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

Charts from 1,074 consecutive emergency department patients who underwent cranial computed tomography (CT) were reviewed for predictors of a CT abnormality. Twenty-six clinical variables and the results of neurologic examination were compared with cranial CT findings. Patients with focal neurologic deficit, unresponsiveness, and hypertension had an increased risk of a CT abnormality. Blurred vision, trauma, loss of consciousness, headache, and dizziness were each associated with a lower risk of a CT abnormality. Multivariate analysis showed that only focal neurologic deficit and unresponsiveness effectively helped predict a CT abnormality. In patients with negative neurologic findings, only intoxication and amnesia were associated with greater than 10% positive scans and an increased risk for a CT abnormality. The data indicate that positive neurologic findings coupled with intoxication and amnesia would have helped detect 90.7% of the positive scans and provide an effective initial approximation strategy for selecting patients to undergo CT. Although 15 patients with positive scans (1.4%) would have been missed, this strategy would have yielded a negative predictive value of 97.3% and eliminated 53.9% of the CT scans obtained.
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PMID:Unenhanced emergency cranial CT: optimizing patient selection with univariate and multivariate analyses. 843 Jan 85

In 102 patients with inducible supraventricular tachycardia (SVT), 56 women and 46 men aged 20-86 (mean, 52) years, underwent electrophysiologic study. SVTs observed at electrophysiologic study were atrial flutter or atrial fibrillation (32%), the "slow-fast" form of atrioventricular (AV) nodal reentrant tachycardia (45%), orthodromic AV reentrant tachycardia (25%), and atrial tachycardia (9%). More than 1 SVT occurred in some patients. Spontaneous symptomatic SVT frequency prior to oral flecainide varied from 3/day to 1/3 months (mean, 3/month). At electrophysiologic study and during SVT, intravenous flecainide, 2 mg/kg body weight, was given at an infusion rate of 10 mg/min up to a maximum dose of 150 mg. Patients were commenced on oral flecainide if SVT termination occurred during intravenous flecainide administration and if reinitiation was not possible after the total dose of flecainide had been given. In patients with AV nodal reentrant tachycardia and AV reentrant tachycardia further criteria for commencing oral flecainide were SVT termination by ventricular-atrial conduction block and persistent ventricular-atrial block after intravenous flecainide administration. Initial oral flecainide dosage was determined by assessing ability to reinitiate SVT after 50 mg, 100 mg, and the total dose of intravenous flecainide had been given. Eighty-nine patients (87%) remained free of symptomatic SVT over a mean follow-up period of 3.9 years (range, 3 months to 6.5 years). Two thirds were still taking the original dosage of flecainide and the rest were SVT-free on a higher dosage. Oral dosages ranged from 50 to 300 mg/day (median dosage, 100 mg twice daily) Nine patients experienced minor side effects, including, lethargy, dizziness, headache, and blurred vision. There were no deaths and no reports of major proarrhythmic events or other major adverse effects.
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PMID:Efficacy and safety of long-term oral flecainide acetate in patients with responsive supraventricular tachycardia. 860 96

