Overview
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Investigating_Complex_Neurodeg["Investigating Complex Neurodegenerative Disorder"] -->|"references"| VCP["VCP"]
Investigating_Complex_Neurodeg["Investigating Complex Neurodegenerative Disorder"] -->|"references"| TARDBP["TARDBP"]
style Investigating_Complex_Neurodeg fill:#4fc3f7,stroke:#333,color:#000
This large observational study investigates the genetic and clinical features of complex neurodegenerative disorders, including Frontotemporal Lobar Degeneration (FTLD) spectrum disorders and Progressive Supranuclear Palsy (PSP). The study establishes a comprehensive longitudinal database and biobank to advance understanding of disease mechanisms, identify biomarkers, and facilitate therapeutic development["@Boxer_2020"].
Study Details
| Parameter | Value |
|-----------|-------|
| NCT Number | NCT03225144 |
| Status | Active, no longer recruiting |
| Study Type | Observational |
| Conditions | FTLD, PSP, CBS, CBD, [Alzheimer's Disease](/diseases/alzheimers-disease), [Parkinson's Disease](/diseases/parkinsons-disease) |
| Sites | Multiple international sites |
Scientific Background
Frontotemporal Lobar Degeneration (FTLD)
FTLD represents a spectrum of clinically and pathologically heterogeneous disorders characterized by progressive degeneration of the frontal and temporal lobes[@Rohrer_2011]. The disease spectrum includes:
...Overview
Mermaid diagram (expand to render)
This large observational study investigates the genetic and clinical features of complex neurodegenerative disorders, including Frontotemporal Lobar Degeneration (FTLD) spectrum disorders and Progressive Supranuclear Palsy (PSP). The study establishes a comprehensive longitudinal database and biobank to advance understanding of disease mechanisms, identify biomarkers, and facilitate therapeutic development["@Boxer_2020"].
Study Details
| Parameter | Value |
|-----------|-------|
| NCT Number | NCT03225144 |
| Status | Active, no longer recruiting |
| Study Type | Observational |
| Conditions | FTLD, PSP, CBS, CBD, [Alzheimer's Disease](/diseases/alzheimers-disease), [Parkinson's Disease](/diseases/parkinsons-disease) |
| Sites | Multiple international sites |
Scientific Background
Frontotemporal Lobar Degeneration (FTLD)
FTLD represents a spectrum of clinically and pathologically heterogeneous disorders characterized by progressive degeneration of the frontal and temporal lobes[@Rohrer_2011]. The disease spectrum includes:
- Behavioral Variant FTD (bvFTD): Characterized by changes in personality, social conduct, and executive function[@Rascovsky_2011]
- Primary Progressive Aphasia (PPA): Language-predominant presentations
- FTD-ALS Spectrum: Overlap with motor neuron disease
Progressive Supranuclear Palsy (PSP)
PSP is a 4R-tauopathy presenting with vertical supranuclear gaze palsy, parkinsonism, and cognitive decline[@Litvan_2017]. The Richardson variant is the most common presentation, though multiple clinical phenotypes are recognized.
Corticobasal Degeneration (CBD/CBS)
Corticobasal syndrome presents with asymmetric cortical sensory loss, apraxia, and extrapyramidal signs[@Armstrong_2020]. Like PSP, it is classified as a 4R-tauopathy with significant clinical overlap.
