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)

Spontaneous dissection of the cervical internal carotid artery (sICAD) causes, in more than 90% of patients, carotid territory ischemia, local signs and symptoms on the side of dissection, or both, whereas the remaining sICAD remain clinically asymptomatic. Local signs and symptoms include head, facial, or neck pain, Horner syndrome, pulsatile tinnitus, and cranial nerve palsy. Head, facial, or neck pain occurs in 64-74% and is the presenting symptom in up to 58.5%, and the only manifestation in 2.2-4.5%. Headache is observed in 65-68%, facial pain in 34-53%, and neck pain in 9-26%. Horner syndrome consisting essentially of miosis and ptosis is detected in 28-41%. Cranial nerve palsy is reported in 8-16%; the lower cranial nerves IX-XII are most commonly affected, in particular the hypoglossal nerve. The facial nerve may also be involved; dysgeusia results mainly from involvement of the chorda tympani (0.5-7.0%) or the glossopharyngeal nerve. Transient pareses of the ocular motor (III, IV and VI) and trigeminal nerves have been observed. Pulsatile tinnitus is reported in 16-27%. About three quarters of sICAD cause ischemic events, which include ischemic stroke in 80-84%, transient ischemic attack in 15-16%, amaurosis fugax in 3%, ischemic optic neuropathy in 4%, and retinal infarct in 1%. Patients with sICAD causing ischemia show a lower prevalence of Horner syndrome and palsy of the caudal cranial nerves than patients with sICAD causing no ischemic events, whereas headache, neck pain, and pulsatile tinnitus are equally frequent in both groups. After an ischemic stroke, independency defined by a moderate Rankin scale score of 0-2 occurs in 63-90%, whereas the outcome of retinal infarct and ischemic optic neuropathy are not well known.
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PMID:Clinical manifestations of carotid dissection. 1729 Jan 13

Retinal ischemic injury is common in patients with diabetes, atherosclerosis, hypertension, transient ischemia attack and amaurosis fugax. Previously, signs of ischemic stress, such as pericyte loss, blood-retinal barrier breakdown and neovascularization, which can lead to occlusion of retinal vessels, have been prevented in diabetic db/db mice with aldose reductase (AR) null mutation. To determine the role in retinal ischemic injury of AR and sorbitol dehydrogenase (SDH), the first and second enzymes in the polyol pathway, mice with deletion of AR (AR(-/-)) or SDH-mutation (SDH(-/-)), or C57BL/6N mice treated with AR or SDH inhibitors were subjected to transient retinal artery occlusion (2h of occlusion and 22h of reperfusion) by the intraluminal suture method. Neuronal loss and edema observed in wildtype (AR(+/+)) retinas after transient ischemia were prevented in the retinas of AR(-/-) mice or C57BL/6N mice treated with an AR inhibitor, Fidarestat. Fewer TUNEL-positive cells and smaller accumulations of nitrotyrosine and poly(ADP-ribose) were also observed in the retinas of AR(-/-) mice. However, SDH(-/-) mice and C57BL/6N mice treated with SDH inhibitor, CP-470,711, were not protected against ischemia-induced retinal damage. Taken together, AR contributes to retinal ischemic injury through increased edema and free radical accumulation. Therefore, AR inhibition should be considered for the treatment of retinal ischemic injury often observed in diabetic patients.
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PMID:Gene deletion and pharmacological inhibition of aldose reductase protect against retinal ischemic injury. 1772 43

A visual impairment occurs in about 50% of patients with giant cell arteritis (GCA), an amaurosis fugax (AF) in about 30%, and diplopia in about 10%. An arteritic anterior ischemic optic neuropathy was found in about 80%-90% of patients with visual loss and an arteritic central retinal artery occlusion in about 10%-20%. Without therapy, involvement of the fellow eye may occur within hours or days in a patient with unilateral blindness. Involvement of the anterior segment of the eye (iris ischemia, episcleritis) is rare. Ocular ischemic syndrome is defined by visual loss with hypotony, ischemia of the iris, and cotton wool spots (CWS). CWS may already occur with AF episodes. In the case of strong suspicion of GCA, immediate therapy with steroids is indicated. Duplex sonography and a gadolinium MRI examination are of diagnostic importance. A biopsy of the temporal artery may be carried out after the initiation of therapy.
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PMID:[Ocular findings and differential diagnoses in giant cell arteritis (Arteriitis cranialis)]. 1922 26

