Visual Impairment

What is Visual Impairment?

"A generic term that includes mild visual impairments, low vision and total blindness." (Winzer) 

Classification by Degree: 

• Near-Normal Vision. Many people have mild impairments but they are usually corrected with prescription glasses. These individuals are able to function without special training. 
• Moderate-Vision Disability. "People in this group have a moderate reduction of acuity, but no significant visual field loss."(Winzer) Lighting and special requirements are needed. 
• Low Vision. "As a term, low vision was introduced after World War 2, when a distinction from totally blind was necessary to tailor specific rehabilitation services for veterans returning to the workforce. Even today, the term low vision is not easily defined; It generally describes people who are neither totally blind nor fully sighted."(Winzer)

Classification by Age of Onset:

• Children with visual impairments are often classified by age of onset of the problems. Congenital low vision usually happens at birth compared to adventitious low vision which is caused by an accident or disease some time after birth. 

Prevalence:

"Only about 1 in 1000 children under the age of 18 have severe visual impairments. Impairment of vision is primarily an adult disability, probably one-tenth as prevalent in children as in adults. People with low vision far outnumber totally or functionally blind people: only 10 to 15 percent of the entire population of persons with visually impairments are totally blind." (Winzer)

Etiology:

"Visual problems arise from any interference with the formation of images on the retina or the transmission of retinal images to the brain. Optical errors, defects of the eyes, diseases, syndromes, and associated conditions all affect vision to a greater or lesser extent."(Winzer)

Types of Visual Impairments:

• Refractive errors(eg. Myopia, cataracts, astigmatism)
• Eye pathologies(eg. Glaucoma, albinism)
• Oculomotor problems(eg. Strabismus)
• Other problems(eg.colour blindness, photophobia)
• Syndromes(eg.Usher's syndrome, Joubert syndrome)

Speech and Language Disorders

Speech and Language Disorders

Speech Disorders
Definition- Individuals with speech disorders encounter difficulties in oral language production, creating sounds, maintaining fluency and articulation of sounds. The ability to produce spoken language is reduced. Speech impairments are not to be confused with regular miss-production of sounds in regular developing children's speech.

Prevalence- Many children have difficulty with the production of speech but eventually catch up with their peers as they mature. Exact numbers on speech disorders are difficult to obtain because the criteria and definitions of speech disorders differ, as well as the fact that most children grow out of their speech impairments. However, we do know that speech disorders tend to be more prevalent in boys then in girls. 75% of speech disorders are articulation issues. 10%-15% of children in preschool have recognized speech disorders and only 6% of children have speech disorders by the time they reach elementary and secondary school grades. 

 Etiology- Speech disorders often stem from structural damage caused by hereditary development, injury, or disease, causing issues in the larynx, tongue, teeth, lips, plate, resonating cavities and the central and/or peripheral nervous system. Speech disorders can also be caused by hearing impairments or even the way the parents or adults interact with children. 

 “The distinction between a speech disorder and a language disorder is an important
one.” (Bennett, Dworet, Weber)
 
Speech Disorders
• difficulty with oral language production
• articulation, fluency and vocal impairments
• delayed onset, or absence of speech
 
Language Disorders
• problems receiving and / or expressing language
• includes delayed, different, deviant language, or no language
 
Although it is most common for individuals to experience speech and language
difficulties simultaneously, some experience difficulties in just one area. For example, an
individual with Cerebral Palsy may have no difficulty with receiving or expressing language
(through computer technology), while experiencing difficulties with oral communication
(speech).
 

Language Disorders
 
Definitions and Characteristics
Students with language disorders experience impairment in understanding or using
verbal and or written communication. Difficulties with language are often, “...associated
with neurological, psychological, physical, or sensory factors,” affecting, “all aspects of a
student’s school life and may be key features of other exceptionalities.” (The Ontario Curriculum
Unit Planner: Special Education Companion © Queen’s Printer for Ontario, 2002 p.42) Language disorders affect individuals socially, as well as academically, in terms of general learning, reading and
writing.
 
Classification
Depending on the severity of difficulties an individual has, they are categorized as
having either a language delay or disorder.
 
Language Disorder
• child experiences difficulty in most aspects of expressive and receptive language
• most cases require specialized intervention
 
Language Delay
• child learns at a slower pace than typical-aged peers
• less responsive to peer / teacher interaction
• talk about 50% less than their peers
• often resolved by age 5 or 6, as children catch up to their peers
• includes problems with receptive and expressive language, alone or in combination
 
Etiology
Language is a part of life from early infancy. Although children typically reach particular
milestones in the area of language development, some experience difficulties and fall behind
their same aged peers, for a variety of reasons. Medical factors like hearing impairments and
orofacial defects can both contribute to language problems. Some individuals acquire a
language problem later in life as a result of damage to the speech and language portions of
the brain, although stroke is the most common cause in adult impairments. Children with a
history of neglect and lack of exposure to language may also struggle in their development. It
has been found that, in some cases, mothers of children with physical and developmental
exceptionalities interact and play with them less, in some cases, depriving children with lower
verbal skills the opportunity to speak for themselves by speaking on their own behalf.

