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

A study of cerebral and cerebellar blood flow reactivity to acetazolamide by xenon-133-inhalation single photon emission computed tomography (133Xe SPECT) was carried out in a patient with bouts of transient basilar ischemia, whose neurological examination, computed tomographic scan, and auditory evoked potentials were normal. Though the patient was symptom-free at the time of the study, 133Xe SPECT demonstrated vertebrobasilar insufficiency by showing an impaired vasodilatory response in both the occipital lobes and the right cerebellar hemisphere. Three weeks later, the patient suffered an extensive stroke in these same areas. We therefore suggest that this method could be of great value in the assessment of vertebrobasilar insufficiency.
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PMID:Vertebrobasilar insufficiency revealed by xenon-133 inhalation SPECT. 278 48

We reviewed the clinical and electronystagmographic findings of 84 patients who presented to our neuro-otology clinic with vertigo of presumed cerebrovascular origin. There was a surprisingly high incidence of isolated episodes of vertigo (abrupt in onset, lasting minutes). In some patients these episodes preceded other symptoms of vertebrobasilar insufficiency or infarction by months. Peripheral vestibular abnormalities were common on electronystagmographic testing; 42% had unilateral hypoexcitability to caloric stimulation. We conclude that the vestibular labyrinth is selectively vulnerable to ischemia within the vertebrobasilar system.
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PMID:Vertigo of vascular origin. Clinical and electronystagmographic features in 84 cases. 229 87

With the use of duplex sonography, quantitative vertebral artery flow measurements have been made in 283 patients who had nonlocalizing symptoms of cerebral ischemia suggestive of vertebrobasilar insufficiency. Net vertebral artery flow was calculated by adding flows from the right and left sides. When net vertebral flow was greater than 200 ml/min, 89 of 148 patients (60%) were found to have a significant stenosis (greater than 50% diameter reduction) in one or both internal carotid arteries. Conversely, when net flow was less than 200 ml/min, 101 of 135 patients (75%) had normal or only mildly diseased carotid system (p less than 0.001). When compared with otherwise matched groups of asymptomatic patients or patients with lateralizing hemispheric symptoms, those with nonlocalizing symptoms were much more likely to have net flow less than 200 ml/min. For the nonlocalizing symptom group this was 135 of 283 patients (48%) compared with only 72 of 208 asymptomatic patients (35%, p = 0.005) and 110 of 310 patients with hemispheric symptoms (35%, p = 0.003). Duplex sonography appears to offer a noninvasive technique for the functional hemodynamic evaluation of patients with suspected vertebrobasilar insufficiency, with the capability to distinguish those patients whose symptoms may be related to thromboembolic carotid artery disease, true vertebrobasilar ischemia, or some other cause.
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PMID:Vertebrobasilar insufficiency: evaluation by quantitative duplex flow measurements. A preliminary report. 295 31

Two cases of subclavian steal syndrome are reported. Symptoms included light-headedness or syncope, reflecting vertebrobasilar insufficiency, and in one case, numbness and tingling in the left upper extremity, reflecting ischemia. Many persons with this syndrome are asymptomatic. Key findings include unilaterally decreased pulses and a significant difference in blood pressure between the upper extremities. Arch aortography, the "gold standard" of diagnosis, must be performed before surgical intervention.
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PMID:Subclavian steal syndrome. A report of two cases. 334 Jun 10

Thirteen patients with transient vertebrobasilar insufficiency caused by emboli from a proximal subclavian artery lesion were treated over a 5-year period. This group was characterized by the absence of significant carotid disease (12 of 13 patients) and equal arm pressures bilaterally in most patients (8 of 13 patients). An isolated supraclavicular bruit (12 of 13 patients) and a history of ipsilateral digital ischemia (5 of 13 patients) were common. Arch angiography demonstrated proximal subclavian lesions in 12 patients, with obvious ulcerations in 10 cases and thrombus in an old carotid-subclavian bypass graft in one case. Surgery directed at removal or exclusion of the lesion was successful in all cases. Isolated lesions in the subclavian artery can be a source of emboli into the vertebrobasilar circulation. These lesions are effectively treated by exclusion and vascular reconstruction.
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PMID:Embolic lesions from the subclavian artery causing transient vertebrobasilar insufficiency. 376 81

