Citations

AbstractBackgroundFrontotemporal dementia spectrum disorders (FTD) display complex neuropathological substrates and poor clinicopathological correlations, which hinders therapy development. Plasma P‐tau217 is an emerging tool to screen for Alzheimer’s disease (AD) pathology and may have diagnostic value in FTD.MethodPlasma P‐tau217 was measured cross‐sectionally by electrochemiluminescence in FTD patients referred to ALLFTD from ARTFL (n = 628, 45.7% female, median age 66 ± 12 years). P‐tau217 differences by baseline phenotype, disease severity and genotype were determined with non‐parametric tests and general linear models. Associations between P‐tau217 and measures of disease severity and neuropsychological performance were determined with linear regressions corrected for age, sex, phenotype and APOE.ResultThe sample included 33% behavioral variant FTD, 23.6% primary progressive aphasia (PPA), 28.5% atypical parkinsonism, 1.6% amnestic dementia (AmDem), 2.8% FTD/motoneuron disease, 3% mild cognitive/behavioral impairment and 7.5% healthy controls. Only 1.6% carried FTD‐causing mutations. P‐tau217 was not related to age (r = 0.034, 95%CI ‐0.03 – 0.12, p = 0.4). Compared to controls (0.18 ± 0.07 pg/mL), P‐tau217 was elevated only in AmDem (0.58 ± 0.9 pg/mL, p = 0.001) and logopenic PPA (lvPPA, 0.71 ± 0.62 pg/mL p < 0.001). P‐tau217 ≥ 0.42 pg/mL effectively discriminated AmDem and lvPPA from all other phenotypes (AUC 0.87, 95%CI 0.77 – 0.96, p = 0.001, 77% sensitivity, 92% specificity). AmDem (60%) and lvPPA (91.7%) had the highest prevalence of high (≥ 0.42 pg/mL) P‐tau217, and the highest prevalence of APOE4 (AmDem 40%, lvPPA 63.6%). APOE4 carriers (0.23 ± 0.22 pg/mL) had higher P‐tau217, than non‐carriers (0.19 ± 0.09 pg/mL), regardless of phenotype (APOE effect p = .002, APOE x phenotype, p = 0.44). P‐tau217 was associated with worse clinical severity, mood, memory and executive function, but not with worse motor symptoms or social cognition.ConclusionWhen FTD is suspected, high plasma P‐tau217 is strongly associated with amnestic dementia and logopenic PPA phenotypes. Pending completion of ongoing neuropathological, CSF and molecular neuroimaging analyses, the data support the use of plasma P‐tau217 to identify atypical AD as a cause or AD as a co‐pathology contributing to FTD clinical presentation.

AbstractBackgroundBlood neurofilament light chain (NfL) is a robust predictor of phenoconversion in familial frontotemporal lobar degeneration (fFTLD). The comparative value of CSF NfL and other CSF markers of degeneration in fFTLD remains unexplored.MethodFLTD‐causing mutation carriers were recruited through ALLFTD (n = 113, 56.6% female, mean age 48.1 ± 13 years; 29 C9orf72, 16 GRN, 34 MAPT, 34 mutation non‐carriers) and prospectively evaluated for 3 years. Baseline CSF was analyzed for NfL, phosphorylated neurofilament heavy chain (p‐NfH), tau, phosphorylated tau181 (p‐tau) and neurogranin using fit‐for‐purpose immunoassays. Mixed effect linear models, with random slopes, corrected for age, sex, genotype and total intracranial volume related CSF biomarkers to longitudinal clinical variables.ResultNfL (β = 0.64, p < 0.001), p‐NfH (β = 0.68, p < 0.001) and tau (β = 0.46, p < 0.001) correlated with age. There were no differences in biomarker concentrations by phenotype or severity, except for higher NfL and p‐NfH in full phenotype, compared to prodromal disease and asymptomatic carriers. Low neurogranin (β = ‐0.39, p < 0.001), low p‐tau (β = ‐0.33, p < 0.001) and high NfL (β = 0.42, p < 0.001) correlated with worse baseline disease severity measured by the CDR® Dementia Staging Instrument plus behavior and language domains from the National Alzheimer’s Disease Coordinating Center FTLD module sum of boxes (CDR®+NACC‐FTLDsb), and with other measures of global cognition, instrumental and daily function, and frontal and temporal brain volumes. Regardless of genotype, the predicted annualized rate of CDR®+NACC‐FTLDsb score worsenings per higher baseline CSF biomarker Log pg/mL were tau: 3.0 ± 0.2, NfL: 2.8 ± 0.2 and p‐NfH: 2.8 ± 0.2. High tau, NfL and p‐NfH also predicted worsening in other measures of global cognition and instrumental and daily function. Neurogranin and p‐tau did not predict clinical decline.ConclusionCSF tau, p‐tau, neurogranin, NfL and p‐NfH reflect important aspects of disease severity in fFTLD. In contrast to Alzheimer’s disease, low p‐tau and neurogranin are inversely related to clinical severity, which suggests a distinctive pathophysiological process and has implications for therapeutic development. CSF NfL, p‐NfH and tau have strong prognostic value in fFTLD.

