Guidelines Released for Alzheimer- and Stroke-Related Care in Down Syndrome

Amy Y. Tsou, MD, MSc

The first set of evidence-based medical care guidelines for adults with Down syndrome has been published after 4 years of rigorous coordination and compilation, with particularly notable recommendations for Alzheimer disease screening among these patients, which the group stated should begin at age 40 years.¹

Those with Down syndrome are at high risk for the development of Alzheimer, and autopsy assessments have revealed that by age 40 years, almost the entirety of this patient population have significant levels of amyloid-beta and tau tangles.² According to the National Down Syndrome Society, roughly 30% of those with Down syndrome in their 50s have Alzheimer dementia, rising to about 50% for those in their 60s.³

The guideline authors, including Amy Y. Tsou, MD, MSc, co-director, Evidence-Based Practice Center, ECRI Institute, noted that since 1983, the life expectancy for people with Down syndrome has more than doubled, from 25 to 60 years, and as this population includes more than 200,000 individuals, guidance such as this is needed to support high-quality care.

“Although guidelines based on expert opinion exist, evidence-based clinical practice guidelines for adults with Down syndrome have not been developed,” Tsou et al. wrote. “This Special Communication presents a clinical guideline with recommendations to support high-quality primary care for adults with Down syndrome.”

The authors wrote that these assessments for Alzheimer should be conducted annually, with particular focus on the presence of decline in the 6 domains specified by the National Task Group–Early Detection Screen for Dementia (NTG-EDSD) to identify early-stage age-related Alzheimer-type dementia, a potentially reversible medical condition, or both.⁴ Those domains include memory and executive function, behavior and personality, language and communication, gait and motor skills, activities of daily living, continence, and sleep patterns.

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The confidence in the quality of evidence was deemed low for prevalence in patients younger than 40 years, but moderate for those older than 45 years. Evidence to support this recommendation included a moderate-quality study including 506 adults with Down syndrome which identified a dementia prevalence of 8.9% (95% CI, 5–12) in 45- to 49-year-olds, increasing every 5 years to 32.1% (95% CI, 22–42) in 55- to 59-year-olds, but then decreasing to 25.5% (95% CI, 12–40) in those 60 years or older. Another study, including 878 adults with Down syndrome, reported an increasing prevalence in those older than 45 years. A trio of studies assessing the prevalence in those under age 40 found low overall prevalence, though only 1 of those utilized a validated diagnostic measure. However, that study identified a 0% prevalence in individuals aged 30 to 39 years.

“Despite absence of disease-modifying dementia treatments, most adults with Down syndrome and their families/caregivers place high value on early diagnosis, accurate diagnosis, or both to modify existing supports and allow for additional resource planning,” Tsou and colleagues noted.

The guidelines also included recommendations regarding the care of these individuals as it relates to stroke risk. The authors ultimately concluded that stroke risk factors should be managed according to the guidelines of the American Heart Association/American Stroke Association. They also noted that adults with Down syndrome who have a history of congenital heart disease should have a periodic cardiac evaluation and a corresponding monitoring plan reviewed by a cardiologist, due to the elevated risk of cardioembolic stroke.

The confidence in the quality of the evidence was considered very low for this recommendation, driven by limited evidence. One study from Australia was included, which compared strokes in 1706 hospitalized adults with Down syndrome with those in 6828 matched controls. Those with Down syndrome experience strokes at a rate of 1.8% compared to 0.5% among those aged 19 to 50 years, and 9.8% compared to 4.9% among those aged 51 years and older (both P <.05). Importantly, strokes occurred at a younger age in those with Down syndrome (mean age, 41.8 vs 57.1 years), with cardioembolic strokes being the most common.

“We are so pleased that the quality of our guideline rose to the occasion of being published in JAMA, and we are deeply grateful to our families and self-advocates for pushing us to work on this difficult project,” said Michelle Sie Whitten, president and CEO, Global Down Syndrome Foundation, in a statement.⁵ “Now we can focus on collaborating with other Down syndrome and disability organizations as well as medical institutions to ensure clinicians are following our Global Guideline and measuring outcomes.”

REFERENCES
1. Tsou AY, Bulova P, Capone G, et al. Medical Care of Adults With Down Syndrome: A Clinical Guideline. JAMA. 2020;324(15):1543-1556. doi:10.1001/jama.2020.17024.
2. Alzheimer’s Association. Down Syndrome and Alzheimer's Disease. Accessed October 30, 2020. alz.org/alzheimers-dementia/what-is-dementia/types-of-dementia/down-syndrome
3. Moran J, Hogan M, Srsic-Stoehr, et al. Aging and Down Syndrome: A Health and Well-Being Guidebook. Published 2013. Accessed October 30, 2020. ndss.org/wp-content/uploads/2017/11/Aging-and-Down-Syndrome.pdf
4. Moran JA, Rafii MS, Keller SM, Singh BK, Janicki MP. The National Task Group on Intellectual Disabilities and Dementia Practices consensus recommendations for the evaluation and management of dementia in adults with intellectual disabilities. Mayo Clin Proc. 2013;88(8):831-840. doi: 10.1016/j.mayocp.2013.04.024.
5. Global Down Syndrome Foundation Announces the 1st Evidence-Based Medical Care Guidelines for Adults With Down Syndrome. News release. Global Down Syndrome Foundation. Accessed October 30, 2020. prnewswire.com/news-releases/global-down-syndrome-foundation-announces-the-1st-evidence-based-medical-care-guidelines-for-adults-with-down-syndrome-301156055.html