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

We reported a 51-year-old male with ischemic disturbance of right inner ear resembling Meniere's disease. The patient had a sudden-onset episode of vertigo, right severe hearing disturbance, nausea, vomiting and gait disturbance. Two days after, he had hypersomnia, vertical gaze palsy, double vision, left Horner's sign, and sensory disturbance of pain and temperature of right half body involving face. Brain MRI disclosed high intensity area in T2-weighted image and proton density in bilateral paramedian thalamo-mesencephalic region and right cerebellum (area of the anterior inferior cerebellar artery). Cerebral angiography showed 90% or more stenosis of the right vertebral artery, 50% stenosis of the left vertebral artery before the posterior inferior cerebellar artery (PICA), and 60% stenosis of distal portion of the basilar artery. Furthermore, stem portion of the posterior cerebral artery, and the right anterior cerebellar artery and the left vertebral artery after the PICA were absent or occluded. Right deafness was evaluated to be Jerger type II, namely disturbance of inner ear. Caloric tests showed no response, and right auditory brainstem response showed no waves. Main cause of this vertigo and right deafness was considered to be disturbance of inner ear due to ischemia of right labyrinthine artery, though this patient was not a typical case of the anterior cerebellar artery syndrome. Ischemic disturbances of inner ear have been reported only in patients with the anterior cerebellar artery syndrome, therefore this patient who had only acute ischemic disturbance of inner ear and did not have disturbance of caudo-lateral portion of the pons was considered to be very rare.
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PMID:[A case of ischemic disturbance of inner ear]. 259 43

To investigate the relationship between middle cerebral artery (MCA) trunk lesions and the etiology of Binswanger type (B type) infarction, which was demonstrated as a diffuse subcortical low density area/high intensity area by CT/MRI, patients with both MCA lesions and B type infarction were studied clinically. Eighteen patients with B type infarction were diagnosed among 224 patients with MCA occlusion/stenosis on angiography accounting for 8%. The incidence was as high as 25% in M2 stenosis. The mean age of B type infarction patients was 64 years and 16 of them were men. Chronologically stepwize/slowly-progressive deterioration of clinical manifestations were observed in 14. All patients had hemiplegia, though half of them were mild or moderate in severity. Furthermore, aphasia, Gerstmann syndrome and dementia were present in 10, 1 and 2 patients, respectively. Twelve had a history of hypertension, while 11 showed transient decreases with marked changes (more than 31 mmHg in mean arterial blood pressure) in arterial blood pressure during their clinical course. Out of 9 patients in whom cerebral blood flow (CBF) was measured by 133Xe injection method/inhalation method, 7 demonstrated mild to moderate decreases in mean CBF (more than 30 ml/100 g/min) with no relation to the severity of MCA lesions. These findings suggested that hemodynamic mechanisms associated with hypoperfusion due to marked fluctuations in blood pressure are accelerating factors of B type infarction and MCA lesions, even though ischemia in the subcortical area due to leptomeningeal anastomosis may be mild or moderate.
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PMID:[Clinical study on the relationship between middle cerebral artery lesions and Binswanger type infarction]. 260 75

Plain-film radiography of the abdomen is often the first-line imaging modality used for the patient in the ED. It is capable of demonstrating abnormal locations of gas, abnormal viscera, calcifications and foreign material, and skeletal and lower lung pathology. PFR findings may aid in the decision to proceed to other modalities. Contrast studies have a limited role in the ED but may be necessary to diagnose disease inadequately visualized by PFR, as in the case of perforated duodenal ulcer, missed on PFR in approximately 15 per cent of cases. Ultrasound is most useful in the ED for obstetric and gynecologic illness, as well as disorders of the hepatobiliary system. Nuclear medicine studies can be very useful for GI bleeding and inflammatory conditions but may not always be as available or convenient as other modalities. CT has very broad usefulness. Angiography is very useful for locating bleeding sites, especially in the large bowel, and for determination of mesenteric arterial patency in suspected mesenteric ischemia. Finally, MRI, which has enormous potential, is not funded by many third-party payment plans for use in emergencies, and must overcome certain obstacles before it assumes common usage in the ED.
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PMID:Imaging of the nontraumatic acute abdomen. 266 52

Magnetic resonance spectroscopy (MRS) has been used effectively in the evaluation of cardiac physiology. Studies have been done at various levels of complexity extending from isolated hearts to man. Correlation of high-energy phosphate compounds with contractile function is achieved by simultaneous or immediate sequential measurement of ventricular contractile function and the phosphorus-31 MR spectra. Studies in isolated hearts have monitored the response to ischemia of normal and hypertrophic hearts and the preservation of myocardial function and high- energy phosphate stores by drugs administered prior to the ischemic event. Regional myocardial ischemia has been evaluated by simultaneous monitoring of myocardial regional segment length by sonomicrometry and regional myocardial 31P MRS in the intact heart of larger animal models. Function and metabolism have been assessed in man by the combined application of cine MRI and 31P MRS acquired with a surface coil.
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PMID:Magnetic resonance spectroscopy of the heart. Overview of studies in animals and man. 269 42

