According to the World Health Organization (WHO) mental retardation is defined as “a condition of arrested or incomplete development of the mind, which is especially characterized by impairment of skills which contribute to the overall level of intelligence”.
Intellectual disability, formerly known as mental retardation, is a lasting neuro-developmental disorder causing impaired intellectual and adaptive functioning. It is characterized by an IQ score falling below 70. It results in significant limitations in self-adaptive functioning in an individual, characterized by significantly sub-average intellectual functioning which exists concurrently with related limitations in two or more of the following adaptive skill areas: communication, self-care, home living, social skills, community use, self-direction, health and safety, functional academics, leisure and work. Persons with Disabilities (Equal Opportunities, Protection of Rights and Full Participation) Act, 1995 defines it as a “condition of arrested or incomplete development of mind of a person which is specially characterized by sub-normality of intelligence”.
The prevalence rate of intellectual disability varies across countries and regions. According to the World Health Organization, it has an overall prevalence of 1-3% in the global scenario. In India, the occurrence of Intellectual disability is reported to be in the range of 0.07 to 40 per 1000. There is a clearly established relationship between poverty and intellectual disability. Malnutrition, lead poisoning and lack of prenatal care are only a few of the factors that may contribute to the disproportionate frequency of mental retardation among poor.
Intellectual disability can be categorized into four ranges contingent on the IQ scores- mild, moderate, severe, and profound. Based on the severity of Intellectual disability, the following characteristics can be identified:
Intellectual disability: Causes
A wide array of factors can result in Intellectual disability in a child. These factors range from environmental to genetic conditions in addition to the phase at which the impairment occurs. However, in one-third of the total intellectual disability cases diagnosed, the cause remains unknown. Following are some of the causes that are known to result in Intellectual disability in various phases.
- Rh incompatibility
- Maternal illness and infections such as rubella, jaundice, high BP, hypertension.
- Malnutrition in mother and child during the first trimester of pregnancy.
- Environmental and occupational hazards.
- Genetic abnormalities (such as Down syndrome, X syndrome, and PKU [phenylketonuria])
- Metabolic disorders (such as hyperbilirubinemia, very high bilirubin levels in babies).
- Natal Causes:
- Birth asphyxia, jaundice, seizures.
- Prematurity with low birth weight.
- Post-natal causes:
- Early childhood sickness, such as whooping cough, measles, seizures or meningitis.
- Environmental factors (lead or mercury poisoning)
Intellectual disability: Symptoms
Intellectual disability influences wide ranging factors associated with the overall development of a child. The abilities affected are significantly lower in children with intellectual disability than in children with IQ in normal ranges at a given age.
- Executive skills including attention and concentration, cognitive flexibility, working memory, planning, organizing, abstract thinking, problem solving etc.
- Affected Speech and use of Language
- Deficits in gross and fine motor abilities
- Disrupted Emotional regulation
- Affected adaptive skills including activities of daily living and self-care.
- Age-inappropriate social development.
The severity of the above listed symptoms and the disruption it entails in the activities associated with daily living is contingent on the range of intellectual disability.
Intellectual disability: Treatment
The first step towards the treatment is the identification of intellectual disability. Various procedures can be employed for the screening of intellectual disability and they vary according to the stage at which the screening is done.
At the pre-natal stage, identification of intellectual disability can be done using one of the following methods keeping in consideration the stage of pregnancy: ultrasonography, aminocentessis, Foetoscopy, Chorionic Villous Sampling.
At the Neonatal and Post-natal stage: Apgar Score at one minute after delivery, Urine screening for metabolic errors - PKU (Phenyle Ketoneuria), Chromosomal analysis for Down Syndrome, deletion of syndromes, Neonatal neuro-behavioural assessments, EEG electroencephalogram for seizure disorder.
Following screening instruments can be employed for diagnostic purpose at various ages:
WISC and KBIT are the most often utilized IQ tests for children and adults to determine the range of intellectual disability. According to DSM-V, an IQ score falling below 70 is used to indicate intellectual disability.
A comprehensive assessment in terms of severity of intellectual disability assessed by an IQ test, patient and family history, co-morbid psychiatric disorders and social impairment is crucial in the treatment of intellectual impairment in individuals.
The objective of the treatment of intellectual disability is to assist the individual in enhancing the affected abilities so that they are at par with the individuals of the same age and help them to get absorbed back into society.