Pathological tortuosity of the carotid arteries is a cause of not only cerebral circulatory disorders, but also visual impairments. There are nonspecific and specific signs of circulatory disorders in the anterior ocular segment - bulbar conjunctiva. In pathological tortuosity of the carotid arteries visual impairments are divided into transient, acute, and chronic. Transient impairments include amaurosis fugax, ocular and orbital pains; acute impairments involve ischemic uveitis, acute retinal ischemia, acute ischemic oculopathy, anterior and posterior ischemic optic neuropathy; chronic visual impairments comprise ischemic uveal, chorioidal, retinal, and ocular neuropathy. Noninvasive ultrasound techniques involving carotid duplex scanning and color Doppler mapping of ocular and orbital vessels are the most objective studies of patients with visual impairments in pathological tortuosity of the carotid arteries.
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PMID:[Changes in the organ of vision in pathological tortuosity and atherosclerotic stenosis of the carotid arteries]. 2132 97

The study aimed to prove the efficacy of carotid endarterectomy in patients with transient monocular blindness caused by carotid arterial stenosis. 31 patients, aged 45-80 years, were included in the study. All patients were divided in 2 groups: 16 patients from the first group had classic carotid endarterectomy with synthetic patch; 15 patients from the second group were treated conservatively. All operated patients had no stroke or transient ischemic attack and were spared from amaurosis attacks and even showed certain vision sharpness improvement. Whereas the majority of patients from the second group showed the recurrence of the amaurosis fugax attacks after the treatment. Carotid endarterectomy significantly improves the condition of an eye and prevents brain ischemia in patients with transient monocular blindness caused by carotid arterial stenosis.
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PMID:[Long-term follow-up results of carotid endarterectomy in patients with carotid stenosis and transient monocular blindness]. 2171 19

Carotid artery dissections are potentially disabling, probably underdiagnosed, and mainly affect young-aged and middle-aged people. We present three consecutive cases illustrating different clinical presentations and thereby emphasizing the diagnostic challenge of carotid artery dissections for the emergency physician. Neck and facial pain, headache, unilateral pulsatile tinnitus, partial Horner's syndrome (or oculosympathetic palsy), amaurosis fugax, retinal infarction, and anterior circulation brain ischemia may all occur in isolation or in various combinations. Medical imaging plays a pivotal role in making the right diagnosis. Clinical vigilance is of utmost importance as early diagnosis and timely treatment favor long-term prognosis and even prevent ischemic complications. We review the literature and discuss the pathophysiology, etiology, clinical presentation, diagnosis, imaging techniques, treatment, and prognosis of carotid dissections.
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PMID:Carotid artery dissection: three cases and a review of the literature. 2326 11

A 74-year-old man with a history of asymptomatic right internal carotid artery (ICA) occlusion experienced amaurosis fugax in the left eye. Angiography showed left cervical ICA stenosis in addition to right cervical ICA occlusion. The right anterior and middle cerebral artery (MCA) territories were perfused from the left ICA via the anterior communicating artery. Brain perfusion single-photon emission computed tomography revealed reduced cerebral blood flow and reduced cerebrovascular reactivity to acetazolamide only in the right cerebral hemisphere. The patient underwent left carotid endarterectomy (CEA). Transcranial Doppler monitoring showed microembolic signals in the left MCA during dissection of the left ICA, but intraoperative monitoring suggested absence of global hypoperfusion or ischemia in the bilateral cerebral hemispheres during left ICA clamping. Transient and slight motor weakness of the left upper extremity was noted on recovery from anesthesia. Diffusion-weighted magnetic resonance imaging demonstrated the development of new spotty ischemic lesions only in the right cerebral hemisphere. The present case suggests that intraoperative cerebral embolism causing postoperative neurological deficits can develop exclusively in the cerebral hemisphere contralateral to CEA if the hemisphere has preoperative hemodynamic impairment and collateral circulation via the anterior communicating artery from the ICA ipsilateral to CEA.
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PMID:Ischemic events due to intraoperative microemboli developing in the cerebral hemisphere contralateral to carotid endarterectomy in a patient with preoperative cerebral hemodynamic impairment. 2245 Apr 81

