الفهرس 
Introduction and Aim of the WorkOnly 14 pages are availabe for public view
 |  | from | 315 |  |  |
| | | from | 315 | | |
Abstract
Pervasive Developmental Disorders (PDD) are neurodevelopmental disorders characterized by severe and persistent qualitative impairments in three primary areas of functioning: impairments in social reciprocity and engagement; language and communicative skills; and the presence of repetitive non-functional behaviors and stereotyped interests.
These signs start to appear before the age of 3 years old, and in some cases as early as 18 months. The prevalence of autism is about 1-2 per 1,000 people; the prevalence of PDD is about 6 per 1,000, more in males than females with a ratio of almost four to one.
The aim of the work is to review literature discussing pathogenesis, clinical picture, and the principles and targets of different methods of rehabilitation of cognitive dysfunction in autism.
There are several anatomical changes in PDD. There is increase in total brain volume in early childhood, which is heritable by more than 90%. There are focal rather than global pattern of cortical dysmaturation that extends beyond childhood and affects brain regions that are involved in social cognition, language and some aspects of executive function, which is heritable by more than 80%.Also, there is decrease in brain connectivity in frontal and temporal white matter, some evidence in cerebellum, corpus callosum and superior temporal gyrus, decrease in fronto-striatal system, grey matter in left medial temporal lobe, and increase in grey matter in left inferior parietal cortex.
The traditional mentalising theory derives from a symbolic, abstract view of cognition, while the broken mirror account is associated with an embodied approach which emphasizes the role of simulation in understanding others. Similarly, the mentalising theory places the primary deficit in ‘high level’ reasoning about and representation of mental states, and assumes that abnormal social behavior in simple situations is a consequence of this. Meanwhile, the broken mirror theory focuses on lower-level problems with imitation and assumes that failure on theory of mind tasks arises because simpler simulation mechanisms are dysfunctional in Pervasive developmental disorders.
Aberrant connectivity theory posits dysfunction in the long distance connections between cortical brain regions in PDD, resulting in impairments in complex cognitive processes such as executive functions, social cognition, and language. The greatest reduction of Corpus Callosum area was observed in anterior regions providing a neuroanatomical link to the prominent executive dysfunction in PDD. Furthermore, the largest reduction at rostral body indicates disruption of fiber tracks originating in presupplementary motor regions . Presupplementary motor regions are crucial for motor planning and disruption of these regions may be the neural substrate for impairments in fine motor skills and imitation.
One striking feature of Autism spectrum disorders (ASD) is the “jagged profile” of performance across subtests of IQ measures such as the Wechsler scales. Most individuals with ASD show relative strengths in tasks which demand visuospatial organization and perceptual organization abilities, and relative impairments on tasks that demand planning and interpretation of practical knowledge or events. ASD is characterized by “islets of ability,” including excellent rote memory abilities, skill with jigsaw puzzles, and savant skills such as calendrical calculation.
There are also impairments in joint attention which is the ability to coordinate one’s attention to an object with another person; and imitation, the mimicking of facial expressions, playful imitation of others, and voluntary gestural imitation.
Moreover 50% of individuals with autism fail to develop functional spoken language abilities. The unique speech style characteristic of ASD includes atypical intonation, prosody, and other speech qualities.
There is increasing evidence that early intervention improves outcomes for children with PDD, especially with multidisciplinary approach.
Applied Behavior Analytic Interventions (ABA) were pioneered by Ivar Lovaas and colleagues in the 1960s, parents have been trained to be co-therapists in order to facilitate generalization and maintenance of new skills, while mainstreaming children with typically developing children. Treatment onset as early as possible in the child’s life, preferably before the age of 3.5 years old, is applied 30-40 h per week of one-to-one intervention.
ABA is considered ‘‘Well Established’’ intervention. Also, it is effective in enhancing global functioning in pre-school children with autism when treatment is intensive and carried out by trained therapists.
Child’s Talk program uses video feedback in order to promote facilitative strategies that lead to closer interpersonal interaction between the children and their parents. It significantly improves expressive language (moderate quality evidence).
Early Intensive Behavioral Interventions (EIBI) programs are initiated as early as possible (typically before the age of 5), and involve up to 40 h per week of one-to-one intervention improving the intellectual abilities of children with ASD, language and adaptive behavior abilities (very low quality evidence).
The Picture Exchange Communication System (PECS) is designed to teach children to request desired items in impressive learning patterns. PECS significantly improves the frequency of non-imitative speech immediately after 6 months of treatment, results in decreased tantrums and other problem behaviors. Furthermore it improves social interactions and expressive language (very low quality evidence).
Neurofeedback refers to a form of operant conditioning of electrical brain activity, in which desirable brain activity is rewarded and undesirable brain activity is inhibited. Neurofeedback is believed to elicit growth and changes at cellular levels of the brain, which in turn support brain functioning and behavioral cognitive performance. After 24 sessions of neurofeedback, parents and teachers reported improvements in behavior, i.e. less anxiety, more flexibility, higher self-esteem, more empathy, improvement in frustration toleration, increased social interaction, and fewer severe mood changes. Also, it improves the executive functions of children with ASD.
Virtual Environments (VE) allow users to interact with a three-dimensional computer based world incorporating impressive graphics and design. They can interact with objects in the scene and are typically represented as a humanoid ‘avatar’. The use of computerized intervention permits the development of skills in a highly standardized, predictable, and controlled environment, while simultaneously allowing an individual to work at his own pace and ability level. Whilst the use of Virtual Reality Therapy (VRT) provides a novel approach to social skills training, and cognitive flexibility for ASD patients.
Treatment and Education of Autistic and Communication Handicapped Children (TEACCH) was founded at the University of North Carolina in 1966. Today, it is the most influential special education program for children with autism used worldwide. It aims at addressing multiple problems such as communication, cognition, perception, imitation and motor skills. Parents are trained in TEACCH methods and schooling at home, and this is supplemented by day therapy or special schooling, given by professionals (very low-quality evidence).
Hanen’s ‘More Than Words’ (HMTW) is a parent training program designed to teach parents of children with ASD practical strategies to use during every day routines to increase children’s communication. Group and individual sessions focus on helping children to reach four goals: (a) improved two-way interaction, (b) more mature and conventional ways of communicating, (c) better skills in communicating for social purposes, and (d) improved understanding of language (very low-quality evidence).
Sensory integration therapy (SIT) is based on a theory developed by Ayres in 1972, emphasizing the relation between sensory experiences, motor and behavioral performance. The intervention strategies involve the use of planned and controlled sensory experiences including vestibular, proprioceptive, and somatosensory activities.
Auditory integration training is based on the hypothesis that individuals have insensitivity or abnormal sensitivity to various frequencies of sound waves, and that behavioral and learning difficulties are a result of this. It is hypothesized that auditory integration training addresses sound sensitivity and ”re-educates” hearing, thus improving associated symptoms. Treatment with auditory integration training involves listening to electronically modified music, heard through headphones, for two daily 30-minute sessions over 10 days. However, the American Academy of Pediatrics has suggested that auditory integration training should be used for research purposes only. Treatment with auditory integration training may involve high costs to the family.
Music Therapy can evoke a great intensity of emotions in ASD individuals, who typically have difficulty in processing emotions. This positive response to music and music making may help children with autism engage and interact with others, thus allowing them to participate in activities that could facilitate the acquisition of social, language, and motor skills.