Background: Specialized strategies are needed to understand the complex neuropsychological impairments reported in individuals with profound intellectual and multiple disabilities (PIMD) associated with rare genetic disorders.
Methods: This narrative review focuses on assessment of individuals with Phelan-McDermid Syndrome (PMS) as a condition commonly associated with PIMD. Published case series and prospective studies were reviewed to evaluate approaches to cognitive, language, motor/sensory, and behavioral domains. This review is framed using general principles for neuropsychological evaluation in PIMD.
Results: Neuropsychological assessment domains and tools varied across published reports. Adaptive behavior measures, out-of-range developmental assessments, and social-communication measures were commonly used. Available findings were used to shape a recommended framework with potential to improve measurement of clinical outcomes and advance scientific discovery.
Conclusions: The recommended framework outlines an inter-disciplinary and multimodal neuropsychological assessment process relying on modified standardized assessments, functional assessments, and caregiver/informant reports when evaluating individuals with PIMD. Arrested development and skill variability/regression are also discussed as additional, important considerations in neuropsychological evaluation of individuals with PIMD and rare genetic disorders.
Trial registration: ClinicalTrials.gov NCT01778504.
Keywords: Intellectual disability; Phelan-McDermid Syndrome; cognition; neuropsychological assessment.