Complications associated with prone surgical positioning during elective spine surgery have the potential to cause serious patient morbidity. Although many of these complications remain uncommon, the range of possible morbidities is wide and includes multiple organ systems. Perioperative visual loss (POVL) is a well described, but uncommon complication that may occur due to ischemia to the optic nerve, retina, or cerebral cortex. Closed-angle glaucoma and amaurosis have been reported as additional etiologies for vision loss following spinal surgery. Peripheral nerve injuries, such as those caused by prolonged traction to the brachial plexus, are more commonly encountered postoperative events. Myocutaneous complications including pressure ulcers and compartment syndrome may also occur after prone positioning, albeit rarely. Other uncommon positioning complications such as tongue swelling resulting in airway compromise, femoral artery ischemia, and avascular necrosis of the femoral head have also been reported. Many of these are well-understood and largely avoidable through thoughtful attention to detail. Other complications, such as POVL, remain incompletely understood and thus more difficult to predict or prevent. Here, the current literature on the complications of prone positioning for spine surgery is reviewed to increase awareness of the spectrum of potential complications and to inform spine surgeons of strategies to minimize the risk of prone patient morbidity.
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PMID:Complications associated with prone positioning in elective spinal surgery. 2589 78

Glucose-dependent insulinotropic polypeptide (GIP) is an incretin hormone with extrapancreatic effects beyond glycemic control. Here we demonstrate unexpected effects of GIP signaling in the vasculature. GIP induces the expression of the proatherogenic cytokine osteopontin (OPN) in mouse arteries via local release of endothelin-1 and activation of CREB. Infusion of GIP increases plasma OPN concentrations in healthy individuals. Plasma endothelin-1 and OPN concentrations are positively correlated in patients with critical limb ischemia. Fasting GIP concentrations are higher in individuals with a history of cardiovascular disease (myocardial infarction, stroke) when compared with control subjects. GIP receptor (GIPR) and OPN mRNA levels are higher in carotid endarterectomies from patients with symptoms (stroke, transient ischemic attacks, amaurosis fugax) than in asymptomatic patients, and expression associates with parameters that are characteristic of unstable and inflammatory plaques (increased lipid accumulation, macrophage infiltration, and reduced smooth muscle cell content). While GIPR expression is predominantly endothelial in healthy arteries from humans, mice, rats, and pigs, remarkable upregulation is observed in endothelial and smooth muscle cells upon culture conditions, yielding a "vascular disease-like" phenotype. Moreover, the common variant rs10423928 in the GIPR gene is associated with increased risk of stroke in patients with type 2 diabetes.
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PMID:Glucose-Dependent Insulinotropic Polypeptide Stimulates Osteopontin Expression in the Vasculature via Endothelin-1 and CREB. 2639 40

Transcranial Doppler ultrasound examination of intracranial vertebral and basilar arteries was performed on a 61-year-old man who presented with symptoms of amaurosis fugax and subclavian steal syndrome. During arm exercise, flow in the basilar artery reversed direction from cephalad to caudal, coincident with symptoms of vertebrobasilar insufficiency. Following bilateral carotid endarterectomies, exercise-induced reverse flow velocities in the basilar artery were markedly increased, and the patient remained asymptomatic. These findings suggest that collateral flow from the anterior cerebral circulation may play an important role in the pathogenesis of brainstem ischemia in subclavian steal syndrome and that transcranial Doppler may identify a subgroup of patients who will benefit from procedures to augment cerebral blood flow.
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PMID:Reversible basilar artery blood flow in subclavian steal syndrome. 2648 3


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