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)

Susceptibility to pressure amaurosis was measured in young research subjects before and during blood pressure elevation induced by intravenous infusions of phenylephrine. Intraocular pressure elevations were produced by paralimbal suction; we measured the highest level to which intraocular pressure could be raised without obliterating perception of a slowly flickering stimulus in the nasal field of vision. Elevation of systemic blood pressure was accompanied in all subjects by a corresponding increase in the highest "safe" level of intraocular pressure. This observation confirms the commonly held hypothesis that pressure amaurosis is the result of pressure-induced neuroretinal ischemia.
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PMID:Blood pressure and pressure amaurosis. 111 22

Amaurosis fugax (transient monocular blindness) is a symptom of retinal ischemia just as contralateral hemiparesis and sensory loss are symptoms of cerebral ischemia. These symptoms are produced by atherosclerotic stenosis of the carotid vessels at the ipsilateral carotid bifurcation and emboli from these areas causing focal, repetitive, retinal ischemia. A study of 31 endarterectomy patients was undertaken to see if eight patients with amaurosis fugax (25%) could be differentiated from 22 patients with transient cerebral ischemia. The patients with amaurosis fugax were found to be younger. They all had 75% or greater stenosis of the internal carotid artery at the bifurcation on the symptomatic side. They all had unilateral visual symptoms and these symptoms were relieved by surgery. The patients with amaurosis fugax were devoid of cardiac disease, while 45% of the cerebral ischemic patients had documented myocardial disease. Amaurosis fugax (transient monocular blindness) in the setting of clinically significant atheroslerosis of the carotid vessels is an indication for carotid endarterectomy.
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PMID:Amaurosis fugax: a clinical comparison. 117 55

In 2 models of reduced cerebral blood flow-permanent occlusion of the vertebral arteries plus transient occlusion of the common carotid arteries (4VO) and transient clamping of the common carotid arteries (BCCA)-the acute effects on the electrical function of the retina were monitored by recording the photopic electroretinogram. During both 4VO and BCCA the amplitude of the b-wave was reduced. Within 30 min of reperfusion after 4VO and after BCCA the b-wave had fully recovered. In contrast, the a-wave was not affected by either treatment. The data suggest that occlusion of common carotid arteries leads to retinal ischemia and might represent a useful model of amaurosis fugax.
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PMID:Retinal ischemia induced by occlusion of both common carotid arteries in rats as demonstrated by electroretinography. 143 91

A 74-year-old man with the isolated complaint of uniocular transient visual loss after exposure to bright light was found to have severe ipsilateral, atherosclerotic carotid occlusive disease. Signs of ocular ischemia that were present included slightly reduced visual acuity, mild afferent pupillary defect, lowered intraocular pressure, increased photostress recovery time, and reduced opthalmodynamometry values on the affected side. After a subclavian to internal carotid artery bypass procedure, the patient's symptoms resolved completely and his ocular signs returned to normal. This patient's initial symptom, referred to as light-induced amaurosis (LIA), is an unfamiliar manifestation of the ocular ischemic syndrome. We discuss the condition and summarize the literature.
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PMID:Light-induced amaurosis associated with carotid occlusive disease. 145 7

Dissection of the cervicocranial arteries is becoming more frequently recognized as a cause of neurological disorders. Typical clinical features seen with dissection include unilateral headache, oculosympathetic palsy, amaurosis fugax, and symptoms of focal brain ischemia. The diagnosis of carotid or intracranial dissection is usually best confirmed by angiography, although magnetic resonance imaging and computed tomography have been shown to visualize intimal dissection. The prognosis in cases of spontaneous dissection is generally benign unless the initial manifestation involves infarction with substantial deficit. The best approach to treatment appears to be the administration of the anticoagulant, heparin, followed by warfarin or antiplatelet therapy. Surgical intervention is reserved for cases of progressive or recurrent ischemic complication that occurs despite the administration of adequate doses of anticoagulants.
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PMID:Cervicocranial arterial dissection. 187 Jun 93

The evaluation and management of retinal ischemia from atherosclerotic carotid disease is in a state of flux reflected by the change from emphasizing surgical management in the '70s toward skepticism about the benefit of surgery in the '80s. In addition, reliable noninvasive diagnostic testing of the carotid artery has reduced the risk. The decision to consider surgical versus medical management must be made on an individual basis based on the patient's health, age, and the risk of angiography and surgery at each institution. In children and young adults, amaurosis fugax is a benign condition. In the older population amaurosis fugax is often the sentinel event of diffuse atherosclerotic disease and possible early death from myocardial infarction. A team including the neurologist, internist, ophthalmologist, and surgeon optimizes care of the whole disease and not just the symptom. It is hoped that information in the next decade will supply additional guidance in the care of this multifaceted malady.
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PMID:Atherosclerotic carotid disease and the eye. 201 Nov 6