Current antidepressants achieve similar efficacy, with 60% to 80% of patients responding adequately. Clinical response is gradual, and differential response factors are difficult to discern. However, side effect profiles and toxicity vary substantially, so the choice of medication depends primarily on tolerability and safety. Dry mouth is prevalent with tricyclic antidepressants (TCAs), whereas nausea occurs more frequently with a serotonin selective reuptake inhibitor (SSRI). Long-term unwanted effects tend not to be a major problem, with a dropout rate of approximately 5% due to side effects. The relationship between suicidality and antidepressants remains under debate. Many TCAs are highly toxic in overdose whereas the SSRIs appear much safer. Nefazodone is a unique antidepressant with demonstrated efficacy. It is different from other antidepressants because of its two actions in the serotonin system, moderate serotonin selective reuptake blocking properties and direct 5-HT2 antagonism, which also can enhance 5-HT1 neurotransmission. The 5-HT2 antagonist properties may limit serotonin-mediated effects and, as a result, nefazodone may be more anxiolytic than other antidepressants. Nefazodone also moderately inhibits norepinephrine reuptake and blocks alpha 1-adrenergic receptors. The data base on the safety of nefazodone currently comprises approximately 3,500 patients from all research trials, which include controlled trials that allow comparisons of nefazodone treatment with several hundred patients taking TCAs or SSRIs and nearly 900 patients receiving placebo. The most frequent adverse experiences with nefazodone as compared with placebo treatment are nausea (21% vs. 14%), somnolence (19% vs. 13%), dry mouth (19% vs. 13%), dizziness (12% vs. 6%), constipation (11% vs. 7%), asthenia (11% vs. 6%), light-headedness (10% vs. 4%), and amblyopia (blurred vision; 6% vs. 3%). Approximately 12% of nefazodone-treated patients dropped out because of adverse experiences, as compared with 7.4% on placebo, 10.4% on SSRIs, but 21.8% on imipramine after short-term exposure in placebo-controlled trials. Long-term safety data include nearly 1,300 patients; nefazodone was well tolerated. Nefazodone was evaluated in normal subjects by the author and was found to produce less impairment than imipramine and was less likely to interact with alcohol. In summary, nefazodone has a favorable adverse-event profile as compared with the TCAs and a rather different one from the SSRIs. It appears to be safe and well tolerated after both acute and long-term use.
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PMID:Tolerability and safety: essentials in antidepressant pharmacotherapy. 862 62

Chronic hypotension, volume nonresponsive, is not rare in hemodialysis patients and is usually refractory to various therapies. Midodrine hydrochloride is an alpha-mimetic drug acting directly on the peripheral alpha-receptor and increases blood pressure. We studied 10 uremic patients on hemodialysis with chronic hypotension to evaluate efficacy and safety of midodrine. Midodrine hydrochloride was administered at a dose of 2.5 mg twice on the dialytic day, 1.25 mg twice on the nondialytic day. Subjective symptoms and objective parameters were evaluated and compared before and after midodrine treatment. Midodrine significantly increased systolic pressure from 73.0 +/- 10.5 mm Hg to 90.5 +/- 12.3 mm Hg (p < 0.01); and diastolic blood pressure from 44.0 +/- 8.4 mm Hg to 55.4 +/- 7.9 mm Hg (p < 0.01) before dialysis. Orthostasis, dizziness, fatigue, blurred vision, dullness, headache, and depression improved an average of 62%. All patients tolerated midodrine treatment well. Only mild side effects were noted, including flush sensation, neck soreness, and headache. We conclude that midodrine may be another choice for uremic patients on hemodialysis with chronic hypotension which responds poorly to other conventional management.
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PMID:Midodrine hydrochloride in patients on hemodialysis with chronic hypotension. 872 63

The chemistry, pharmacology, pharmacokinetics, and clinical efficacy of nefazodone hydrochloride, a new antidepressant, are described. Nefazodone enhances serotonin (5-hydroxytryptamine [5-HT]) synaptic transmission by acting as an antagonist at 5-HT2 receptors and by inhibiting the reuptake of 5-HT. These two mechanisms combined may enhance 5-HT1A-mediated transmission. In addition, nefazodone weakly inhibits the reuptake of norepinephrine. Nefazodone is a structural analogue of trazodone but is pharmacologically distinct. In placebo-controlled trials, nefazodone was as effective as imipramine for the treatment of major depression and produced clinical benefits in patients with depression-related anxiety and sleep disturbances. More than 2000 patients have received nefazodone in clinical trials. The most commonly reported adverse drug reactions (ADRs) are asthenia, somnolence, dry mouth, nausea, constipation, dizziness, lightheadedness, confusion, abnormal vision, and blurred vision. The incidence of sexual-dysfunction ADRs may be less than that reported for other antidepressants. Nefazodone does not inhibit rapid-eye movement sleep. Nefazodone, an inhibitor of the hepatic P-450 isoenzyme CYP3A4, may increase concentrations of drugs metabolized by this isoenzyme, such as terfenadine, astemizole, triazolam, alprazolam, and midazolam. Caution should be exercised in administering nefazodone hydrochloride with triazolobenzodiazepines, and coadministration with terfenadine or astemizole is contra-indicated. The dosage should start at 100 mg twice daily and then be increased, depending on occurrence of ADRs and the patient's clinical response, to 300-600 mg daily. In elderly or debilitated patients, the initial dosage should be half the usual dosage. Nefazodone hydrochloride is as effective as other available antidepressants and may cause fewer ADRs.
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PMID:Nefazodone: a new antidepressant. 889 78