Objectives
Primary Objectives
Establish a Longitudinal Clinical Database: Create a well-characterized cohort with standardized clinical assessments over time[@Bang_2018]
Collect Biological Samples: Assemble a comprehensive biobank including:
- DNA for genetic analysis
- Plasma and cerebrospinal fluid for biomarker studies[@Chen_2018]
- Skin fibroblasts for cellular models
Develop Diagnostic Criteria: Refine clinical diagnostic criteria through correlation with neuropathology
Create a Therapeutic Development Resource: Establish infrastructure for clinical trials in these rare disorders[@Boxer_2023]Secondary Objectives
- Identify genetic risk factors and modifiers
- Characterize genotype-phenotype correlations
- Develop surrogate endpoints for clinical trials
- Establish natural history data for endpoint selection
Study Design
Baseline Assessment
- Comprehensive neurological examination
- Standardized cognitive batteries (MMSE, MoCA, FAB)
- Movement disorder assessments (MDS-UPDRS, PSP Rating Scale)
- Behavioral questionnaires (NPI, FBI)
- Functional capacity measures (ADL, CDR)
Longitudinal Follow-up
- Annual follow-up visits with repeated assessments
- Tracking of disease progression rates[@Bang_2018]
- Documentation of phenotypic evolution
Biobanking Protocol
| Sample Type | Use |
|------------|-----|
| Blood (EDTA) | DNA extraction and genetic analysis |
| Blood (serum) | Biomarker studies (NfL, p-tau)[@Benutti_2022] |
| CSF | Fluid biomarker profiling[@Chen_2018] |
| Skin fibroblasts | Induced pluripotent stem cell derivation |
Neuroimaging Repository
- High-resolution MRI with volumetric analysis
- Diffusion tensor imaging for white matter integrity
- FDG-PET for metabolic patterns[@Irwin_2018]
- Tau and amyloid PET (in selected cases)
Clinical Assessments
Cognitive Testing Battery
Global Cognition
- Mini-Mental State Examination (MMSE)
- Montreal Cognitive Assessment (MoCA)
Executive Function
- Trail Making Test A & B
- Wisconsin Card Sorting Test
- Verbal fluency
Memory
- Rey Auditory Verbal Learning Test
- Rey-Osterrieth Complex Figure Test
Language
- Boston Naming Test
- Western Aphasia Battery
Motor Assessment
- MDS-UPDRS: Unified Parkinson's Disease Rating Scale
- PSPRS: PSP Rating Scale
- CBS Assessment: Standardized corticobasal evaluation
- Ocular motor examination
Behavioral Measures
- Neuropsychiatric Inventory (NPI): Behavioral disturbance assessment
- Frontal Behavioral Inventory (FBI): Frontal lobe symptom assessment
- Cambridge Cognitive Examination (CAMCOG): Comprehensive cognitive screening
Key Findings and Contributions
The study has contributed substantially to the field:
Diagnostic Criteria Refinement
- Improved clinical criteria for PSP variants[@Litvan_2017]
- Refined CBS diagnostic criteria[@Armstrong_2020]
- Better characterization of FTLD subtypes
Genetic Discoveries
- Identification of new genetic risk factors
- Characterization of genotype-phenotype correlations
- Understanding of modifier genes
Biomarker Development
- Validation of neurofilament light chain (NfL) as a progression marker[@Benussi_2022]
- Identification of CSF biomarker profiles
- Development of imaging biomarkers[@Irwin_2018]
Eligibility Criteria
Inclusion Criteria
Clinical Diagnosis: Suspected or confirmed diagnosis of:
- Behavioral variant FTD
- Primary Progressive Aphasia
- PSP (any variant)
- Corticobasal Syndrome
- Related neurodegenerative disorder
Age: 18 years or older
Capacity: Able to provide informed consent (or appropriate proxy consent)Exclusion Criteria
Other neurological conditions that could explain symptoms
Medical conditions precluding comprehensive assessment
Inability to undergo MRI or other imaging
Current enrollment in interventional clinical trialsSignificance for Research
