DEVELOPMENTAL DISORDERS
Autism Spectrum Disorder (ASD)
Definition:
Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder characterized by deficits in social interaction, communication, and repetitive behaviors.
Causes & Risk Factors:
- Genetic factors (Strongest association, seen in twin studies)
- Environmental triggers (Prenatal exposure to valproic acid, advanced paternal age)
- Neurological differences (Abnormal brain connectivity and amygdala dysfunction)
Signs & Symptoms:
- Impaired social interaction (Poor eye contact, lack of response to name, social withdrawal)
- Delayed or absent speech development
- Repetitive behaviors (Hand flapping, rocking, spinning objects)
- Fixated interests (Strong attachment to specific objects or topics)
- Sensory sensitivities (Hyper or hypo-reactivity to sounds, lights, textures)
Complications:
- Intellectual disability (Varies; some children have normal or high IQ – “high-functioning autism”)
- Seizures (Common in ~25% of ASD cases)
- Self-injurious behaviors (Head-banging, biting)
Diagnosis:
- M-CHAT (Modified Checklist for Autism in Toddlers) – Screening tool
- DSM-5 Criteria for ASD
- Speech and language evaluation
- Genetic testing (If associated with syndromes like Fragile X syndrome)
Management:
- Applied Behavior Analysis (ABA therapy – Gold standard for ASD treatment)
- Speech and occupational therapy
- Parent training and structured learning environments
- Medications (Risperidone or Aripiprazole for severe irritability/aggression)
Attention-Deficit/Hyperactivity Disorder (ADHD)
Definition:
ADHD is a neurodevelopmental disorder characterized by inattention, hyperactivity, and impulsivity, impairing daily functioning.
Types (DSM-5 Classification):
- Predominantly Inattentive Type
- Predominantly Hyperactive-Impulsive Type
- Combined Type (Most common)
Causes & Risk Factors:
- Genetics (Highly heritable, associated with dopamine transporter gene mutation – DRD4, DAT1)
- Low birth weight, Prematurity
- Prenatal exposure to nicotine, alcohol, lead poisoning
Signs & Symptoms:
- Inattention (Difficulty sustaining focus, forgetfulness, careless mistakes in schoolwork)
- Hyperactivity (Fidgeting, excessive talking, unable to stay seated in class)
- Impulsivity (Interrupts conversations, acts without thinking, difficulty waiting turn)
Complications:
- Academic underachievement
- Increased risk of substance abuse in adolescence
- Oppositional Defiant Disorder (ODD) and Conduct Disorder (CD) association
Diagnosis:
- Conner’s ADHD Rating Scale (Used by parents and teachers)
- DSM-5 criteria (Symptoms must be present in 2 or more settings and before age 12)
Management:
- Behavioral therapy (First-line for preschoolers, recommended for all age groups)
- Stimulant medications (Methylphenidate, Amphetamine – First-line for children >6 years)
- Non-stimulants (Atomoxetine, Guanfacine – If stimulants are not tolerated)
Intellectual Disability (ID)
Definition:
Intellectual Disability (ID) is a neurodevelopmental disorder characterized by significant limitations in intellectual functioning (IQ <70) and adaptive behavior, affecting daily life.
Causes & Risk Factors:
- Genetic disorders (Down Syndrome, Fragile X Syndrome, Rett Syndrome)
- Prenatal factors (Maternal infections – Rubella, CMV, Fetal alcohol syndrome)
- Perinatal causes (Birth asphyxia, Prematurity, Low birth weight)
- Postnatal causes (Lead poisoning, Malnutrition, Hypothyroidism)
Signs & Symptoms:
- Delayed developmental milestones (Walking, talking, toilet training)
- Difficulty with reasoning, problem-solving, and learning new skills
- Limited adaptive functioning (Communication, Social skills, Self-care difficulties)
Complications:
- Increased dependence on caregivers
- Higher risk of psychiatric disorders (Anxiety, Depression, Autism in severe ID)
Diagnosis:
- IQ Testing (Wechsler Intelligence Scale for Children – WISC, Stanford-Binet test)
- Vineland Adaptive Behavior Scales (Measures adaptive functioning)
- Genetic testing (If syndromic features are present)
Management:
- Early intervention (Special education, speech and occupational therapy)
- Individualized Education Program (IEP) in school
- Supportive care and life skills training
Specific Learning Disorder (Dyslexia, Dyscalculia, Dysgraphia)
Definition:
A learning disorder is a neurodevelopmental condition affecting academic skills, such as reading (Dyslexia), writing (Dysgraphia), or mathematics (Dyscalculia), despite normal intelligence.
