Predicting Early Cochlear Implant Performance: Can Cognitive Testing Help?

INTRODUCTION

There is significant variability in speech recognition outcomes in adults who receive cochlear implants (CIs). Little is known regarding cognitive influences on very early CI performance, during which significant neural plasticity occurs.

METHODS

Prospective study of 15 postlingually deafened adult CI candidates tested preoperatively with a battery of cognitive assessments. The mini-mental state exam (MMSE), forward digit span, Stroop measure of inhibition-concentration, and test of word reading efficiency were utilized to assess cognition. consonant-nucleus-consonant words, AZBio sentences in quiet, and AZBio sentences in noise (+10 dB SNR) were utilized to assess speech recognition at 1- and 3-months of CI use.

RESULTS

Performance in all speech measures at 1-month was moderately correlated with preoperative MMSE, but these correlations were not strongly correlated after correcting for multiple comparisons. There were large correlations of forward digit span with 1-month AzBio quiet ( ≤ 0.001, rho = 0.762) and AzBio noise ( ≤ 0.001, rho = 0.860), both of which were strong after correction. At 3 months, forward digit span was strongly predictive of AzBio noise ( ≤ 0.001, rho = 0.786), which was strongly correlated after correction. Changes in speech recognition scores were not correlated with preoperative cognitive test scores.

CONCLUSIONS

Working memory capacity significantly predicted early CI sentence recognition performance in our small cohort, while other cognitive functions assessed did not. These results differ from prior studies predicting longer-term outcomes. Findings and further studies may lead to better preoperative counseling and help identify patients who require closer evaluation to ensure optimal CI performance.