From 1977 through 1985, 1043 patients underwent operation for supra-aortic occlusive disease. One hundred thirty-four of these patients (13%) with 146 lesions of the aortic arch branches (innominate, 25; subclavian, 103; and multiple, 10) had one or more symptoms of subclavian steal (78%), transient ischemic attacks (37%), arm ischemia (37%), and others (7%). However, according to results of a critical prospective neurologic examination, the classic steal syndrome appeared in only 13 patients (10%), vertebrobasilar insufficiency in 32 patients (24%), and hemispheric symptoms in 48 patients (36%). Symptomatic and/or significant internal carotid occlusive disease was present, ipsilateral in 28% and contralateral in 31% of the patients. Other supra-aortic vessels were involved in 49% of the patients. During the same period 192 patients with supra-aortic occlusive disease were treated without surgical intervention for various reasons. Fifty-five patients (27%) were completely asymptomatic except for the presence of reversed flow within the vertebral artery. The surgical approach in 138 operations was extrathoracic (ET) in 71% of patients (innominate artery, 2; subclavian artery, 95; and arch syndrome, 1) and transthoracic (TT) in 29% of patients (innominate artery, 23; subclavian artery, 8; and arch syndrome, 9). Generally, bypass procedures were preferred, but for 72 (71%) of the subclavian lesions subclavian-carotid transposition (SCT) was performed. Three patients had been referred for complications of previous carotid-subclavian bypass. The grafts were removed and vertebral and arm circulation restored by SCT. Carotid end-arterectomy was performed simultaneously (20%) or staged (3%) in 8% of the innominate procedures and 25% of the subclavian reconstructive procedures.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The role of subclavian-carotid transposition in surgery for supra-aortic occlusive disease. 379 92

Repeated CBF-measurements can be performed after inhalation or intravenous injection of 133Xe. After the development of a bicompartmental model by Obrist et al. in 1975 atraumatic CBF-measurements became widely used but there were still some difficulties concerning the sensitivity of different flow-indices towards CBF changes in normals under test conditions or ischemia in stroke patients. Due to the "slippage phenomenon" mostly noncompartmental flow-indices are used for the detection of ischemic brain areas. In this study a scintillation camera, that is usually available in every nuclear medicine department, was used for atraumatic CBF-studies. A collimator consisting of hexagonal lead tubes (septa 0.2 mm thick; FWHM 1.7 cm in 10 cm) was constructed for this purpose. The obtained counting rate varied between 2432 and 9081 cps over the whole hemisphere and 116-1094 cps in regions of approximately 2.5 X 2.5 cm. In 31 patients with CVD CBF was measured with the intracarotid (i.c.) technique and 1 hour later after i.v. 133Xe-injection. Intravenous flow values were comparable to those obtained after i.c. 133Xe injection (fB X MFr = 0.904; p less than 0.001). In 12 of the used 13 regions also significant correlation coefficients were found. In order to estimate the reproducibility of the intravenous injection method CBF-measurements were performed in both hemispheres of 10 patients on two consecutive days. Highly significant correlation coefficients were found for hemispheric blood flow (r = 0.933; p less than 0.001) and temporal, frontotemporal, temporoparietal and praecentral regions, while in the high parietal, frontal and occipital region lower reporducibility was found. Normal CBF-values were obtained from 12 healthy volunteers (MF right hemisphere: 50.7 +/- 4.6 ml/100 g/min; MF left hemisphere: 50.6 +/- 4.6 ml/100 g/min). MF did not show any hyperfrontality, while F1 and the ISI gave highest flow values in frontal regions. The clinical status of 76 patients suffering from cerebral ischemia (68 with flow disturbances in one hemisphere, 8 with vertebrobasilar insufficiency) was estimated by a semiquantitative scorescale at time of admission and after an observation period lasting from 6 to 35 months. In each case CBF was measured twice: once in the subacute stage after onset of symptoms and once after the observation period. The duration of neurologic symptoms (TIA, RIND, CS) was compared to the obtained flow values. A significant relationship was found between the duration of symptoms and impairment of CBF, thus showing the prognostic value of intravenous CBF measurements.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[Noninvasive measurement of cerebrovascular circulation with the scintillation camera. A neurologic nuclear medicine study]. 659 71