 Prevalence 
Many instances of language impairments go unreported, and the validity of survey
results on the topic is questionable. These factors make it difficult to measure the number of
children effected by language problems, and their various degrees of impairment. It is
believed that 7-10% of all children have a combined speech and language disorder, while only
about 1% display only a language disorder. It is also estimated that, “...of all children with
language disabilities, about 2/3 are boys.” (Winzer)
There is also debate over how to classify and define various language impairments.
Some common terms used to define common language problems include: language delay,
language disorder, aphasia/ dysphasia (developmental/ acquired)*, receptive and/ or
expressive language problems*.
While children with average learning levels can exhibit language problems, they most
commonly affect individuals with physical and developmental exceptionalities. Children with
hearing impairments often experience problems with language, as well as those with autism
spectrum disorders. Some adults are also effected by language difficulties, due to life-long
exceptionalities, and medical conditions like stroke, head injury, and disease (dysphasia/
acquired aphasia*).

 *Definitions*Aphasia- “conditions that affect language reception and expression.” (Winzer)
Dysphasia/ Acquired Aphasia- “...conditions (trauma) that occur after language has been developed.” (Winzer)
Receptive Language Disorders-“...interfere with the comprehension of spoken
language.” (Winzer)
Expressive Language Disorders-“...affect the formulation of grammatic utterances.”
(Winzer)

Pervasive Developmental Disorders

Pervasive Developmental Disorders

 

Definition of PDD'S: " A term that describes individuals who suffer from chronic disabilities, attributable to mental or physical impairments, or a combination of these, that are manifested before age twenty-two and that result in functional limitations in major life activities, requiring special services that are lifelong or of extended duration". (Winzer)

 

Pervasive implies that it is probable the conditions will be extremely long lasting, if not, lifelong.

Developmental implies that the conditions represent a significant delay in the developmental process and many, if not all developmental domains will be affected.

INTELLECTUAL DISABILITIES

 Definitions and Classification:  

"A delayed intellectual growth that is manifested in immature reactions to environmental stimuli and below average social and academic performance. Intellectual disabilities are also known as Developmental Disabilities." (Winzer) 

To be classified with an intellectual disability an individual must meet the following criteria:

• have a score below 70 on a standardized IQ test.
• have deficits in adaptive behaviour (including self care, home living, social skills, health and safety).

There are four degrees of intellectual disabilities measured by a standardized IQ test:

• Mild (IQ= 55-70): The student is capable of basic academic subjects.
• Moderate (IQ= 40-55): The student is capable of attaining self-help skills, communication skills, and social adjustment skills.
• Severe (IQ= 25-40): The student shows basic communication and self-help skills.

• Profound (IQ= below 25): The student can learn basic self-help and communication skills with intensive intervention.  

 Etiology: 

Chromosomal:

• individuals can have too many, too few or attached chromosomes.
• abnormalities in structure and number of chromosomes can be caused by natural mutations of genes, radiation and other factors.

Genetic Defects: 

• specific disorders are associated with distinctive behavioural phenotypes, which play a key role in a child's behaviour and learning styles. 
• 1/3 of intellectual disabilities come from genetic defects.

Infections/Intoxicant: 

• occurs in pregnant mothers passed on to their unborn children (rubella,syphilis etc.), infants and young children.
• intoxicants and poison (alcohol, nicotine etc.)  in a mother can cause an intellectual disability.

Environmental Influences:

• deprived background.
• psychological disadvantages.
• poverty 
•  inadequate nutrition.
• dysfunctional family dynamics.
• lack of educational opportunities.
• unstimulating infant environment. 

Prevalence:   

In the case of intellectual disabilities, mild conditions prove elusive and difficult to accurately pinpoint. Mild cases go unreported, although this is not true in the case of significant intellectual impairments.
Theoretically 2.27% of the populatoin may fall into the classification of intellectually disabled. In reality about 1 to 1.5% of the population meet the A.A.M.R definition of "retarded" in both intellectual and adaptive behaviour. 

