Autoimmune Encephalitis
Conditions
Keywords
Autoimmune Encephalitis, PET, FDG, NMDAr, LGI1, CASPR2, GAD
Brief summary
Prospective cohort study evaluating FDG PET in 56 patients with confirmed autoimmune encephalitis - based on 2016 Graus criteria, and 2021 paraneoplastic neurological syndromes criteria - at the acute phase, before immunomodulating treatment, or within 10 days of treatment initiation.
Detailed description
Autoimmune encephalitis is a diagnostic challenge, and requires early diagnosis for improved neurological outcomes. FDG PET has shown very high sensitivity, suggesting better performances than MRI, but almost exclusively in small sized retrospective studies. Brain FDG PET is therefore not included in current diagnostic criteria, conversely to brain MRI. This study will include 56 patients with confirmed - seropositive or seronegative - autoimmune encephalitis, based on 2016 Graus criteria for autoimmune encephalitis and 2021 criteria for paraneoplastic neurological syndromes. The main objective is to conduct a prospective evaluation of the diagnostic value of FDG PET performed in the acute phase before treatment initiation, or within 10 days of treatment initiation. A follow-up PET performed 3 months after treatment initiation will also be performed and analysed for all patients as part of secondary objective analyses.
Interventions
OTHERFDG PET
Brain FDG PET performed 3 months after treatment initiation
Sponsors
Assistance Publique - Hôpitaux de Paris
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Age ≥ 18 years old * Newly diagnosed autoimmune encephalitis based on at least 1 of the 3 following criteria : 1. Definite limbic autoimmune encephalitis according to 2016 Graus et al. criteria 2. Possible autoimmune encephalitis according to 2016 Graus et al. criteria AND typical autoantibody detected in serum or CSF 3. Probable or certain paraneoplastic neurological syndrome according to Graus et al. 2021 criteria (excluding peripheral neurological syndromes) * Less than 6 months since first neurological symptoms imputable to autoimmune encephalitis * Affiliated or entitled to a social security system (except AME) * Obtaining free, written and informed consent (patient or legal representative or the close relative)
Exclusion criteria
* History of brain tumor, head trauma, infarction or cerebral hematoma likely to result in altered cerebral carbohydrate metabolism on PET * Patients who hae been on immunotherapy (corticosteroid bolus, IVIg, plasma exchange, endoxan, rituximab or other immunotherapy) fr more than 10 days * Pregnant or breast-feeding woman * Ventilated intubated patient * Absolute contraindication to MRI (Pacemaker, cochlear implant, etc.) * Presence of cognitive disorders incompatible with goog cooperation with the PET scan * Algic or agitated patient unable to remain immobile in supine position for 30 minutes * Deprived of liberty or under a protective measure (guardianship or curatorship) * Patient taking part in other interventional research involving radiopharmaceutical injections
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Main analysis of initial brain FDG PET | PET performed at the acute phase, before immunomodulating treatment (or within 10 days of treatment initiation) | Automated region-based and voxel wise quantitative PET analysis, estimation of the proportion of patients with PET anomalies (overall and by region of interest). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Analysis of initial whole body FDG PET | PET performed at the acute phase, before immunomodulating treatment (or within 10 days of treatment initiation) | Evaluation of whole body FDG PET diagnostic performance for identifying neoplasms in paraneoplastic syndromes |
| Analysis of follow-up brain FDG PET | PET performed 3 months after treatment initiation, compared to initial brain PET | Automated region-based and voxel wise quantitative PET analysis comparatively to initial brain PET |
| Secondary analysis of initial brain FDG PET | PET performed at the acute phase, before immunomodulating treatment (or within 10 days of treatment initiation) | Subgroup PET analysis according to autoantibody subtype or seronegative status |
| Secondary analysis of initial and follow-up brain FDG PET | PET performed at the acute phase, before immunomodulating treatment (or within 10 days of treatment initiation), and follow-up PET 3 months after treatment initiation | Correlation of PET treatment response to clinical symptom treatment response |
Countries
France
Contacts
Primary ContactAurélie Kas, Pr
Outcome results
None listed