Summary
Neurodevelopmental disorders are a group of conditions that begin in early childhood and affect the development of the brain and nervous system. These disorders impact areas such as learning, communication, behavior, motor skills, and social functioning. They are typically lifelong and vary in severity. Diagnosis is usually made by a trained developmental specialist (e.g., child adolescent psychiatry, geneticist) using the DSM-5 criteria and involves assessing delays and/or impairment in cognitive and adaptive functioning. Management includes a combination of rehabilitative therapy, behavioral therapy, educational support, and, in some cases, medication. Early intervention is the key to improving outcomes.
Autism spectrum disorder, attention deficit hyperactivity disorder (ADHD), and tic disorders are covered in separate articles.
Overview
Types of neurodevelopmental disorders [1]
Neurodevelopmental disorders frequently co-occur and are often associated with psychiatric comorbidities. [1]
- Intellectual developmental disorders
- Communication disorders
- Autism spectrum disorder
- ADHD
- Specific learning disorder
- Neurodevelopmental motor disorders
Management of neurodevelopmental disorders [2][3][4]
- Perform an evaluation for abnormal pediatric development to help exclude differential diagnoses.
- Refer to a specialist in pediatric development for assessment.
-
Recommend publicly funded programs to address developmental concerns while awaiting formal diagnostic confirmation. [2][5]
- Children < 3 years of age: early intervention program
- Children ≥ 3 years of age: any public school, regardless of enrollment status
- Academic support (e.g., Individualized Education Program)
- Rehabilitative therapies (e.g., physical, occupational, speech, language)
- For children with a confirmed diagnosis, refer to relevant therapy services as needed, e.g.:
- Manage medical problems that may exacerbate behavioral symptoms (e.g., seizures and epilepsy, GERD in children).
- Encourage extracurricular activities to improve social competence. [6]
- Provide caregivers with support as needed. [7][8]
Intellectual developmental disorders
Intellectual developmental disorders are conditions with onset in the developmental period that affect intellectual and adaptive functioning. [1]
Definitions [1]
-
Global developmental delay
- Provisional diagnosis given to children < 5 years of age who are considered too young to be adequately assessed
- The child must have missed developmental milestones in ≥ 2 areas of intellectual functioning
- If symptoms persist into later childhood, a diagnosis of intellectual disability is made.
-
Intellectual disability
- A neurodevelopmental disorder that manifests during the developmental period
- Affects an individual's intellectual abilities (e.g., abstractive thinking, language, memory) and adaptive functioning (e.g., communication, independent living)
- Diagnosed in children ≥ 5 years of age who are able to participate in testing
Epidemiology [9][10]
The prevalence of intellectual developmental disorders is ∼ 1–3%.
Etiology [1][9][11]
- Congenital
- Genetic syndromes (e.g., trisomy 21, fragile X syndrome, Klinefelter syndrome, Rett syndrome)
- Inborn errors of metabolism (e.g., phenylketonuria, lysosomal storage diseases, maple syrup urine disease)
- Brain malformation (e.g., microcephaly) [1][11]
- Prenatal
- Birth complications (e.g., pre-eclampsia, premature rupture of membranes, hypoperfusion injuries)
- Infections (e.g., TORCH, herpes simplex virus)
- Congenital hypothyroidism
- Intrauterine exposure to toxins and/or teratogens (e.g., alcohol, valproate)
- Postnatal
- Kernicterus (due to untreated neonatal jaundice) [12]
- Central nervous system (CNS) infections (e.g., encephalitis, meningitis)
- Brain tumor
- Seizure and epilepsy
- Traumatic brain injury
- Child maltreatment
- Poisoning (e.g., lead poisoning) [9]
Diagnosis of intellectual developmental disorders [1][9][11]
- Confirm the diagnosis using the DSM-5 diagnostic criteria for intellectual disability.
- Determine the extent of severity in the following domains to determine whether impairment is mild, moderate, severe, or profound: [1]
- Conceptual domain
- Social domain
- Practical domain
- Assess for underlying conditions (e.g., congenital syndromes).
- Evaluate for comorbid psychiatric conditions (e.g., ADHD, impulse and conduct disorders) and medical conditions (e.g., epilepsy, obesity). [1][11]
Intellectual developmental disorders are typically identified during well-child visits, pediatric growth assessments, and/or developmental screenings.
