autism


 References

Sensory Integration Theory

Sensory integration is "the organization of sensory input for use" (Ayres 1979). The term sensory integration which signifies a neurological process was first developed by Ayres. This process enables the spatial-temporal usage of the sensory information the individual gets from his body and environment and the perception, interpretation, and integration of information in order to plan and form organized motor behavior. According to this theory, mild and moderate problems in learning are related to motor in coordination and weak sensory process (Ayres 1972a, Ayres 1972c, Bundy and Fisher 1992, Fisher and Bundy 1992, Scheerer 1997).

Sensory integration theory is based on the view that neural plasticity and sensory integration occur in the developmental order, and brain functions integrate with the related systems hierarchically. Adaptive motor response is the most significant parameter of sensory integration. "An adaptive response is a purposeful, goal directed response to a sensory experience" (Ayres 1972b, 1979).

Three main sensory systems play a role in the growth and development of the child - tactile, vestibular, and proprioceptive systems (Williamson and Anzalone 2001):

  1. Tactile System; provides information about the environment by the sense of touch. The stimulus of the tactile system is received by the receptors in the skin which is the largest organ of the body. The tactile system has two components. The first is the protective system which informs when touching is harmful, and the other is the discriminative system which informs of the difference between harmful and beneficial touch.
  2. Proprioceptive System; is a system which receives sensory stimulus from the muscles and joints. Push and pull activities related to muscles and joints provide maximum stimulus to this system. The proprioceptive system is also important for the development of fine and gross motor muscles. The insufficient proprioceptive system also negatively affects motor planning ability.
  3. Vestibular System; Vestibular system receptors are within the inner ear and are related to hearing. The receptors in this system respond both to movement and gravity. The vestibular system is a system that affects balance, eye movements, posture, muscle tone and attention.

Assessment

In a child with an intellectual disability; motor, perceptual and cognitive skills should be considered comprehensive assessments. A multidisciplinary team consisting of a doctor, physiotherapist, occupational therapist, psychologist, language and speech pathologist, social worker and special educators will make the best assessment and intervention plan for the child. In all levels of function, motor development, oral function and nutrition, sensory integration, seeing, hearing and intelligence should be assessed (Swaiman 1989).

In the functional assessment, one or more measurement results are used in making some decisions about the functional performance of the child (Ottenbacher et al. 1999, Ottenbacher et al. 2000, Uyanik et al. 2003b).

These measurements can be divided into three groups which assess the measurements of motor functions, activities of daily living (ADL), and make developmental assessment. The majority of the tests examine both motor functions and daily-life activities (Taggart and Aguilar 2000).

Two commonly used pediatric functional assessment methods are The Functional Independence Measure for Children (WeeFIM®) and Pediatric Evaluation of Disability Inventory (PEDI). WeeFIM® comprises 13 motoric-based daily living skills and 5 cognitive items (Msall et al. 1994). PEDI is a comprehensive test consisting of 197 items used in the assessment of self-care, mobility and social functions of children between 6 to 90 months of age (Haley et al. 1992).

In Occupational Therapy, the focus is on the assessment of occupational performance. Occupational performance areas (self-care, productivity, and leisure), performance components (mental, physical, sociocultural, and spiritual), and environment (physical, social, cultural) should be assessed (Watson 1992).

The following are the occupational therapy tests that can be used specifically in the assessment of mental retardation:

  • Loewenstein Occupational Therapy Cognitive Assessment-LOTCA (Itzkovich et al. 1993) for the assessment of cognitive problems
  • Automatic Postural Reactions Tests (Bobath 1990) for the assessment of motor functions
  • Gross Motor Function Measure-GMFM (Russell et al.1993) for the assessment of gross motor functions
  • AAMR Adaptive Behavior Scale-School Second Edition (Lambert et al. 1993) for the assessment of adaptive behavior processes
  • The Pediatric Clinical Tests of Sensory Interaction for Balance (P-CTSIB) (Richardson et al. 1992) for the assessment of balance deficits in children
  • Southern California Postrotary Nystagmus Test (SCPNT) (Ayres 1975) for the assessment of vestibular functions
  • Bruininks-Oseretsky Test of Motor Proficiency (BOTMP) (Bruininks 1978) for the assessment of motor skills
  • Southern California Sensory Integration Tests (SCSIT) (Ayres 1972b) for the measurement of sensory perceptual motor performance
  • Sensory Integration and Praxis Tests (Ayres 1989) which consist especially the assessment of praxis and sensory integration

Researchers who have used the assessment tests stated above have determined the condition range of children with special needs (Kantner et al. 1976, Russell et al. 1998, Uyanik et al.1999, Uyanik et al. 2001, Uyanik et al. 2003b, Düger T et al. 1999, Tural et al. 2001, Bumin et al. 2002, Jobling 2006, Aki et al. 2007).