AbstractBackgroundUp to 30% of frontotemporal dementia (FTD) cases are due to known pathogenic mutations (f‐FTD). Little is known about the factors that predict who will choose to learn their results. Upcoming clinical trials in f‐FTD may require disclosure prior to enrollment, even before symptom onset, and thus characterizing this sample is important. Furthermore, understanding the mood impacts of genetic disclosure may guide genetic counseling practice.MethodF‐FTD participants (n=568) from families with a known pathogenic mutation (MAPT, C9orf72, GRN) were enrolled through the ARTFL/LEFFTDS Longitudinal FTD Study (ALLFTD) and provided the opportunity for disclosure. Independent‐sample t‐tests compared demographic and psychosocial factors between participants who did and did not receive their results. In participants who were asymptomatic at baseline and follow up (n=199,177 with follow‐up), linear mixed effects modeling was used to investigate pre‐ to post‐disclosure changes in the 15‐item Geriatric Depression Scale (GDS).ResultOf participants from families with a known pathogenic genetic mutation, 47% received genetic disclosure. Of the asymptomatic subset (n=386), 36% know their mutation status. Of these asymptomatic learners, 46% received disclosure through the study, and the remainder learned their genetic status prior to study enrollment. None of the analyzed demographic or psychosocial factors (i.e., sex, age, education, having children) differed between learners and non‐learners (p’s > 0.05). In the longitudinal analysis of asymptomatic participants, learners showed a pre‐ to post‐increase of 0.31 GDS points/year (95%CI: ‐0.08, 0.69, p = 0.12), whereas non‐learners showed a slight decline (‐0.15 points/year, 95%CI: ‐0.36, 0.06, p = 0.16). This difference between slopes was statistically significant (0.46, 95%CI: 0.02, 0.89, p=0.04) but represents a small clinical effect. In asymptomatic learners, slopes did not differ based on mutation status (0.28, 95%CI: ‐0.66, 1.20, p=0.55). Conclusions were based on the estimates and full range of confidence intervals.ConclusionThe majority of asymptomatic research participants do not know their genetic status, which will be a consideration for clinical trials that require disclosure. No considered demographic factors were strongly associated with the decision to receive disclosure. The findings suggest that disclosure in asymptomatic participants has minimal impact on depressive symptoms regardless of genetic results.

AbstractBackgroundNeocortical tau can be present in over half of patients with Lewy body disease at autopsy, and may influence the timing of when a diagnosis of Dementia with Lewy bodies (DLB) can be made. We examined whether the core features, onset age and latency of probable DLB diagnosis differ by pathological subgroups.MethodAll patients (n=176) met clinical criteria for probable DLB, underwent autopsy and were classified as transitional or diffuse Lewy body disease (TLBD, DLBD). The TLBD and DLBD groups were further subdivided based on the absence of neocortical tangles represented by a low (L) Braak NFT stage of 0‐III or by the presence of neocortical tangles represented by a high (H) Braak NFT stage of IV‐VI. Onset age and latency from cognitive symptom onset to probable DLB were compared for TLBD‐L (n=30), DLBD‐L (n=47), DLBD‐H (n=78) and TLBD‐H (n=21).ResultThe TLBD‐H group met criteria for DLB at an older age (median 76 years) compared to TLBD‐L, DLBD‐L or DLBD‐H groups (median age 70 years, p<0.001). The latency to probable DLB from cognitive onset was shortest for TLBD‐L and DLBD‐L (median < 1 year), which was shorter than DLBD‐H (median 2 years; p=0.016), each of which were shorter than TLBD‐H (median 7.3 years; p<0.001). RBD was more common in men (79% men vs. 40% women, p<0.001) and in patients without neocortical tangles (86% vs. 57%, p<0.001). Patients with RBD met criteria for probable DLB at a younger age than those without a history of RBD (median 69 years vs. 76 years, p<0.001). Men had a shorter latency to probable DLB than women (median 1.0 year vs. 2.8 years, p<0.01), but this was related to RBD status that was more common in men.ConclusionPresence of RBD in both sexes led to a younger onset age and shorter latency to diagnosis of probable DLB. Patients with more widespread tau relative to α‐synuclein pathology (TLBD‐H) were older when probable DLB was diagnosed compared to those with so‐called pure Lewy body disease (TLBD‐L, DLBD‐L) or those with diffuse α‐synuclein and tau pathology (DLBD‐H).

