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Neurodevelopmental disorders

Last updated: October 27, 2021

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Neurodevelopmental disorders are a class of psychiatric disorders characterized by childhood-onset, potentially lifelong deficits resulting in the impairment of personal, social, academic, and occupational function. The specific causes of neurodevelopmental disorders are unknown but assumed to be multifactorial, with certain associations having been established (e.g., fragile X syndrome, tuberous sclerosis, Rett syndrome, epilepsy, low birth weight).

Intellectual disability is characterized by impaired mental abilities (e.g., abstract thinking, academic learning, problem solving) that cause impairments in adaptive functioning (e.g., communication, independent living). Global developmental delay is defined as a significant delay in ≥ 2 of the major developmental domains (gross motor, fine motor, language, cognition, and social milestones) in children < 5 years of age. Specific learning disorders are characterized by persistent impairment in a specific function, i.e., reading, written expression, or maths. The disorder typically manifests in the first few years of schooling and results in poor academic performance in the corresponding discipline. Language disorders and speech sound disorders are characterized by deficits in the acquisition and/or comprehension of language, speech, and communication. Childhood-onset fluency disorder (stuttering) is characterized by disturbances in the normal fluency of speech that manifests with sound and syllable repetition, sound prolongation, and broken words.

Other neurodevelopmental disorders, including autism spectrum disorder and attention deficit hyperactivity disorder, are discussed in separate articles.

For information regarding neurodevelopmental motor disorders, including stereotypical movement disorder, and tic disorders (Tourette syndrome, persistent motor tic disorders, persistent vocal tic disorder, and sporadic transient tic disorder), see “Tourette syndrome.”

References: [1][3][4]

References:[5][6]

  • Definition
    • A neurodevelopmental disorder that occurs due to a combination of genetic, epigenetic, and environmental factors and results in difficulties learning and applying specific academic skills
    • Features should be present for more than 6 months despite academic interventions to address these problems.
  • Prevalence: 5–15% in the school-age population [3]
  • Clinical features
    • Inability to acquire age-appropriate academic skills, such as reading (most common), spelling, writing, operations with numbers,or mathematical reasoning
      • Dyslexia: a specific learning disability characterized by difficulties with word recognition and decoding, as well as spelling, which often results in below-average reading comprehension, limited vocabulary, and delayed language development that cannot be attributed to intellectual disability (IQ < 70)
      • Dyscalculia: a specific learning disability with impairment in mathematics. It is characterized by problems processing numerical information, learning arithmetic facts, and performing accurate or fluent calculations that can not be attributed to intellectual disability (IQ < 70)
    • General cognitive abilities (e.g., reasoning, abstract thinking) are normal (in contrast to intellectual disability)
  • Management
    • Academic support (e.g., individualized learning programs)
    • Regular school psychology consultations
    • Individual or family psychotherapy
    • Extracurricular activities to improve academic and social inclusion

References: [3]

  • Definition: : A condition characterized by disturbances in the normal fluency of speech with onset in the early developmental period.
  • Prevalence: 5–10% of preschool children [7]
  • Clinical features
    • Onset of symptoms typically between age 2–7 years
    • Sound and syllable repetition
    • Sound prolongation of letters
    • Repetition of monosyllabic words
    • Broken words and speech blocking
    • Substitution of words to avoid problematic words
    • Secondary maladaptive behavior (e.g., word avoidance, mannerisms, avoidance of speaking) may develop in some patients
  • Diagnostic criteria (DSM-5)
    • Persistent disturbances in the normal fluency of speech
    • Stuttering results in anxiety related to speaking, impaired social participation, and/or poor academic performance in childhood
    • Not attributable to sensory impairment or speech-motor deficit, or other medical condition (e.g., stroke, CNS trauma)
  • Management [7]
    • Spontaneous resolution in 65–85% of preschool children with disfluency by the age of 7 years
    • Speech therapy for severe or persistent cases
      • Develop compensatory techniques to improve fluency
      • Treat maladaptive behavior
  • Definition: A communication disorder characterized by a delayed and/or impaired ability to comprehend and/or produce language.
  • Classification
    • Expressive language delay
      • Characterized by an inability to formulate language (e.g., spoken, written, signed language)
      • Manifestations include word-finding difficulty, omission of words within sentences, and use of incorrect tenses.
    • Receptive language delay
      • Characterized by an inability to understand and process language (e.g., spoken, written, signed language)
      • Manifestations include impaired ability to understand and follow directions, misunderstanding the words and meanings of stories or information
  • Diagnostic criteria (according to DSM-V) [3]
    • Persistently reduced ability to learn, understand, and use language (written, spoken, and/or signed), characterized by limited vocabulary for age, incorrect understanding of word meanings, difficulty with sentence structure, and/or incorrect grammar use
    • A significant deviation of language abilities below those expected for age, resulting in impaired communication, social participation, and/or poor academic performance
    • The language difficulties begin to manifest during the early developmental period.
    • The symptoms are not due to another condition (e.g., hearing impairment, intellectual disability, cerebral palsy).
  • Differential diagnosis [8]
  • Management: : language therapy
  • Definition: a communication disorder characterized by persistent difficulties in phonology and/or articulation .
  • Diagnostic criteria (according to DSM-V) [3]
    • Impaired verbal communication and speech intelligibility due to persistent difficulty in speech sound production.
    • The communication difficulties cause impaired social participation and/or poor academic performance in childhood.
    • The speech difficulties begin during the early developmental period.
    • The symptoms are not due to an underlying condition (e.g., hearing impairment, cleft palate, cerebral palsy).
  • Differential diagnosis [9]
  • Management: : speech therapy for articulation and/or phonological techniques
  1. Vasudevan P, Suri M. A clinical approach to developmental delay and intellectual disability. Clin Med (Northfield Il). 2017; 17 (6): p.558-561. doi: 10.7861/clinmedicine.17-6-558 . | Open in Read by QxMD
  2. Harrison JN, Cluxton-Keller F, Gross D. Antipsychotic Medication Prescribing Trends in Children and Adolescents. Journal of Pediatric Health Care. 2012; 26 (2): p.139-145. doi: 10.1016/j.pedhc.2011.10.009 . | Open in Read by QxMD
  3. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders (DSM–5). undefined. 2013 . doi: 10.1176/appi.books.9780890425596 . | Open in Read by QxMD
  4. Marrus N, Hall L. Intellectual Disability and Language Disorder. Child Adolesc Psychiatr Clin N Am. 2017; 26 (3): p.539-554. doi: 10.1016/j.chc.2017.03.001 . | Open in Read by QxMD
  5. Intellectual Disability. http://www.merckmanuals.com/en-ca/professional/pediatrics/learning-and-developmental-disorders/intellectual-disability. Updated: February 1, 2016. Accessed: July 1, 2017.
  6. Thomaidis L, Zantopoulos GZ, Fouzas S, Mantagou L, Bakoula C, Konstantopoulos A. Predictors of severity and outcome of global developmental delay without definitive etiologic yield: a prospective observational study. BMC Pediatr. 2014; 14 (40). doi: 10.1186/1471-2431-14-40 . | Open in Read by QxMD
  7. Sander RW, Osborne CA. Stuttering: Understanding and Treating a Common Disability. American Family Physician. 2019 .
  8. Spoken Language Disorders. https://www.asha.org/practice-portal/clinical-topics/spoken-language-disorders/. . Accessed: September 7, 2021.
  9. Speech Sound Disorders-Articulation and Phonology. https://www.asha.org/practice-portal/clinical-topics/articulation-and-phonology/#collapse_2. . Accessed: September 7, 2021.