Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0018681 (headache)
 56,091 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Respiratory insufficiency of any cause has significant effects on the nervous system. Headache, mental status changes, papilledema, and numerous motor abnormalities including asterixis are commonly seen. Abnormalities in ventilation and gas exchange result in hypoxia, hypercapnia, and respiratory acidosis, and these, in turn, interfere with cerebral metabolism, increase CBF, and may raise intracranial pressure. Chronic respiratory insufficiency can persist for many months with minimal neurologic symptoms, as numerous compensatory mechanisms, particularly renal, may take effect. Treatment includes restoring adequate ventilation and improving gas exchange and may require tracheal intubation and assisted ventilation. Supplemental oxygen therapy should be carefully monitored, as high rates of flow may suppress the hypoxic drive for respiration and lead to significant carbon dioxide retention. The sleep apnea syndromes are a group of disorders in which abnormal respiratory patterns during sleep result in hypercapnia and hypoxemia. Intermittent obstruction of the upper airway and abnormalities of brainstem respiratory centers cause frequent nocturnal awakenings and apneas in these patients. Treatments vary and include weight loss in obese subjects, respiratory stimulants, tracheostomy, and diaphragmatic pacing. Rapid ascent to high altitudes may result in headache, changes in mental status, papilledema, and other neurologic symptoms in certain individuals: a syndrome known as high-altitude sickness. Hypoxia leading to cerebral edema, nocturnal periodic breathing, and hypobaria produces neurologic symptoms in these individuals. Acetazolamide and dexamethasone may be effective in minimizing symptoms of this disorder. Sustained hyperventilation produces acral and circumoral paresthesias and lightheadedness in anxious individuals and can be maintained by relatively normal ventilatory patterns once established. These symptoms are due to hypophosphatemia and respiratory alkalosis, the latter reducing CBF and causing localized tissue hypoxia. Rebreathing into a paper bag at the first awareness of symptoms is the most effective form of treatment.
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PMID:Neurologic manifestations of pulmonary disease. 267 37

The incidence of acute mountain sickness was determined by questionnaire in 454 individuals who attended week-long continuing medical education programs at ski resorts in the Rocky Mountains with base elevations of about 2000 m. As a control group, 96 individuals who attended continuing medical education programs at sea level in San Francisco completed similar questionnaires. Study subjects were classified as having acute mountain sickness when they reported three or more of the five possible cardinal symptoms: headache, insomnia, dyspnea, anorexia, and fatigue. Only symptoms with an intensity of at least grade 2 (moderate) out of 5 were analyzed. Acute mountain sickness-like symptoms occurred in 25% of subjects at 2000 m compared with 5% of subjects at sea level. The incidence of acute mountain sickness at 2000 m was greatest among subjects who had come from lower altitudes. Half of the subjects with symptoms took medication. The duration of symptoms was short, with 90% of all symptoms that were reported occurring in the first 72 hours. Acute mountain sickness is common at intermediate altitudes, and it is frequently severe enough to prompt self-medication.
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PMID:Incidence of acute mountain sickness at intermediate altitude. 291 Nov 69

To test the value of dexamethasone acetate for ameliorating acute mountain sickness (AMS), we conducted a double-blind, randomized study that compared the effects of 4 mg of dexamethasone acetate or a placebo (given every six hours for six doses beginning at the time of exposure) at 2700 and 2050 m. Study subjects, who were recruited from health professionals who attended continuing medical education programs at ski resorts in the Rocky Mountains, were classified as having AMS when they reported three or more of the five usual symptoms (headache, insomnia, dyspnea, anorexia, and/or fatigue) on a single day. All symptoms with an intensity of at least grade 2 (moderate) out of 5 were analyzed. At 2700 m, there was a 50% decrease in the mean AMS symptom score in the dexamethasone group (0.94 +/- 1.11 vs 1.84 +/- 1.44 [mean +/- SD]) and the incidence of AMS was 20% of that in the control group (3/38 vs 14/35). At 2050 m, there was no difference between dexamethasone and a placebo in the mean AMS symptom score (1.52 +/- 1.50 vs 1.24 +/- 1.33) and the incidence of AMS (5/25 vs 4/25). Dexamethasone ameliorates the usual symptoms of AMS at 2700 m but not at 2050 m.
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PMID:Effects of dexamethasone on the incidence of acute mountain sickness at two intermediate altitudes. 291 Nov 70

The interest in mountain tracking and climbing has increased and there is a need for knowledge of altitude-related diseases. About one million non-acclimatized individuals annually frequent areas around 2,000 to 3,000 m above sea level and incur unpleasant symptoms in the form of acute altitude sickness or potentially fatal conditions such as pulmonary and/or cerebral oedema. Headache is the most prominent sign of acute altitude sickness but fainting fits, loss of appetite, hesitant gait, euphoria, or confusion also occur. Dyspnoea, cyanosis at rest, and a dry cough are signs of pulmonary oedema. Cerebral oedema may be feared when inexperienced climbers are afflicted by severe headaches, vomiting, and hesitant gait. Coma ensues relatively soon. Treatment consisting in descent to lower altitude, administration of oxygen, and possible medicinal therapy is effective if immediately introduced.
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PMID:[Altitude sickness]. 291 57