In a randomised double-blind longterm study the value of acetylsalicylic acid in prophylaxis against relapse was investigated against placebo in 58 patients with transitory ischemic attacks of prolonged reversible insults. During the 24 months of observation, significantly fewer relapses of cerebral ischemia occurred in patients with carotid transient ischemia attacks under acetylsalicyclic acid than in the control group. The recurrences usually took the form of transitory ischemic attacks. Of the 5 cerebral infarcts, 4 occurred in the control group, 3 patients died. Patients with vertebrobasilar insufficiency showed no response. On account of the relatively small number of patients the result of the study is to be regarded rather as a confirmation of the results of a larger series of investigations in the USA and Canada than solely a proof of the efficacy of acetylsalicylic acid.
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PMID:[The treatment of transitory ischemic attacks with acetylsalicylic acid: results of a double-blind-study (author's transl)]. 677 99

We studied the complications and long-term results of percutaneous transluminal angioplasty (PTA) of subclavian artery stenosis in 11 patients. In all patients but one, the systolic blood pressure before PTA in the arm on the involved side was at least 30 mmHg lower than that in the opposite arm. PTA of 11 left subclavian arteries and one right subclavian artery was attempted. Five of the patients suffered from symptoms of vertebrobasilar insufficiency as well as ischemia of the upper limb, two had only cerebral symptoms, two had only ischemia of the upper limb, and another had no symptoms related subclavian arterial lesion. Standard techniques for PTA were employed, using the femoral route eight times and the axillary route four times. Angioplasty was successful in 11 lesions (92%). In the successfully treated patients, the blood pressure in the ipsilateral arm was significantly increased after PTA. No complications occurred during or after the procedure. The patients were followed for 2-74 months (mean 25.7 months). During this time, no recurrence of the stenosis was observed, although the symptoms of vertebrobasilar insufficiency did not always improve. These results suggest that PTA is useful for treating subclavian artery stenosis.
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PMID:[Percutaneous transluminal angioplasty of the subclavian arteries]. 812 74

Extrathoracic revascularization has become the most popular form of surgical correction of symptomatic subclavian artery lesions. During a 10-year period ending in December 1991, 41 extrathoracic bypass procedures were performed on 37 patients for proximal subclavian artery stenosis or occlusion. This included 25 females and 12 males, with a mean age of 56 years. Surgery was performed for manifestations of upper extremity ischemia in 19 patients (51%), vertebrobasilar insufficiency in four patients (11%), and both upper extremity ischemia and vertebrobasilar insufficiency in 11 patients (30%). Three patients (8%) had angina pectoris caused by "coronary-subclavian steal" following internal mammary-coronary artery bypass. Severe proximal stenosis or complete occlusion of the subclavian artery was demonstrated angiographically in all cases. Procedures performed included: carotid-subclavian bypass (n = 28), subclavian-carotid transposition (n = 6), axilloaxillary bypass (n = 4), and subclavian-subclavian bypass (n = 3). Saphenous vein was used as the bypass conduit in 6 of the carotid-subclavian bypass procedures, and prosthetic grafts were used for the remainder. There were no perioperative strokes or deaths in this series, and the mean postoperative hospital stay was 4 days. Follow-up ranged from 2 to 96 months (mean, 35.6 months). The overall patency rate was 95% at 1 year, 86% at 3 years, and 73% at 5 years. Patency at 5 years was significantly higher for procedures utilizing the common carotid artery as the donor vessel as compared with those using the contralateral subclavian or axillary arteries (83% versus 46%, P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Subclavian artery revascularization: a decade of experience with extrathoracic bypass procedures. 817 Jan 36


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