ETIOLOGIES OF DEAFBLINDNESS
AND IMPLICATIONS FOR COMMUNICATION

by Kirralee Lewis, The Deaf-Blind Association

(from a paper presented at the 1998 Renwick College Winter School on Deafblindness)

Understanding etiologies can provide vital information to families and services providers that:

·assists in explaining characteristics and behaviours;
·indicates whether the condition is degenerative or stable;
·indicates medical needs;
·guides decisions for educational instruction, adaptation, orientation and mobility, and communication methods.

Diagnosis

Diagnosis may be difficult for a number of reasons:

·Genetic evaluations and studies of environmental factors do not always display clear results;
·Many hearing and vision evaluations may be inconclusive;
·Individuals with deafblindness may have additional disabilities;
·Definite diagnosis may be insufficient due to medical knowledge and technology.

A diagnosis acts as a guideline for information. It should not be used as a limiting factor of all the things a person can and cannot do.
It does not totally predict an individuals academic, vocational or independent living success.
Identification of etiology provides assistance in decision making and understanding some of the challenges.
How a person functions will rely on several factors including (but not limited to):

·age of onset;
·degree and type of vision and hearing loss;
·stability and degree residual vision and hearing;
·additional disabilities that influence intellectual and physical functioning;
·general health;
·interventions and adaptations to facilitate learning;
·experiences presented; and
·support systems available to enhance the persons quality of life

CATEGORIES OF DEAFBLINDNESS

1. Congenital deafblindness;
2. Acquired deafblindness;
3. Congenital deafness and acquired blindness;
4. Congenital blindness and acquired deafness.

1. Congenital Deafblindness
·Dual visual and hearing impairments at birth or by age two (during the developmental period).
·Frequently have a functional intellectual disability, depending on the etiology of the dual sensory impairment and effectiveness of early intervention and school programs.
·Lack access to environmental information, except what is within arms reach.
Historically, education has been based in special schools for students with multiple and/or severe disabilities.
Historically, institutionalisation was a common adult service outcome.
eg. Congenital Rubella Syndrome, prematurity, pre- and prenatal trauma, CHARGE association and at least 80 other identified syndromes associated with a dual sensory loss.

2. Acquired Deafblindness
Experience dual sensory losses later in life, post-lingually.
Vision and hearing losses may occur at separate times and/or be progressive, or
Vision and hearing losses may be simultaneous and/or acute.
Very traumatic for the individual, self image is shattered.
Have already mastered important movement and communication skills using vision and hearing.
Typically are educated and have employment histories, similar to hearing-sighted people. Growing up in a hearing-sighted world, speech has been the expressive form of communication.
However, now they lack the receptive communication skills and need to learn new tactile systems.
Counselling may be helpful for psychological-emotional issues.
May have additional disabilities.
All skills need to be relearned including social, vocational, independent living, recreation, etc.
eg. brain injury, diseases resulting in high fever, diabetes, meningitis, encephalitis, reactions to medications, ageing, stroke, etc.

3. Congenital Deafness and Acquired Blindness
Hearing impaired or deaf from birth or by age two and experiences a severe vision loss or blindness later.
Typically educated in schools for the deaf (historically residential schools) or in classrooms with deaf or hard of hearing students.
Delays in learning reading and writing skills because of delayed language development.
Generally master daily living activities through visual imitation.
Either use sign language (Auslan, ASL, BSL) as the primary language, or oral & lip reading
Need to learn tactile signing and other tactile, non-visual communication methods.
eg Usher syndrome

4. Congenital Blindness and Acquired Deafness
Vision impaired or blind from birth or by age two and experiences a severe hearing loss or deafness later.
Typically educated in schools for the blind (historically residential schools) or in classrooms with blind or vision impaired students.
Rely on spoken language, movement and tactile information to support their concept and mobility development.
Rely on speech as an expressive and receptive communication method.
Generally competent in braille and orientation and mobility.
Need to develop tactile receptive communication systems and retraining in orientation and mobility to reduce the reliance on auditory cues.
eg. ear damage due to accidents, infections or drugs, syndromes.

The Changing Deafblind Population
Reasons for the increase in children with multiple disabilities could include:
1. Many children born prematurely or contract early infections are now enabled to survive as a result of advances in technology and medical knowledge. Historically these children would not have survived much beyond birth or trauma.
2. There has been an increase in willingness and ability for specialist deafblind services to accept children with multiple disabilities.
3. Increase awareness of services and support available to assist children who were previously defined as having profound and multiple learning difficulties and whose sensory impairments were not recognised or considered the least of their problems.