Behavioral, physiologic and exertional fatigue is differently defined, though symptoms are similar. The beneficial effect of amantadine on fatiguability in multiple sclerosis is accompanied by neuropeptide and lactate changes in the circulation. Exercise sometimes overwhelms temperature regulating mechanisms and may be associated with heat stroke. Endogenous opioids are markedly increased in the circulation during heat stroke and the use of specific opioid antagonists therapeutically has been proposed for heat stroke. Sympathetic activity changes in endurance trained subjects and vasoconstrictor responses are markedly attenuated. Similar changes occur in parasympathetic function which can be abnormal in up to 90% of endurance trained subjects. Hormonal secretion during prolonged exertion is altered and the normal signals (inhibiting or activating feedback mechanisms) are different in endurance trained subjects. Altitude, associated with acute mountain sickness, is also accompanied by an increase in cranial bloodflow. Circadian and temporal variation in autonomic function are manifest by changes in mast cell numbers and 5-HT containing nerve fibers in temple skin of patients with cluster headache. The remission rate induced by vagal stimulation in subjects with intractable hiccups is also affected by circadian hormonal or neurogenic influences.
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PMID:The autonomic nervous system and fatigue. 296 78

Forty-seven climbers participated in a double-blind, randomized trial comparing acetazolamide 250 mg, dexamethasone 4 mg, and placebo every eight hours as prophylaxis for acute mountain sickness during rapid, active ascent of Mount Rainier (elevation 4,392 m). Forty-two subjects (89.4 percent) achieved the summit in an average of 34.5 hours after leaving sea level. At the summit or high point attained above base camp, the group taking dexamethasone reported less headache, tiredness, dizziness, nausea, clumsiness, and a greater sense of feeling refreshed (p less than or equal to 0.05). In addition, they reported fewer problems of runny nose and feeling cold, symptoms unrelated to acute mountain sickness. The acetazolamide group differed significantly (p less than or equal to 0.05) from other groups at low elevations (1,300 to 1,600 m), in that they experienced more feelings of nausea and tiredness, and they were less refreshed. These drug side effects probably obscured the previously established prophylactic effects of acetazolamide for acute mountain sickness. Separate analysis of an acetazolamide subgroup that did not experience side effects at low elevations revealed a prophylactic effect of acetazolamide similar in magnitude to the dexamethasone effect but lacking the euphoric effects of dexamethasone. This study demonstrates that prophylaxis with dexamethasone can reduce the symptoms associated with acute mountain sickness during active ascent and that acetazolamide can cause side effects that may limit its effectiveness as prophylaxis against the disease.
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PMID:A randomized trial of dexamethasone and acetazolamide for acute mountain sickness prophylaxis. 333 64

High altitude cerebral oedema is a severe form of acute mountain sickness occurring at heights above 4500 metres. The clinical features are of headache, impairment of consciousness and a variety of neurological signs. The condition occurs during acclimatisation and also at extreme altitudes above 7500 metres when it is often fatal. Case histories of cerebral oedema patients, pathological findings and treatment are reviewed. Other forms of altitude-related illness are also reviewed, including stroke and retinal haemorrhage.
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PMID:High altitude cerebral oedema. 338 23

Twenty-one climbers who were members of the American Ultima Thule Everest Expedition participated in a double-blind, randomized clinical trial of phenytoin prophylaxis for acute mountain sickness during the approach to the northeast ridge of Mount Everest. The study was carried out between Beijing and base camp at 16,800 feet. Time spent ascending from Beijing to base camp averaged 13 days. High-altitude symptom questionnaires were filled out beginning in Lhasa at 11,800 feet and in Xigatse at 12,000 feet, in Xegar at 14,000 feet, and at base camp. Computer analysis of the questionnaire answers performed by an impartial analyst revealed that climbers who took phenytoin were less likely to have headaches at base camp. No other statistically significant differences were observed, but the power of the sample size was low.
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PMID:Phenytoin and acute mountain sickness on Mount Everest. 351 May 39

A self-completed questionnaire (modified Environmental Symptoms Questionnaire) was evaluated in a study of acute mountain sickness (AMS). The questionnaire scores for headache, nausea, and the general feeling of ill health correlated well with AMS scores obtained by clinical interview. Modifications in the instructions and the phrasing of some of the questions are suggested and we doubt whether factor analysis provides any better data than more simple statistical methods. The questionnaire is a useful additional method for the assessment of symptoms of AMS.
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PMID:The Environmental Symptoms Questionnaire in acute mountain sickness. 401 70

A double-blind randomized study of 45 climbers on Mt. Rainier was conducted to test the effectiveness of antacids in preventing acute mountain sickness. All 45 climbed to 3353 m, and 31 continued to the summit. Ten climbers listed acute mountain sickness as the reason for not attaining the summit. Of symptoms monitored throughout the climb, neither headache, nausea, dizziness, pounding heart, nor shortness of breath differed in severity between antacid-treated and placebo-treated groups. In both groups vital capacity decreased significantly with ascent (p less than 0.05), while peak flow (p less than 0.005) and minute ventilation (p less than 0.001) increased significantly. The 7 climbers with the most severe AMS symptom scores above 4000 m had significantly lower peak flow at sea level prior to ascent compared with the other 25 climbers who completed sea level tests (p less than 0.005). The results of this study fail to document efficacy for antacid use for the prevention of acute mountain sickness.
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PMID:Acute mountain sickness, antacids, and ventilation during rapid, active ascent of Mount Rainier. 634 73


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