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Query: UMLS:C0018681 (headache)
 56,091 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Patients suffering from neuromuscular diseases and thoracic deformities may develop global respiratory failure during their illness. We wanted to judge clinical parameters and information from the patients' medical history to reliably, quickly and noninvasively diagnose a ventilatory failure. Therefore we evaluated 105 situations with and without mechanical ventilation from 29 patients with indication for noninvasive nocturnal mask ventilation. 6 clinical parameters (e.g. heart rate, oxygen saturation, relative vital capacity), 2 test results (pH and partial pressure of carbon dioxide (pCO2)) and 6 parameters from the patients' medical history (e.g. nycturia, frontal headache in the morning, breathlessness) were investigated. After statistical evaluation we could show a relation between heart rate and pCO2 (Spearman's correlation: r = 0.331, p = 0.001, n = 105; one-tailed significance: r = 0.335, p = 0.038, n = 29). Significant differences between the groups of nycturia incidence indicate a tight relation between the incidence of nycturia and the height of hypercapnia levels (ANOVA--analysis of variance: p = 0.001). Using logistic regression we could show that information regarding medical history, especially nycturia, frontal headache and indrawings, gives important indications for global respiratory failure (sensitivity 97.62-100%, specificity 57.14-76.19%). Pathogenesis needs to be elaborated further.
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PMID:[Importance of medical history in diagnosis of respiratory insufficiency in patients suffering from neuromuscular diseases and thoracic deformities]. 1138 81

There is still some controversy about alterations in velocity of blood flow and in cerebral vasomotor reactivity of intracranial arteries in migraineurs during the interictal phase. By means of simultaneous bilateral transcranial Doppler ultrasonography we, therefore, assessed intracranial blood flow velocities and cerebrovascular reactivity to carbon dioxide of all three basal brain arteries in 20 migraineurs during the interictal phase and 30 nonheadache-prone control subjects. Mean blood flow velocities were higher in migraineurs than in controls in all three arteries on both sides, with a significant difference (P < 0.05) for the right anterior cerebral artery and middle cerebral artery under basal conditions and for the right posterior cerebral artery during hypercapnia. Similarly, the cerebrovascular reactivity to carbon dioxide was always higher in patients than in controls, with a significant difference for the left anterior and the right middle cerebral arteries (P < 0.05) and the right posterior cerebral artery (P < 0.01). The broad overlap of cerebrovascular blood flow velocities and CO2 reactivities in patients and controls precluded identification of values diagnostic of migraine. Nevertheless, transcranial Doppler ultrasonography offers the opportunity to noninvasively monitor cerebral blood flow parameters and, therefore, represents a valuable tool for vascular research in migraine.
Headache 1998 Sep
PMID:Cerebral blood flow and CO2 reactivity in interictal migraineurs: a transcranial Doppler study. 1139 4

Interictal cerebrovascular reactivity and blood flow velocities were tested in 23 patients with migraine without aura and 10 age- and sex-matched healthy controls by using the breath holding index (BHI). The mean systolic, diastolic and mean velocities and pulsatility indices were not different in the controls and patients. The BHI was found to be significantly greater (P=0011) in the patients (1.64 +/- 0.33) compared with the controls (1.26 +/- 0.37), showing an exaggerated reactivity to hypercapnia in migraineurs. Reactivity to pCO2 theoretically depends on pre-existing arteriolar tone and thereby on baseline velocity. Our finding of similar blood flow velocities in controls and patients suggests that the underlying cause for this high reactivity may not be an increased vasotonus but an increased sensitivity to changes in blood CO2 levels.
Cephalalgia 2002 May
PMID:Exaggerated interictal cerebrovascular reactivity but normal blood flow velocities in migraine without aura. 1210 91

To investigate further the pharmacological mechanism of an anti-migraine drug, sumatriptan, a 5-HT1B/1D receptor agonist, we studied its effect on the cerebral circulation in seven anaesthetized rats, particularly during hypercapnia. After injection of 0.6 or 6.0 microg/kg sumatriptan succinate, no significant change in cerebral blood flow (CBF) was observed either in the striatum or in the parietal cortex. The increase in CBF both in the parietal cortex and the striatum during 5% CO2 inhalation was significantly less when sumatriptan succinate 6.0 microg/kg was injected. Sumatriptan appeared to have a vasoconstrictor effect on the relaxed vessels by CO2 inhalation. This mechanism might be attributable to vasoconstriction through activation of 5-HT1B receptors located in the vascular smooth muscle rather than 5-HT1B receptors in the vascular adventitia.
Cephalalgia 2002 Jul
PMID:Effects of sumatriptan on cerebral blood flow under normo- and hypercapnia in rats. 1213 47