Causes & Risk Factors:
- Genetic predisposition (Runs in families, associated with left hemisphere dysfunction)
- Prematurity, low birth weight
- Neurodevelopmental abnormalities in phonological processing
Signs & Symptoms:
- Dyslexia (Reading difficulty) – Poor phonemic awareness, slow reading speed
- Dyscalculia (Math difficulty) – Trouble with numbers, patterns, mental calculations
- Dysgraphia (Writing difficulty) – Poor handwriting, difficulty forming letters correctly
Complications:
- Low self-esteem, Anxiety, Depression
- Poor academic performance leading to school dropout
Diagnosis:
- Psychoeducational Testing (Cognitive and academic skill assessments)
- DSM-5 Criteria for Specific Learning Disorder
Management:
- Specialized education interventions (Multi-sensory teaching, phonics-based reading programs)
- Speech and occupational therapy (For Dysgraphia, Dyslexia)
- Extra time for exams, assistive technology (Text-to-speech software, audiobooks)
Developmental Coordination Disorder (DCD)
Definition:
DCD, also known as “Clumsy Child Syndrome,” is a motor skills disorder affecting coordination, balance, and fine motor abilities.
Causes & Risk Factors:
- Prematurity, Low birth weight
- Cerebellar dysfunction (Possible underlying neurological basis)
Signs & Symptoms:
- Poor handwriting (Difficulty with pen grip, slow writing speed)
- Clumsiness (Frequent tripping, difficulty catching balls, riding a bike)
- Delays in achieving motor milestones (Crawling, walking, tying shoelaces)
Complications:
- Poor academic performance (Due to writing difficulties)
- Social isolation (Avoidance of sports, group activities)
Diagnosis:
- Movement Assessment Battery for Children (MABC-2)
- Clinical observation of motor coordination
Management:
- Occupational and physical therapy
- Motor skill training (Hand-eye coordination exercises, balance training)
Key Points for Competitive Exams
✔️ Most common neurodevelopmental disorder? – ADHD
✔️ Best screening tool for autism? – M-CHAT (Modified Checklist for Autism in Toddlers)
✔️ Most effective treatment for ADHD? – Stimulants (Methylphenidate, Amphetamines)
✔️ Best test for intellectual disability? – Wechsler Intelligence Scale (WISC)
✔️ Most common cause of inherited intellectual disability? – Fragile X Syndrome
Physical Disabilities (Handicapped Children)
Definition:
A handicapped child has a permanent physical or motor impairment that limits mobility, daily activities, or learning capacity.
Types of Physical Disabilities:
- Neuromuscular Disorders – Cerebral Palsy, Muscular Dystrophy
- Orthopedic Disorders – Clubfoot, Spina Bifida, Limb Deficiencies
- Trauma-Induced Disabilities – Spinal Cord Injury, Amputations
Causes & Risk Factors:
- Congenital conditions (Cerebral Palsy, Spina Bifida)
- Birth-related complications (Hypoxia, Birth trauma, Prematurity)
- Postnatal infections (Meningitis, Polio, Encephalitis)
- Accidents and trauma (Fractures, Spinal cord injuries)
Signs & Symptoms:
- Delayed motor milestones (Sitting, standing, walking difficulty)
- Abnormal muscle tone (Hypertonia or Hypotonia)
- Contractures or joint deformities
- Difficulty in fine motor tasks (Writing, Grasping objects)
Complications:
- Mobility impairment → Dependency on assistive devices
- Contractures and scoliosis (In severe cases of neuromuscular disorders)
- Speech and communication difficulties (If associated with neurological damage)
Diagnosis:
- Clinical examination (Neurological and orthopedic assessment)
- Imaging (MRI Brain for Cerebral Palsy, X-ray for orthopedic disorders)
- Electromyography (EMG) and Nerve Conduction Studies (For neuromuscular disorders)
Management:
- Physical and Occupational Therapy (Improves mobility and function)
- Assistive Devices (Braces, Wheelchairs, Prosthetics)
- Speech therapy (For communication difficulties)
- Surgical interventions (For severe orthopedic deformities)
Intellectual Disability (Mental Retardation)
Definition:
Intellectual Disability (ID) is a neurodevelopmental disorder characterized by an IQ <70 and significant deficits in adaptive functioning.
