Dual Sensory Impact in Down Syndrome: Unlocking Developmental Potential (alternate title: Dual Sensory Impact in Down Syndrome: Implications for Function, Language, and Learning)

1. Elizabeth Boatwright (Co-chair, DSMIG DS+CVI Workgroup)
2. Lisa Lind (Down Syndrome Innovations Kansas City, Children's Mercy Hospital, Kansas City, Public School System, Kansas City)
3. Linda Larence (Private Practice, Salina Kansas, Consultant, Kansas School for the Blind)
4. Jennifer Saentz (Tufts Medical Center)
5. Rudaina Banihani (Sunnybrook Health Science Center, Toronto Canada, Associate Professor of Pediatrics, University of Toronto)
6. Ilse Willems (Perkins School for the Blind, Watertown MA)
7. Rachel Pilling (University of Bradford, UK)

Correspondence: Boatwrights2@mac.com

Individuals with Down syndrome (DS) are living longer, fuller lives than in generations past, due to advances in our understanding of associated medical conditions, learning profiles, and developmental strengths and challenges. This “Down syndrome phenotype” guides interventions in health care, education, and therapy which have resulted in improvements in daily functioning and higher expectations for babies born with DS today. However, despite these advances, we continue to see a wide range of developmental outcomes and functioning in individuals with DS (Baumer), suggesting that important contributors to variability remain under-recognized.

In this symposium, we explore emerging research revealing a high prevalence of cerebral/cortical visual impairment (CVI), a brain-based visual impairment, in individuals with Down syndrome (DS). CVI impacts how the brain perceives the visual information it receives, and is characterized by fatiguability, difficulty with complexity and variable function when dealing with multi sensory inputs. Therefore CVI affects access and participation across development and daily life.

In isolation, visual or hearing differences may be partially compensated; however, when CVI co-occurs with the well-documented prevalence of hearing differences in DS, these sensory vulnerabilities interact and compound, creating a “perfect storm” of sensory impacts that can disproportionately challenge the foundations for language and learning. We describe this dual sensory impact on language as "functional deafblindness," a functional framework that captures the combined and multiplicative effects of reduced visual and auditory access, rather than a categorical diagnosis.

With simple proactive, affirming, low/no-cost strategies to simplify sensory input, children can navigate these conditions successfully. Early identification of CVI and dual sensory impact, leading to early deafblind-informed supports, can reduce barriers and create stability, allowing language to take root and relationships to flourish. Practical strategies—such as visual/tactile anchors, reducing sensory clutter, and supporting joint attention—help children build strong foundations for language, learning, and community belonging. With these supports, children don’t just cope—they connect, learn, and thrive in family life, education, and social environments.

Through a series of talks placed in a framework of “See It, Find It, Use It,” we will discuss CVI/dual sensory impact in DS: ways to recognize this condition in individuals with DS, how to refer/where to go for evaluation, and how to support learning and independence using practical strategies.

Reference:

Baumer N, DePillis R, Pawlowski K, et al. Developmental Milestones for Children With Down Syndrome. Pediatrics. 2024;154(4):e2023065402

See it: What are CVI and Dual Sensory Impact in DS?

1. Elizabeth Boatwright (Co-chair, DSMIG DS+CVI Workgroup)
2. Linda Lawrence (Private Practice, Salina Kansas, Consultant, Kansas School for the Blind, DSMIG DS+CVI Workgroup)

Correspondence: Boatwrights2@mac.com

In this session, we will discuss the foundational definition of vision as encompassing both the eye and the brain. We will discuss the common visual conditions seen in Down syndrome, including both ocular conditions and CVI. We will summarize recent literature discussing CVI in DS that builds on the seminal paper by Woodhouse et al (Woodhouse, 2021) describing a high prevalence of CVI behaviors in individuals with DS. New articles include a case series describing three teens with DS+CVI (Heidary, 2025) which looks at developmental and functional sequelae of CVI in DS as well as risk factors for CVI, and early (unpublished) prevalence data of CVI in a cohort of students with DS in a special needs school in Peru (Boatwright, Lind, Childress, Pincon, Willems, Pilling, Lawrence poster in process).

We will present the dual sensory “perfect storm” that occurs when the high prevalence of visual issues (ocular and CVI) co-occur with the high prevalence of hearing issues in DS, impacting communication, cognition, social development, and behavior. We will touch on the “DS phenotype” and the risk of “diagnostic overshadowing” in which behaviors or delays are attributed to DS alone, resulting in missing or misunderstanding CVI/dual sensory impact in DS.

References:

Boatwright E, Banihani R, Willems I, Lehman K, Mazel E, Mark H, Wong M, Vietzman S, Chandna A and Heidary G (2025) Cerebral/Cortical visual impairment (CVI) in Down syndrome: a case series. Front. Hum. Neurosci. 19:1563420. doi: 10.3389/fnhum.2025.1563420

Wilton GJ, Woodhouse R, Vinuela-Navarro V, England R and Woodhouse JM (2021) Behavioural Features of Cerebral Visual Impairment Are Common in Children With Down Syndrome. Front. Hum. Neurosci. 15:673342. doi: 10.3389/fnhum.2021.673342

Find it: Identifying CVI/dual sensory impact in DS

1. Jennifer Saentz (Tufts Medical Center, DSMIG DS+CVI Workgroup)
2. Rudaina Banihani (Sunnybrook Health Science Center, Toronto Canada, Associate Professor of Pediatrics, University of Toronto, DSMIG DS+CVI Workgroup)

Correspondence: hicks.jenny@gmail.com

In this session, we will use case examples/short video clips to demonstrate ways in which CVI/dual sensory impact may appear in DS. We will look at developmental, communication, social, and behavioral implications of CVI/dual sensory impact in DS, pointing out functional “red flags” for this condition. We will emphasize the language risk of dual sensory impact in DS as a foundational concern, as it has implications for cognition, development, social engagement, and behavior.

We will discuss having a “universal screening mindset” when approaching individuals with DS: encouraging the audience to suspect CVI in all individuals with DS, and to suspect functional deaf blindness in all individuals with DS+CVI.

Use it: Practical Strategies to Address CVI/dual sensory impact in DS

1. Ilse Willems (Perkins School for the Blind, Watertown MA, DSMIG DS+CVI Workgroup)
2. Rachel Pilling (University of Bradford, UK, DSMIG DS+CVI Workgroup)

Correspondence: ilse.willems@perkins.org

In this final segment, we will discuss practical ways to address CVI/dual sensory impact in DS. We will discuss how a diagnosis of CVI is made, and recommend referral patterns. In the meantime, we will emphasize strategies that can be implemented even before a formal diagnosis of CVI/DB is made. In fact, response to visual accommodations and deafblind strategies can confirm the suspected diagnosis of CVI/DB in an individual with DS.

More detailed explanations of actionable language intervention strategies will be discussed, including creating visual anchors, using optimal visual field, minimizing visual clutter and reducing search burden, providing explicit teaching of salient visual and auditory features, minimizing auditory clutter, supporting joint attention, and using multi-sensory pairing.