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Query: UMLS:C0012833 (dizziness)
 9,689 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The symptom of sudden tilting of the visual surroundings is described in detail based on experience with five patients. Patients perceive the visual fields as suddenly turning through a variable arc, most frequently 90-180 degrees, usually associated with dizziness. In three patients with vertebral-basilar artery disease, visual tilting was more closely related to local pontomedullary ischemia than to posterior cortical ischemia. It is suggested that most instances of this illusion are due to disorders of the vestibular-otolithic apparatus or its central connections, most frequently from vertebral-basilar ischemia.
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PMID:Illusion of tilting of the visual environment. Report of five cases. 622 17

Permanent or transient reduction of blood flow to the hindbrain is often responsible for symptoms of disequilibrium, dizziness and occasionally sensorineural hearing loss. Recent advances in CT technology and the development of continuous rapid rotational CT brain scanning now permit a practical and relatively non-invasive method for evaluation of regional brain circulation. It is the purpose of this presentation to review displays of normal CT hindbrain circulation and compare them with displays from patients with hindbrain ischemia. Dynamic CT provides a useful clinical index of brain blood circulation and can be used to detect and differentiate insufficiency due to pathology of the brain, of the artery supplying it, or of the cardiovascular system. Finally, the quantitative hemodynamic benefit from surgery of the carotid or vertebral arteries can be properly evaluated by this technique.
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PMID:Evaluation of the regional blood circulation of the hindbrain by dynamic computed tomography. 728 99

A rare case of persistent primitive trigeminal artery variant (PTAV) with cerebellar ischemia is reported. A 23-year-old male complained of sudden dizziness and nausea after playing valley ball. CT scan and MRI on admission revealed no abnormal findings. Left carotid angiography demonstrated a PTAV anastomoting precavernous portion of left internal carotid artery to the left superior cerebellar artery. The 37 cases reported in literature were reviewed to characterise PTAV. Ninety-seven% of the cases arising from precavernous portion of internal carotid artery, and terminated in anterior inferior cerebellar artery in 73%, posterior inferior cerebellar artery in 13.5% and superior cerebellar artery in 13.5%. Approximately 22.2% of patients with PTAV have cerebral aneurysms. The hypotension or mechanical compression of PTAV on playing valley ball with poor vascular supply to the part of cerebellum possibly caused cerebellar ischemia in this case.
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PMID:[Persistent carotid-superior cerebellar artery anastomosis presenting with cerebellar ischemic attack: a case of persistent trigeminal artery variant]. 749 18

Forty-five ASA physical status I volunteers, divided in three groups of 15 each, received intravenous regional anesthesia (IVRA) of the upper limb with 40 mL meperidine 0.25%, lidocaine 0.5%, or 0.9% sodium chloride (isolated ischemia) by random allocation. Using a double-blind method, the onset and recovery of sensory block was tested at six sites of the forearm and hand. The onset of complete motor block was also assessed. The symptoms after deflation of the tourniquet were recorded. The onset of block, as determined by pin-prick touch, and cold was significantly faster in the meperidine group (P < 0.001) than in the saline group, but also slower (P < 0.001) than in the lidocaine group. After the tourniquet was deflated, recovery occurred in reverse order. A complete motor block was noted in all volunteers from the meperidine and lidocaine groups, but in only 11 cases from the 0.9% sodium chloride group (P < 0.01). In the meperidine group, motor block developed concomitantly or prior to sensory block. There was a significant increase in the incidence of dizziness, nausea, and pain at the injection site in the meperidine group in comparison with the lidocaine group. We conclude that meperidine has local anesthetic action on the peripheral nerve in vivo, but that its single use for IVRA should be a second choice for patients allergic to local anesthetics.
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PMID:Intravenous regional anesthesia with meperidine. 953 32

Spin-echo magnetic resonance imaging (MRI) was evaluated to 530 cases in order to investigate the clinical, significance of pontine high signals. The subjects comprised 109 cases of pontine infarction with high signal on T2-weighted image and low signal on T1-weighted image (PI group), 145 of pontine high signal with high signal on T2-weighted image but normal signal on T1-weighted image (PH group) and 276 of age-matched control without abnormality either on T1 or T2-weighted images (AC group). Subjective complaints such as vertigo-dizziness were more frequent in the PH group than in the PI group. In both PI and PH groups, periventricular hyperintensity as well as subcortical high signals in the supratentorium were more severe than in the AC group. These degrees were higher in the PI group than in the PH group. In conclusion, PH as well as PI may result from diffuse arteriosclerosis and PH is considered to be an early finding of pontine ischemia.
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PMID:[Clinical significance of pontine high signals identified on magnetic resonance imaging]. 825 23

Some forms of dizziness, imbalance, and hearing change have been suspected to result from a vertebral basilar artery circulatory deficit. Microvascular hypoperfusion of the central nervous system (CNS) is proposed as a more likely mechanism than thromboembolic phenomena of the parent arteries. Symptoms of end-organ pathology must be differentiated from CNS causes to assure implementation of an appropriate treatment strategy. Guidelines for the evaluation of these patients are provided. Changes in platelet and red and white blood cell morphology are proposed as more significantly influencing blood flow than blood pressure or vessel caliber. Medications that alter blood rheology, have been found to alleviate the acute symptoms of microvascular hypoperfusion. Residual balance deficits from presumed long-term CNS ischemia have then been relieved by balance rehabilitation training. With the recognition of this disease entity there appears another means of aiding patients with dizziness and balance problems who have previously experienced long-term disability. The results of a preliminary study of 378 patients merits further investigation of the proposed pathophysiology and treatment measures.
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PMID:William F. House Lecture. Neurotologic manifestations of microvascular hypoperfusion. 857 75