Interventions in Sensory Integration Dysfunctions

The fundamental principle in the intervention of sensory integration dysfunctions is enabling planned and controlled sensory stimuli with adaptive responses in order to increase the level of organization of the brain mechanism. The therapist's role in sensory integration programs is to arrange the stimuli coming from the environment so as to enable the individuals to demonstrate appropriate motor behavior, and develop self-care, play and school skills (Troyer 1961). Ayres stated that sensory integration is significantly related to the development of hearing and language skills besides motor coordination (Ayres 1979).

Sensory integration assessment, which is performed prior to sensory integration intervention, enables analyzing, synthesing, and interpreting the individual's sensory-perceptual motor behaviors. The assessment consists of the assessment of sensory motor process integration, the adaptation process of the individual, the effects of the maturation and behavior process and defining the developmental profile (Dengen 1988, Ayres 1989, Ayres 2005).

Acquiring skills requires the integration of information. In enabling the child to acquire skills, the therapist uses oral stimuli, supportive visual stimuli, the positioning of the child, passive movement and the suitable environment. The first stage in enabling the learning of the skills is to direct the child toward the desired goal (Gentile 1992).

There are four fundamental principles in the intervention of sensory integration dysfunctions:

  1. The intervention process begins with assessment. The assessment of sensory-motor state and environmental adaptations are important in assessing the effect of the intervention, intervention methods and urgent therapeutic goals. The issues below should be considered in order to plan the intervention:
    1. The level of function of the child
    2. The developmental status of sensory integration process of the child
    3. What are the primary aims of the intervention and what intervention methods should be used with what purpose?
    4. How often should the child be treated and what home programs should be given?
  2. The intervention program should follow the sequence of motor development seen in typically developing children. When the individual achieves highly controlled behaviors such as running, hopping, writing, and reading, an improvement in the assimilation and adaptation process of the visual, tactile, proprioceptive and vestibular stimuli occurs. Integrating intervention activities into the general play of the children in the program can be beneficial.
  3. The intervention depends on the intersensory integration process. The organization of sensory stimulus which is internalized by the adaptation of the body, and the sensory integration process are the main steps of the intervention.
  4. It should also be noted that home care for the child provided by parents and family and emotional and social development also play an important role in the intervention. The child's success depends on the therapist's communication and coordination with the patient's family and with other disciplines while planning the intervention program. Specialized programs depend on the age, gender, function loss, skills and interest of the child and the therapist's education (Gilfoyle and Grady 1971, Dengen 1988).

Activity training for sensory perceptual –motor dysfunction

The appropriate adaptation of the environment is very important in the intervention of sensory integration. The environment should be interesting to the child. The following activities are suggested in sensory integration intervention according to the child's proper sequence of development:

  1. Tactile, vestibular, proprioseptive input and feedback

    Gross motor accommodation; gross postures and patterns of motion (rolling pivot prone, on elbows, all fours, standing, walking in unusual patterns and different surfaces, running, hopping, jumping on twister spots, catching, throwing)

    Motor planning (praxis): is the ability of the brain to conceive of, organize, and carry out a sequence of unfamiliar actions as necessary when learning new skills. Activities directed toward goal achievement help to develop motor planning skills. Net hammock and ball activities can help to improve gross motor accommodation and praxis.

  2. Tactile, vestibular, proprioseptive input and feedback

    Righting and equilibrium reactions, and integrative patterns of different positions can maintain these stimulations. Play of boat in the ocean in the quadruped position can facilitate balance and equilibrium reactions. Therapists say "you are a boat in the ocean, and I am the hurricane you should try not to fall down" and therapist pushes the child very slowly for couple of times in order to disrupt the child's balance (Kramer 2007).

  3. Tactile, vestibular, proprioseptive and visual input and feedback

    Apedal and quadrupedal activities; skooter board, bean bag, ball playing, rolling, crawling, relays, follow the leader, rhythm bands etc.

