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)

Dural fistulas are acquired arteriovenous shunts, accounting for 10-15p.cent of cerebrovascular malformations. Symptoms are commonly tinnitus or intracranial hemorrhage. Rarely, patients with dural fistulas can present with rapid cognitive impairment. We report two women with rapidly evolving dementia. Cerebral angiography revealed dural arteriovenous fistula, with retrograde drainage into cortical veins, related to thrombosis of both transverse sinuses. Intra-arterial and intra-venous endovascular approaches failed to cure the fistula. Venous embolization via a transcranial approach was required to occlude the fistula, leading to resolution of the symptoms. Dural arteriovenous fistulas may lead to dementia with diffuse white matter changes related to venous ischemia, and must be considered as a reversible cause of vascular dementia. A transcranial approach for venous embolization is sometimes required.
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PMID:[Dural arteriovenous fistula. A rare cause of treatable dementia]. 1510 67

The sudden onset of hearing impairment or hearing loss can be a characteristic sign of a vertebrobasilar circulatory disturbance. We report on a 65 year old male patient with an acute left-sided tinnitus followed by hearing loss as an initial symptom of an infarction of the left anterior inferior cerebellar artery (AICA). Successively, additional symptoms with vertigo, nausea, vomiting and a transient dysarthria and ataxia of the left upper extremity occurred. In the course of the illness, the hearing loss, ataxia and dysarthria completely recovered. MRI of the brain showed an infarction in the area of the anterior inferior cerebellar artery; neurosonographic examination of the basilar and vertebral arteries was normal. Therefore, in patients with acute hearing impairment or hearing loss, an AICA-ischemia should be considered and the patient carefully examined for additional brainstem symptoms, since this can be the first sign of an life-threatening basilar artery thrombosis.
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PMID:[Sudden hearing loss as the leading symptom of an infarction of the left anterior inferior cerebellar artery]. 1565 56

Hypoxia/ischemia may play an important role in the pathogenesis of sensorineural tinnitus due to the characteristics of the cochlear blood supply. In addition, hypoxia modulates molecular processes both in the acute and chronic forms of tinnitus. Transcription factor HIF-1 (hypoxia-inducible factor) may play a key role in the cells' adaptation to hypoxia and ischemia, while under hypoxic/ischemic conditions, HIF-1 induces changes in the gene expression which may contribute to the remodeling of particular structures within the cochlea. Disturbances in the cochlear blood supply may result in membrane changes, perineural edema, inflammation, disturbances in ion homeostasis and in the formation of reactive oxygen species. Thus, the pharmacotherapy of acute tinnitus may be aimed at the improvement of cochlear blood supply and the prevention of acute processes leading to cell damage. Pharmacotherapies with colloidal plasma substitutes, vasodilators, calcium antagonists, procaine, and cortisone have been described in the literature and are discussed here. Many of the pharmacological treatments have not been validated in double blind studies. Although it is impossible to deduce the cause of tinnitus from a drug's efficiency, there is some evidence that it can be effectively suppressed by improving blood supply, at least at certain stages. The aim is to achieve an improved pharmacotherapy by means of sophisticated diagnostic instruments for classifying particular types of tinnitus.
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PMID:[Pharmacotherapy in acute tinnitis. The special role of hypoxia and ischemia in the pathogenesis of tinnitis]. 1613 81

Internal carotid artery dissection typically manifests as an unilateral facial or latero-cervical pain, is often accompanied by an oculosympathetic palsy (myosis and palpebral ptosis) and may be followed by cerebral or retinal ischemia. Deficits of the IXth to XIIth cranial nerves or a pulsatile tinnitus have been described. These symptoms challenge our clinical skills and call for an early diagnosis in order to prevent ischemic complications. Both helical computed tomographic angiography and transcranial ultrasonography coupled with Doppler flow colour are excellent first-line imaging techniques. Conventional angiography has been replaced by magnetic resonance techniques as gold standard. In this article, we describe the case of a patient evaluated at our outpatient clinic and review briefly the literature on this topic.
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PMID:[Partial Horner's syndrome and facial pain: a diagnosis one should not miss]. 1656 38

