Severe neurological impairment: a review of the definition.

Severe neurological impairment (SNI) is a term commonly used in the medical literature, though there is no agreed definition. This limits opportunities for research into healthcare needs, treatment opportunities, resource planning, and outcome. We reviewed the literature to establish consistency of use of the term and to place it in the context of other commonly employed terms used to describe children with severe, complex medical needs. Forty-two articles were included for full-text analysis, with 23 including a definition of SNI. Motor impairment, intellectual disability, communication difficulties, and increased care needs were included in the definition in 80%, 70%, 30%, and 13% of papers respectively. Dependence on others for decision-making, chronicity, and distinction between disorders of the central nervous system and peripheral nervous system were less frequently included. There is wide variation in the use of the term SNI. A consensus-based definition of this term would be useful to facilitate future research. WHAT THIS PAPER ADDS: There is inconsistency in use of the term severe neurological impairment (SNI), limiting research efforts. In defining SNI, considerations are mobility, intellectual disability, communication difficulties, and increased care needs. Distinction between acute and chronic, central and peripheral nervous system disorders, and dependence on others for decision-making were less significant.