DSM-5 diagnostic criteria for intellectual disability [1]
The diagnosis is confirmed based on the following criteria:
- Impaired intellect (e.g., reasoning, problem-solving, abstract thinking, judgment, academic learning) confirmed by clinical assessment and standardized intelligence testing [1]
- Impaired adaptive functioning impacting independence across multiple settings (e.g., home, school)
- Onset in early childhood
Global developmental delay is a provisional diagnosis in children < 5 years of age who do not meet developmental milestones in multiple intellectual domains. [1][9]
Assessment for an underlying cause [9][11]
- Family history (≥ 3 generations) to identify inheritance pattern [9]
-
Physical examination findings suggestive of an underlying genetic disorder [9]
- Dysmorphic features: distinctive facial features, limb defects
- Skin findings: café-au-lait-spots, skin and/or hair abnormalities
- Abnormal body odor
- Heart murmur
- Hepatosplenomegaly [9]
- Neurological conditions: seizures, focal neurological deficits, vision or hearing loss [9]
- Refer to a specialist (e.g., genetics, neurology) for consideration of further testing, e.g.: [9]
- Additional testing for inborn errors of metabolism
- Genetic testing (e.g., FMR1, karyotype, genome sequencing)
- Imaging (e.g., MRI brain)
Developmental regression is concerning for a neurodegenerative brain disease and warrants urgent referral to a specialist (e.g., neurology, genetics). [9]
Inborn errors of metabolism are treatable if detected early. [9]
Differential diagnosis [1]
- Borderline intellectual functioning: a poorly defined condition characterized by intellectual limitations that impair daily functioning but do not meet the criteria for an intellectual disability [13][14]
- Major neurocognitive disorder or mild neurocognitive impairment
- Other neurodevelopmental disorders (e.g., autism spectrum disorder, communication disorders)
Management [11][15]
- Refer to a specialist (e.g., child adolescent psychiatrist, psychologist, rehabilitation therapist) for:
- Nonpharmacological treatment, e.g.:
- Psychotherapy (e.g., cognitive behavioral therapy)
- Occupational therapy and/or speech therapy
- Applied behavioral analysis
- Pharmacological treatment (e.g., atypical antipsychotics) for severe irritability and aggression
- Nonpharmacological treatment, e.g.:
- Address comorbid conditions (e.g., ADHD, depressive disorders).
- Reassess development in school-age children at least every 3 years. [11]
- See also "Management of neurodevelopmental disorders."
Intellectual disability
- Definition: a neurodevelopmental disorder that manifests during the developmental period ; and affects an individual's intellectual abilities (e.g., abstractive thinking, language, memory) and adaptive functioning (e.g., communication, independent living).
- Prevalence: ∼ 1% in the general population [16]
-
Etiology
- Congenital
- Genetic conditions (e.g., fragile X syndrome, trisomy 21, Klinefelter syndrome)
- Exposure to teratogens in utero (e.g., fetal alcohol syndrome)
- Congenital hypothyroidism
- Congenital infections (e.g., toxoplasmosis, rubella)
- Perinatal hypoxia
- Perinatal trauma
- Acquired
- CNS infections (e.g., viral encephalitis, meningitis)
- CNS malignancies (e.g., neuroblastoma)
- Traumatic brain injury
- Intoxications (e.g., lead, mercury)
- Iodine deficiency
- Malnutrition
- Congenital
-
Clinical features
- The following features should be present:
- Deficits in cognitive functioning such as learning, problem-solving, reasoning, abstract thinking, judgment, and planning
- Impaired adaptive functioning (e.g., inability to maintain personal independence and social responsibility) leading to educational, occupational, communication, and social problems
- Onset during the developmental period (during childhood or adolescence)
- Other features include:
- Features of accompanying mental conditions (e.g., apathy and depressed mood in depression, poor attention in ADHD)
- Features of the causative conditions (e.g., characteristic appearance in trisomy 21, behavioral problems in Lesch-Nyhan syndrome)
- The following features should be present:
-
Diagnostics
- Intelligence quotient (IQ) testing
- Workup for identification of underlying disease (e.g., genetic testing, neuroimaging)
-
Management
- Nonpharmacological
- Psychotherapy (e.g., cognitive-behavioral therapy, family-oriented therapy)
- Occupational therapy
- Special education programs
- Speech-language therapy
- Pharmacological: used to control psychiatric symptoms of accompanying conditions
- Atypical antipsychotics (e.g., risperidone, aripiprazole, olanzapine) [17]
- Antidepressants (e.g., SSRIs)
- Nonpharmacological
References: [15][16][18]
Global developmental delay
- Definition: significant delay in ≥ 2 of the major developmental domains (gross motor, fine motor, language, cognition, and social milestones) in children < 5 years of age
- Prevalence: up to 5% of children in developed countries
-
Etiology
- Chromosomal abnormalities (e.g., trisomy 13, trisomy 18, trisomy 21, Turner syndrome, Klinefelter syndrome)