For Basic Science
The biobank and database enable:
- Molecular studies of disease mechanisms
- Development of cellular and animal models
- Identification of therapeutic targets
For Clinical Research
- Clinical trial readiness through natural history data
- Biomarker validation studies
- Endpoint validation
For Therapeutic Development
- Patient cohorts for enrollment
- Biomarker endpoints for trials
- Understanding of disease heterogeneity
See Also
- [Frontotemporal Dementia](/diseases/frontotemporal-disease) — Primary disease category
- [Progressive Supranuclear Palsy](/diseases/progressive-supranuclear-palsy) — Related disorder
- [Corticobasal Degeneration](/diseases/corticobasal-degeneration) — Related disorder
- [MAPT Gene](/genes/mapt) — Tau gene associated with PSP and FTD
- [GRN Gene](/genes/grn) — Progranulin gene in FTD
- [C9orf72 Gene](/genes/c9orf72) — Common FTD-ALS gene
- [Tau Protein](/proteins/tau) — 4R-tau in PSP and CBD
External Links
- [ClinicalTrials.gov NCT03225144](https://clinicaltrials.gov/study/NCT03225144)
- [PubMed Search: FTLD biomarkers](https://pubmed.ncbi.nlm.nih.gov/)
- [KEGG Pathways](https://www.genome.jp/kegg/pathway.html)
Related Pages
- [CBS/PSP Genetic Architecture](/diseases/psp-genetic-variants)
- [PSP Genetic Variants](/diseases/psp-genetic-variants)
- [CurePSP Genetics Program](/clinical-trials/curepsp-genetics-program)
- [Genetic Frontotemporal Dementia Study](/diseases/frontotemporal-disease)
- [4R-Tauopathies Overview](/proteins/tau)
- Neurodegenerative Disease Biomarkers
- [Genetic Frontotemporal Dementia Study](/diseases/frontotemporal-disease)
- [4R-Tauopathies Overview](/proteins/tau)
- Neurodegenerative Disease Biomarkers](/diseases/frontotemporal-dementia)## Scientific Background: FTLD Spectrum Disorders
Classification of Frontotemporal Lobar Degeneration
Frontotemporal lobar degeneration (FTLD) represents a heterogeneous group of neurodegenerative disorders characterized by progressive atrophy of the frontal and temporal lobes. The FTLD spectrum includes several clinical syndromes:
Primary FTLD Syndromes
Behavioral Variant Frontotemporal Dementia (bvFTD)
- Characterized by progressive behavioral changes and executive dysfunction
- Disinhibition, apathy, loss of empathy, and compulsions
- Typically presents in the 5th-6th decade of life
Semantic Variant Primary Progressive Aphasia (svPPA)
- Progressive loss of word meaning and object knowledge
- Fluent speech with intact grammar and motor speech
- Typically presents with anomia and comprehension deficits
Non-fluent/agrammatic Variant Primary Progressive Aphasia (nfvPPA)
- Agrammatic speech with impaired grammar
- Motor speech deficits (apraxia of speech)
- Preservation of word comprehension
Logopenic Variant Primary Progressive Aphasia (lvPPA)
- Impaired word retrieval and sentence repetition
- Usually associated with Alzheimer's pathology
- Part of the language variant spectrum
FTLD Overlap Syndromes
FTLD frequently co-occurs with other neurodegenerative conditions:
- FTLD with Amyotrophic Lateral Sclerosis (FTLD-ALS)
- FTLD with Parkinsonism (FTLD-PD)
- [Corticobasal Syndrome (CBS)](/diseases/corticobasal-syndrome)
- [Progressive Supranuclear Palsy (PSP)](/diseases/progressive-supranuclear-palsy)
Neuropathological Classification
FTLD is characterized by the accumulation of specific protein inclusions:
Tauopathies (~50% of FTLD)
- Pick disease: 3R tau inclusions
- CBD: 4R tau inclusions
- PSP: 4R tau inclusions
- FTLD-tau: Various tau mutations
TDP-43 Proteinopathies (~45% of FTLD)
- FTLD-TDP Type A: Neuronal cytoplasmic inclusions, frontotemporal dementia
- FTLD-TDP Type B: Neuronal cytoplasmic inclusions,ALS
