Case Study of Central Auditory Processing in Patients with Stroke

Abstract

This study aimed to investigate central auditory processing dysfunction in patients with stroke. Three patients who had suffered strokes with confirmed auditory pathway involvement, participated. All subjects had normal hearing bilaterally, and were right-handed. All subjects completed K-MMSE (Korean version of Mini-Mental State Exam) and K-WAB (Korean version-the Western Aphasia Battery), and performed Korean Central Auditory Processing Assessment (CAPA-K) battery, including Frequency Pattern test, Dichotic Digit test, Filtered Word test, Compressed Speech test, Speech in Noise test, and Binaural Fusion test. The scores for the each test were evaluated by comparing the normative data in young adult population for the standardization of CAPA-K battery. The results of the study revealed that all three subjects had difficulties in central auditory processing. S1 (male, 17 years, Rt. middle cerebral artery infarction including Rt. insula and basal ganglia) showed poor performance in contralateral ear to the lesion in all speech recognition tests. Contralateral ear suppression was also seen in dichotic testing. Furthermore, frequency pattern recognition was poorer in the linguistic labeling condition than in the humming condition in both ears. S2 (female, 46 years, both pontine infarction including lateral lemniscus and superior olivary complex) demonstrated difficulties through the entire tests whereas S3 (male, 51 years, Lt. pontine infarction including lateral lemniscus) showed normal performance in speech recognition test and monaural-low redundancy speech tests in both ears. Regardless of side of lesion, temporal processing difficulties in both ears were found in patients associated with pontine infarction. In these cases, auditory dysfunction resulting from stroke varied with the location and extent of auditory pathway infarction. Therefore, more cases are needed to identify the central auditory dysfunction in patients with stroke.