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Objective To observe neurophysiological changes and pulmonary function in obstructive sleep apnea syndrome (OSAS) and analyze their inter-relationship. Methods Sixty OSAS patients were studied. Their lung function and phrenic motor nerve conduction (PNC) were examined. Thirty cases without respiratory disorder served as controls. The lung function tests included percentage of the predicted value of vital capacity ( VC% ), percentage of the predicted value of maximal voluntary ventilation ( MVV% ), percentage of the predicted value of forced expiratory volume in one second ( FEV1% ), inspiratory capacity ( IC), and expiratory reserve volume (ERV). The phrenic nerve was stimulated electrically, and the latent period and the diaphragmatic compound muscle action potential (dCMAP) were recorded. Results The VC%, MVV%, FEV1% , IC and ERV of the patients with OSAS were significantly lower than those of the controls. There was no significant difference between the patients and the controls with regard to their PNC latency. In the OSAS patients the amplitude ratio of their dCMAPs was positively correlated with VC% , MVV% , FEV1% , IC and ERV, and negatively with an apnea hypopnea index (AHI).Conclusions PNC examination can provide valuable information for evaluating diaphragmatic dysfunction in those with abnormal lung function. Decreased dCMAP might be associated with abnormal lung function.
ABSTRACT
OBJECTIVE@#To investigate the clinical characteristics and common etiology of vertigo.@*METHOD@#The clinical data of 168 patients with vertigo in the department of otolaryngolology and neurology from December 2007 to March 2009 were retrospectively analyzed The patients were inquired and examined by pure tone average thresholds, videonystagmography, Dix-Hallpike test, cervical spine X-ray, skull CT and (or) MRI and transcranial Doppler.@*RESULT@#One hundred and thirty-four patients with vertigo were of peripheral origin, with 66 cases benign paroxysmal positional vertigo, 30 cases Meniere's disease, 24 cases sudden deafness, 5 cases vestibular neuritis, 5 cases otitis media ,2 cases ear herpes zosters and 2 cases ototoxicity. Among 26 patients with vertigo of central, 20 patients were vertebrobasilar TIA.@*CONCLUSION@#The most common etiology of the vestibular peripheral vertigo is the benign paroxysmal positional vertigo. Detailed history and the features of vertigo, particular about the duration of vertigo and hearing change, may provide the important evidences for the accurate diagnosis and differential diagnosis of vertigo.