Lupus anticoagulants and anticardiolipin antibodies are antiphospholipid antibodies (APLAb) with related antigenic specificities and are newly recognized markers for an increased risk of thrombosis. We studied 48 patients who presented with cerebral or visual dysfunction associated with APLAb to help clarify the diagnostic, clinical, laboratory, radiologic, and pathologic features in these patients. Most patients presented with transient cerebral ischemia or cerebral infarction. Recurrent and stereotypic events were frequent. Visual disturbances resulted from amaurosis fugax, retinal arterial or venous occlusion, occipital ischemia, diplopia, and migraine-like disturbances. Three patients presented with severe atypical classic migraine. Recurrent infarcts of brain and eye were significantly associated with the presence of cigarette smoking, hyperlipidemia, and a positive antinuclear antibody. During 44.4 patient-years of prospective follow-up, the combined stroke and systemic thrombotic event rate was 0.27 events per patient-year and was 0.54 events per patient-year if TIA and death were included. Forty (83%) of the patients did not have systemic lupus erythematosus (SLE). Thrombocytopenia was present in 15 (31%) and a false-positive VDRL in 11 (23%) of the patients. Cerebral angiography was normal or revealed large-vessel occlusion or stenosis without changes suggestive of vasculitis. Patients with only transient dysfunction generally had normal radiologic studies, including angiography. Organs and arterial vessels studied pathologically revealed thrombotic occlusive disease without vasculitis. APLAb are strongly associated with an immune-mediated thrombotic tendency, generally in the absence of SLE. Other stroke risk factors may add to the risk of recurrent ischemic events in patients with APLAb.
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PMID:Cerebrovascular and neurologic disease associated with antiphospholipid antibodies: 48 cases. 238 25

Twelve patients with brachial ischemia and/or subclavian steal syndrome underwent PTA of the subclavian, innominate and axillary artery. One technical failure occurred in a patient with a high grade stenosis of the subclavian artery. All other patients were successfully dilated. On long-term follow-up (mean: 12 months) only one patient had a recurrent stenosis which was successfully recanalized by PTA. This patient is asymptomatic since 12 months. The only severe complication was a transient amaurosis which occurred during catheterization. Balloon angioplasty was, therefore, not performed. In summary, PTA is an effective therapy for patients with brachial ischemia and/or subclavian steal syndrome. The long- and short-term results compare favorably with results obtained by surgery.
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PMID:PTA of the subclavian and innominate artery: short- and long-term results. 252 92

Nonspecific aortoarteritis is a systemic autoimmune disease eventuating in gradual stenosis of the aorta and the main vessels with ischemia of the respective organs. Ophthalmologic symptoms have been examined in 54 patients with nonspecific aortoarteritis. Subjective disorders of vision (short-term binocular blindness, metamorphopsia, pain behind the eye, amaurosis fugax) have been detected in 52% of the examinees. Organic lesions of the eye have been diagnosed in 60% of the patients: hypertensive angiopathy (22%), venous stasis retinopathy (17%), occlusion of the central retinal artery (1%), etc. Three possible mechanisms of the development of ocular symptoms have been established: (1) a result of symptomatic hypertension, (2) chronic ocular ischemia, (3) acute hemodynamic ocular circulation insufficiency.
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PMID:[Ophthamologic pathology in non-specific aortoarteritis]. 256 80

Between January 1978 and December 1986, 69 polytetrafluoroethylene bypass grafts on the ascending aorta were placed in 53 patients with atherosclerotic occlusive disease of the innominate and left common carotid arteries. Thirty-six patients had symptoms predominantly of amaurosis fugax, verebrobasilar ischemia, and upper limb ischemia. The remaining 17 patients had no symptoms but had severe hemodynamically significant occlusive disease. All operations were accomplished via median sternotomy. One patient died after surgery (operative mortality rate 1.9%), and one patient had minor postoperative neurologic deficit that partially improved on long-term follow-up. Patency of the reconstruction was routinely assessed by a Doppler device combining (1) a continuous wave Doppler and (2) real-time mechanical sector B-mode imaging with frequencies of 3.5 MHz and 7.5 MHz. There were two early asymptomatic occlusions; one was related to a technical error that was successfully revised and the other to low systemic perfusion. The mean follow-up time was 50.5 months. Two patients were lost to follow-up and a further six patients died, for a cumulative 5-year survival rate of 84.9%. One patient had only partial improvement in symptoms and one patient sustained a late postoperative neurologic deficit after internal carotid occlusion distal to a patent aortocarotid bypass. The remaining patients were free of symptoms. There were no infective complications. All the patients underwent late assessment by Doppler ultrasonography and B-mode scanning. One asymptomatic occlusion was thereby identified to be a result of diminished runoff. The overall secondary patency rate at 5 years was 96.1%.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Long-term results of aortoinnominate and aortocarotid polytetrafluoroethylene bypass grafting for atherosclerotic lesions. 266 65


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