Transdermal scopolamine patches have been extensively prescribed for nonspecific dizziness and vestibular disorders. Patient response may be favorable and side effects are generally limited to xerostomia and blurred vision. However, subtle dependency and outright addiction may develop. Tapered reduction and drug elimination will suffice to eliminate the dependency. However, hospitalization may be necessary to treat severe cases of physiological chemical dependency. Long-term use of transdermal scopolamine patches carries a risk of chemical dependency. Prescribing physicians should review and heed the manufacturer's recommended use.
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PMID:Clinical manifestations of transdermal scopolamine addiction. 893 44

Disabling orthostatic hypotension, due to insufficiency of the autonomic nervous system, is a common complication of type I familial amyloidotic polyneuropathy (FAP). We investigated whether oral treatment with L-threo-3,4-dihydroxyphenylserine (L-threo-Dops), a noradrenaline precursor, might be of therapeutical benefit. In twenty untreated FAP patients, aged 33 to 44 years, who, because of severe orthostatic hypotension, were bedridden or constrained to a sitting life, supine and erect blood pressure (BP), plasma noradrenaline and tilting time, defined as the interval (s) between the beginning of a 60 degrees head-up tilt and the occurrence of orthostatic symptoms (dizziness, blurred vision or near syncope) were determined before and at repeated intervals during oral treatment with L-threo-Dops, 100 mg bid, for 6 months. Before treatment supine mean BP was 80 (76-85) mmHg (mean and 95% CI), supine plasma noradrenaline was low, 59 (41-77) pg/ml and tilting time ranged from 38 to 118 s. In response to tilt, mean BP immediately fell by 36 (31-41) mmHg, whereas plasma noradrenaline increased by only 11 (0-21) pg/ml (p = 0.05). After 3 to 5 days of treatment with L-threo-Dops all patients experienced marked improvement of their orthostatic tolerance as reflected by their ability to walk freely around. This effect sustained throughout the six months of treatment. Plasma noradrenaline increased moderately by 37 (11-63) pg/ml (p = 0.02) and supine mean BP increased by 8.6 (5.8-12.4) mmHg (p < 0.001) during chronic treatment. Supine or nocturnal hypertension did not develop, the fall in mean BP in response to tilt diminished by 12.5 (6.5-17.3) mmHg (p < 0.001) and tilting time became longer than 600 s in all patients. Because of its efficacy, its sustained duration of action and the lack of side effects, L-threo-Dops is advocated to improve orthostatic tolerance in patients with autonomic insufficiency due to FAP.
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PMID:Improved orthostatic tolerance in familial amyloidotic polyneuropathy with unnatural noradrenaline precursor L-threo-3,4-dihydroxyphenylserine. 902 51

