Learning about the causes of deafblindness has lead to dramatic changes in the deafblind population. For instance, as a result of widespread MMR vaccinations there are far fewer children affected by rubella. Research into the deafblind population has been slow to develop. This is mainly due to the fact that dual sensory impairment has only been recognised fairly recently.
Congenital Rubella Syndrome
In the early parts of last century rubella epidemics were commonplace and as a result, many babies were born with Congenital Rubella Syndrome. This condition can cause several complications in newborns including problems with hearing loss in one or both ears due to inner ear damage. Similarly problems with the heart can be caused by the condition and it can also severely affect a child's brain. Children with Congenital Rubella Syndrome often develop problems with sight including cataracts, Nystagmus (a condition in which the eyes flicker from side to side) and several other rare conditions which cause sight to gradually worsen. The condition also increases the risk of additional physical and mental health problems in adulthood. Fortunately, since the widespread use of vaccinations the number of babies born with Congenital Rubella Syndrome has fallen sharply and it's no longer the leading cause of deafblindness.
The most common cause of deafblindness today is as a result of multiple disabilities. These can be caused by a severe infection during pregnancy, premature birth and several other causes. As the number of cases of Congenital Rubella Syndrome dropped, research indicates that deafblindness due to multiple disabilities has gradually increased. Although the exact causes of this rise are not currently known, it's thought that due to advances in medical science, more babies are surviving infections or premature births that would have been fatal ten or even five years ago.
Usher syndrome is a genetic condition in which children are born with partial hearing or complete deafness and then begin to lose their sight during their early teens. Usher Syndrome is a recessive trait, which means in order to develop the syndrome a person has to receive a mutated form of a specific gene from each parent. If both parents are carriers (which means they carry the mutated gene but show no symptoms of the syndrome), they have a one-in-four chance of having a child who will develop Usher syndrome.
Three main types of Usher syndrome have been identified and each has different characteristics;
Those with type one Usher syndrome are frequently deaf from birth and can develop severe balance problems. Of those suffering from type one, many are unable to use hearing aids to great effect and as such, it's recommended that you consult with medical professionals as early as possible in order to find the best method of communication for the child. It's generally thought that language should be introduced as early as possible in the child's life; this is due to the fact that in the early years a child's brain is more receptive to learning language. Due to difficulties with balance, children suffering from type one have difficulty sitting without support. Similarly they won't usually walk independently until around 18 months. Problems with vision usually begin with difficulty seeing at night but usually advances rapidly until the sufferer is totally blind.
Those suffering from type two are usually born with moderate or severe hearing loss. Although the severity of the condition varies from case to case, those with type two generally get more use out of hearing aids and are often better suited to communicate orally. Balance disorders associated with type two are usually less severe than those in other types. The deterioration of vision usually occurs at a slower pace than in type one and retinitis pigmentosa often doesn't manifest until the teenage years.
Those with type three Usher syndrome usually have normal hearing from birth. Similarly most with type three have normal balance, although it's not unusual for problems to occur in later life. In this type of Usher syndrome hearing and sight tend to get gradually worse over time, but the rate of decline varies from case to case. Most people with type three require hearing aids by early adulthood and night-blindness begins during the onset of puberty. It's typical for blind spots to appear in the late teens and the sufferer is usually completely blind by mid-adulthood.
Research indicates that most of those seeking help for Usher syndrome used to be related to Type 1. However this has been rapidly overtaken by those suffering from type 2, who face several different challenges. It's thought that this is a result of improvements in diagnosing the condition and a greater awareness of it in the medical community. These improvements mean that intervention in a child's life can occur earlier and planning for the future will be much more effective.
Deafblindness in Older People
More and more people are living longer and as such, the number of cases involving sight and hearing loss has steadily grown. More than half those over the age of 60 experience impaired vision whereas only one in 12 people in this age group will develop hearing loss. The effects vary greatly from case to case and the severity largely depends upon the cause of the problem. Most older people experiencing sensory impairments have, at one time, had full sight and hearing. In many cases older people don't have enough time to adjust to the loss of one sense before the other begins to fade.