- Metabolic disorders (e.g., phenylketonuria, lysosomal storage diseases, maple syrup urine disease)
- Infections (e.g., TORCH, herpes simplex, meningitis)
- Intrauterine exposure to toxic substances/drugs (e.g., alcohol, phenytoin, valproate)
- Birth complications (e.g., preeclampsia, multiparity)
- Prematurity
- Untreated neonatal jaundice
- Undernutrition, neglect
- Heavy metal poisoning (lead, mercury)
- Severe head injuries, intracranial bleeds
- Cerebral palsy (associated with prematurity, SGA, and perinatal asphyxia)
-
Clinical features
- Mild forms may not be detected until preschool age
- Severe delay in meeting milestones (see “Developmental milestones” for details) in ≥ 2 of the major developmental domains (gross motor, fine motor, language, cognition, and social milestones) < 5 years of age
- Commonly associated with behavioral abnormalities (e.g., ADHD, autism spectrum disorders, bipolar disorders)
-
Diagnostics of global developmental delay
- Screening for developmental and intelligence quotient
- Detailed history, physical examination, and assessment of milestones and primitive reflexes
- MRI of the brain: to identify CNS malformation, intracranial bleeding, or hydrocephalus
- Genetic testing: if chromosomal anomalies are suspected
- Screening for infections (e.g., TORCH, HIV): in children with failure to thrive, cranial/cerebral malformations or intracranial calcifications
- Serum and urine analysis and enzyme studies: In infants suspected of having a metabolic disorder
-
Management
- Treatment of the underlying cause (if reversible)
- Early intervention to minimize the severity of disability
- Multidisciplinary team: neurologists, orthopedics, physical therapists, speech therapists, nutrition
- Special schooling and occupational therapy
References:[19][20]
Specific learning disorder
Specific learning disorder is a neurodevelopmental disorder caused by a combination of genetic, epigenetic, and/or environmental factors that affect an individual's ability to acquire and use academic skills despite having average or above average intelligence and adequate educational opportunities. [1]
Epidemiology
Prevalence: 5–15% in school-age children [1]
Risk factors [1]
- Family history of specific learning disorder
- Neurofibromatosis type 1
- Exposure to environmental toxins (e.g., lead, air pollution, nicotine)
- Low socioeconomic status
- Preterm delivery
- Very low birth weight
DSM-5 diagnostic criteria for specific learning disorder [1]
- The diagnosis is confirmed based on the following criteria: [1]
-
Difficulties with learning and applying ≥ 1 of the following academic skills over ≥ 6 months despite strategies to improve the specific deficits:
- Inaccurate or slow word reading (e.g., reads single words aloud incorrectly, frequently guesses words)
- Understanding the meaning of words read
- Spelling
- Written expression (e.g., multiple grammatical errors, poor structure)
- Understanding of numbers (e.g., sense, facts, or calculation)
- Mathematical reasoning (e.g., applied concepts, problem-solving)
- Academic skills are lower than expected for the individual's age and interfere with academic performance and/or daily life (must be confirmed by a standardized assessment) [1]
- Onset during school-age years
- Difficulty is not better explained by intellectual disability, neurological deficits, psychiatric conditions, and/or inadequate education
-
Difficulties with learning and applying ≥ 1 of the following academic skills over ≥ 6 months despite strategies to improve the specific deficits:
- Specifiers (frequently children have impairment in more than one domain)[1][21]
- With impairment in reading (e.g., poor accuracy in reading and comprehension, slow reading rate)
- With impairment in written expression (e.g., spelling, grammar, organization of work)
- With impairment in mathematics (e.g., difficulty understanding numerical information and performing calculations, also known as dyscalculia) [22]
The term dyslexia is often used to describe when impairments affect both reading (e.g., word recognition, decoding) and spelling. [1][23]
Ensure difficulties with reading and writing are not secondary to limited English-language proficiency; inquire after difficulties in all languages that a child speaks. [1]
Differential diagnoses [1]
- Normal variation in academic achievement
- Intellectual development disorder
- Learning difficulties secondary to neurologic or sensory disorders
- Neurodegenerative cognitive disorders
- ADHD
- Psychotic disorders
Management
- Academic support and accommodations are typically required. [21]
- See also "Management of neurodevelopmental disorders." [4]
Complications [1]
- Poor educational attainment
- Lower income and workforce engagement
- Psychological distress
- Depression and suicidal thoughts
Communication disorders
Communication disorders are a group of conditions affecting language, speech, and communication. They include language disorder, speech sound disorder, childhood-onset fluency disorder (stuttering), and social (pragmatic) communication disorder.