Scombroid fish poisoning is a food-borne chemical intoxication caused by certain spoiled fish that contain a large amount of histamine and some biogenic diamines. It has gradually become a world-wide medical problem and probably is the most common cause of fish poisoning. As the data on the incidents of scombroid fish poisoning in Taiwan remains scarce, we report 2 incidents of scombroid fish poisoning in Northern Taiwan. We collected data of the 2 outbreaks of suspected fish poisoning which were reported to us in 1996. An epidemiological investigation was undertaken. Questionnaire interviews were given to persons who ate lunch in the same cafeteria in outbreak 2. The leftover fish were sent for species identification and toxin analysis. The first incident involving 4 women occurred in March 1996. All cases experienced flush, dizziness, blurred vision and skin rashes after eating lunch. A non-scombroid fish of Makaira with histamine levels as high as 84.13 mg/100 g flesh was implicated in this incident. In August 1996, another incident involving some cases who ate lunch at the same cafeteria were investigated. A total of 146 questionnaires were distributed with a return of 132 questionnaires (90.4%). Fifty-five employees reported positive signs or symptoms; 48 persons who ate fish and 7 women who did not eat fish were ill. Fish was the only food associated with the illness with an attack rate of 73.8% (p < 0.001). The incriminated fish was later identified as a scombroid fish of Euthynnus with a histamine content of 271.9 mg/100 g flesh in 1 leftover piece and 118.5 mg/100 g flesh in another piece. Most cases in these 2 outbreaks received treatment with antihistamines and had rapid and complete recovery. The diagnosis of scombroid fish poisoning could be misdiagnosed as food allergy or bacterial food poisoning if physicians are not aware of such poisoning. The nonspecific but characteristic symptomatology of histamine food poisoning and previous consumption of fish should alert physicians to the possibility of scombroid fish poisoning. Unless complicated with shock or respiratory distress, supportive treatment with antihistamines usually concludes with a good prognosis. Toxin analysis of the fish flesh remains the most important step in approaching a confirmed diagnosis.
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PMID:Scombroid fish poisoning: an overlooked marine food poisoning. 925 Nov 76

This paper investigates the acute effects of carbofuran in workers of two pesticide-formulating plants. Mean airborne carbofuran concentrations ranged from 0.025 to 1.115 mg/m3 in plant A and from 0.018 to 0.067 mg/m3 in plant B, respectively. In workers of plant A the post-shift blood cholinesterase activity was significantly reduced, compared to pre-shift values. No difference in blood cholinesterase activity was found between pre- and post-shift values in workers of plant B. During the investigation, 25 cases of acute carbofuran poisoning were diagnosed by their clinical picture and depressed cholinesterase activity in blood. Usual symptoms included dizziness, weakness, blurred vision, nausea and sweating. Pallor, epigastric pain, vomiting and chest tightness occurred only in a few cases. Myosis was recorded in 24 cases. Fasciculation of muscle gastrocnemius induced by percussion was found in 6 cases, and four of them had also fasciculation of muscle orbicularis oculi. Inhibition of cholinesterase activity in the blood was related with the clinical features; however, the inhibition was rapidly reversible. In most cases, recovery was complete within 2-3 hours, with or without atropine treatment, after the subjects were removed from exposure. Rapid onset, mild illness and quick recovery are typical characteristics of occupational acute carbofuran poisoning.
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PMID:Acute effects of carbofuran in workers of two pesticide plants. 1021 31

The flight crews of aircraft often report symptoms including dizziness, nausea, disorientation, blurred vision and tingling in legs and arms. Many of these incidents have been traced to contamination of cabin air with lubricating oil, as well as hydraulic fluid, constituents. Considering that these air contaminants are often subjected to temperatures in excess of 500 degrees C, a large number of different exposures can be expected. Although the reported symptoms are most consistent with exposures to volatile organic compounds, carbon monoxide, and the organophosphate constituents in these oils and fluids, the involvement of these agents has not been clearly demonstrated. Possible exposure to toxic elements, such as lead, mercury, thallium and others, have not been ruled out. In order to assess the potential of exposure to toxic elements a multi-elemental analysis was done on two hydraulic fluids and three lubricating oils which have been implicated in a number of air quality incidents. A secondary objective was to establish if the multi-elemental concentrations of the fluids tested are different enough to allow such an analysis to be used as a possible method of identifying the source of exposure that might have been present during aircraft air quality incidents. No significant concentrations of toxic elements were identified in any of the oils or hydraulic fluids. The elemental compositions of the samples were different enough to be used for identification purposes and the measurement of only three elements was able to achieve this. Whether these findings have an application, in aircraft air quality incident investigations, needs to be established with further studies.
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PMID:Multi-elemental analysis of jet engine lubricating oils and hydraulic fluids and their implication in aircraft air quality incidents. 1041 67


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