Causes & Risk Factors:
- Genetic Conditions (Down Syndrome, Fragile X Syndrome, Rett Syndrome)
- Prenatal Factors (Fetal Alcohol Syndrome, Maternal infections – Rubella, CMV)
- Perinatal Factors (Birth asphyxia, Prematurity, Hypoglycemia at birth)
- Postnatal Factors (Malnutrition, Lead poisoning, Hypothyroidism)
Signs & Symptoms:
- Delayed speech and motor development
- Difficulty in problem-solving, reasoning, and adaptive skills
- Social immaturity (Difficulty making friends, following rules)
- Limited academic performance (Struggles in reading, writing, and math)
Complications:
- Dependency on caregivers for daily tasks
- Risk of psychiatric disorders (Anxiety, Depression, Autism in severe cases)
- Social isolation and bullying
Diagnosis:
- IQ Testing (Wechsler Intelligence Scale for Children – WISC, Stanford-Binet Test)
- Adaptive Behavior Scales (Vineland Adaptive Behavior Scales – VABS)
- Genetic Testing (Karyotyping for Down Syndrome, Fragile X DNA test)
Management:
- Special Education and Early Intervention Programs
- Speech and Occupational Therapy
- Behavioral Therapy for social skill development
- Medication for associated disorders (ADHD, Anxiety, Epilepsy)
Hearing Impairment (Deafness)
Definition:
Hearing impairment is a partial or complete inability to hear sounds, affecting speech and communication development.
Types of Hearing Loss:
- Conductive Hearing Loss – Middle ear issues (Otitis Media, Earwax blockage)
- Sensorineural Hearing Loss – Inner ear or nerve damage (Genetic disorders, Ototoxic drugs, Infections)
- Mixed Hearing Loss – Combination of conductive and sensorineural loss
Causes & Risk Factors:
- Congenital (Genetic mutations, Congenital Rubella Syndrome, Birth asphyxia, Prematurity)
- Infections (Meningitis, Mumps, CMV, Measles, Chronic Otitis Media)
- Ototoxic drugs (Aminoglycosides, Furosemide, Chemotherapy drugs)
- Head trauma, Noise exposure
Signs & Symptoms:
- Delayed speech and language development
- Lack of response to sounds, No reaction to loud noises
- Difficulty following conversations, Mispronunciations
- Tinnitus (Ringing in the ears)
Complications:
- Speech and language delay
- Academic difficulties and social isolation
- Cognitive delay (If not diagnosed early)
Diagnosis:
- Newborn Hearing Screening (Otoacoustic Emission – OAE, Auditory Brainstem Response – ABR tests)
- Audiometry (Pure tone test for older children)
- Tympanometry (To assess middle ear function)
Management:
- Hearing Aids (For mild to moderate hearing loss)
- Cochlear Implants (For profound sensorineural hearing loss)
- Speech Therapy and Lip-Reading Training
- Sign Language and Special Education Programs
Visual Impairment (Eye Errors)
Definition:
Visual impairment is a decrease in the ability to see to a significant degree that cannot be corrected with standard glasses or contact lenses.
Types of Eye Disorders in Children:
- Refractive Errors:
- Myopia (Nearsightedness) – Blurred distant vision
- Hyperopia (Farsightedness) – Blurred near vision
- Astigmatism (Uneven cornea curvature) – Blurred or distorted vision at any distance
- Amblyopia (“Lazy Eye”) – Poor vision development in one eye due to lack of use
- Strabismus (Crossed Eyes) – Misalignment of the eyes
- Congenital Cataracts & Glaucoma – Clouding of the lens or high intraocular pressure in infants
Causes & Risk Factors:
- Genetic disorders (Retinitis Pigmentosa, Albinism)
- Prematurity (Retinopathy of Prematurity – ROP)
- Infections (Congenital Rubella, Toxoplasmosis, Syphilis)
- Vitamin A Deficiency (Night blindness, Xerophthalmia)
Signs & Symptoms:
- Frequent squinting, Head tilting
- Difficulty reading or seeing distant objects
- Poor hand-eye coordination
- White reflex in the pupil (Leukocoria – Suggestive of Retinoblastoma or Cataracts)
Complications:
- Permanent vision loss if untreated (Amblyopia, Cataracts, Glaucoma)
- Learning difficulties due to poor visual perception
Diagnosis:
- Vision Screening Tests (Snellen Chart, Retinoscopy, Cover-Uncover Test for Strabismus)
- Fundoscopy (To check retinal abnormalities)
- Tonometry (For Glaucoma)
Management:
- Corrective Lenses (Glasses, Contact lenses for refractive errors)
- Patching Therapy (For Amblyopia to strengthen weaker eye)
- Strabismus Surgery (If non-surgical treatment fails)
- Vitamin A Supplementation (For deficiency-related eye diseases)
Key Points for Competitive Exams
✔️ Most common cause of childhood blindness? – Vitamin A Deficiency
✔️ Best screening test for hearing loss in newborns? – ABR (Auditory Brainstem Response)
✔️ Most common genetic cause of intellectual disability? – Fragile X Syndrome
✔️ Gold standard for diagnosing hearing loss? – Audiometry
✔️ Gold standard for diagnosing intellectual disability? – IQ Testing (Wechsler Scale, Stanford-Binet Test)