Epidemiology
- Prevalence: up to 13% of children between 2–5 years of age [24]
Risk factors for communication disorders [1][2]
- Male sex
- Hearing deficits
- Birth weight ≤ 2500 grams
- Family history of communication disorders
Multilingual children may have initial mild delays in language acquisition but are not at increased risk for communication disorders. [1][2]
Clinical features
- Difficulties in speech, language, and/or social communication.
- Children may fail to meet language developmental milestones.
- May also present as difficulties with:
- Intelligibility of speech [1]
- Fluency of speech
- Ability to communicate appropriately in different social settings
Diagnostics for communication disorders [1]
- Perform language assessment across all languages known to the child. [1]
- Diagnose communication disorders based on:
Management of communication disorders [2]
- Exclude hearing impairments and craniofacial defects (e.g., cleft palate).
- Early referral to speech therapy is vital.
- See also "Management of neurodevelopmental disorders."
School-aged children with persistent communication delay are five times more likely to have reading difficulties and adverse outcomes that persist into adulthood (e.g., lower-skilled jobs, psychosocial impairment). [2]
Childhood-onset fluency disorder
Childhood-onset fluency disorder (stuttering) is a communication disorder characterized by disturbances in the normal fluency of speech, with onset in early childhood. [1]
Epidemiology
The incidence of childhood-onset fluency disorder is 5–10% of children between 2–7 years of age. [25][26]
Stuttering is heritable; the risk of stuttering is three times higher in first-degree relatives of individuals who stutter compared to the general population. [1]
DSM-5 diagnostic criteria for childhood-onset fluency disorder [1]
The diagnosis is confirmed based on the following criteria:
- Persistent disturbances in the normal fluency of speech of ≥ 1 of the following:
- Sound and syllable repetitions
- Prolongation of consonants and vowels
- Broken words (e.g., pauses)
- Circumlocutions (e.g., problematic words exchanged out for others)
- Words produced with excess force
- Repeating short, one-syllable words (e.g., "I-I-I have a ball")
- Distress about speaking or limitations in social engagement and/or academic or work achievement
- Onset in early childhood
- Not attributable to speech-motor or sensory impairment, neurological deficit, or other medical conditions
Differential diagnoses [1]
- Normal early childhood dysfluencies
- Hearing or other sensory impairment
- Adult-onset dysfluency (e.g., due to neurological insult, medical conditions, or psychiatric disorders)
- Specific learning disorder with impairment in reading
- Tourette syndrome
- Medication side effects
Management [26][27]
- Reassure the child and caregivers that resolution of the disorder is common. [1]
- Refer to speech therapy. [2][26]
- Evaluate the child for psychosocial stress related to the condition.
- See also "Management of neurodevelopmental disorders."