- FTLD-TDP Type C: Lentiform inclusions, semantic variant
- FTLD-TDP Type E: Extensive neuronal loss
FTD-FUS (~5% of FTLD)
- [Fused in sarcoma (FUS) protein inclusions](/proteins/fused-in-sarcoma)
- Associated with ALS andFTLD-NOS
Genetics of FTLD Spectrum
Autosomal Dominant FTLD Genes
| Gene | Protein | Inheritance | Phenotype |
|------|---------|------------|-----------|
| MAPT | Tau | AD | bvFTD, PSP, CBD |
| GRN | Progranulin | AD | bvFTD, nfvPPA, CBS |
| C9orf72 | Dipeptide repeats | AD | bvFTD, ALS |
| FUS | Fused in sarcoma | AD | FTLD, ALS |
| TARDBP | TDP-43 | AD | FTLD, ALS |
Risk Factors
- VCP: Valosin-containing protein mutations (inclusion body myopathy)
- CHMP2B: Charged multivesicular body protein 2B
- TBK1: TANK-binding kinase 1
The Role of PSP in FTLD Spectrum
Progressive supranuclear palsy represents a key intersection within the FTLD spectrum:
Clinical overlap: PSP shares features with both FTLD (behavioral changes, executive dysfunction) and parkinsonian syndromes (bradykinesia, rigidity)
Pathological overlap: PSP is classified as both an atypical parkinsonism and a tauopathy within the FTLD spectrum
Genetic overlap: MAPT mutations can cause both FTLD and PSP phenotypes
Therapeutic implications: Understanding PSP within the FTLD context informs clinical trial design and treatment targetingStudy Design and Methodology
Baseline Comprehensive Assessment
Neurological Examination
Standardized neurological examination includes:
- Motor assessment: MDS-UPDRS, PSPRS
- Ocular motor testing: Vertical supranuclear gaze assessment
- Cognitive testing: Comprehensive neuropsychological battery
- Behavioral assessment: Frontal behavioral inventory
Neuropsychological Testing
Cognitive domains assessed:
Executive function: Trail Making Test, Wisconsin Card Sorting Test
Memory: Rey Auditory Verbal Learning Test, Rey-Osterrieth Complex Figure
Language: Boston Naming Test, Semantic Fluency, Token Test
Visuospatial: Rey-Osterrieth Copy, Line Orientation
Social cognition: Reading the Mind in the Eyes, Faux Pas recognitionNeuroimaging Protocol
- MRI: 3D T1, T2/FLAIR, SWI sequences
- Volumetric analysis: Hippocampal, frontal, temporal volumes
- DTI: White matter integrity assessment
- FDG-PET: Regional glucose metabolism (optional)
- Tau PET: Flortaucipir binding (selected centers)
Biobanking Protocol
Sample Collection
| Sample Type | Collection | Processing | Storage |
|-------------|------------|------------|---------|
| DNA | Whole blood | EDTA tubes | -80°C |
| Plasma | Venipuncture | BD PPT tubes | -80°C |
| CSF | Lumbar puncture | Polypropylene tubes | -80°C |
| PBMCs | Whole blood | Ficoll gradient | -80°C |
Genetic Analysis Pipeline
SNP array: Genome-wide genotyping
Whole genome sequencing: Comprehensive variant detection
Segregation analysis: Family variant validation
Functional studies: In silico pathogenicity assessmentAnnual Follow-up Protocol
Visit Schedule
- Year 1-2: Annual visits
- Year 3-5: Optional bi-annual visits
- Long-term: Annual telephone follow-up
Assessment Battery
| Timepoint | Clinical | Cognitive | Imaging | Biosamples |
|-----------|----------|-----------|---------|------------|
| Baseline | Full | Full | Yes | Full |
| Year 1 | Full | Full | Yes | Full |
| Year 2 | Full | Full | Optional | Full |
| Subsequent | Brief | Brief | Optional | Optional |
Key Scientific Contributions
Diagnostic Refinement
The study has contributed to improved diagnostic criteria for:
FTLD subtypes: Refined clinical and pathological correlations
CBS phenotype: Better characterization of corticobasal presentation
PSP variants: Identification of cortical PSP and other variants
FTLD-ALS: Consensus criteria for combined presentationsGenetic Discoveries
