Auditory processing deficits in subacute stroke.

Background: Stroke is the second leading cause of disability worldwide. Stroke results in focal neurological deficit and often leads to auditory problems due to its impact on the auditory pathway. Altered connections in the auditory pathway, caused by stroke, can result in hearing difficulties ranging from impaired sound detection to altered auditory perception. A better understanding of how stroke affects these early sound processing mechanisms will provide valuable insights into stroke recovery and rehabilitation options.

Methods: We recruited forty consecutive adult patients with stroke (30 males, 10 females) due to ischemic or intracerebral hemorrhage > 3 and up to 12 months after stroke (subacute stage). Brain MRIs were performed on all patients, and we calculated a central auditory nervous system stroke severity index (CANS SSI) according to number of CANS areas involved and an extended CANS definition of auditory responsive areas. All patients underwent cognitive screening assessment, basic audiological assessments, and a hierarchical central auditory processing assessment battery with the Queen Square Tests of Auditory Cognition (early perceptual processing, apperceptive processing, semantic Processing) and Gaps in Noise tests.

Results: When comparing patients with auditory responsive cortical lesions and with versus without Heschl's gyrus involvement (primary auditory cortex), patients with Heschl's gyrus involvement exhibited worse early perceptual scores. The CANS SSI showed a significant negative correlation with early perceptual test scores.

Conclusion: This study demonstrates a correlation between stroke severity, characterized by a higher number of lesions involving auditory areas in patients with subacute stroke, and worse early perceptual scores. Heschl's gyrus involvement is associated with poorer early perceptual score.