Most children with childhood-onset fluency disorder with onset before 7 years of age will eventually develop normal speech. [26]
Language disorder
A language disorder is a communication disorder characterized by a delayed and/or impaired ability to comprehend and/or produce language (i.e., spoken, written, signed). [1]
Clinical features [1]
- Delay in expressive language and/or receptive language [1]
- Shyness
- Communication limited to familiar individuals
- Language delay affects all languages known to the child
- May have features of common comorbid disorders (e.g., specific learning disorder, ADHD, ASD)
Language disorders in children ≥ 4 years of age are likely to persist into adulthood. [1]
DSM-5 diagnostic criteria for language disorder [1]
The diagnosis is confirmed based on the following criteria:
-
Enduring difficulties with acquiring and/or using language (e.g., written, spoken, signed) due to comprehension or production difficulties, including:
- Limited vocabulary
- Difficulty forming complex sentences
- Difficulty putting sentences together to communicate an idea
- Language skills are below the standard for expected age, resulting in difficulties in communication, social engagement, and/or academic or work achievements
- Onset in early childhood
- Not attributable to hearing or other sensory impairment, global developmental delay, or intellectual development disorder
Assess children in all the languages they speak to prevent limited proficiency in English being mistaken for a language disorder. [1]
Differential diagnosis [1]
- Normal variations in language acquisition (especially in children < 4 years of age) [1]
- Specific learning disorders (e.g., dyslexia)
- Autism spectrum disorder
- Intellectual disability
- Other neurological disorders (e.g., epilepsy, hearing impairment)
- Child neglect
Management [2]
- Speech therapy
- See also “Management of communication disorders.”
Speech sound disorder
Speech and sound disorder is a communication disorder characterized by difficulty producing speech sounds correctly or fluently due insufficient phonological knowledge or inability to create the sounds. [1]
DSM-5 diagnostic criteria of speech sound disorder [1]
The diagnosis is confirmed based on the following criteria:
- Intelligible speech due to persistent difficulty producing the speech sound
- Limited ability to communicate impairs social participation and/or interferes with achievement (e.g., school, work)
- Onset in early childhood
- Symptoms are not due to an underlying condition (e.g., hearing impairment, cleft palate, cerebral palsy).
Speech sound disorder is associated with genetic disorders (e.g., FOXP2 gene mutation, 22q11.2 deletion syndrome, Down syndrome); refer to a geneticist for further testing as needed. [1]
Differential diagnosis [1]
- Normal variations in speech (e.g., speech errors in multilingual children)
- Hearing impairment
- Selective mutism
- Dysarthria (e.g., due to cerebral palsy)
- Structural abnormalities (e.g., cleft palate)
Management [2]
- Speech therapy
- See also “Management of communication disorders.”
Social (pragmatic) communication disorder
Social (pragmatic) communication disorder affects a person's ability to use verbal and nonverbal communication appropriately in social situations. [1]
Epidemiology [1][24]
- Isolated social (pragmatic) communication disorder is rare (prevalence < 1.3%)
- Often co-occurs with other neurodevelopmental disorders (e.g., other communication disorders, autism spectrum disorder, ADHD) [1]
DSM-5 diagnostic criteria of social (pragmatic) communication disorder [1]
The diagnosis is confirmed based on the following criteria:
- Difficulty with verbal and nonverbal communication in social interactions, including all of the following:
- Social communication (e.g., greeting, sharing information)
- Adapting communication to different contexts (e.g., classroom vs. playground)
- Following standard communication rules (e.g., taking turns, using nonverbal cues)
- Understanding nonexplicit information (e.g., idioms, humor, metaphors)
- An inability to effectively communicate that impairs social relationships, and/or achievement (e.g., academic, occupational)
- Onset in early childhood (may not be apparent until demands exceed the individual's capacities)
- Not attributable to another medical condition (e.g., autism, intellectual disability, or global developmental delay)
Differential diagnosis [1]
- Autism spectrum disorder
- ADHD
- Social anxiety disorder
- Intellectual developmental disorder (e.g., intellectual disability, global developmental delay)
Management [24][28]
- The optimum treatment for social (pragmatic) communication disorder is unclear because it is rare. [28]
- General management of neurodevelopmental disorders is likely applicable.