The following treatments facilitate the development of the abilities commonly affected in an individual with intellectual disability. The treatment methods can be employed for a specific difficulty or overall impairment. In addition to the treatment, psychosocial support, rehabilitation and family counseling are other important requisites for the treatment of intellectual disability.
SPECIAL SCHOOLS: Schools designed for individuals with intellectual disability comprise of a comprehensive program attending to a variety of facilities ranging from vocational training, adaptive skills, cognitive functions and communication skills.
ARTS-BASED THERAPY: Dance therapy facilitates rhythm, facial expressions, body language. Music as an accompaniment adds to the therapeutic effects. Dance promotes the spacio-motor perception and bilateral movements; it provides follow up to balancing skills, posture corrections and other fine and gross motor skills required in performing daily living activities. Other therapies included are yoga, music, arts-crafts.
BEHAVIOR THERAPY: Behavior therapy including behaviour modification is commonly used to alter and teach adequate and appropriate behaviour in several domains. It can also be used to reinforce appropriate behaviour and eliminate destructive behavior including aggressive and self-injurious behaviour.
OCCUPATIONAL THERAPY: It provides immense help in acquisition of adaptive and self care skills and for activities of daily living.
SPEECH THERAPY: Speech therapy improves the diminished development of speech using various exercises of facial muscles and other techniques and further use of language as a way of expression.
COGNITIVE THERAPY: Cognitive therapy such as dispelling false beliefs and relaxation exercises with self – instruction has also been recommended for mentally retarded person who can follow instructions.
FAMILY COUNSELLING AND PSYCHOEDUCATION: Psycho-educating the family members of an individual with intellectual disability is one of the essential aspects of treatment. It entails providing information about intellectual disability, the severity, the implications and the way ahead. It also includes addressing the expectations of family members, their emotional stability and caretakers’ burden.
STEM CELL THERAPY FOR MENTAL RETARDATION
The current conventional treatments of intellectual disability are insufficient in mending the underlying brain damage seen in mental retardation. Stem cell therapy, however, can be of assistance to a great extent in improving the affected domains in intellectual disability. It is known that stem cells work at their best when combined with rehabilitation.
STEM CELL THERAPY: MECHANISM
The management of mental retardation requires a multi-dimensional approach to address to the various impairments. However, most of the patients reach a stationary stage with prolongs use of pharmacological, rehabilitative and surgical therapies. Stem cell therapy on the contrary, along with management of impairments, attempts, to stimulate the nervous system to repair the damage in the nervous tissue seen in affected individuals.
Cellular based therapies or more specifically, autologous (self derived) bone marrow derived stem cell therapy has found to show a promising premise in the arena of management of mental retardation.
Stem cells are believed to possess special properties of self-renewal as well as differentiation, which allow them to grow into different cell types. The stem cells also bring about changes in the surrounding tissue either altering the micro- or macro environments of the damaged tissue and these paracrine effects include changes in the internal repair process of affected neurons, immune modulation, secretion of various growth factors, secretion of vascular endothelial growth factor (VEGF), formation of new blood vessels, regulation of cell death, reduction of inflammation, and activation of neighboring stem cells.
All these processes by repairing the damage improve the function and networking in the brain which may be seen as clinical improvements leading to decrease in dependency and improvement in overall quality of life.
STEM CELL THERAPY OUTCOME AT NEUROGEN:
Over 25 patients with INTELLECTUAL DISABILITY have been treated at Neurogen with all of them showing excellent improvements in the affected areas.
On follow up, majority of the patients improved in various domains of symptoms such as cognition, social interaction, communication, toilet training, self care, home living, etc. Their school performance and learning ability improved leading to improvement in the mental development that starts to become age appropriate. Overall mental development is improved which is recorded as improvement in IQ scores. This consequently, helps the individual in gaining independence in terms of activities of daily living and reduces the responsibility of the care taker and the family.
Besides, improvement in symptomatic parameters, the neurological damage that is seen in mental retardation also shows repairs as reported by the radiological findings by PET-CT Scan.
Autologous stem cell therapy is a safe and feasible, alternate treatment option for INTELLECTUAL DISABILITY. By improving cognition, learning, and other functions, stem cell therapy decreases the gap between these patients with low IQ and that of normal IQ. It kick-starts the halted mental development and advances towards normal development.