Noninvasive positive-pressure ventilation (NPPV) should be considered a standard of care to treat COPD exacerbations in selected patients, because NPPV markedly reduces the need for intubation and improves outcomes, including lowering complication and mortality rates and shortening hospital stay. Weaker evidence indicates that NPPV is beneficial for COPD patients suffering respiratory failure precipitated by superimposed pneumonia or postoperative complications, to allow earlier extubation, to avoid re-intubation in patients who fail extubation, or to assist do-not-intubate patients. NPPV patient-selection guidelines help to identify patients who need ventilatory assistance and exclude patients who are too ill to safely use NPPV. Predictors of success with NPPV for COPD exacerbations have been identified and include patient cooperativeness, ability to protect the airway, acuteness of illness not too severe, and a good initial response (within first 1-2 h of NPPV). In applying NPPV, the clinician must pay attention to patient comfort, mask fit and air leak, patient-ventilator synchrony, sternocleidomastoid muscle activity, vital signs, hours of NPPV use, problems with patient adaptation to NPPV (eg, nasal congestion, dryness, gastric insufflation, conjunctival irritation, inability to sleep), symptoms (eg, dyspnea, fatigue, morning headache, hypersomnolence), and gas exchange while awake and asleep. For severe stable COPD, preliminary evidence suggests that NPPV might improve daytime and nocturnal gas exchange, increase sleep duration, improve quality of life, and possibly reduce the need for hospitalization, but further study is needed. There is consensus, but without strong supportive evidence, that COPD patients who have substantial daytime hypercapnia and superimposed nocturnal hypoventilation are the most likely to benefit from NPPV. Adherence to NPPV is problematic among patients with severe stable COPD.
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PMID:Noninvasive ventilation for chronic obstructive pulmonary disease. 1473 24

Headache occasionally occurs during or after scuba diving. Although its significance often is benign, headache may signal a serious neurological disorder in some circumstances. In addition to the usual causes of headache, the diagnostic evaluation should consider otic and paranasal sinus barotrauma, arterial gas embolism, decompression sickness, carbon dioxide retention, carbon monoxide toxicity, hyperbaric-triggered migraine, cervical and temporomandibular joint strain, supraorbital neuralgia, carotid artery dissection, and exertional and cold stimulus headache syndromes. Focal neurologic symptoms, even in the migraineur, should not be ignored, but rather treated with 100% oxygen acutely and referred without delay to a facility with a hyperbaric chamber.
Curr Pain Headache Rep 2004 Aug
PMID:Headache and facial pain in scuba divers. 1522 93

The genuine closed cranial window model, in which the thinned parietal bone constitutes the covering of the preparation, has contributed to a better understanding of the pathophysiological mechanisms in migraine. In its present form, only measurements of the middle meningeal artery (MMA) are performed. The aim of this study was, in addition, to measure pial artery/arteriole (PA) diameter and cortical cerebral blood flux in the same cranial window. The model was evaluated by studying the effects of hypotension and changes in arterial carbon dioxide pressure (PaCO2), because these parameters might influence the interpretation of pharmacological experiments. Out of 23 successful experiments it was possible to measure all three parameters in 19 animals. In four, PA diameter could not be measured, while MMA diameter and local cortical cerebral blood flux (LCBF(Flux)) always could. Haemorrhage-induced hypotension (-64+/-0.8 mmHg) caused an increase of MMA diameter of 11.8+/-8.4%, PA diameter of 61.2+/-7.7% and a decrease in LCBF(Flux) of -36.4+/-2.5%. The decrease in blood pressure did not significantly change the MMA (P=0.38); however, the PA diameter and the LCBF(Flux) were affected (P<0.001). All three parameters were sensitive to hypo- and hypercapnia. In conclusion, we have shown that not only MMA but also PA diameter and LCBF(Flux) can be measured in the same cranial window. Tight control of PaCO2 is essential in pharmacological experiments. If test substances possess hypotensive actions, it may be difficult to interpret whether the PA dilation is caused by the induced hypotension per se or is a direct pharmacological action or a combination. In contrast, the MMA does not autoregulate and MMA diameter changes in pharmacological studies may exclusively be due to direct pharmacological effects.
Cephalalgia 2005 Jan
PMID:Effect of hypotension and carbon dioxide changes in an improved genuine closed cranial window rat model. 1560 66