The incidence of sensorineural hearing loss often caused by direct damage to the cochlear hair cells is by far more frequent and more serious than disorders affecting the external ear or the middle ear. Mechanisms that are discussed to be relevant for the genesis of tinnitus and acquired hearing impairment are hair cell loss, signal transduction disturbances in the region of the outer and inner hair cells and the spiral ganglion, impairment of cochlear blood flow, mechanical disturbance, and hypoxia and ischemia. The present model surveys the possible cellular and molecular biological causes of peripherally developing hearing loss and tinnitus. In particular, the paper discusses the roles of hypoxia and ischemia in the cochlea and in the etiology of the neurosensory types of tinnitus. Peripheral origins of hearing disturbances and tinnitus may be: (a) damage to the stereocilia and the tip links, (b) dysfunction of potassium channels or (c) modification of the glutamate release. Moreover, the hypoxia inducible factor-1 may have an important role to play as a key transcription factor in the cells' adaptation to hypoxia and ischemia. An impairment of the cochlear blood flow may be induced by the expression of target genes like nitrogen monoxide synthase and endothelin-1 resulting in tinnitus. The paper discusses consequences resulting from the present model for the medical treatment of peripherally developing tinnitus and hearing loss.
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PMID:A model of peripherally developing hearing loss and tinnitus based on the role of hypoxia and ischemia. 1675 23

Congenital atresia of the external ears and severe tinnitus has been reported by two patients to be contralateral to the atretic ear. The use of the nuclear medicine imaging technique of single-photon emission computed tomography (SPECT) of brain has demonstrated hypoperfusion in brain areas supplied by the middle cerebral artery on the side of the atretic ear. Ultrahigh-frequency audiometry (UHFA) has revealed a bilateral loss of hearing greater than expected for the age of affected patients. Quantitative electroencephalography (QEEG) has shown a significant central nervous system electrical dysfunction correlated with the SPECT of brain findings. One case is reported in detail at this time. Completion of the medical audiological tinnitus patient protocol, including SPECT of brain, UHFA, and QEEG, accurately established the clinical tinnitus diagnosis of predominantly a central-type tinnitus, a clinical hypothesis that the medical significance of the tinnitus is a "soft" sign of cerebrovascular disease, and provided a rationale for treatment directed to a presumed ischemia of brain based on a receptor-targeted therapy targeted to the GABA-A receptor, resulting in significant tinnitus relief. Questions that have arisen include (1) the incidence of occurrence of hypoperfusion of the middle cerebral artery in congenital atresia patients; (2) implications and long-term consequences of this finding in this patient population for development of cerebrovascular disease; (3) brain plasticity for tinnitus relief (i.e., neuronal reprogramming, particularly in response to treatment recommendations for complaints of the cochleovestibular system in general and specifically for tinnitus); (4) the clinical significance of the UHFA thresholds of bilateral hearing loss greater than expected for the age of the patient; and (5) whether congenital atresia of the external ear may be part of a syndrome that includes hypoperfusion in brain areas supplied by the middle cerebral artery on the side of the atretic ear, ultra-high-frequency bilateral loss of hearing greater than expected for the age of the patient, and significant central nervous system electrical dysfunction. As far as we can determine, these findings, highlighted by the brain SPECT, have not previously been reported in patients with congenital atresia of the external ear.
Int Tinnitus J 2006
PMID:Congenital atresia of the external ear and tinnitus: a new syndrome. 1714 36

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

Some evidence in the literature supports the topical application of papaverine to the cochlear nerve to prevent internal auditory artery vasospasm and cochlear ischemia as a method of enhancing the ability to preserve hearing during acoustic neuroma surgery. The authors report a case of transient facial nerve palsy that occurred after papaverine was topically applied during a hearing preservation acoustic neuroma removal. A 58-year-old woman presented with tinnitus and serviceable sensorineural hearing loss in her right ear (speech reception threshold 15 dB, speech discrimination score 100%). Magnetic resonance imaging demonstrated a 1.5-cm acoustic neuroma in the right cerebellopontine angle (CPA). A retrosigmoid approach was performed to achieve gross-total resection of the tumor. During tumor removal, a solution of 3% papaverine soaked in a Gelfoam pledget was placed over the cochlear nerve. Shortly thereafter, the quality of the facial nerve stimulation deteriorated markedly. Electrical stimulation of the facial nerve did not elicit a response at the level of the brainstem but was observed to elicit a robust response more peripherally. There were no changes in auditory brainstem responses. Immediately after surgery, the patient had a House-Brackmann Grade V facial palsy on the right side. After several hours, this improved to a Grade I. At the 1-month follow-up examination, the patient exhibited normal facial nerve function and stable hearing. Intracisternal papaverine may cause a transient facial nerve palsy by producing a temporary conduction block of the facial nerve. This adverse effect should be recognized when topical papaverine is used during CPA surgery.
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PMID:Transient facial nerve palsy after topical papaverine application during vestibular schwannoma surgery. Case report. 1797 79

