Outcomes of Late Implantation in Usher Syndrome Patients

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Introduction Usher syndrome (US) is an autosomal recessive disorder characterized by hearing loss and progressive visual impairment. Some deaf Usher syndrome patients learn to communicate using sign language. During adolescence, as they start losing vision, they are usually referred to cochlear implantation as a salvage for their new
condition. Is a late implantation beneficial to these children? Objective The objective of this study is to describe the outcomes of US patients who received cochlear implants at a later age. Methods This is a retrospective study of ten patients diagnosed with US1. We collected pure-tone thresholds and speech perception tests from pre and one-year post implant.

Results Average age at implantation was 18.9 years (5–49). Aided average thresholds were 103 dB HL and 35 dB HL pre and one-year post implant, respectively. Speech perception was only possible to bemeasured in four patients
reoperatively, who scored 13.3; 26.67; 46% vowels and 56% 4-choice. All patients except one had some kind of
communication. Two were bilingual. After one year of using the device, seven patients were able to perform the speech tests (from four-choice to close set sentences) and three patients abandoned the use of the implant.

Conclusion We observed that detection of sounds can be achieved with late implantation, but speech recognition is only possible in patients with previous hearing stimulation, since it depends on the development of hearing skills and the maturation of the auditory pathways.

The Usher syndrome is an autosomal recessive disease characterized by varying degrees of sensorineural hearing
loss and progressive visual impairment, caused by retinitis pigmentosa (RP).1 The syndrome’s incidence is estimated as 3–6/100.000 persons in the general population. Among the deaf population, the prevalence of the syndrome is 3 to 6%. It is the most frequent cause of adult blindness and deafness. Studies underestimate the true prevalence of the disease due to lack of early diagnosis or for being misdiagnosed. The average age at diagnosis is 10 years and some children are implanted before vision loss and even before the diagnosis of Usher’s disease.1

Three distinct subtypes of the syndrome have been described. Usher Type I (USHI) is characterized by profound
sensorineural hearing loss at birth or during the first year of life, abnormal vestibular function, and delayed motor development. Children with Usher type II (USHII) have hearing loss from birth moderate to severe and normal vestibular function. Affected childrenwith Usher type III (USHIII) are usually born with normal hearing and undergo progressive hearing loss. Their vestibular function may be affected. The vision loss is gradual and usually begins in adolescence or adulthood.2 The severity of hearing loss and blindness is higher in Usher syndrome type I.
Several studies of patients with Usher syndrome concluded that cochlear implant (CI) is an effective treatment for such patients, since there is a deterioration of a duplicate sensory.

Benefits vary from a better quality of life, observed in questionnaires, 3 to superior performance in oral
ommunication.2,4–6 This variability of the results is seen as being dependent on factors such as age of
mplantation, duration of deafness, and type communication prior to implantation.6,7 Families have sought the solution for children with Usher syndrome who did not have the opportunity to receive cochlear implants in early childhood, since the visual loss is progressive, starting in adolescence. We seek to investigate whether late implant patients presenting Usher syndrome type I with pre-lingual hearing loss can benefit the cochlear implant.

We selected 10 patients implanted (7 men, 3 women) diagnosed with USHI. The average age for implantation was 18.9
years (5–49). ►Table 1 describes the summary of the characteristics of each patient. Average pre auditory threshold (PTA HA) was 103 dB HL (►Fig. 1). Itwas possible tomeasure speech perception in four patients preoperatively (1, 2, 4, and 6), who could only detect speech. Other patients failed to perform the speech perception tests. All patients except one had some kind of effective communication. Two were bilingual (►Table 2). One year after the
implantation, the average auditory threshold (PTA CI)was 35 dB (►Fig. 1). Only three patients improved
their performance in speech perception to 40%, 30%, and 10% for recognition of sentences in closed set, espectively (1, 2 and 3); five patients had only speech detection, and twowere not able to carry out tests (►Table 2). Three patients abandoned the use of CI (8, 9, and 10).