AbstractIntroductionWe examined the temporal sequence of the core features in probable dementia with Lewy bodies (DLB).MethodsIn 488 patients with probable DLB, the onset of each core feature and time to diagnosis was determined for men and women, and a pathologic subgroup (n = 209).ResultsREM sleep behavior disorder (RBD) developed before the other core features in men and women. Men were more likely to have RBD and were diagnosed with probable DLB earlier than women. Visual hallucinations developed after the other core features in men, but in women, they appeared earlier and concurrently with fluctuations and parkinsonism. Women were older and more cognitively impaired at first visit, were less likely to have RBD, more likely to be diagnosed with probable DLB later than men, and more likely to have neocortical tangles.DiscussionAn earlier latency to probable DLB was associated with men, RBD, and Lewy body disease without neocortical tangles.

Subjective cognitive decline (SCD) is prevalent in the general population, particularly among Hispanic adults. SCD increases the risk of mild cognitive impairment (MCI) and dementia. While non-pharmacologic interventions are recommended to mitigate cognitive decline and preserve daily function in SCD and MCI, such interventions are not readily available for Spanish-speaking Hispanic adults with SCD. This pilot study, preregistered at clinicialtrials.gov, aimed to develop a linguistically and culturally appropriate adaptation of an existing memory compensation intervention, the Memory Support System (MSS), from English to Spanish, and to gather data to assess its impact in this population. Twenty Spanish-speaking Hispanic adults with SCD and 16 support partners were recruited. Measures of treatment adherence, daily function, self-efficacy for memory, quality of life, mood, anxiety, and caregiver burden were assessed at baseline, treatment end, and 8-week follow-up. By treatment end, participants with SCD improved their general functional status, daily activities requiring organizational skills, and depression and anxiety symptoms. Partners reported improvement in anxiety by treatment end and in caregiver burden at follow-up. The MSS was successfully translated into Spanish and readily learned by participants with SCD and their partners. The MSS in Spanish may help with daily functioning and aspects of patient and family well-being.

AbstractBackgroundFamilial frontotemporal dementia (f‐FTLD) is typically caused by mutations in one of three genes: microtubule‐associated protein tau (MAPT), progranulin (GRN), and a repeat expansion in the chromosome 9 open reading frame 72 (C9orf72) gene. Accurate characterization of the natural history of each mutation is important for clinical prognostication and clinical trial design, and it could shed light on disease biology. Such models have not been thoroughly developed using participants that represent all disease stages, with longitudinal data. We characterized the trajectory of atrophy in each gene by using longitudinal voxel‐wise analyses of gray matter volume, and we assessed whether functional independence declined in tandem.MethodF‐FTLD participants (n=100) with a known mutation (MAPT+ (n=28), GRN+ (n=33), C9orf72+ (n=39)) were grouped according to disease stage (CDR®+NACC FTLD module). We included participants with at least two structural MRIs at a given disease stage: presymptomatic (CDR®+NACC‐FTLD=0, n=57), mild/questionable (CDR®+NACC‐FTLD=0.5, n=15), and symptomatic (CDR®+NACC‐FTLD ≥1, n=28). We fitted longitudinal linear mixed effects models to extract mean atrophy rates in each lobe compared to longitudinal imaging from family members without mutations (n=60). All results presented below were significant at p<.001.ResultUsing the left frontal lobe as an exemplar, in the presymptomatic stage, MAPT mutation carriers showed the greatest rate of atrophy compared to controls (88 mm3/year more volume loss than controls), followed by GRN+ (65 mm3/year) and then C9orf72+ (49 mm3/year). In the mild/questionable stage, MAPT+ showed a greater divergence from controls (374 mm3/year) than did GRN+ (107 mm3/year) or C9orf72+ (223 mm3/year). In the symptomatic stage, MAPT+ again lost volume at the fastest rate (2,099 mm3/year), followed by GRN+ (1,360 mm3/year). C9orf72 expansion carriers showed a much slower rate of volume loss (115 mm3/year). Similar patterns were observed for other brain regions. In contrast to the imaging results, C9orf72+ exhibited similar rates of functional decline compared to GRN+ and MAPT+ at all levels of disease severity.ConclusionThe primary f‐FTLD genes show divergent atrophy trajectories as a function of disease stage, with C9orf72 expansion carriers exhibiting a slow degeneration throughout the disease course, possibly due to unique pathophysiological mechanisms.

