[Perform vestibular test among all small deaf children! Early detection of Usher syndrome improves the possibilities of communication in the event of later deaf-blindness].Lakartidningen. 1998 Jan 28; 95(5):379-81.L
Although deaf children depend upon sight for communication, retinitis pigmentosa is present in 6 per cent of those with a profound hearing deficit. Usher syndrome type 1 (USH-1) is an autosomal recessive disease characterised by profound hearing impairment, absent vestibular function, and progressive loss of vision due to retinitis pigmentosa. Owing to the severe handicap of the combined disorders, early diagnosis of USH-1 is of crucial importance. The profound hearing deficit is often detected at hearing tests in infancy, but as the sight problems do not develop until later diagnosis is often delayed. The diagnosis of Usher's syndrome is established by electroretinography (ERG), as confirmation of the retinitis pigmentosa is a prerequisite. As the progressive deterioration of sight hinders the use of sign language, a cochlear implant constitutes an invaluable aid at an early age. Early diagnosis is thus of both medical and educative importance. To avoid delay in diagnosis past the age when optimal results may be expected from a cochlear implant, a screening test was sought for infants with profound hearing loss to identify those at increased risk of USH-1, for whom ERG is a priority. Although conventional vestibular testing methods are not well tolerated by infants, with recently developed equipment for video or CCI) (charge-coupled device) camera inspection of eye movements, vestibular screening can now be performed in the office. In our experience it is possible to screen most infants, given a careful approach by the investigator. Children with clinically diagnosed USH-1, without any vestibulo-ocular reflex, manifested no vestibular responses during 'video-nystagmoscopy' when rotated on the parent's lap, preliminary findings strongly suggest that vestibular function should be tested in all children with a profound congenital hearing deficit, as it is important for children with USH-1 to be provided with a cochlear implant permitting aural reception of communication from the environment at an early age, because of the progressive deterioration of vision and the ultimate double handicap.