Cognitive composites for genetic frontotemporal dementia: GENFI-Cog

Montreal Cognitive Assessment vs the Mini-Mental State Examination as a Screening Tool for Patients With Genetic Frontotemporal Dementia

BACKGROUND AND OBJECTIVES

With upcoming clinical trials targeting preclinical stages of genetic frontotemporal dementia (FTD), early detection through cognitive screening is crucial. The Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) have potential as screening instruments for early-stage genetic FTD. However, no comparative evaluation has been performed. We aimed to compare MMSE and MoCA performance among presymptomatic, prodromal, and symptomatic pathogenic variant carriers to analyze which screening test has superior discriminative abilities.

METHODS

We used cross-sectional and longitudinal data from 2 longitudinal genetic FTD cohort studies in the Netherlands and the United Kingdom, collected between 2021 and 2024. Participants were either presymptomatic, prodromal, or symptomatic pathogenic variant carriers or healthy controls (first-degree family members without pathogenic variants for FTD). Grouping was based on the global CDR-plus-NACC-FTLD score. Participants were assessed with both MoCA and MMSE. Statistical analyses compared total and subscores between groups and evaluated predictive and classification accuracy of both tests.

RESULTS

A total of 243 participants (mean age 49.9 ± 13.1 years, mean education 14.5 ± 3.0 years, 56% female), 157 of whom were pathogenic variant carriers (MAPT, GRN, C9orf72, TARDBP, and TBK1) and 86 controls, were included. Carriers were classified as presymptomatic (n = 119), prodromal (n = 18), or symptomatic (n = 20). Both MoCA [F(3,239) = 16.565, p < 0.001] and MMSE [F(3,239) = 13.529, p < 0.001] total scores differed significantly between groups, with controls (median MoCA 28.5, 95% CI 28.0-29.0; median MMSE 30, 95% CI 30.0-30.0) outperforming prodromal (median MoCA 26, 95% CI 23.0-27.0; median MMSE 29, 95% CI 27.5-29.5) and symptomatic (median MoCA 20.5, 95% CI 17.0-24.0; median MMSE 26, 95% CI 23.5-29.0) carriers. MoCA distinguished between presymptomatic carriers and controls (median MoCA 28, 95% CI 27.0-29.0), but MMSE did not. MoCA demonstrated superior discriminative ability compared with MMSE (MoCA area under the curve [AUC] = 0.87, 95% CI 0.81-0.94; MMSE AUC = 0.80, 95% CI 0.72-0.89).

DISCUSSION

Its higher sensitivity and better discriminative power make MoCA a more valuable tool for cognitive screening in upcoming clinical trials targeting preclinical FTD. Future studies should aim for larger sample sizes from additional study centers.

Further description of the phenotypic spectrum of neuronal ceroid lipofuscinosis type 11

PURPOSE

Ceroid lipofuscinosis type 11 (CLN11) is a very rare disease, being reported in only 13 unrelated families so far. Further reports are necessary to comprehend the clinical phenotype of this condition. This article aims to report 9 additional cases of CLN11 from 9 unrelated Latin American families presenting with relatively slow disease progression.

METHODS

This was a retrospective observational study including patients with CLN11. Patients were identified through an active search for granulin precursor gene (GRN) pathogenic variants across the entire database of next-generation sequencing of a commercial laboratory and by contacting attending physicians to check for clinical and radiologic findings compatible with a neuronal ceroid lipofuscinosis phenotype.

RESULTS

Nine CLN11 patients from unrelated families were evaluated. Age of onset varied between 3 to 17 years. The most common findings were visual impairment, cerebellar ataxia, seizures, myoclonus, and cognitive decline. One patient had a previously unreported finding of cervical, perioral, and tongue myoclonus. Most of the patients were able to walk unassisted after an average of 14.2 years (SD 4.76 y) from disease onset.

CONCLUSION

We describe 9 new cases of a very rare type of neuronal ceroid lipofuscinosis (CLN11) from Latin America with a recurrent p.(Gln257ProfsTer27) and a novel p.(Cys83Ter) nonsense variant. Our findings suggest that a slowly progressive neuronal ceroid lipofuscinosis might be a clue for the diagnosis of CLN11.

Progranulin AAV gene therapy for frontotemporal dementia: translational studies and phase 1/2 trial interim results

