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.

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.
Adolescent ; Adult ; Aged ; Electronystagmography ; Female ; Humans ; Male ; Middle Aged ; Retrospective Studies ; Vertigo ; diagnosis ; etiology ; physiopathology ; Young Adult

Objective: To explore the relationship between overnight urinary sodium to potassium ratio and the risk of cardiovascular disease (CVD). Methods: A subsample of 10 percent of the participants (35-59 years old) from the People's Republic of China-United States Collaborative Study of Cardiovascular and Cardiopulmonary Epidemiology (prospective survey) were used. Three consecutive overnight urine samples were collected in the autumn of 1983-1984 and the spring in 1985-1986, respectively. Urinary sodium and potassium were detected and calculated for 8 hours excretion. The occurrences of cardiovascular events were recorded in 2 years interval from 1987-1988 until December 31, 2005. Participants were divided into first ratio group, second ratio group, and third ratio group based on the tertiles of sodium to potassium ratio. Cox proportional hazard regression model was used to determine the relationship between sodium to potassium ratio and risk of CVD. In addition, participants were divided into 2 subgroups by the median of overnight urinary sodium and potassium, and then combined each other for 4 subgroups including low sodium-low potassium group, low sodium-high potassium group, high sodium-low potassium group, and high sodium-high potassium group, to explore the relationship between different sodium-potassium combinations and the risk of CVD. Results: A total of 954 participants were included in the final analysis, of whom 459 (48.1%) were males. There were 318 cases in the first, second and third ratio group, respectively. There were 347 cases in low sodium-low potassium group and high sodium-high potassium group, and 130 cases in low sodium-high potassium group and high sodium-low potassium group. After a median follow-up of 18.6 (18.3, 19.3) years, cardiovascular events occurred in 81 participants, including 64 stroke and 20 coronary heart disease events. Multivariate analysis showed that comparing with the first ratio group, the hazard ratios (HR) in the second and the third ratio groups were 2.04 (95%CI 1.06-3.95, P=0.034) and 2.07 (95%CI 1.07-4.03, P=0.032), respectively. The CVD risk in low sodium-low potassium group was 24% higher than the low sodium-high potassium group (reference), but this result did not reach statistical significant level (P=0.685). The risks in high sodium-high potassium group (HR=3.32, 95%CI 1.26-8.76,P=0.015) and high sodium-low potassium (HR=3.04, 95%CI 1.05-8.83, P=0.041) group were both significantly increased. Conclusions Overnight urinary sodium to potassium ratio is positively correlated with the risk of cardiovascular events. High urinary sodium plays a more important role for the increased risk of cardiovascular events than low potassium.