Bleeding and thrombosis are major causes of morbidity and mortality in patients with chronic myeloproliferative disorders. We retrospectively evaluated 101 consecutive patients affected by primary thrombocytosis (46 male, 55 female, aged 18-84 years; mean +/- SD 61 +/- 15) followed for a period ranging from 6 months up to 10 years (median 5 years) at our hematological unit. At the time of diagnosis 48 patients were asymptomatic; 26 had clinical evidence of atherothrombosis (cerebral ischemic attacks, ischemic heart disease, peripheral occlusive arterial disease), ten had venous thrombosis, four experienced major hemorrhages, 23 presented microvascular ischemic manifestations namely erythromelalgia, paresthesias, acrocyanosis and dizziness. At presentation 51.2% of the patients had elevated serum lactic dehydrogenase, 34.5% hyperuricemia, and 23.4% serum creatinine > 1.2 mg/dL. Color Doppler ultrasound provided evidence of vascular stenosis or medium-intimal hyperplasia of epiaortic vessels in 48.9% of patients studied, and similar alterations of lower limb arteries in 23.8% of cases. Therapy modality included an antiplatelet agent (picotamide 300 mg/bid); a cytoreductive agent (busulphan, hydroxyurea, pipobroman or melphalan) was used when platelet count was > 800000/microL. Symptoms due to microvascular ischemia promptly regressed after picotamide and cytoreductive therapy. During follow-up. nine patients suffered from atherothrombotic events (transient ischemic attacks, ischemic stroke, unstable angina pectoris) and five developed deep vein thrombosis or superficial thrombophlebitis. Five patients experienced major hemorrhages (two melena, two hematuria, one perioperative bleeding); the two gastrointestinal hemorrhages occurred in patients self-medicated with non steroidal anti-inflammatory drugs, and the two episodes of hematuria occurred on oral anticoagulant therapy and aspirin respectively. No major bleeding occurred in patients on continuative therapy with picotamide, even in the presence of upper digestive tract disorders. Seven patients died: mortality resulted from one sudden coronary death, three solid neoplasia, one blast crisis, one anile, and one massive hemorrhage due to abdominal aortic prosthesis tearing. Our study suggests that a long-term antithrombotic prophylaxis with picotamide may be of benefit in patients affected by primary thrombocytosis; a controlled clinical trial is warranted to assess whether picotamide can ameliorate the natural history of the disease.
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PMID:Thrombotic and hemorrhagic complications in chronic myeloproliferative disorders. 895 59

This discussion has focused primarily on the history and physical examination of the patient with dizziness which, in fact, are the two most important elements in the evaluation process. To perform the examination expeditiously and completely, a broad differential diagnosis of dizziness must be kept in mind. The clinician should also keep in mind two basic objectives: first, to identify serious pathology (e.g., central nervous system lesion, brainstem ischemia, cardiac arrhythmia); and second, to recognize diseases that can be specifically treated, such as an endocrine abnormality, middle ear infection, Meniere's disease, or a drug reaction. Reassurance and/or vestibular rehabilitation are the mainstays of therapy for the patients not falling into the above two categories.
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PMID:Evaluation of the dizzy patient. 936 Jul 99

Dizziness of cortical origin is the subjective correlate of a disturbance of spatial orientation resulting from cerebrocortical dysfunction. Cortical dizziness in the form of vertigo is rare. If present, it most probably reflects a dysfunction of a vestibular representation in the insula. It may be accompanied by tinnitus, sensory disturbance and possibly also spontaneous nystagmus. The dysfunction of this region may result either from a focal seizure or from a lesion, for instance due to ischemia. Nondirectional, visual dizziness is most probably much more common than vertigo. This latter type of dizziness results from a functional disturbance of those parts of parietooccipital cortex, contributing to the discrimination of self-induced and externally-induced retinal image slip. It is not accompanied by additional symptoms and should immediately cease upon closure of the eyes or avoidance of ego motion.
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PMID:[Cortical vertigo]. 941 72

In controlled trials, long-term treatment of patients with chronic heart failure with beta-blockers improves symptoms, slows progression of disease, and reduces morbidity and mortality rates. However, in some patients the introduction of therapy can be associated with a period of clinical instability, including risks of fluid retention, hypotension, and bradycardia. Appropriate patient selection and optimization of background therapy can minimize the risk during the introduction of therapy. With vigilance for early signs of clinical deterioration and appropriate adjustment of background medications, the care of most patients exhibiting clinical instability can be successfully managed so the patient is able to continue with the long-term therapy, a prerequisite to realizing beneficial effects. With the initiation of carvedilol, any evidence of fluid retention warrants a prompt increase in the diuretic dosage, and in more pronounced cases the carvedilol dose may need to be reduced or interrupted. In contrast, symptoms of hypotension (most commonly dizziness) generally resolve without intervention, although persistent problems may necessitate adjusting the timing of dose administration or perhaps temporarily reducing the dose of vasodilators or diuretics (the latter with care to avoid fluid retention). Bradycardia should be managed as standard practice would indicate. During long-term treatment, adjustments in beta-blocker dosage may be required in the event of an exacerbation of heart failure. Dosages should be adjusted as would be the case with other heart-failure medications, based on the severity of the clinical decompensation, but with care to minimize abrupt changes unless mandated by the patient's condition and to avoid precipitating ischemia or further deterioration. The occurrence of effects such as these does not necessarily indicate that a patient cannot respond favorably to long-term beta-blockade, but all require understanding, vigilance, and the availability of medical personnel, especially during the introduction of this therapy.
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PMID:Use of carvedilol in chronic heart failure: challenges in therapeutic management. 971 23


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