In an evolving clinical experience since 1979, the medical significance of the symptom of tinnitus has been identified as a "soft" sign of neurodegeneration (ND) in the central nervous system (CNS) in a particular subset of tinnitus patients diagnosed with a predominantly central-type, severe, disabling, subjective idiopathic tinnitus. To highlight this experience, a retrospective review and analysis of consecutive tinnitus patients (N = 96) was conducted. Ninety-six tinnitus patients (ages 22-90 years) were seen in neurotological consultation from November 1, 2005, to June 30, 2007, all of whom had subjective idiopathic tinnitus of the severe disabling type (SIT). Of these 96 patients, 54 had SIT of the predominantly central type and of these, 18 (ages 39-75 years) were recommended for nuclear medicine imaging (single-photon emission computed tomography [SPECT] and fluorodeoxyglucose-positron emission tomography/computed tomography [FDG-PET/CT]). Patient selection for nuclear medicine imaging fulfilled the criteria of a medical-audiological ND tinnitus profile: completion of a patient protocol that diagnosed a predominantly central-type, severe, disabling, subjective, idiopathic tinnitus lasting in excess of 1 year, and failure of existing modalities of treatment attempting tinnitus relief. In 16 of the 18 patients, objective evidence of ND was reported in multiple neural substrates of brain obtained with SPECT or FDG-PET/CT of brain. Classification of CNS ND and tinnitus differentiated between (1) ND of nonspecific or unknown etiology; (2) ND manifested by perfusion asymmetries in brain associated with ischemia (n = 11/18); and (3) neurodegenerative CNS disease consistent with nuclear medicine criteria for senile dementia of the Alzheimer's type (n = 5/18). The diagnosis has been associated with cerebrovascular disease (n = 16/18). The identification of neurodegenerative CNS disease in a selected cohort of patients with subjective idiopathic tinnitus as a soft sign of such CNS disease has implications for diagnosis and treatment.
Int Tinnitus J 2007
PMID:Central nervous system neurodegeneration and tinnitus: a clinical experience. Part I: Diagnosis. 1822 91

Whether the rotational vertebral artery syndrome (RVAS), consisting of attacks of vertigo, nystagmus and tinnitus elicited by head-rotation induced compression of the dominant vertebral artery (VA), reflects ischemic dysfunction of uni- or bilateral peripheral or central vestibular structures, is still debated. We report on a patient with bilateral high-grade carotid stenoses, in whom rightward headrotation led to RVAS symptoms including a prominent nystagmus. Three-dimensional kinematic analysis of the nystagmus pattern, recorded with search coils, revealed major downbeat nystagmus with minor horizontal and torsional components. Magnetic resonance angiography demonstrated a hypoplastic right VA terminating in the posterior inferior cerebellar artery, a dominant left VA, and a hypoplastic P1-segment of the left posterior cerebral artery (PCA) that was supplied by the left posterior communicating artery (PCoA). The right PCA and both anterior inferior cerebellar arteries were supplied by the basilar artery. The right PCoA originated from the right internal carotid artery. Color duplex sonography showed severe reduction of diastolic blood flow velocities in the left VA during RVAS attacks. The nystagmus pattern can be best explained by vectorial addition of 3D sensitivity vectors of stimulated right and left anterior and horizontal semicircular canals with slightly stronger stimulation on the left side. We hypothesize that in RVAS, compression of dominant VA leads to acute vertebrobasilar insufficiency with bilateral, but asymmetric ischemia of the superior labyrinth. With regard to RVAS etiology, our case illustrates a type of pure vascular RVAS. Severity of attacks markedly decreased after successful bilateral carotid endarterectomy.
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PMID:Rotational vertebral artery syndrome: 3D kinematics of nystagmus suggest bilateral labyrinthine dysfunction. 1827 4


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