[Prediction of verbal and numerical comprehension in patients with cochlear implants]

Cognitive abilities determine the outcome of cochlear implantation. Neuropsychological tests of intellectual, memory, attentional and emotional functions were applied pre-operatively in 33 deaf patients receiving a cochlear implant. The outcome of verbal and numerical comprehension was measured in a subgroup of 14 patients post-operatively and correlated with pre-operative neuropsychological performance.

Neuropsychological performance was recorded using standardized tests for intellectual abilities (abbreviated Wechsler Adult Intelligence Scale [WAIS], crystallized intelligence scale), memory performance (Benton Visual Retention Test), attentional functions (d2 letter-cancellation-test), reaction time (Vienna Reaction Test) and emotional state (personality inventories). Verbal and numerical comprehension was measured post-operatively following adaptation of the speech processor. Performance and comprehension data were correlated.

Cognitive performance parameters did not differ significantly from those of a healthy group. There was a correlation of r = +0.65 between numerical comprehension and the "mosaic-test", a subtest of the WAIS and of r = +0.78 between numerical comprehension and the crystallized intelligence scale.

Pre-operative cognitive parameters may predict the outcome of cochlear implants.