• more than 75% of those identified are in the mild range.
• moderate, severe and profound account for 3 to 4 persons out of 1000, with severe and profound being extremely low-incidence conditions.
•  for a variety of reasons the number of boys identified is greater than that of girls by factors of five to ten. (Bennett) 
• the disablility also has a significantly higher prevalence in children from lower socio-economic classes.(Bennet)

The following is a list of the more common conditions with their prevalences. For a more detailed list see Winzer p184,185, table 6.5

Down Syndrome ( trisomy 21)         1 in 1,000.
Turners Syndrome                          1 in 2,500.
Prader-Willi Syndrome                    1 in 10,000 to 25,00.
Angleman Syndrome                       1 in 12,000 to 20,000.
Williams Syndrome                         1 in 20,000 to 25,000
Fragile X Syndrome                         1 in 25,000 to 1 in 40,000.

*Fetal Alcohol Syndrome (F.A.S.) is now considered to be the second major cause of intellectual and developmental disability in Western countries. Although conclusive data on the prevalence of F.A.S. are still being developed, there is concensus that the numbers are rising.

LEARNING DISABILITIES: Definitions, Etiology & Prevalence

learn·ing dis·a·bil·i·ty

Noun: A condition giving rise to difficulties in acquiring knowledge and skills to the "normal level"expected of those of the same age.



DEFINITION:

"Across Canada, there are differences in the definitions and major emphases of learning disabilities." (Winzer)

"Learning Disabilities is the most elusive of all areas in Special Education. Learning disabilities refers to a variety of disorders that affect the acquisition, retention, understanding, organization, or use of verbal and/or non-verbal information." (Bennett et al.)

"Learning Disabilities is a syndrome of behaviours that manifests differently in different individuals although the components of the syndrome itself are varied and confused." (Winzer) 

ETIOLOGY:

 

 

(Winzer/Bennet et al.)

 

PREVALENCE:

In Canada, students with learning disabilities make up the largest single group of children with disabilities (2-4% of the general child population and 48% of all students in  special education classes as per Winzer text, table 1-2)

Boys outnumber girls with learning disabilities with a ratio of at least 4:1. (Winzer)
 
 
CATEGORIES:

 CLASSIFICATIONS:

 

 

Hearing impairment- Chronological approach pictures

 Newborn                                                   Infant

 
                                                                 

Toddler                                               Preschool



School Age                                       Adolescence






www.google.ca

CLASSIFICATION OF BEHAVIOURAL DISORDERS

·         DSM = Diagnostic and Statistical Manual of Mental Disorders

·         The DSM is a manual primarily used by psychiatrists and psychologists to diagnose mental health problems. 

·         APA = American Psychological Association

·         SEVERITY

·         Tells the clinician how much the behavior differs from the norm. 

·         DIMENSIONAL

·         Based on the work of Quay et al.  Dimensional classification provides a relatively reliable  basis for describing five distinctive behavioural disorders.

·         TYPE

·         This is not a formal classification system.  However, it is used by some assessors to distinguish between behaviours which are internalized and behaviours which are externalized.  Internalized behaviours include nausea, pains, headaches, phobias, fears, obsessions, shyness, nightmares, depression and withdrawal.  Externalized behaviours include disobedience, lying, stealing, fighting, sexual delinquency and destructiveness. 

·         AGE OF ONSET

·         Early starters are those whose symptoms occur before the age of 10 and late starters are those whose symptoms occur after the age of 10.   Early starters are of greatest concern because the long-term impact of the disorder is more severe.  Once started, deviant patterns of behavior are very difficult to change and very unlikely to be reversed or eliminated. 

 

 For more information visit,

          http://www.knowledge.offordcentre.com/index.php

Behavioural Disorders: Definitions and Characteristics

DEFINITIONS AND CHARACTERISTICS

Students who are behaviourally disordered include those with conduct disorders, anxiety and withdrawal, socialized aggression, Attention Deficit Hyperactivity Disorder (ADHD) and childhood psychoses. 

All categories of behavioural disorders are difficult to define.  In fact, a universally agreed upon definition is still unavailable..  However, educators agree that all students in this category of exceptionality have common characteristics including but not limited to:

• All types of behavioural disorders are CHRONIC
• All behaviours EXTEND FAR BEYOND THE NORM
• Regardless of the specific characteristics, all children in this category RESPOND in SOCIALLY UNACCEPTABLE ways to their environments
• The behaviours exhibited INTERFERE with expected AGE APPROPRIATE FUNCTIONING
• The behaviours exhibited VIOLATE both SOCIAL and CULTURAL EXPECTATIONS
• Children with behavioural disorders also experience LOW levels of ESTEEM, have problematic INTERPERSONAL RELATIONSHIPS and often POOR SCHOOL ACHIEVEMENT