Deconstructing Dravet syndrome neurocognitive development: A scoping review

Area of Science:

• Neuroscience
• Developmental Psychology
• Genetics

Background:

• Dravet syndrome (DS) is a severe epilepsy characterized by developmental delays and behavioral issues.
• Cognitive impairments in DS include visuospatial, sensorimotor, and expressive language deficits.
• Existing hypotheses for DS cognitive development lack an encompassing framework.

Purpose of the Study:

• To map the current understanding of cognitive and behavioral profiles in Dravet syndrome.
• To summarize evidence supporting theoretical frameworks for DS development.
• To identify a unified framework for DS cognitive and behavioral abnormalities.

Main Methods:

• A scoping review of literature from PubMed, Scopus, PsycInfo, and MEDLINE (1978-March 2020).
• Adherence to Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines.
• Data extraction and tabulation by three independent reviewers from 21 selected reports.

Main Results:

• Eighteen reports showed variable global intellectual disability; 11 indicated greater impairment in performance than verbal scales.
• Specific deficits included visual processing, motor skills, sensorimotor integration, spatial processing, executive functions, and expressive language.
• Behavioral abnormalities, including autistic traits and ADHD, were reported and showed slight improvement with age.

Conclusions:

• The cognitive and behavioral profile in Dravet syndrome may be explained by a unified framework.
• This framework integrates sensorimotor integration deficits, dorsal stream dysfunction, and cerebellar deficits.
• Further research is needed to validate this encompassing theoretical model for DS.