DMS-III criteria and Hachinski's ischemia score. Location and area of patchy high-intensity areas including small infarcts, the degree of periventricular high intensity (PVH), and the degree of brain atrophy were examined with MR images. Independent variables were: history of hypertension, diabetes mellitus, other complications; systolic and diastolic blood pressure, atherosclerotic index, hematocrit, history of smoking, level of education, and activities of daily life (ADL). Hayashi's quantification method II was used to analyze the data. The most significant correlation was found between history of hypertension and dementia (partial correlation coefficient: 0.39). Significant correlations were also found between ADL and dementia (0.32), between thalamic infarction and dementia (0.31), and between PVH and dementia (0.27). Age, brain atrophy index, and history of diabetes mellitus contributed little to dementia. The contribution to dementia did not differ significantly between right and left patchy high-intensity areas on MR images. Location of infarcts, except for bilateral thalamic infarcts and large PVH, contributed little to dementia. Thus it would be difficult to base a prediction of the prevalence of vascular dementia on MRI findings. However, both hypertension and ADL contribute to vascular dementia and both are treatable, which may be significant for the prevention of dementia.
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PMID:[Difference in MRI findings and risk factors between multiple infarction without dementia and multi-infarct dementia]. 749 60

This study was aimed at assessing the MR patterns of transient osteoporosis of the hip and, consequently, the role of MRI in the diagnosis and follow-up of this condition. Even though this condition was originally observed in pregnant women, young or middle-aged men are most frequently affected. There is a spontaneous onset of pain, usually progressing over several weeks. The patients have no risk factors for osteonecrosis; they may have a history of minor trauma and there is a possible relationship to the third trimester of pregnancy. Laboratory values are negative. Pain may be severe enough to cause the patient to limp and to impair joint function. The possible causes of transient osteoporosis have been debated by many authors and include trauma, synovitis, neurovascular dysfunction and transient or reversible ischemia. Transient osteoporosis is a self-limiting disease which does not require surgical treatment. The differential diagnosis of transient osteoporosis of the hip is very important because this condition may simulate cancer, septic arthritis, osteomyelitis or avascular necrosis. We report the initial and follow-up features of transient osteoporosis of the hip on the MR images of 6 patients (M/F = 5/1; age: 37-49 years, mean: 41.8 years). The right side was involved in 3 patients, the left side in 2 patients. The patient with bilateral transient osteoporosis was a woman in the 3rd trimester of pregnancy. In all patients, MRI was performed with an 0.5 T MR unit. The MR changes in our 6 patients were rather uniform and included heterogeneous decrease in the signal intensity of the affected bone marrow on T1-weighted images and increased signal intensity on T2-weighted and STIR images, with no evidence of focal lesions. This pattern is known as the "bone marrow edema" (BME) pattern. All the patients received conservative treatment. The clinical symptoms and the MR abnormalities regressed completely within 6-10 months, with no late sequelae. To conclude, this follow-up MR study demonstrates the transient, reversible character of transient osteoporosis of the hip. Until the natural history of the BME pattern is better understood, we suggest a conservative management of this condition, especially in the patients with no risk factors for osteonecrosis. Radiographic and MR follow-up is recommended.
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PMID:[Transient osteoporosis of the hip in magnetic resonance imaging]. 750 20

A 74-year-old man was admitted to our hospital with abrupt onset of hemichorea-hemiballism in the left arm and leg. On admission, the blood glucose level was 296 mg/dl, glycosylated hemoglobin Alc was 17.0%, and the serum osmolality was 296 mOsm/l. Urinalysis was negative for ketone bodies, but was strongly positive for glucose. After normalization of the blood glucose level, ballistic movement disappeared, but choreiform movement of the left arm and leg continued for 10 months. Brain CT showed a slight high density of the right putamen, which disappeared on 37th day after the onset. MRI showed high intensity on T1-weighted images and low intensity on T2-weighted images in the right putamen, which disappeared 10 months after the onset. SPECT on the 21th day after the onset showed hyperperfusion in the right putamen. 4 months later, the blood flow slightly reduced in the right putamen. The abnormality in the right putamen was considered to be the cause of his involuntary movements. High intensity in the putamen on T1-weighted MR images in the present case are presumed to have developed following mild ischemia and the reversible deposition of calcium or other material which occurred in association with nonketotic hyperglycemia.
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PMID:[Hemichorea-hemiballism associated with nonketotic hyperglycemia and presenting with unilateral hyperintensity of the putamen on MRI T1-weighted images--a case report]. 760 83