GRN mutations cause progranulin haploinsufficiency, which eventually leads to frontotemporal dementia (FTD-GRN). PR006 is an investigational gene therapy delivering the granulin gene (GRN) using an adeno-associated virus serotype 9 (AAV9) vector. In non-clinical studies, PR006 transduced neurons derived from induced pluripotent stem cells of patients with FTD-GRN, resulted in progranulin expression and improvement of lipofuscin, lysosomal and neuroinflammation pathologies in Grn-knockout mice, and was well tolerated except for minimal, asymptomatic dorsal root ganglionopathy in non-human primates. We initiated a first-in-human phase 1/2 open-label trial. Here we report results of a pre-specified interim analysis triggered with the last treated patient of the low-dose cohort (n = 6) reaching the 12-month follow-up timepoint. We also include preliminary data from the mid-dose cohort (n = 7). Primary endpoints were safety, immunogenicity and change in progranulin levels in cerebrospinal fluid (CSF) and blood. Secondary endpoints were Clinical Dementia Rating (CDR) plus National Alzheimer's Disease Coordinating Center (NACC) Frontotemporal Lobar Degeneration (FTLD) rating scale and levels of neurofilament light chain (NfL). One-time administration of PR006 into the cisterna magna was generally safe and well tolerated. All patients developed treatment-emergent anti-AAV9 antibodies in the CSF, but none developed anti-progranulin antibodies. CSF pleocytosis was the most common PR006-related adverse event. Twelve serious adverse events occurred, mostly unrelated to PR006. Deep vein thrombosis developed in three patients. There was one death (unrelated) occurring 18 months after treatment. CSF progranulin increased after PR006 treatment in all patients; blood progranulin increased in most patients but only transiently. NfL levels transiently increased after PR006 treatment, likely reflecting dorsal root ganglia toxicity. Progression rates, based on the CDR scale, were within the broad ranges reported for patients with FTD. These data provide preliminary insights into the safety and bioactivity of PR006. Longer follow-up and additional studies are needed to confirm the safety and potential efficacy of PR006. ClinicalTrials.gov identifier: NCT04408625 .

Reliability and Validity of Smartphone Cognitive Testing for Frontotemporal Lobar Degeneration

Importance

Frontotemporal lobar degeneration (FTLD) is relatively rare, behavioral and motor symptoms increase travel burden, and standard neuropsychological tests are not sensitive to early-stage disease. Remote smartphone-based cognitive assessments could mitigate these barriers to trial recruitment and success, but no such tools are validated for FTLD.

Objective

To evaluate the reliability and validity of smartphone-based cognitive measures for remote FTLD evaluations.

Design, Setting, and Participants

In this cohort study conducted from January 10, 2019, to July 31, 2023, controls and participants with FTLD performed smartphone application (app)-based executive functioning tasks and an associative memory task 3 times over 2 weeks. Observational research participants were enrolled through 18 centers of a North American FTLD research consortium (ALLFTD) and were asked to complete the tests remotely using their own smartphones. Of 1163 eligible individuals (enrolled in parent studies), 360 were enrolled in the present study; 364 refused and 439 were excluded. Participants were divided into discovery (n = 258) and validation (n = 102) cohorts. Among 329 participants with data available on disease stage, 195 were asymptomatic or had preclinical FTLD (59.3%), 66 had prodromal FTLD (20.1%), and 68 had symptomatic FTLD (20.7%) with a range of clinical syndromes.

Exposure

Participants completed standard in-clinic measures and remotely administered ALLFTD mobile app (app) smartphone tests.

Main Outcomes and Measures

Internal consistency, test-retest reliability, association of smartphone tests with criterion standard clinical measures, and diagnostic accuracy.

Results

In the 360 participants (mean [SD] age, 54.0 [15.4] years; 209 [58.1%] women), smartphone tests showed moderate-to-excellent reliability (intraclass correlation coefficients, 0.77-0.95). Validity was supported by association of smartphones tests with disease severity (r range, 0.38-0.59), criterion-standard neuropsychological tests (r range, 0.40-0.66), and brain volume (standardized β range, 0.34-0.50). Smartphone tests accurately differentiated individuals with dementia from controls (area under the curve [AUC], 0.93 [95% CI, 0.90-0.96]) and were more sensitive to early symptoms (AUC, 0.82 [95% CI, 0.76-0.88]) than the Montreal Cognitive Assessment (AUC, 0.68 [95% CI, 0.59-0.78]) (z of comparison, -2.49 [95% CI, -0.19 to -0.02]; P = .01). Reliability and validity findings were highly similar in the discovery and validation cohorts. Preclinical participants who carried pathogenic variants performed significantly worse than noncarrier family controls on 3 app tasks (eg, 2-back β = -0.49 [95% CI, -0.72 to -0.25]; P < .001) but not a composite of traditional neuropsychological measures (β = -0.14 [95% CI, -0.42 to 0.14]; P = .32).

Conclusions and Relevance

The findings of this cohort study suggest that smartphones could offer a feasible, reliable, valid, and scalable solution for remote evaluations of FTLD and may improve early detection. Smartphone assessments should be considered as a complementary approach to traditional in-person trial designs. Future research should validate these results in diverse populations and evaluate the utility of these tests for longitudinal monitoring.

Diagnostic accuracy of research criteria for prodromal frontotemporal dementia

BACKGROUND

The Genetic Frontotemporal Initiative Staging Group has proposed clinical criteria for the diagnosis of prodromal frontotemporal dementia (FTD), termed mild cognitive and/or behavioral and/or motor impairment (MCBMI). The objective of the study was to validate the proposed research criteria for MCBMI-FTD in a cohort of genetically confirmed FTD cases against healthy controls.

