ABSTRACT
Chronic Obstructive Pulmonary Disease (COPD), a progressive and partially reversible disease, has drawn world-wide attention for its moderate prevalence rate and causing central and peripheral neuropathy. Considering its severity in causing visual pathway impairment, the present investigation was carried out to find out the functional integrity of the visual pathway through visual evoked potentials (VEP) and to determine the factors influencing the condition in COPD patients. A total of 30 COPD patients of both sexes, classified according to the severity of the disease based on spirometric indices, were subjected to VEP testing and series of wave forms were measured and compared with equal number of control subjects. The latency of N75 and P100 were prolonged (P<0.01) and the P100 amplitude was reduced significantly (P<0.01) in COPD patients. Thus, the influence of COPD causing the optic neuropathy is apparent from the significant VEP changes. Non-invasive procedure can possibly be utilized as a routine screening test for COPD patients for better medical care.
ABSTRACT
Background: Obstructive Sleep Apnea (OSA) is the most prevalent form of sleep disordered breathing and could become an important public health issue in India. Patients with OSA have high levels of sympathetic nerve activity during sleep. The autonomic alterations persist during wakefulness and are considered to contribute to the cardiovascular disorders associated with OSA. Aims & Objective: The aim of the present study was to study autonomic function in adults with Obstructive Sleep Apnea using autonomic cardiovascular tests. Material and Methods: 30 normal controls (Group I) and 30 patients with Obstructive Sleep Apnea (Group II) of both sexes in the age group of 35-45 years were subjected to a battery of autonomic function tests. The heart rate response to standing (30:15 ratio), heart rate response to deep breathing (E:I ratio), and the Valsalva ratio were used to assess parasympathetic function while the isometric hand- grip exercise and cold pressor tests were used to assess sympathetic function. Statistical analysis was done using SPSS 17 and unpaired student t test. Results: The 30:15 ratio, E:I ratio and Valsalva Ratio were significantly lower (p value < 0.001) in the patients with OSA when compared to the controls, while the diastolic pressure difference in the isometric hand-grip exercise test and the cold pressor tests were significantly higher (p value < 0.001) in the patients with OSA. Conclusion: Our study revealed that there was sympatho-vagal imbalance in adult patients with Obstructive Sleep Apnea, with decreased parasympathetic and increased sympathetic activity.