The sensitivity of MRI to changes in water state and volume makes it the most desirable modality for imaging early brain ischemia. Its sensitivity is reflected in the ability to show ischemic changes in the white matter of the asymptomatic elderly, which are attributed to axonal loss, demyelination, and gliosis. In large infarcts, however, contrast enhancement with Gd-DTPA can be used to add specificity, should doubt exist as to the proper diagnosis. The ability of MR to image flow is a valuable adjunct, and MR angiography has the potential partially to replace invasive angiography. Applications of MR such as diffusion-perfusion studies, sodium imaging, and spectroscopy could all prove to be useful in the future.
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PMID:Brain ischemia. 269 63

A 22-year-old male developed a tic of neck-flexion at the age of 14. The tic occurred 40 to 50 times per minute on its peak at age 16. Since then he noticed the atrophy and weakness of his both upper limbs. His right leg became weak at age 22. On admission, neurological examination revealed tic of lip and neck, severe muscle atrophy and weakness of bilateral upper limbs, mild muscle weakness and spasticity of right lower limb and hyperreflexia in four limbs. Needle EMG studies revealed fibrillation, positive sharp wave and giant MUP in the biceps, triceps and first interossei muscles. There were no abnormal findings suggesting cervical spondylosis or disc herniation on neck roentgenogram and neck MRI in neutral position. Neck MRI in the ventro-flexed position showed a flattening of the lower cervical cord and a band-like isointensity lesion in the posterior epidural space at C4-6. This isointensity lesion was considered to represent a congestion of the internal vertebral venous plexus. These findings suggest that frequent neck flexion by itself causes the injury of the lower cervical cord through (1) over-stretching of the cord, (2) compression of the cord by dural sac, (3) arterior ischemia, and/or (4) stagnant hypoxia due to venous congestion. Flexion myelopathy may represent one of the most important mechanisms of cervical cord injury accompanied with involuntary movement of neck.
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PMID:[Flexion myelopathy due to tic of neck]. 275 44

We encountered two cases of typical transient global amnesia (a 53-year-old woman and a 50-year-old man). Both cases showed no evidence of abnormal findings which caused the attack on examinations of CSF, EEG, brain CT, brain MRI and cerebral angiography. Examinations of positron emission tomography, using 15O labeled CO2 and O2, were performed on 14 and 8 days after the attack in the female and male cases, respectively, and those disclosed decreased regional blood flow (CBF), increased oxygen extraction ratio (OER), and decreased oxygen metabolic ratio (CMRO2) in the bilateral medial temporal and occipital lobes, which were supplied by the bilateral posterior cerebral arteries. PET, performed on about one month after the attack, revealed normalized values of CBF, OER, CMRO2 in both cases. These findings strongly suggested that transient global amnesia in our cases may be related to ischemia of the bilateral posterior cerebral arteries.
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PMID:[Positron emission tomography in two cases of transient global amnesia]. 279 10

In summary, then, the major strength of MRI in evaluating cerebral ischemia is in the sensitivity that this methodology provides for detection of the disease process. However, it must be realized that edema is a nonspecific event related to various insults affecting the brain. There is still an uncertain capability of MRI in separating acute hemorrhagic from acute ischemic events. The superior sensitivity of MRI should help in investigations aimed at evaluating various forms of intervention in acute ischemia. Because some of these acute changes are at the biochemical rather than morphologic level, proton MRI alone probably will be insufficient to explore numerous variables. For this reason, the potential offered by MRS in cerebral ischemia research and in clinical settings is important. Vascular imaging is relatively complex. Several techniques show promising results but at the present time have poor resolution in comparison to ultrasound and angiography. For the immediate future, they will remain investigational.
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PMID:Magnetic resonance imaging of cerebral ischemia and infarction. 307 44

A right facial paralysis led to the discovery of a tumor on the left side of the medulla oblongata. A neurinoma was suspected on MRI and confirmed by surgery and pathological examination. Ultrasonic aspiration was on interest in this case. The mechanism of the facial paralysis is uncertain: ischemia, compression and pure coincidence may be considered.
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PMID:[Neurinoma of the vagus nerve, contralateral peripheral facial paralysis]. 319 9

To investigate the ability of MRI to detect alterations due to renal ischemia, a rabbit renal artery stenosis (RAS) model was developed. Seven rabbits had RAS induced by surgically encircling the artery with a polyethylene band which had a lumen of 1 mm, 1 to 2 weeks prior to imaging. The stenosis was confirmed by angiography, and the rabbits were then imaged in a 1.4 T research MRI unit. T1 was calculated using four inversion recovery sequences with different inversion times. Renal blood flow, using 113Sn-microspheres, and regional water content by drying were then measured. The average T1 of the inner medulla was shorter for the ischemia (1574 msec) than for the contralateral kidney (1849 msec), while no change ws noted in the cortex. Ischemic kidneys had less distinct outer medullary zones on IR images with TI = 600 msec than did contralateral or control kidneys. Blood flow to both the cortex and medulla were markedly reduced in ischemic kidneys compared with contralateral kidneys (119.5 vs. 391 ml/min/100 gm for cortex and 19.8 vs. 50.8 ml/min/100 gm for medulla). Renal water and blood content were less affected. Our rabbit model of renal artery stenosis with MRI, radionuclide, and angiographic correlation has the potential to increase our understanding of MR imaging of the rabbit kidney.
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PMID:Induced renal artery stenosis in rabbits: magnetic resonance imaging, angiography, and radionuclide determination of blood volume and blood flow. 337 82


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