    Ocular control: activities which require the movement of hands and large muscle groups such as throwing and catching, and activities which require little muscle movement such as drawing pictures and drawing lines help to develop ocular control.

  4. Tactile, vestibular, proprioseptive and visual input and feedback

    Activities for bipedal positions; running, jumping, skipping, hopping games, playground equipment( swings, barrels, slide, climbing bars), ball playing, musical games.

    Bilateral motor coordination: When both sides of the body work together in coordination, purposeful hand movements appear and the child can cross the midline of his body.

    Proprioceptive activities: climbing, pushing, pulling, carrying heavy objects, working against resistance and pressure

    Visual–Spatial Perception: Children with dysfunctions of visual space perception have difficulty in writing and working with numbers. Learning and understanding direction concepts help to develop visual space perception. Activities directed toward vestibular and ocular controls which require knowing the position of objects in space help to develop visual-spatial skills. It is stated that there is a strong relation between visual perception and motor performance (Brien et al. 1988). Motor planning activities and visual space perception games have motor planning components, because motor planning and visual space perception interrelate. Motor activities such as walking, running, stair climbing can be structured to encourage a child to attend visually to spatial features (Kramer 2007). Serial activities (e.g nesting cups and graduated pegs) and many constructional tasks (puzzles, block designs, and graphic copying) can be given as examples to visual– spatial perception.

  5. Tactile, proprioceptive and visual input and feedback

    In the learning of fine motor skills, appropriate postural stability is important. Also good co-contraction of head, neck and arm muscles is required. Good ocular control, bilateral motor coordination and tactile sense affect hand functions. The child needs activities which consist of all these components in order to develop fine motor skills. For example; puzzles, finger plays, origami, peg boards (Ayres 1979, Lerner 1985, Scheerer 1997, Wilson 1988, Bumin and Kayihan 2001, Uyanik et al. 2003a).

The Role of the Vestibular System in Motor Development

The vestibular system is important in the achievement of normal motor development and coordination (Weeks 1979a, Cohen and Keshner 1989a, Cohen and Keshner 1989b, Shumway-Cook 1992). The vestibular dysfunction is observed in many developmental disorders as motor discoordination and learning disabilities (Magrun et al. 1981, Schaaf 1985, MacLean et al. 1986, Horak et al. 1988, Shumway-Cook 1992). The vestibular system is one of the first sensory systems that develop prenatally and is functional at birth due to the completion of its structure anatomically (Shumway-Cook 1992).

Normally, vestibuloocular inputs are significant in eye-head coordination which is important for stabilizing the look at one point, whereas vestibulospinal inputs are significant in maintaining postural stability with visual and somatosensory inputs (Nashner et al. 1982). The vestibulonuclear complex, the cerebellum and the reticular formation have reciprocal associations and affect motor behavior. The vestibular system is one of the wide sensory systems. Fibers pass into the vestibulonuclear complex from which they pass into the cerebellum and also into the 3. 4. 6. cranial nerves that enable extra ocular muscle movements and into all spinal levels that affect muscle tone (Ottenbacher and Petersen 1983, Kelly 1989).

The vestibular system is particularly important in the development of motor skills, the integration of postural reflexes, forming coordinated eye movements, and visual attention skills, and also in developing inquiring-behavior, and regulating the level of liveliness (Ottenbacher and Petersen 1983).

In contrast to children with isolated vestibular pathology, serious problems are observed in the motor sufficiency of children who demonstrate insufficiency in efficiently organizing visual somatosensorial inputs and normal vestibular inputs for postural control. Therapists who treat children with vestibular dysfunction stimulate the vestibular system with equipment such as swings, scooter boards, and hammocks (Shumway-Cook 1992). Ayres stated that, according to the sensory integration theory, the effect of vestibular stimulation in the central nervous system stems from the plasticity of the nervous system, and that the improvement observed in children in the period following the intervention is continuous because of undeveloped brain plasticity (Ayres 1972a, 1979).

