Delayed recovery of speech discrimination after fractionated stereotactic radiotherapy for vestibular schwannoma in neurofibromatosis 2.

Hearing loss commonly occurs after radiation therapy for an acoustic neuroma, and it is highly unusual for hearing to return after a prolonged period of time. We report the case of a 12-year-old boy with neurofibromatosis 2 who underwent fractionated stereotactic radiotherapy for the treatment of a left-sided vestibular schwannoma. Following treatment, he demonstrated an elevation of pure-tone audiometric thresholds and a sudden decrease in speech discrimination score (SDS) to 0%. However, 20 months postoperatively, his SDS suddenly and spontaneously rose to 92%, although there was no improvement in his speech reception threshold. We discuss the possible reasons for the unusual outcome in this patient.