Novel Genetic Risk Factors
- Identification of rare variants in TBK1 as FTLD risk factor
- Characterization of C9orf72 founder effects in specific populations
- Discovery of GRN expression modifiers affecting age of onset
Genotype-Phenotype Correlations
- MAPT haplotypes and phenotype specificity
- GRN null mutations and nfvPPA
- C9orf72 repeat size and clinical presentation
Biomarker Development
Fluid Biomarkers
- NfL as disease progression marker in FTLD
- p-tau181 differentiation between FTLD and AD
- Progranulin as diagnostic marker for GRN carriers
Imaging Biomarkers
- Frontal atrophy patterns distinguishing FTLD subtypes
- Midbrain-to-pontine ratio for PSP diagnosis
- Connectivity changes in behavioral variant FTD
Clinical Significance
Enabling Therapeutic Development
This study provides essential infrastructure for clinical trials:
Patient registry: Pre-screened, genetically characterized cohorts
Natural history data: Informs trial design and endpoint selection
Biorepository: Ready access to matched biosamples
Expertise network: Multi-center collaboration infrastructurePersonalized Medicine Applications
- Genetic counseling: For at-risk family members
- Prognostic information: Based on genotype and phenotype
- Risk stratification: For prevention trials in pre-symptomatic individuals
- Treatment selection: Genotype-informed therapeutic decisions
Healthcare Delivery Improvements
- Diagnostic algorithms: Evidence-based diagnostic pathways
- Clinical decision support: Integrated genetic and clinical data
- Care coordination: Multi-specialty management protocols
Future Directions
Emerging Research Directions
Single-cell genomics: Understanding cellular heterogeneity in FTLD
Proteomics: Biomarker discovery through unbiased profiling
Epigenetics: Understanding gene-environment interactions
Neuroinflammation: Role of microglia and astrocytes in FTLDInternational Collaboration
The study participates in:
- FTLDNI: Frontotemporal Lobar Degeneration Neuroimaging Initiative
- GENFI: Genetic Frontotemporal Dementia Initiative
- ALLFTD: Art and Science of Learning to See Clearly
- CurePSP Registry: Foundation for PSP and Related Disorders
Page updated: 2026-03-27References
[ClinicalTrials.gov NCT03225144](https://clinicaltrials.gov/study/NCT03225144)[@investigating]
[Ranasinghe et al., Neurodegenerative disease biomarkers (2022)](https://pubmed.ncbi.nlm.nih.gov/35279234/)[@ranasinghe_2022]
[Boxer et al., FTD and related disorders: from molecules to therapeutics (2020)](https://pubmed.ncbi.nlm.nih.gov/32092166/)[@Boxer_2020]
[McGough et al., Update on biomarkers in neurodegenerative diseases (2023)](https://pubmed.ncbi.nlm.nih.gov/37526723/)[@McGough_2023]
[Rascovsky et al., Diagnostic criteria for bvFTD (2011)](https://pubmed.ncbi.nlm.nih.gov/21810889/)[@Rascovsky_2011]
[Litvan et al., Clinical diagnostic criteria for PSP (2017)](https://pubmed.ncbi.nlm.nih.gov/28327879/)[@Litvan_2017]
[Armstrong et al., Clinical criteria for CBS (2020)](https://pubmed.ncbi.nlm.nih.gov/32128918/)[@Armstrong_2020]
[Bang et al., Longitudinal changes in PSP and CBD (2018)](https://pubmed.ncbi.nlm.nih.gov/29349711/)[@Bang_2018]
[Rohrer et al., Clinical features of FTD (2011)](https://pubmed.ncbi.nlm.nih.gov/21047878/)[@Rohrer_2011]
[Boxer et al., Clinical trials in FTD (2023)](https://pubmed.ncbi.nlm.nih.gov/37153892/)[@Boxer_2023]
[Chen et al., Fluid biomarkers in neurodegenerative disease (2018)](https://pubmed.ncbi.nlm.nih.gov/30148620/)[@Chen_2018]
[Benussi et al., Neurofilament light chain as biomarker (2022)](https://pubmed.ncbi.nlm.nih.gov/35499099/)[@Benussi_2022]
[Irwin et al., Neuroimaging biomarkers (2018)](https://pubmed.ncbi.nlm.nih.gov/29068454/)[@Irwin_2018]
Page updated: 2026-03-27