The following can be beneficial as the therapeutic effects of vestibular stimulation (Weeks 1979b, Magrun et al. 1981, Pfaltz 1983, Sandler and McLain 1987, Arendt et al. 1991, Dave 1992, Uyanik et al. 2003a, Uyanik et al. 2003c):

  1. Developing gross motor functions and reflex integration
  2. Regulation functional balance
  3. Increasing perception-motor skills
  4. Developing hearing-language skills and intellectual functions
  5. Increasing socio-emotional development
  6. Decreasing self-injurious and/or stereotypical behavior
  7. Helping the beginning of intervention by enabling individuals to be more receptive to the different forms of intervention

In assessments of determining the indication of the vestibular stimulation intervention, it is necessary that most of the following findings have positive outcomes: shortening of the post-rotary nystagmus duration, inefficiency in pivot prone (prone extension) position, hypotonicity in extensor muscles, weakness in equilibrium and support reactions, decrease in (co-contraction) joint stability, feeling of gravitational insecurity, and intolerance to movement (Fisher and Bundy 1989).

Vestibular stimulation intervention methods

In the application of vestibular stimulation, the structure and position of the vestibular stimulus is significant in the efficiency of stimulation. Whether the vestibular stimulation has excitatory or inhibitory effects is determined by the form of the stimulation. Slow, rhythmic, and passive movement has inhibitory effect; rapid movement has excitatory effect. Rotational movement and linear acceleration-deceleration stimulate different receptors. Different types of sensory stimuli form by rolling, and swing back and forth. In addition, positioning upside down, lying prone and supine or side-sitting activate different parts of the canals and otoliths at different degrees. The horizontal position and especially the prone position activate otoliths more efficiently than the upright position. The horizontal position is also the best position for semicircular canal stimulation. Ayres pointed out that different head positions and movements are necessary for the stimulation of vestibular receptors, but particularly the horizontal position is more important (Ayres 1979, Kelly 1989).

Types of vestibular stimulation:

  1. To normalization of extensor muscle tone by increasing otolith organ input, linear activities are given in accordance with the order of motor development. These are:
    1. bouncing-jumping activities (whilst sitting, kneeling, or standing)
    2. linear swinging activities (using platform and T-swing, glider, hammock and barrel swinging in kneeling, standing, sitting, creeping and, prone and supine positions)
    3. other linear activities (jumping or falling onto pillows or mattress in sitting, prone and supine positions)
  2. To development of equilibrium reactions by increasing semicircular canal responses, the center of gravity is changed to create disorganization for a short time and thus phasic head movements are made to appear. For this,
    1. by moving the support surface, the center of gravity is changed as active or passive.
    2. by pushing-pulling activities, displacement of the center of gravity is created. These are activities which enable active equilibrium on steep surfaces such as stairs, ramps and unfamiliar surfaces by using equipments such as balance boards, therapy balls and barrel.
  3. To lessen the fear of movement or positional change by increasing the weak passing of otolith input, linear vestibular stimulation is applied in tolerable speeds and durations and in unthreatening positions (Fisher and Bundy 1989).

There are a number of precautions to consider the vestibular stimulation:

  1. As a result of over stimulation, sensory overload occurs and this results in organization dysfunctions in the central nervous system. Therefore, over stimulating should be avoided, and before, during, and after vestibular stimulation, the child should be checked for evidence of over stimulation or under stimulation and allowed to determine his own speed.
  2. The over inhibition of the brainstem is the greatest potential harm resulting in seizures, cyanosis, and depression in vital functions.
  3. In children with hypertonicity, a counter effect in the form of more tone increase may occur.

Sensory stimulation response is different in each child, and the child should be checked carefully at this time (MacLean et al. 1986, Fisher and Bundy 1989).

 

1. Schaaf, R.C., and L.J. Miller. 2005. "Occupational Therapy Using a Sensory Integrative Approach for Children    with Developmental Disabilities." Ment.Retard.Dev.Disabil.Res.Rev. 11(2):143-148.

2. Dempsey, I., and P. Foreman. 2001. "A Review of Educational Approaches for Individuals with Autism."    International Journal of Disability, Development and Education v48 n1 p103-16 Mar 2001.

3. Marr, D., et al. 2007. "The Effect of Sensory Stories on Targeted Behaviors in Preschool Children with    Autism." Phys Occup Ther Pediatr. 27(1):63-79.

4. Baranek, G.T. 2002. "Efficacy of Sensory and Motor Interventions for Children with Autism." Journal of    Autism and Developmental Disorders v32 n5 p397-422 Oct 2002.

5.http://cirrie.buffalo.edu/encyclopedia/en/article/48/#s8

 

 


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