David Brown (1997) of Sense in the UK suggests some implications for professional services:
1. Environmental factors, especially the suitability of the premises for access, mobility and storage of specialised equipment necessary for those with a significant physical disability.
2. Medical, nursing and therapy consultancy, as appropriate, to cater for the variety of needs.
3. As a large number of professionals are likely to be involved with this population, it is necessary to establish a clear system to achieve and maximise the effectiveness of the interaction between the multi-disciplinary team.
4. Current staffing ratios may be inappropriate and inadequate and may need to be re-evaluated.
5. A balance between teaching and maintaining adequate care may need to be redefined. Not only will people need to adapt to a slower time scale, but previous approaches to communication work may be inappropriate.

CAUSES OF DEAFBLINDNESS

Congenital Deafblindness:
CONGENITAL RUBELLA SYNDROME (CRS)
Babies who acquire rubella at, or before birth, can continue to shed the virus in nose and throat secretion and in the urine for 1 year or more.
Most adults and children fully recover from rubella with few complications.
If a pregnant woman is infected by the virus during the first 3 months of pregnancy, it can result in miscarriage, foetal death, or the baby could be born with several health care concerns, including:
Vision impairments (eg. congenital cataracts, late onset glaucoma, detached retina, possibly from self-injurious behaviours);
Sensorineural severe to profound hearing loss;
Congenital heart defects;
Diabetes;
Hypertension;
Liver or skin problems;
Intellectual disabilities;
(Rare) progressive rubella panencephalities - a slow, progressive, neurological deterioration with seizures, behaviour outbursts, ataxia and dementia.

CHARGE ASSOCIATION
C Coloboma: Incomplete fusion of the retina, iris, or optic nerve.
H Heart defects: Many children may require treatment or surgery
A Choanal Atresia: Blockage of the nasal passage
R Retarded growth and development: Usually below the third percentile of physical growth norms.
G Genitalia and urinary tract anomalies: Incomplete or under development of the external genitals (common in males).
E Ear anomalies: Effect the external ear (lop or cup shaped, large small or absent), abnormal ear development resulting in chromic ear infections, conductive, sensorineural or mixed hearing loss.

Multi-featured disorder characterised by a unique combination of diverse abnormalities. The cause is unknown.
Other problems in addition to the above may include:
intellectual disability
facial palsy, abnormal tongue size
cleft lip and/or palate
renal abnormalities
complications of the larynx and oesophagus
skeletal abnormalities
poor immune response

CYTOMEGALOVIRUS
Potential prenatal cause of deafblindness
Means large call virus and is a commonly occurring virus.
It belongs to the herpes virus group, which includes chicken pox, cold sore, glandular fever.
The infection frequently passes unnoticed or there may be mild flu-like symptoms.
Once the infection has taken place, the virus remains dormant or harmless in the body, usually with no ill-effects.
The virus is spread by saliva, urine and other body fluids.
If a pregnant woman contracts CMV, the virus may be passed onto the developing foetus.
Pre-natal diagnosis is not possible and there is no vaccine.
Problems resulting from congenital cytomegalovirus may include:
Hearing impairment;
Vision impairment;
Jaundice, blood spots of the skin;
Enlargement of the liver or spleen;
Spasticity;
Intracranial and other calcifications (deposit of calcium within organic tissue);
Intellectual disabilities;
Seizures

Acquired Deafblindness
ACQUIRED BRAIN INJURY
Head injury from an accident, trauma or similar neurological disorder (eg stroke).
May have various degrees of vision, hearing, cognitive and motor impairments.
May process and interpret auditory and visual information with minor errors or significant distortions.
Eye and ear functions may be intact, but the brain does not use any of the visual or auditory information it receives.
May have difficulty sorting and processing information from the senses when several forms of information is being received at the same time.
Requires slow and repeated introduction of movement and tactile information.
Can benefit from structured, individualised, multisensory instructional programs.

