High-altitude (HA) environments have adverse effects on the normal functioning body of people accustomed to living at low altitudes because of the change in barometric pressure which causes decrease in the amount of oxygen leading to hypobaric hypoxia. Sustained exposure to hypoxia has adverse effects on body weight, muscle structure and exercise capacity, mental functioning, and sleep quality. The most important step of acclimatization is the hyperventilation which is achieved by hypoxic ventilatory response of the peripheral chemoreceptors. Hyperventilation results in increase in arterial carbondioxide concentration. Altitude also affects sleep and cardiac output, which is the other determinant of oxygen delivery. Upon initial exposure to HA, the resting pulse rate increases rapidly, but with acclimatization, heart rate and cardiac output tend to fall. Another important component that leads to decrease in cardiac output is the reduction in the stroke volume with acclimatization. During sleep at HA, the levels of CO2 in the blood can drop very low and this can switch off the drive to breathe. Only after the body senses a further drop in O2 levels breathing is started again. Periodic breathing is thought to result from instability in the control system through the hypoxic drive or the response to CO2.
Although the relationship between the development of myringosclerosis and ROS had been well documented previously, the present study is the first that has directly measured the levels of ROS in the tympanic membrane and middle ear mucosa. These results are relevant because they correlate with histological findings. It has also been demonstrated that topically applied vitamin E is effective in decreasing the ROS levels.
The aim of this study was to document patients with clinical mastoiditis who were reported to have mastoiditis by radiologists due to increased fluid signal intensity in the mastoid air cells on magnetic resonance imaging (MRI). Brain and temporal bone MRI reports between January 2004 and November 2009 were obtained from the radiology units of four different hospitals of the same Health Care Group. MRI reports for keyword mastoiditis and 406 patients were reported to have radiological mastoiditis on MRI due to increased fluid signal intensity. Otoscopic examination findings of 275 of these 406 radiological mastoiditis patients were documented and compared with MRI reports for clinical infectious otological disease. Forty-eight (17, 45%) (48/275) patients were found to have clinical otological disease on examination. The remainder of the patients (227/275, 82%) did not show any evidence of clinical otologic infectious disease. Of these 48 patients, 18 patients (37, 5%) had eustachian tube dysfunction, 13 patients (27%) had serous otitis media, nine patients (9%) had chronic otitis media, five patients (10%) had tympanosclerosis, and three patients (6%) had acute otitis media. The results of this study showed that MRI is not an effective diagnostic tool for mastoiditis. 82% of the MRI mastoiditis did not show clinical mastoiditis contradicting MRI reports. Fluid signal in the mastoid on MRI should not always be interpreted as mastoiditis by radiologists. Radiological mastoiditis does not necessarily point out to clinical mastoiditis.
The authors review their 5 years' experience with endonasal endoscopic repair of the anterior skull base fistulas presenting with cerebrospinal fluid (CSF) rhinorrhea. A total of 12 patients were managed endoscopically between 2004 and 2008. Seven patients (58.3%) had nonsurgical posttraumatic CSF rhinorrhea, 2 patients (16.7%) had CSF rhinorrhea due to surgical/iatrogenic trauma, and 3 patients (25%) had spontaneous onset of CSF rhinorrhea. Radiosurgical correlation for CSF fistula identification was positive in all patients. The most common site of leak was the fovea ethmoidalis. The repair method consisted of an extradural underlay closure of a defect with fascia lata. The largest diameter of a defect to be closed was 15 mm. Immediate results were good in all patients, but later in the follow-up, CSF rhinorrhea recurred in 2 patients, and each patient had a revision 2 times. In the first revisions, transcranial approach was used, whereas in the second revisions endonasal endoscopic route was resorted. The primary closure rate was 83.3%, and the overall closure rate was 100%. The average follow-up period thus far is 21 months. Endonasal endoscopic technique well known to otolaryngologists should be considered as the first choice of surgery in the repair of CSF rhinorrhea because of low morbidity and a higher closure rate. The possibility of revision with the same technique makes this approach ideal for the repair of cranionasal osteodural defects.
Although symptomatic improvement at the 6-month follow-up is statistically indifferent, PAEA has been shown to be superior to CA with its superior performance in providing a near-total elimination of the adenoid mass in a shorter operating time.
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