Neurodevelopmental motor disorders
Neurodevelopmental motor disorders include developmental coordination disorder, tic disorders, and stereotypic movement disorder. Tic disorders are covered in a separate article.[1]
Stereotypic movement disorder
Stereotypic movement disorder is a neurodevelopmental condition characterized by repetitive, purposeless movements that interfere with daily functioning and may cause self-injury. [1][3]
Epidemiology [1][3]
- Common in individuals with intellectual disability [1]
- More common in boys [29]
- Prevalence is high in children with sensory deficits (e.g., blindness). [3]
Risk factors [1]
- Social isolation
- Stress
- Fear
- Painful medical conditions (e.g., GERD, acute otitis media, dental cavities syndromes, e.g.:
- Rett Syndrome
- Lesch-Nyhan syndrome
- Cornelia de Lange syndrome
- Fragile-X syndrome
- Family history of stereotypic movement disorder
- Frequently associated with other conditions (e.g., ADHD, motor coordination disorders)
Clinical features [1][3]
- Often begins ≤ 3 years of age [1][3]
- Types of movements
- Noninjurious (e.g., rocking, hand flapping, mouth opening) [3]
- Self-injurious movement (e.g., banging head, poking eye)
- Episodes:
- Last seconds to minutes
- Can occur multiple times per day or have lapses of weeks between movements
- Movements are usually suppressible with redirection in otherwise typically developing children. [1]
Diagnosis of stereotypic movement disorder [1][3]
- Use caregiver rating scales to identify:
- Severity
- Types of repetitive movements
- Related behaviors
- Evaluate for other neurological comorbidities (e.g., ADHD, learning disorders, anxiety).
- Diagnosis is confirmed using the DSM-5 diagnostic criteria for stereotypic movement disorder.
DSM-5 diagnostic criteria for stereotypic movement disorder [1]
- The diagnosis is confirmed based on the following criteria:
- Repetitive, compulsive movements without a practical purpose (e.g., hand-waving, head banging, body rocking)
- Movements interfere with social and academic functioning and may be self-injurious
- Onset in early childhood
- Not attributable to another medical condition or mental disorder (e.g., obsessive compulsive disorder, trichotillomania)
- Specifiers
- Injurious or noninjurious behavior
- Associated with a genetic and/or other medical condition
- Severity (mild, moderate, severe)
Differential diagnosis [1]
- Normal development
- Autism spectrum disorder
- Tic disorder [1]
- Obsessive-compulsive disorder
- Tardive dyskinesias
- Neurologic disorders causing chorea, dystonia, or myoclonus
- Substance use disorder
- Functional neurological symptom disorder
Simple stereotypic movements are common in early childhood in otherwise normally developing children and often resolve spontaneously. [1]
Management [3]
- For problematic stereotypic behavior: [3]
- Encourage caregivers to interrupt and redirect behaviors.
- Refer for habit reversal therapy.
- Refer to pediatric neurology for possible pharmacological treatment for:
- Self-injurious behavior
- Refractory symptoms
- See also "Management of neurodevelopmental disorders."
Noninjurious stereotypical behavior that does not cause emotional distress does not usually require any intervention. [3]
Developmental coordination disorder
Developmental coordination disorder (also known as childhood dyspraxia) is a neurodevelopmental disorder characterized by difficulties in acquiring and executing motor skills.
Epidemiology [1]
- Prevalence: 5–8% of children
- ♂ > ♀
Etiology [1]
- Prematurity
- Low birth weight
- Prenatal alcohol exposure
- Often comorbid with other neurodevelopmental disorders (e.g., ADHD, autism spectrum disorder, specific learning disorder)
DSM-V diagnostic criteria for developmental coordination disorder [1]
- Development of coordinated motor skills is substantially below what is expected for the child's age.
- Deficits cause significant impairment in daily life, e.g.:
- Clumsiness
- Struggles using utensils or buttoning clothes
- Poor handwriting
- Difficulties with catching balls and playing sports
- Difficulties learning to ride a bicycle
- Onset in early childhood
- Symptoms are not caused by an underlying condition (e.g., intellectual development disorder, visual impairment, neurological condition).
Developmental coordination disorder is not usually diagnosed in children < 5 years of age due to variation in early childhood motor development. [1]
Some children may have additional motor activity (such as mirror movements); the significance of these neurological soft signs is unclear. [1]
Differential diagnoses [1]
- Motor impairments secondary to an underlying medical condition (e.g., cerebral palsy)
- Joint hypermobility syndrome
- Intellectual developmental disorders
- ADHD
- Autism spectrum disorder