Congenital Deafness and Acquired Blindness
USHER SYNDROME
Inherited condition which results in partial or total hearing loss and a progressive loss of vision from Retinitis Pigmentosa (RP).
The hearing loss is congenital and ranges from moderate to profound.
RP is a group of hereditary diseases of the retina. The retina is the light sensitive tissue inside the eye in which seeing takes place. When the retina slowly deteriorates it loses its ability to transmit pictures to the brain.
Symptoms include:
Night blindness (difficulty in seeing at night or adapting in bright light or rapidly changing light conditions);
Loss of visual field or tunnel vision (lose ability to locate objects which are not directly in front);
Loss of central acuity, macula degeneration (lose ability to see the details of the object in front).

Four different types of Usher syndrome have been identified. Types III and IV are rare forms. The most common two are:
Type I:
Most common form (approx. 90% of all people with Usher have Type I);
Profound congenital deafness;
RP usually evident within the first 10 years of life;
Balance problems;
Links with Deaf Community;
Usually use signing as preferred method of communicating;
Symptoms are similar within the same families

Type II:
Mild to severe congenital hearing impairment;
RP evident from late adolescence to late twenties;
No balance problems;
People do not identify with the Deaf Community;
Hearing loss is not usually progressive, but can be affected through ageing;
Level of hearing and vision impairments vary within family members.
A diagnosis of Ushers can be very distressing and people typically go through a grieving process. The grief is the emotional response to the loss of sight, identity, aspirations and dreams for the future.

Congenital Blindness and Acquired Deafness
MENINGITIS
Infection of the membranes surrounding the brain and spinal cord.
Caused by many different viruses and bacteria.
Symptoms (can occur suddenly) often include high fever, severe and persistent headache, nausea, stiff neck and vomiting.
Changes in behaviour such as confusion, sleepiness, fatigue.
Other causes of congenital blindness and acquired deafness:
Disease (Norries),
Diabetes,
Chemical toxins,
Lebers amaurosis,
Damage to ears from accidents or infections.
Meningitis can also cause acquired deafblindness.

IMPLICATIONS OF ETIOLOGIES ON COMMUNICATION
The development of communication for any person with deafblindness is complex and should begin with an assessment of:
the etiology and age of onset of the vision and hearing loss;
the amount and type of any residual vision and hearing losses.
Other factors that will influence the method of communication a deafblind person may use are visual and auditory memory, educational experience, additional physical and intellectual disabilities, environment and needs.

Congenital Deafblindness
Communication is often delayed in a person who is congenitally deafblind.
Some may develop some level of competency with functional sign language and supplement it with other symbolic systems (eg objects of reference).
Those with additional physical and intellectual disabilities may rely totally on non-symbolic communication methods, or a combination of both.
To understand impact of congenital deafblindness, need to understand child development.

CHILD DEVELOPMENT
The human being is born social. Babies are more attentive to social stimulation than to others. For normal babies, learning opportunities are optimal because the learning is based on the childs own activities are the responses are instant.
Babies with deafblindness show little activity which can be interpreted, and any activity which does occur can be unusual and unexpected.
Deafblind babies have the appearance of inactivity as the expression of high attention level while listening.
This is easily mistaken for passivity and lack of attention and interest.
Deafblind babies are less awake because they are less stimulated by visual input, they cry less and move their limbs less.
When deafblind babies cry less than other children, they are deprived of the attention from the care givers and the learning opportunities which are embedded in this.

Smile
The smile is a reflex smile in the beginning, however, the social smile, which involves eye contact, at one month of age.
In deafblind babies, the social smile may be delayed for 6 months. It may also be more vague in appearance.
Imitation situations are opportunities for dialogue and are essential for general development, especially language development.
Deafblind children are at risk of developing intellectual disabilities because of the deprivation of learning opportunities.

Interactions
The deafblind child is at risk of not being able to initiate social interaction and give rewarding feedback due to the sensory impairments, eg smile, give eye contact, be comforted through visual and auditory stimulations.
By 6 months of age, a normal child acquires motor skills to assist with exploration of the world and as a result, expand his space of interaction. When the deafblind child does not do this, his motor and cognitive development will be delayed. Interference with the babys development pattern will affect the social, emotional, cognitive and language development.
Structuring the childs environment, activities, time and localities can be effective and necessary for their development.
It can prevent the development of stereotyped, self-injurious or aggressive behaviour. Structuring is a way by which the deafblind person can increase his feeling of security.
As the world becomes more ordered, the deafblind child can find cues and references to assist with interaction. As a result, the possibilities for communication increases.

