Audiological profile in cases with cerebrovascular accidents

Abstract

IntroductIonCerebrovascular disorders are pathologic condition of the blood vessels in the brain (Smith-1983). Epidemiology originally signified the study of epidemics, but it is now used more broadly for the study of groups: Epi = among; demos = people; logos = study. India is a vast country with diverse geographic variation. It would be interesting and highly educative to study the epidemiology of stroke in such a diverse group.Unfortunately in India, epidemiological information on annual incidence, prevalence rates, morbidity and mortality trends in well-defined populations is not available. Most of the data published is from a retrospective analysis of subjects admitted to urban medical hospitals though the majority of Indian population lives in small towns and villages. Some of the studies lack proper stroke terminology and baseline investigations.Despite these limitations, analysis of data collected from major urban hospitals suggests that nearly 2% of all hospital admissions; 4-5% of medical and 20% of neurological admission have cardiovascular disease (CVD). The incidence of stroke in the young (<40 years of age) is high (13-32%) when compared to similar data from the west. Many studies on the epidemiology of stroke in India are deficient with respect to randomization of data, making comparison difficult between them. Data show prevalence of CVD in the range of 52-843/100,000 population.Background: Over the past decades there has been increase demand of audiological complaints coinciding with neurological impairments due to cerebrovascular accidents (CVAs). Most of the cases represent inconsistent responses to acoustic stimuli or total lack of response to sound, documented as auditory agnosia. Aim: The present investigation aims at understanding of potential anatomical co-relates to the involvement of the cortical structure and the processing of auditory stimuli. Materials and Methods: A case series with convenient sampling method included eight cases (six male and two female) with age range 45-55 years with CVA, were taken for this study. Of them two cases were found with lesion in right middle cerebral artery, four cases with left middle cerebral artery and two cases with left posterior cerebral artery lesion confirmed from magnetic resonance imaging scan. Audiological test battery including otoscopy, tuning fork test, pure tone audiometry, speech audiometry, immittance audiometry, dichotic-diotic listening test, auditory brainstem responses, otoacoustic emissions and gap detection tests were carried out including routine ENT evaluation. Results and Conclusion: Result suggests; there is a significant difference in hearing threshold and speech perception in all the eight subjects. The findings and compromised vascular anatomy in all these cases were discussed in this article.