Adaptation of the Clinical Dementia Rating Scale for adults with Down syndrome

Abstract

BackgroundAdults with Down syndrome (DS) are at increased risk for Alzheimer disease dementia, and there is a pressing need for the development of assessment instruments that differentiate chronic cognitive impairment, acute neuropsychiatric symptomatology, and dementia in this population of patients.MethodsWe adapted a widely used instrument, the Clinical Dementia Rating (CDR) Scale, which is a component of the Uniform Data Set used by all federally funded Alzheimer Disease Centers for use in adults with DS, and tested the instrument among 34 DS patients recruited from the community. The participants were assessed using two versions of the modified CDR—a caregiver questionnaire and an in-person interview involving both the caregiver and the DS adult. Assessment also included the Dementia Scale for Down Syndrome (DSDS) and the Raven’s Progressive Matrices to estimate IQ.ResultsBoth modified questionnaire and interview instruments captured a range of cognitive impairments, a majority of which were found to be chronic when accounting for premorbid function. Two individuals in the sample were strongly suspected to have early dementia, both of whom had elevated scores on the modified CDR instruments. Among individuals rated as having no dementia based on the DSDS, about half showed subthreshold impairments on the modified CDR instruments; there was substantial agreement between caregiver questionnaire screening and in-person interview of caregivers and DS adults.ConclusionsThe modified questionnaire and interview instruments capture a range of impairment in DS adults, including subthreshold symptomatology, and the instruments provide complementary information relevant to the ascertainment of dementia in DS. Decline was seen across all cognitive domains and was generally positively related to age and negatively related to IQ. Most importantly, adjusting instrument scores for chronic, premorbid impairment drastically shifted the distribution toward lower (no impairment) scores.

The AT(N) framework for Alzheimer's disease in adults with Down syndrome

“…A number of cognitive assessment instruments are currently being evaluated in natural history studies of AD in DS, including the ABC–DS 43 . At this time, there is no single cognitive instrument that has been longitudinally validated in the context of AD biomarkers in DS but many are being presently intensely researched 51‐55 …”

“…43 At this time, there is no single cognitive instrument that has been longitudinally validated in the context of AD biomarkers in DS but many are being presently intensely researched. [51][52][53][54][55] Once arriving at the suspected clinical diagnosis of MCI or dementia, the AT(N) framework can be used to stage an individual with DS along the AD continuum with respect to extent of underlying biomarker changes (Table 1). This staging can be used to provide expected clinical prognosis, including an estimated duration of independent functioning, time to dementia, and to also enrich for more homogenous samples in clinical trials.…”

Clinical efficacy of idebenone in stroke patients with mild cognitive impairment, and its effect on regional homogeneity of resting-state functional magnetic resonance imaging of the brain

“…The clinical dementia rating (CDR) scale [15] was used for rapid assessment of the severity of a patient's condition by interviewing the patient and their families to obtain information necessary for assessment of cognitive level. The scores obtainable was 0, 0.5, 1, 2 and 3 points.…”

The Global Deterioration Scale for Down Syndrome Population (GDS-DS): A Rating Scale to Assess the Progression of Alzheimer’s Disease

“…Interestingly, an adaptation of the CDR, the CDR for frontotemporal lobar degeneration (CDR-FTDL) [ 36 ], was developed with the inclusion of language and behavior domains not contemplated in the original CDR, and has been shown to be sensitive in distinguishing disease progression between FTLD and AD in the general population [ 37 ]. Additionally, a modified CDR for adults with DS based on questionnaires and patient/caregiver interviews is available [ 38 ], capturing the progressive deterioration of AD in this population.…”