Pervasive Development Disorder (PDD) means presence of something aversive in the child during the growing years. Though it’s a neurological disorder, the exact aetiology/ cause behind it, is not known. There are many hypotheses that suggest that PDD like syndrome occur due to some defect in the functioning of temporal lobe of the brain, while other say it’s because of biochemical factors and so on but as of now there is no concrete or say a particular reason that can be attributed to cause PDD.
Parents may note symptoms as early as infancy, but the typical age of onset is before 3 years of age and they become concerned about their child by 18 months as (further) language development does not occur as expected or is subsequently lost.
Many children with PDD are not identified until school age, because they make relatively less demands, have minimal conflicts with peers due to their lack of interest in social affairs.
The three Characteristic Symptoms of PDD are as follows:
- Aberrant Language Development
- Restricted Behaviour Repertoire
- Impaired Reciprocal Social Interactions
There are 5 categories that fall under this PDD umbrella, that include Autism. It is a neurological disorder characterised by marked impairments in all the above 3 characteristics mentioned just above. Males are affected more than the females. The symptoms like qualitative impairment in social interaction, impairment in communication and restricted repetitive and stereotyped patterns of behaviour or lesser areas of interest, may range from mild-moderate-severe, thus, at times it is referred to as Autism Spectrum Disorder (ASD). These children often get adamant and resist changes in their routine.
Rett’s disorder that occurs typically in girls is another category that falls under PDD umbrella. Parents gives a history say, my girl was growing well but we noticed some aversive features in her when she was nearing her first birthday. Scientists have discovered that a mutation in the sequence of a single gene can cause Rett ‘s syndrome.
Asperger’s disorder also falls under PDD umbrella. It’s a condition in which the child is markedly impaired in social relatedness and shows repetitive and stereotyped patterns of behaviour without a delay in language development and also these children have high cognitive abilities and normal adaptive skills. Bladder or bowel control, play and motor skills may also be affected in these children apart from the characteristic three features. Bollywood actor Sharukh khan played one such character in the movie “My Name is Khan”.
Childhood disintegrative disorder (CDD) as another category under PDD umbrella has a strong male preponderance. Symptoms may appear by two years of age. However, the average age of onset is between 3 and 4 years. Until his time, the child has age-appropriate skills in communication and social relationships.
The long period of normal development before regression helps differentiate CDD from Rett’s syndrome. The loss of skills is more dramatic in CDD than they are in classical autism. The diagnosis requires extensive and pronounced losses involving motor, language, and social skills. CDD is also accompanied by loss of bowel and bladder control and oftentimes seizures and a very low IQ.
Occupational therapy have elaborate assessment tools like sensory profile, childhood autism rating scale, among others., that can give more depth to all the symptoms and hence make a therapeutic intervention plan best suited for the child covering all the areas affected.
The use of ‘Sensory Integrative Frame Of Reference’ by an occupational therapist can help produce certain desirable changes or say appropriate adaptive response, to varied degrees, if all occupational therapy domains are considered.
Inconsistency is the hallmark of sensory integration dysfunction (inclusive of all the 5 categories in PDD), i.e., the child may not show a particular characteristic of dysfunction every time.
This fact makes it inevitable for the parent to see an occupational therapist as early as possible and seek help for the child so that s/he can lead a better and not isolated life to the extent possible.
An Occupational Therapist with the cooperation of the parents can carve out myriad ways to help the child with Autism and other conditions. A sensory diet can accordingly be planned to keep the nervous system of the child calm and organized. Once it is organized, nervous system can be made to focus on other things of daily life.