Disease relevance of Dizziness

• These findings suggest that the release of vasopressin that follows isosmolar hypovolemia achieved by orthostasis may occur independently of changes in the renin-angiotensin system in the presence of propranolol [1].
• Midodrine improved (p < 0.05) the following symptoms of orthostatic hypotension compared to placebo: dizziness/lightheadedness, weakness/fatigue, syncope, low energy level, impaired ability to stand, and feelings of depression [2].
• Forearm venous plasma dihydroxyphenylglycol and norepinephrine were determined at rest and during graded orthostasis in 47 normotensive control subjects and 58 outpatients with essential hypertension [3].
• Prick tests to natural latex elicited a 4+ reaction associated with immediate flushing, tachycardia, urticaria, and light-headedness [4].
• High doses of PCP produce disturbing manifestations including psychosis, numbness, light-headedness, vertigo, ataxia, and nystagmus due to acute intoxication [5].

Psychiatry related information on Dizziness

• Noradrenaline (NA), adrenaline (Ad), dopamine (DA), platelet serotonin (p-5HT), plasma serotonin (f-5HT) and plasma tryptophan (TRP) were assessed during the morning (supine resting + 1-min orthostasis + 5-min exercise) and at night (supine resting + slow wave sleep (SWS) + REM sleep) [6].
• Most adverse reactions to cetiedil are related to its anticholinergic properties (dryness of mouth, blurred vision, spacy feelings, disorientation) or vasodilatory effects (light-headedness, vertigo, cold extremities); these side-effects were dose-related with regard to incidence, severity and duration [7].

High impact information on Dizziness

• Side effects were reported by 35 patients--21 in the nicotine group and 14 in the placebo group--the most common of which were nausea, lightheadedness, and itching [8].
• The interrelationship between the release of renin and vasopressin as defined by orthostasis and propranolol [1].
• The function of the edema-protective baroreceptor-mediated and local nervous vasoconstrictor reflexes of the lower leg during orthostasis in moderate and severe CHF has largely been unexplored [9].
• The most potent stimuli of norepinephrine were treadmill exercise, orthostasis, caffeine, the cold pressor test, sodium restriction and handgrip exercise, in descending order [10].
• However, incidence of vasodilator side effects (flushing, dizziness, and light-headedness) was significantly less frequent with nifedipine GITS (standard nifedipine, 12; nifedipine GITS, six; p less than 0.05) [11].

Chemical compound and disease context of Dizziness

• Initial treatments with elastic stockings, fludrocortisone acetate, and dihydroergotamine mesylate resulted in no obvious improvement of his orthostasis [12].
• Atenolol induced a marked decrease in blood pressure and pulse rate during recumbency, orthostasis and exercise concomitant with a marked increase in plasma noradrenaline concentration (p less than 0.0125) and a pronounced decrease in plasma renin concentration (p less than 0.01) [13].
• All patients were studied before and after each treatment by response to two stimulatory tests, acting through two different pathways; orthostasis test (O-T) and the furosemide test (Furo-T) [14].
• In control studies orthostasis induced significant increases only in plasma renin activity and aldosterone [15].
• While the release of NE during orthostasis appeared to be suppressed in the indomethacin-treated state, it was unchanged during the cold pressor test [16].

Biological context of Dizziness

• The rise of heart rate induced by orthostasis was diminished by AQ-A 39 to 4 +/- 2 beats min-1 and by propranolol 9 +/- 2 beats min-1 [17].
• In addition, data were presented that document invasive and noninvasive techniques of measurement used during investigations of baroreflex and hemodynamic mechanisms of blood pressure regulation during lower body negative pressure (LBNP), a laboratory technique that simulates orthostasis [18].
• 2. We have measured the urinary excretion rate of retinol-binding protein overnight, during orthostasis and during a hyperinsulinaemic euglycaemic clamp (blood glucose concentration 7.0 mmol/l) with stable diuresis in 34 normotensive, normoalbuminuric insulin-dependent diabetic patients and in 10 normal control subjects [19].
• Regional blood flow in the calf and plasma endothelin during prolonged orthostasis in humans [20].
• This increase in cardiopulmonary baroreflex control buffers the heightened sympathetic neural drive in mildly hypertensive subjects in the supine position, but withdrawal of this increase during orthostatic stress produces exaggerated reflex sympathetic vasoconstrictor responses to orthostasis in mildly hypertensive subjects [21].

Anatomical context of Dizziness

• Central nervous system side effects (sedation or lightheadedness) were reported in six hydrocodone/acetaminophen patients compared with 16 codeine/acetaminophen patients (P less than .005) [22].

Gene context of Dizziness

• We studied volume-pressure sensitivity, as estimated by the plasma AVP response to orthostasis, in healthy young (19-31 yr old; n = 12) and old (62-80 yr old; n = 15) subjects [23].
• Patients but not normals showed significant rises of DBP at orthostasis and exercise (5') periods, which were positively correlated with NA rises [24].
• In all craniopharyngioma patients, the counterregulatory glucagon response to hypoglycemia was preserved and orthostasis increased both catecholamines and the heart rate similar to in the patients with hypopituitarism as well as in the healthy controls [25].
• This was the most frequent of a triad of features, the others being infrequent attacks, of coryza and light-headedness [26].
• Our study demonstrated normal interictal autonomic function in patients with epilepsy, but, variations in BP and HR during orthostasis and CPT were significantly (p < 0.05) higher in epilepsy patients than in controls with or without CBZ [27].

Analytical, diagnostic and therapeutic context of Dizziness

• Changes in blood osmolality and/or volume were produced by each of 3 procedures--fluid deprivation, orthostasis, and hypertonic saline infusion--and the resultant changes in plasma AVP were measured by radioimmunoassay and expressed as a function of the simultaneous level of plasma osmolality [28].
• Placental blood perfusion, the maternal heart rate, and arterial blood pressure were measured before and after a single intramuscular dose of ritodrine hydrochloride during orthostasis in 11 healthy pregnant women, 10 pre-eclamptic patients, and 11 pregnant patients with essentially hypertension [29].
• After quick titration of pergolide with domperidone cotreatment, no symptomatic side effects were seen except for lightheadedness in one patient, which disappeared after dose reduction [30].
• However, the incidence of orthostasis may be increased with the use of 10 mg/h. Thus, 5 mg/h of epidural bupivacaine (.05% at 10 mL/h) improved analgesia, decreased opioid requirements, and did not have detectable hemodynamic effects [31].

References