Metabolic Imaging for Diagnosis and Prognostication of Autoimmune encephalitiS

NCT06432803 | Active Not Recruiting

• 1 other identifier: 69HCL24_0511
• Study Type: observational
• Target: 28
• Locations: 1 country
• Sites: 1

Brief Summary

Autoimmune encephalitis (AE) is a rare neurological disorder mediated by autoimmune antibody response against neuronal cell surface and intraneuronal proteins associated with specific brain areas, resulting in severe inflammation and damage in the associated brain regions, all most frequently manifesting diverse cognition and memory impairment symptoms at follow-up. However, these symptoms may co-exist or mimic other CNS autoimmune and neurodegenerative disorders. The most common guideline for diagnosing autoimmune encephalitis relies on cerebrospinal fluid (CSF) antibody testing which might take several weeks to obtain, making it not optimal for the early diagnosis of AE. As for magnetic resonance imaging (MRI), which is the most common imaging tool utilized for aiding in the diagnosis of AE, can possess several limitations as some patients, like anti-NMDAr AE patients, can present memory and behavioral deficits even in the presence of normal brain MRI. Positron emission tomography (PET) with 2-deoxy-2-\[fluorine-18\] fluoro-D-glucose (18F-FDG) have been addressed by several studies as an important examination for the early diagnosis of AE . One study demonstrated that the fraction of having an abnormal MRI in AE patients is lower than having an abnormal PET, by which certain PET patterns were associated with autoantibody types of AE. Moreover, one report demonstrated that even with autoantibody negative test and normal brain MRI, FDG-PET examination showed abnormal hypometabolism and hypermetabolism patterns. More specifically, these distinct patterns include medial temporal and striatal hypermetabolism with cortical diffuse hypometabolism. Leiris et al. revealed that the methadology used for the analysis of these PET images is highly variable, especially intensity normalization methods, where most possess some limitations (e.g., proportional scaling) as they can impede the accurate differential diagnosis of autoimmune encephalitis (AE) by potentially indicating false hypermetabolism in otherwise preserved brain regions. Absolute quantification is not possible since the disease presents both diffuse hypometabolism and hypermetabolism on PET images. So, they suggested that it's best to parametrize the brain's activity by dividing it by that of the striatum. Their voxel-based analysis, comparing individuals with AE to both healthy subjects and those with mild cognitive impairment (MCI), demonstrated that a decrease in the cortex/striatal metabolic ratio is a robust biomarker for the early diagnosis of AE.

Conditions

Paraneoplastic Neurological Syndrome; Autoimmune Encephalitis

Keywords

Paraneoplastic neurological disorders; autoimmune encephalitis; auto-antibodies; PET-SCAN

Outcome Measures

Primary Outcomes (1)

• Ratio metabolic cortex-striatum

  Decrease in the metabolic ratio cortex/striatum in included patients, compared to a control reference cohort.

  Up to 10 months

Study Arms (2)

Auto-immune encephalitis patients

Analysis of PET-scan

Other: PET-Scan analysis

Paraneoplastic Neurological Syndromes patients

Analysis of PET-scan

Other: PET-Scan analysis

Interventions

PET-Scan analysis OTHER

Investigate and determine the clinical value of different cortex/striatal metabolic ratio patterns in each antibody-specific subtype of autoimmune encephalitis

Auto-immune encephalitis patients; Paraneoplastic Neurological Syndromes patients

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Patients will be included from the from the database of the French Reference Centre for Paraneoplastic Neurological Syndromes and Autoimmune Encephalitis (Lyon, France)

You may qualify if:

• patient with positivity of auto-antibody in CSF
• patient \>18 years old
• patient with auto-immune encephalitis or paraneoplastic neurological syndrome

You may not qualify if:

• \- patient without data

Sponsors & Collaborators

• Hospices Civils de Lyon: lead

Study Sites (1)

CHU Lyon

Pierre-Bénite, 69495, France

Location

MeSH Terms

Conditions

Autoimmune Diseases of the Nervous System

Condition Hierarchy (Ancestors)

Nervous System Diseases; Autoimmune Diseases; Immune System Diseases

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: RETROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: May 14, 2024
• First Posted: May 29, 2024
• Study Start: March 1, 2024
• Primary Completion: June 1, 2024
• Study Completion: December 31, 2024
• Last Updated: May 29, 2024

Record last verified: 2024-05

Data Sharing

• IPD Sharing: Will not share

Locations

FR (1)