Auditory processing in patients with Charcot-Marie-Tooth disease type 1A.

Hypothesis: It is unclear whether Charcot-Marie-Tooth (CMT) disease, type1A, causes auditory processing disorders. Therefore, auditory processing abilities were investigated in five CMTI A patients with normal hearing. Background: Previous studies have failed to separate peripheral from central auditory processing disorders. Materials and Methods: Five genetically confirmed CMT1A cases in patients with normal hearing underwent behavioral and objective testing. Pure tone audiometry, speech audiometry, and OAE assessment were followed-up by an auditory processing test battery comprising sentences-in-noise test, pattern recognition tests, words-in-noise test, dichotic digit test, filtered speech test, binaural fusion test, and categorical speech perception test. Subsequently, ABR and ERP measurements were conducted. Results: Either the behavioral or objective test scores of 4 out of the 5 CMT I A patients did not differ significantly from those of subjects with normal hearing. Significantly lower scores of one patient on auditory processing tests and ABR measurements could be ascribed to subnormal hearing. Conclusion: The authors conclude that CMT1A patients with normal peripheral hearing have auditory processing abilities that were not indicative for an auditory processing disorder. Furthermore, the presence of a peripheral hearing loss complicates the interpretation of auditory processing abilities.