Interaction of Dual Sensory Loss, Cognitive Function, and Communication in People who are Congenially Deaf-Blind

Being congenitally deaf-blind dramatically affects person's ability to communicate. It is well known that the development of social interaction and communication is important for the development of children and adults who are congenitally deaf-blind, and the development depends on the skills of partner (such as teacher of students with visual impairments, teacher of students who are deaf and hard of hearing, and parents) in deaf-blind communication (Janssen & Rodbroe, 2007; Nafstad & Rodbroe, 1999; Rodbroe & Souriau, 1999). It can be hypothesized that cognitive function is related to the communicative abilities of the person who is congenitally deaf-blind and his or her communication partner. Limited communicative abilities may affect the cognitive function of the person who is congenitally deaf-blind. No research has been conducted on congenital deaf-blindness and cognitive function, but research on people with acquired deaf-blindness has reported decreased cognitive function compared to people without or with only visual or hearing impairment. Laforge, Spector, and Sternberg (1992) found, after adjusting for age, sex, and cognitive status, that persons who had visual impairments or both visual and hearing impairments were 2.5 and 3.5 times, respectively, more likely to experience functional decline than were unimpaired older adults. In large study of 6,112 women aged 69 and older, Lin et al. (2004) found similar odds of reduced cognitive function (2.19) for women with combined visual and heating impairments compared to women without impairments. The odds of reduced cognitive function for women with visual impairments alone were only 1.78, and hearing impairment was not associated with reduced cognitive function. No studies have investigated if the higher rate of reduced cognitive function is related to communicative abilities. The purpose of this study was to investigate the relationship, if any, between communicative abilities and cognitive function among persons who are congenitally deaf-blind. In 2003, the Danish Resource Centre on Congenital Deaf-Blindness published Aging Processes and Late Manifestations in Adults Who Are Congenitally Deaf-Blind in Denmark using questionnaires distributed in 2000 to 58 persons with congenital deaf-blindness. Different hypotheses of specific medical and psychosocial symptoms were discussed, but evaluating cognitive function was not the aim of the study, and no conclusions could be made. This study is new and updated version of the 2003 publication, including larger number of participants and new clinical experiences about cognitive function among people who are congenitally deaf-blind. This article focuses on cognitive function among people who are congenitally deaf-blind, in general, not on delayed manifestations in any group with specific etiology, such as rubella syndrome (see Sever, South, & Shaver, 1985, for review). Delayed manifestations among individuals with rubella syndrome constituted separate aspect of the study and will be published in separate article. THE STUDY Participants All 123 people in Denmark aged 18 and older who were known to be congenitally deaf-blind were included in the study. The Scandinavian definition of deaf-blindness was used: a combined vision and hearing disability [that] limits activities of person and restricts full participation in society to degree that requires that society compensates by means of specific services, environmental alterations and/or technology (Nordisk Lederforum, 2007). The participants were recruited from an updated national survey from 2004 (Danish Resource Centre on Congenital Deaf-Blindness, 2004; see also Dammeyer, 2010) using screening method devised by Andersen and Rodbroe (2000). Questionnaires were distributed to all 123 individuals by mail. Six persons were omitted from the study because they (or their guardians or committees) did not want to participate. …