Marianna Spatola, Ruben L. Caparó Oblitas, Leslie Benson, Josep Dalmau, Ana Felipe, Thaís Armangue, Francesc Graus, Mark P. Gorman, Mar Petit-Pedrol, Maria I. Barcelo Artigues, Fernanda J. Castro, Mateus Mistieri Simabukuro, Maria R. Julià Benique, Myrna R. Rosenfeld, Institut Català de la Salut, [Spatola M] Institut d'Investigacions Biomèdiques August Pi i Sunyer, University of Barcelona, Barcelona, Spain. University of Lausanne, Lausanne, Switzerland. [Petit-Pedrol M] Institut d'Investigacions Biomèdiques August Pi i Sunyer, University of Barcelona, Barcelona, Spain. Centro de Investigación Biomédica en Red de Enfermedades Raras Madrid, Spain. [Simabukuro MM] Neurology Division, Hospital das Clínicas, São Paulo, Brazil. São Paulo University, São Paulo, Brazil. [Armangue T] Institut d'Investigacions Biomèdiques August Pi i Sunyer, University of Barcelona, Barcelona, Spain. Centro de Investigación Biomédica en Red de Enfermedades Raras Madrid, Spain. Neurology Service, Hospital Sant Joan de Déu, Barcelona, Spain. [Castro FJ] Hospital de Base, Brasília, Brazil. [Barcelo Artigues MI] Service of Neurology, University Hospital of Son Espases, Mallorca, Spain. [Felipe A] Hospital Universitari Vall d'Hebron, Barcelona, Spain., and Vall d'Hebron Barcelona Hospital Campus
Objective:To report the clinical features, comorbidities, receptor subunit targets, and outcome in patients with anti-GABAA receptor (GABAAR) encephalitis.Methods:Clinical study of 26 patients, including 17 new (April 2013–January 2016) and 9 previously reported patients. Antibodies to α1, β3, and γ2 subunits of the GABAAR were determined using reported techniques.Results:Patients' median age was 40.5 years (interquartile range 48.5 [13.75–62.35] years; the youngest 2.5 months old; 13 female). Symptoms included seizures (88%), alteration of cognition (67%), behavior (46%), consciousness (42%), or abnormal movements (35%). Comorbidities were identified in 11 (42%) patients, including 7 tumors (mostly thymomas), 2 herpesvirus encephalitis (herpes simplex virus 1, human herpesvirus 6; coexisting with NMDAR antibodies), and 2 myasthenia without thymoma. Brain MRI was abnormal in 23 (88%) patients, showing in 20 (77%) multifocal, asynchronous, cortical-subcortical T2/fluid-attenuated inversion recovery abnormalities predominantly involving temporal (95%) and frontal (65%) lobes, but also basal ganglia and other regions. Immunologic or tumor therapy resulted in substantial improvement in 18/21 (86%) assessable patients; the other 3 (14%) died (2 status epilepticus, 1 sepsis). Compared with adults, children were more likely to have generalized seizures (p = 0.007) and movement disorders (p = 0.01) and less likely to have a tumor (p = 0.01). The main epitope targets were in the α1/β3 subunits of the GABAAR.Conclusions:Anti-GABAAR encephalitis is characterized by frequent seizures and distinctive multifocal cortical-subcortical MRI abnormalities that provide an important clue to the diagnosis. The frequency of symptoms and comorbidities differ between children (more viral-related) and adults (more tumor-related). The disorder is severe but most patients respond to treatment.