Deafblindness is not caused by a single medical condition. People can be born deafblind, possibly as a result of infection, a genetic syndrome or birth trauma. This is often referred to as congenital deafblindness. Acquired deafblindness refers to occasions where a person becomes deafblind later in life, for example as the result of a progressive condition or through infection, accident or the process of ageing.
- Infections as a cause of deafblindness
- Genetic conditions as a cause of deafblindness
- Birth trauma as a cause of deafblindness
- Accidents or other trauma as a cause of deafblindness
- Deafblindness associated with ageing
Rubella caught during pregnancy used to be a major cause of deafblindness before the introduction of vaccination programmes.
Other infections which can affect the developing fetus include cytomegalovirus (CMV) or toxoplasmosis. Meningitis is an example of an infection which can cause impairments at any time in life, depending on the strain and severity of the infection. Some particular types of meningitis affect young babies more than other groups.
A number of genetic conditions can give rise to deafblindness, for example Usher syndrome. Usher syndrome is due to a gene irregularity which is present from birth with effects appearing gradually over the course of the years. Hearing impairment is usually present from birth or soon after and can range from moderate to profound. Visual impairment is progressive and can occur in late childhood to early adolescence. It is not possible to predict how much sight will be lost.
Vision and hearing impairment can arise as a result of problems at birth or soon after. Children who are born with such problems usually have additional, often multiple, impairments. They may have severe physical impairment, learning disabilities and communication difficulties.
Any accident involving head injury can damage the parts of the brain that deal with how we process information through sight and hearing.
The injury can have many different effects that are difficult to understand. Some other kinds of trauma can result in deafblindness, for instance, a stroke (a cerebral haemorrhage). Again parts of the brain that deal with sight and hearing may be affected.
The most common cause of deafblindness is simply age. After the age of around 50 years hearing and vision impairments become more common. The prevalence of sensory impairment increases with age.