METHODS

A total of 398 participants were enrolled, 117 of whom were carriers of an FTD pathogenic variant with mild clinical symptoms, while 281 were non-carrier family members (healthy controls (HC)). A subgroup of patients underwent blood neurofilament light (NfL) levels and anterior cingulate atrophy assessment.

RESULTS

The core clinical criteria correctly classified MCBMI vs HC with an AUC of 0.79 (p < 0.001), while the addition of either blood NfL or anterior cingulate atrophy significantly increased the AUC to 0.84 and 0.82, respectively (p < 0.001). The addition of both markers further increased the AUC to 0.90 (p < 0.001).

CONCLUSIONS

The proposed MCBMI criteria showed very good classification accuracy for identifying the prodromal stage of FTD.

Defining the presymptomatic phase of frontotemporal dementia

PURPOSE OF REVIEW

Frontotemporal dementia (FTD) is a clinically, pathologically and genetically heterogeneous disorder. Whilst disease modifying therapy trials are mostly focused on the symptomatic phase, future studies will move earlier in the disease aiming to prevent symptom onset. This review summarizes the recent work to better understand this presymptomatic period.

RECENT FINDINGS

The presymptomatic phase can be split into preclinical and prodromal stages. The onset of the preclinical phase is defined by the first presence of pathological inclusions of tau, TDP-43 or fused in sarcoma in the brain. Definitive biomarkers of these pathologies do not yet exist for FTD. The prodromal phase is defined by the onset of mild symptoms. Recent work has highlighted the wide phenotypic spectrum that occurs, with the concept of mild cognitive ± behavioural ± motor impairment (MCBMI) being put forward, and additions to scales such as the CDR plus NACC FTLD now incorporating neuropsychiatric and motor symptoms.

SUMMARY

It will be important to better characterize the presymptomatic period moving forward and develop robust biomarkers that can be used both for stratification and outcome measures in prevention trials. The work of the FTD Prevention Initiative aims to facilitate this by bringing together data from natural history studies across the world.

The Benson Complex Figure Test detects deficits in visuoconstruction and visual memory in symptomatic familial frontotemporal dementia: A GENFI study

OBJECTIVE

Sensitive cognitive markers are still needed for frontotemporal dementia (FTD). The Benson Complex Figure Test (BCFT) is an interesting candidate test, as it assesses visuospatial, visual memory, and executive abilities, allowing the detection of multiple mechanisms of cognitive impairment. To investigate differences in BCFT Copy, Recall and Recognition in presymptomatic and symptomatic FTD mutation carriers, and to explore its cognitive and neuroimaging correlates.

METHOD

We included cross-sectional data from 332 presymptomatic and 136 symptomatic mutation carriers (GRN, MAPT or C9orf72 mutations), and 290 controls in the GENFI consortium. We examined gene-specific differences between mutation carriers (stratified by CDR® NACC-FTLD score) and controls using Quade's / Pearson Χ2 tests. We investigated associations with neuropsychological test scores and grey matter volume using partial correlations and multiple regression models respectively.

RESULTS

No significant differences were found between groups at CDR® NACC-FTLD 0-0.5. Symptomatic GRN and C9orf72 mutation carriers had lower Copy scores at CDR® NACC-FTLD ≥2. All three groups had lower Recall scores at CDR® NACC-FTLD ≥2, with MAPT mutation carriers starting at CDR® NACC-FTLD ≥1. All three groups had lower Recognition scores at CDR® NACC FTLD ≥2. Performance correlated with tests for visuoconstruction, memory, and executive function. Copy scores correlated with frontal-subcortical grey matter atrophy, while Recall scores correlated with temporal lobe atrophy.

CONCLUSIONS

In the symptomatic stage, the BCFT identifies differential mechanisms of cognitive impairment depending on the genetic mutation, corroborated by gene-specific cognitive and neuroimaging correlates. Our findings suggest that impaired performance on the BCFT occurs relatively late in the genetic FTD disease process. Therefore its potential as cognitive biomarker for upcoming clinical trials in presymptomatic to early-stage FTD is most likely limited.

Temporal order of clinical and biomarker changes in familial frontotemporal dementia

Unlike familial Alzheimer's disease, we have been unable to accurately predict symptom onset in presymptomatic familial frontotemporal dementia (f-FTD) mutation carriers, which is a major hurdle to designing disease prevention trials. We developed multimodal models for f-FTD disease progression and estimated clinical trial sample sizes in C9orf72, GRN and MAPT mutation carriers. Models included longitudinal clinical and neuropsychological scores, regional brain volumes and plasma neurofilament light chain (NfL) in 796 carriers and 412 noncarrier controls. We found that the temporal ordering of clinical and biomarker progression differed by genotype. In prevention-trial simulations using model-based patient selection, atrophy and NfL were the best endpoints, whereas clinical measures were potential endpoints in early symptomatic trials. f-FTD prevention trials are feasible but will likely require global recruitment efforts. These disease progression models will facilitate the planning of f-FTD clinical trials, including the selection of optimal endpoints and enrollment criteria to maximize power to detect treatment effects.