Involvement of respiratory muscles is a nearly constant feature of neuromuscular disorders, leading to respiratory failure. A careful respiratory follow up adapted to the variable time course of each disease is therefore mandatory. As the first step, a systematic clinical evaluation is essential to detect the subtle respiratory symptoms and signs related to respiratory muscle failure. Dyspnea and orthopnea are often late findings in patients with a usually severe functional impairment due to peripheral muscle weakness. Nocturnal respiratory events (obstructive sleep apnea syndrome and hypoventilation) are strongly suggested by daytime hypersomnolence and frequent morning headaches. Physical evaluation is essential to detect accessory muscle recruitment, supine abdominal paradox, and encumbrance of upper or lower airways. Vital capacity (VC) is the most classical lung function test. The major limitation of spirometry is its poor sensitivity to detect a moderate inspiratory muscle weakness. Supine VC may improve the detection of diaphragmatic involvement. Peak expiratory flow during cough (cough PEF) gives an overall evaluation of cough efficiency, values below 160 to 270 L/min suggesting poor airway clearance. Arterial blood gases are performed in case of clinical signs, significant deterioration of lung function tests, or sleep desaturations. Hypercapnia is weakly related to lung function results in patients with Steinert dystrophy and those with bulbar involvement. A specific evaluation of respiratory muscle strength is mandatory, as these tests are both sensitive and highly prognostic. Possible discrepancies (particularly in bulbar patients) between maximal inspiratory pressure (PImax) and sniff nasal inspiratory pressure (SNIP) justify to perform both measurements and to select the highest pressure. A maximal expiratory pressure (PEmax) below 45 cm H2O may indicate a compromised cough efficiency but the correlation with cough PEF may be poor. A screening nocturnal oxymetry is useful to detect sleep apneas and hypoventilation. Criteria defining significant desaturations remain however controversial. Suspicion of obstructive sleep apnea syndrome on clinical grounds or oxymetry findings should be confirmed by a conventional polysomnography.
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PMID:[Neuromuscular disorders - assessment of the respiratory muscles]. 1658 4

Obtructive sleep apnoea syndrome (OSAS) is a common disorder in the general population with an estimated prevalence in an adult population of 2% in women and 4% in men. Although several studies have suggested that headaches, particularly morning headaches, are more common in patients with OSAS than in normal subjects, others have yielded contradictory findings. When the sleep-related breathing disorder was treated with success, the headache generally disappeared, supporting a causal role of the sleep disorder for headache. Several hypotheses have been proposed to explain the relationship between OSAS and the occurrence of headache, particularly on awakening. Night-time fluctuations of oxygen saturation during the night with hypercapnia, vasodilatation, increased intracranial pressure and impaired sleep quality are all considered contributing factors. However the exact mechanisms of headache pathogenesis and the relationship between OSAS, headache and morning headaches in particular remain controversial.
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PMID:Sleep-related breathing disorders and headache. 1668 20

Respiratory involvement is an almost constant feature of als, with a usually rapid progression leading to respiratory failure. These characteristics justify a close follow up, usually at three-month intervals. A systematic, careful clinical evaluation is essential to detect the subtle respiratory symptoms and signs related to respiratory muscle failure. Dyspnea and orthopnea are often late findings in patients with a usually severe functional impairment due to peripheral muscle weakness. Nocturnal respiratory events (obstructive sleep apnea syndrome and hypoventilation) are strongly suggested by daytime hypersomnolence and frequent morning headaches. Physical evaluation is essential to detect accessory muscle recruitment, supine abdominal paradox, and encumbrance of upper or lower airways. Vital capacity (VC) is the most classical lung function test. The major limitation of spirometry is its poor sensitivity to detect a moderate inspiratory muscle weakness. Supine VC may improve the detection of diaphragmatic involvement. Peak expiratory flow during cough (cough PEF) gives an overall evaluation of cough efficiency, values below 160 to 270 L/min suggesting poor airway clearance. Arterial blood gases are performed at first evaluation and subsequently in case of clinical signs, significant deterioration of lung function tests, or sleep desaturations. Hypercapnia is weakly related to lung function results in bulbar patients. A specific evaluation of respiratory muscle strength is mandatory, as these tests are both sensitive and highly prognostic. Possible discrepancies (particularly in bulbar patients) between Maximal inspiratory pressure (PImax) and sniff nasal inspiratory pressure (SNIP) justify to perform both measurements and to select the highest pressure. A maximal expiratory pressure (PEmax) below 45 cm H2O may indicate a compromised cough efficiency but the correlation with cough PEF may be poor. Screening nocturnal oxymetry is useful to detect sleep apneas and hypoventilation. Criteria defining significant desaturations remain however controversial. Suspicion of obstructive sleep apnea syndrome on clinical grounds or oxymetry findings should be confirmed by a conventional polysomnography.
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PMID:[Amyotrophic lateral sclerosis (ALS): evaluation of respiratory function]. 1712 9


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