Multimodal temporal dissociation in anti-GABAA receptor encephalitis: functional recovery precedes structural resolution-a case report

Abstract

Background Anti-γ-aminobutyric acid A receptor (GABAA receptor) encephalitis is a rare but severe subtype of autoimmune encephalitis (AE), typically characterized by refractory seizures and rapidly progressive neurological dysfunction. Although structural abnormalities on magnetic resonance imaging (MRI) are frequently observed, the temporal relationships among clinical manifestations, electrophysiological changes, immune activity, and neuroimaging findings remain insufficiently characterized. Case presentation We report a 61-year-old man with anti-GABAA receptor encephalitis who underwent longitudinal multimodal evaluation. In the early stage, the patient presented with nonspecific vestibular symptoms accompanied by subtle cortical abnormalities on MRI. The disease rapidly progressed to status epilepticus and cognitive impairment. Electroencephalography (EEG) revealed widespread epileptiform discharges, while cerebrospinal fluid (CSF) analysis demonstrated inflammatory changes, and both serum and CSF were positive for anti-GABAA receptor antibodies. Following timely immunotherapy, the patient exhibited rapid clinical improvement, marked attenuation of epileptiform activity, and subsequent antibody negativization. Notably, structural MRI abnormalities persisted and resolved more slowly than clinical and electrophysiological recovery. Translocator protein positron emission tomography (TSPO-PET) using the 18F-DPA714 demonstrated increased tracer uptake in the bilateral temporo-parieto-occipital cortices, indicating persistent neuroinflammation despite clinical improvement. Conclusions This case provides longitudinal multimodal observations supporting the concept that anti-GABAA receptor encephalitis may represent a dynamic and potentially reversible disorder of network hyperexcitability rather than a purely structural inflammatory injury. The temporal dissociation between functional recovery and delayed structural resolution highlights the critical value of multimodal monitoring, particularly EEG and immunological biomarkers, in assessing disease activity and guiding immunotherapy.