The Laryngoscope Lippincott Williams & Wilkins, Inc. © 2007 The American Laryngological, Rhinological and Otological Society, Inc. Cochlear Implantation in Cockayne Syndrome: Our Experience of Two Cases With Different Outcomes David P. Morris, Bsc, MBBS, FRCS (ORL-HNS); Wael Alian, MD, MBBCh; Heather Maessen, MSc, Aud(C); Cathy Creaser, MSc, Aud(C); Stephanie Demmons-O’Brien, MSc, SLP(C); Rene Van Wijhe, Ing, BSc, MEng; Manohar Bance, MB, MSc, FRCS(C) Cockayne syndrome is a rare autosomal reces- sive defect in DNA repair resulting in a classic facies with potential visual and auditory impairment. The hearing loss begins peripherally and may become central as the condition progresses. Coexisting sen- sory deprivation from visual impairment and the pos- sibility of progressive deterioration in mental func- tion conspire with a lack of published experience to produce many challenges for the cochlear implant team. To the best of our knowledge, we present the first case reports with documented follow-up of co- chlear implantation in two patients with different manifestations of Cockayne syndrome. Laryngoscope, 117:939 –943, 2007 INTRODUCTION In 1936, Edward Alfred Cockayne (1880 –1956), a London physician, described a syndrome of “dwarfism with retinal atrophy and deafness” in two siblings. Ten years later, he published an update on these patients’ progress. Neill and Dingwall 1 reported “A syndrome re- sembling progeria” in two brothers with a similar condi- tion, and Wilkins added another case to the literature and included the condition with “progeria.” MacDonald et al. 2 described three children with this syndrome in one family, and the largest series has re- ported on some 140 cases. 3 Cockayne syndrome is a rare, progressive, autosomal recessive disorder of “transcription- coupled” DNA repair. If either the ERCC8 or the ERCC6 gene is defective, DNA damage is not repaired, and accumulated damage leads to premature cell death and the features of the syndrome (Table I). Cockayne syndrome has been classi- fied into four main types (Table II). HEARING LOSS IN COCKAYNE SYNDROME More than half of the patients with Cockayne syn- drome have mild to severe bilateral sensorineural loss, 4 but this may not manifest until the teens. Shemen et al. 5 revealed inner and outer hair cell losses in the basal turn of the cochlea with neuron losses in the spiral ganglion, and they corroborated this with audiometric data from living subjects. They concluded that the changes resem- bled presbyacusis and corresponded with the premature aging process characteristic of the disease. Gandolfi et al. 6 verified histologic changes in a 17- year-old deaf patient with Cockayne syndrome. The co- chlear showed marked atrophy of the spiral ganglion and attenuation of the cochlear nerve. Trans-synaptic degen- eration was observed in the ventral cochlear nucleus, me- dial dorsal olivary nucleus, and inferior colliculus. Progressive chronologic changes in auditory brain- stem responses have been documented in Cockayne syn- drome. Iwasaki and Kaga 7 concluded that “the disease spreads from the upper brainstem to the cochlear nerve and that the site of the lesion causing [hearing loss] . . . is in the brainstem lesion as well as the peripheral one.” COCHLEAR IMPLANTATION IN COCKAYNE SYNDROME Progressive loss of neurons in the spiral ganglia with retrograde atrophy of auditory pathways and loss of neu- rons in the brainstem nuclei is a concern when considering cochlear implant candidacy. Neill and Dingwall 1 have commented previously on the normal social adaptation shown by children with Cockayne syndrome despite low intelligence, and a few notable cases have been reported of individuals with features of Cockayne syndrome yet nor- mal intelligence. 8,9 Despite this, the probability in most cases of progressive mental handicap, visual impairment, and a centrally progressive auditory deficit contribute a considerable challenge to the cochlear implant team. From the Nova Scotia Cochlear Implant Program, Halifax, Canada. Editor’s Note: This Manuscript was accepted for publication Decem- ber 21, 2006. Send correspondence to David P Morris, Bsc, MBBS, FRCS (ORL- HNS), Rm. 3037-3rd Floor Dickson Building, 5820 University Avenue, Dalhousie University, Halifax, Nova Scotia, B3H 2Y9 Canada. DOI: 10.1097/MLG.0b013e3180325106 Laryngoscope 117: May 2007 Morris et al.: Cochlear Implantation in Cockayne Syndrome 939