Metabolic Imaging for Diagnosis and Prognostication of Autoimmune encephalitiS

NCT ID: NCT06432803

Last Updated: 2024-05-29

Basic Information

• Recruitment Status: ACTIVE_NOT_RECRUITING
• Total Enrollment: 28 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2024-03-01
• Study Completion Date: 2024-12-31

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

Study Design

• Observational Model Type: COHORT
• Study Time Perspective: RETROSPECTIVE

Study Groups

Auto-immune encephalitis patients

Analysis of PET-scan

PET-Scan analysis

Intervention Type: OTHER

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

Paraneoplastic Neurological Syndromes patients

Analysis of PET-scan

PET-Scan analysis

Intervention Type: OTHER

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

Interventions

PET-Scan analysis

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

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

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

Exclusion Criteria

• patient without data

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Hospices Civils de Lyon

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Locations

CHU Lyon

Pierre-Bénite, , France

Countries

France

Other Identifiers

69HCL24_0511

Identifier Type: -

Identifier Source: org_study_id