The purpose of this paper is to report a case of medullary ischemia diagnosed by MRI and to determine any MRI characteristics that may be useful for the diagnosis in the light of the published data. The patient was a 60 year-old male with hypertension and diabetes, referred to us for flaccid paraparesis and sphincter disorders of acute onset. Physical examination revealed, beside flaccid paraparesis, both superficial and deep hypoesthesia at L1 level and greater on the right. MRI showed a small area of signal hyperintensity on T2 weighted images and in proton density localized in the posterior part of the spinal cord at the level of T12 body. The patient was treated with oral antidiabetic, antiaggregant and antihypertensive drugs as well as neuromotor rehabilitation, and his clinical conditions improved; a control MRI, six months later, showed disappearance of the previous finding and only mild medullary atrophy at the level of the lesion. Medullary ischemia has been observed in a variety of pathological conditions (inflammatory, neoplastic, traumatic degenerative and iatrogenic), and most frequently involves the dorsal portion of the spinal cord. Four clinical-pathological manifestations of medullary ischemia have been described: infarction from occlusion of the anterior spinal artery; "patchy" or "lacunae infarction"; "transverse ischemic infarction"; selective ischemia in the regions of the posterior spinal arteries. A review of the literature yielded 61 cases of spinal ischemia diagnosed by MRI for a total number of 80 MRI scans, 12 of which were long-term controls.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Spinal cord ischemia diagnosed by MRI. Case report and review of the literature. 762 69

We report two diabetic patients with hemichorea-hemiballism associated with striatal lesions detected by MRI. Case 1 was a 57-year-old woman. On May 5, 1990, hemichorea-hemiballism of the right upper extremity developed suddenly. The blood glucose level at the time of onset was 695 mg/dl. Plain cranial CT scanning revealed a small high-density lesion in the left putamen. On MRI, this lesion showed a high signal intensity on T1-weighted images, while it showed as an irregular low-intensity area on T2-weighted images. Three and a half months later, the high intensity lesion on MRI decreased gradually and almost disappeared. Case 2 was a 68-year-old woman. In late August 1992, hemichorea-hemiballism of the right upper and lower extremities developed suddenly. The blood glucose level at the time of onset was 365 mg/dl. Plain cranial CT scanning was normal. MRI revealed a high signal intensity lesion involving the left putamen, globus pallidus and head of the caudate nucleus on T1-weighted images, while the lesion was almost isointense on T2-weighted images. The high-intensity lesion on MRI thereafter decreased gradually and disappeared almost completely one year after the onset. It is characteristic that the lesions responsible for hemichorea-hemiballism showed high-intensity areas on T1-weighted MRI in these two diabetics. In the hyperglycemic state, the Krebs cycle is inhibited and GABA is utilized as an energy source. The possibility has been suggested that striatal ischemia is likely to occur in diabetics because the GABA content of the corpus striatum is decreased by hyperglycemia.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Two diabetics with hemichorea-hemiballism and striatal lesions]. 766 16

We employed diffusion-weighted MRI (DWI) to identify regions of focal brain ischemia during the first 3 hours after permanent occlusion of the middle cerebral artery in rats. Using DWI as early as 30 minutes after the onset of ischemia, it was possible to identify the areas of brain destined to progress to infarction over the next 24 hours in untreated animals, as demonstrated by postmortem evaluation. DWI studies revealed the cerebroprotective effects of a noncompetitive N-methyl-D-aspartate receptor antagonist, CNS 1102, administered 15 minutes postocclusion, both on the cortical and caudoputaminal regions during the initial 3 hours of ischemia. Although the treatment effect lessened over the next 21 hours in a few animals with lower plasma drug levels at 3 hours, postmortem studies demonstrated a 66% reduction in the total volume of infarcted tissue with the treatment and confirmed the DWI results. T2-weighted MRI obtained at similar times revealed little or no abnormality. These results suggest that DWI provides a sensitive in vivo measure of focal cerebral ischemic injury and can assess the beneficial effects of cytoprotective therapy. DWI may be useful in the early evaluation of human stroke patients and in monitoring the effects of cerebroprotective therapies in the clinical setting.
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PMID:Effects of a novel NMDA antagonist on experimental stroke rapidly and quantitatively assessed by diffusion-weighted MRI. 767 81


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