Relating to the world
In working with deafblind people, it is necessary to prevent or solve problems in the areas of communication, access to information and orientation and mobility. It is through communicating with the surrounding, exploring and moving freely that an individual gains understanding of it.
A persons relationship or interaction with the world will be dysfunctional and will not be able to increase in understanding if communication, information, orientation and freedom of movement are deprived.

Most mothers of deafblind children comment that they lack or have poor contact with their baby.
This is apparent through the lack of adult-child interaction, which as a result affects dialogue. Dialogue structure like mutual imitation, turn taking and give and take are very dependant on both vision and hearing.
These patterns are the basic prerequisites for social communication. The dialogue between a deafblind person and care giver will typically depend on the care giver.
The role of the care giver is to facilitate the deafblind persons discoveries of the world on all levels, from basic reflex behaviour through to the most advanced communication with the environment.

HEARING AND ITS IMPACT ON COMMUNICATION DEVELOPMENT
In the development of spoken language, hearing is first and foremost. Hearing can help in establishing contact, increase comprehension of a message and guarantee security for a deafblind person when exploring.
Normally, hearing is functioning at birth, and is even reported to be functional in utera.
Soon after birth, the connection between auditory and visual input can be made and the baby can direct its glance towards the sound source.
A deafblind baby with some residual hearing will use auditory input to establish contact, eg a slight turning of the head, ceased motor activity, quietness, changes in breathing, movements of the mouth and fingers, etc.
Often the signals may be delayed, so the care giver needs to be aware of the adequate reaction that the child displays when he hears a sound.
It is important to give the child multiple experiences with sound to establish and use auditory input as other cues. Sound can be used to establish a common focus of attention, if it is made meaningful an distinctive. Verbal communication will never be the only medium, it is important to support communication with other communication methods, eg sign.

VISION AND ITS IMPACT ON COMMUNICATION DEVELOPMENT
Vision is important for many activities which are interpreted as communicative behaviour, eg eye contact, glancing, smiling, grasping, crawling towards a person/object, etc.

When a child initiates interaction, vision serves two purposes; as an indicator and interest, and for stimulus perception to trigger child activity. It is estimated that 70-90% of the childs activity is related to vision.
Little visual input and few vision related signals make passivity a essential problem when the baby does not see. It is important to use special methods to create spontaneous activity.
For the deafblind child, hearing and visual aids help use any residual capacity, in additional to this, vibratory stimulation becomes important. The child needs extra cues and more time to process the information.

Acquired Deafblindness
The deafblind person will often need to develop alternatives to their former communication skills.
Unlikely to have either Auslan or braille skills.
Likely to chose fingerspelling or POP.
Tadoma may be used as a method of reception communication. The receiver places his/her thumb in the lips of a speaker with the fingers on the throat. The hand placement allows the receiver to detect breath, nasal sounds, lip movements and vibrations

Congenital Deafness and Acquired Blindness
Communication for people who are congenitally deaf and acquire blindness typically would concentrate on either the development and fluency of sign language (Auslan), or the oral method.
Need to adjust their receptive communication methods.

USHER I: Auslan is their native language
To communicate receptively will need to position themselves so that they can see the person who is signing to them within their restricted visual fields.
Physical distance from the person signing to them is also a critical factor.
With severe vision loss, may adjust to tactile signing as form of receptive communication.
Expressively, the deafblind person may continue to use visual signing or sometimes speech.

USHER II: English is their native language.
With adequate residual vision, speech reading can be an effective method of receptive communication.
If they know any sign language it is most likely to be Signed English or pidgin Signed English.
Will continue to use speech as expressive communication.

Congenital Blindness and Acquired Deafness
Typically educated in schools for people who are blind or in special educations programs in public schools.
Most communicate expressively through speech and receptively through speech and braille
Usually do not know Auslan and may chose to learn fingerspelling, POP or Signed English if their hearing loss interferes with communication.
Portable braillers are available (Tellatouch) which is used for receptive communication - translating typed English into braille or braille into print.


PRINCIPLE METHODS OF COMMUNICATION

Touch cues
Gestures
Objects of reference
Picture symbols
Sign language (Auslan, ASL, BSL)
Tactile sign
Fingerspelling
Signed English
Pidgin Signed English
Makaton
Key word sign
Coactive sign
Print-on-palm (POP)
Braille
Raised alphabet cards
Large print
Tadoma method of speech reading
Lip-reading
Body movements, eye gaze, vocalisations
Communication aids, electronic and non-electronic

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