AbstractBackgroundDementia with Lewy Bodies (DLB) is the second most common cause of degenerative dementia but the evolution of the core clinical features of DLB has not been clearly defined. The objective of this study was to identify the temporal relationship between each core feature from the estimated onset of cognitive symptoms.MethodParticipants include 485 patients with probable DLB who were evaluated at the Mayo Clinic Alzheimer Disease Research Center with neurologic and neurocognitive assessment. Each core clinical feature was compared using Kaplan‐Meier (KM) curves with the sentinel event representing age at which each core feature developed, or time from estimated cognitive onset.ResultThe sample was disproportionately male (76%). Patients were followed longitudinally, with 84% followed until death. Mean MMSE at the last evaluation was 18.3 ± 7.8. KM curves for age of onset and cumulative incidence for DLB core features as time from cognitive onset are provided. REM‐sleep behavior disorder (RBD) developed earliest and in 77% of our sample with a median KM survival estimate of 69 years (95% CI: 67.6–70.8). RBD was present in greater than 50% of patients at cognitive symptom onset. The median KM survival estimate for cognitive symptom onset was 70.2 years (95% CI: 69.3‐71.0). Parkinsonism developed in 89% with a median KM survival estimate of 73.7 years (95% CI: 72.7‐74.7). 76% had fluctuations with a similar median KM survival estimate of 74.6 years (95% CI: 73.7‐75.8). Visual hallucinations (VH) were present in 70% emerging at a median KM survival estimate of 80.2 years (95% CI: 79.5‐ 81.3). Cumulative incidence estimates for median time from cognitive onset to parkinsonism, fluctuations and VH were 2 years (95% CI: 2.0‐2.5), 2.3 years (95% CI: 2.0‐3.2) and 4.3 years (95% CI: 4.0‐4.8 years), respectively.ConclusionIn this DLB cohort, RBD was most likely to precede cognitive onset. The evolution of the other core features after cognitive onset was parkinsonism and fluctuations and then VH. While VH occur about 4 years after cognitive symptom onset, parkinsonism and fluctuations occur within the first 2 years.

AbstractBackgroundSubjective cognitive decline (SCD) affects 1 in 9 Hispanics aged ≥45 in the U.S., including 1 in 3 who report that SCD interferes with instrumental activities of daily living (IADLs) and 1 in 2 who give up IADLs or need help performing household tasks. A curriculum and calendar/note‐taking system [Memory Support System (MSS)] has proven effective to sustain independence in IADLs in patients with mild cognitive impairment, and protect mood among program partners compared to controls. Until recently, the MSS had only been utilized among English‐speaking, predominately Caucasian, samples.MethodThis study investigated the use of a translated and culturally‐adapted MSS in 20 Spanish‐speaking participants with SCD [80% female, age M = 66.8 (SD = 10.3), education M = 14.8 (SD = 3.6)] and their program partners. A within‐subject multiple baseline design in a 10‐session, 2 to 6‐week MSS training schedule was utilized. Outcome measures included treatment adherence and self‐ and informant‐report questionnaires of IADLs, anxiety, depression, self‐efficacy, caregiver burden, and quality of life.ResultMSS training significantly improved adherence to the MSS calendar by treatment completion (d = ‐3.75). Participants with SCD also showed significant improvement in overall functional status (d = 0.72), and in daily activities requiring organizational skills (d = 0.66). Symptoms of depression (d = 0.99) and anxiety (d = 0.84) also improved by treatment end, and program partners reported significant improvement in their own anxiety (d = 0.84). There was a significant association between MSS adherence and anxiety in participants with SCD (r = ‐.51).ConclusionOverall, preliminary findings suggest that with appropriate training, Spanish‐speaking participants with SCD can and will use a memory notebook system to help compensate in daily life for their SCD and decrease emotional distress. Future research should investigate the Spanish MSS efficacy over time in a randomized controlled trial.