Clinical characteristics and prognostic analysis of anti-gamma-aminobutyric acid-B (GABA-B) receptor encephalitis in Northeast China

Abstract

Objective: To investigate the clinical characteristics and prognosis of anti-gamma-aminobutyric acid-B (GABA-B) receptor encephalitis.

Methods: This retrospective study enrolled nineteen patients with anti-GABA-B receptor encephalitis. Clinical manifestations, radiological and electroencephalogram features, treatment and outcomes were collected and analyzed. The neurological function was evaluated according to the modified Rankin Scale (mRS).

Results: There were eleven patients in the favorable-prognosis group (mRS ≤ 2) and eight patients in the poor-prognosis group (mRS > 2). In the favorable-prognosis group, clinical symptoms included memory deterioration (n = 10; 90.9%), epileptic seizures (n = 9; 81.8%), psychiatric disorders (n = 9; 81.8%), and conscious disturbance (n = 5; 45.5%); magnetic resonance imaging (MRI) indicated an involvement of the limbic system in three (27.3%) cases in this group. Lung cancer was detected in one patient (9.1%). After an average follow-up period of 11.7 months, four (36.4%) patients were cured, and seven (63.6%) patients showed significant improvements. In the poor-prognosis group, all patients presented with memory deterioration, epileptic seizures, psychiatric disorders, and conscious disturbance; five (62.5%) patients had convulsive status epilepticus, and five (62.5%) patients developed respiratory failure; MRI indicated an involvement of the limbic system in seven (87.5%) cases. Malignant tumors were detected in five (62.5%) patients. After an average follow-up period of 14.8 months, seven (87.5%) patients died and one (12.5%) patient remained dependent in daily life.

Conclusions: The clinical manifestations of anti-GABA-B receptor encephalitis include epileptic seizures, cognitive impairment and psychiatric disorders. Patients with convulsive status epilepticus or respiratory failure have poor outcomes. In anti-GABA-B receptor encephalitis, limbic system involvement is associated with a poor prognosis in and radiological examinations can reflect disease progression. Early diagnosis and appropriate treatment should be highlighted.

Keywords: Anti-gamma-aminobutyric acid-B receptor encephalitis; Autoantibody; Convulsive status epilepticus; Limbic encephalitis; Prognosis.

Fig. 1

Magnetic resonance imaging of Case two. a-b Magnetic resonance imaging (fluid-attenuated inversion recovery sequence; FLAIR) shows abnormal signals in the bilateral hippocampus, as indicated by the red arrows. c-d Repeated magnetic resonance imaging 7 months later shows significantly improvement

Fig. 2

Magnetic resonance imaging of Case eight. a-b Magnetic resonance imaging (FLAIR) shows abnormal signals in the left hippocampus, as indicated by the red arrow. c-d One month later, the clinical symptoms of the patient were aggravated, and repeated magnetic resonance imaging shows an enlargement of the lesion

Fig. 3

Magnetic resonance imaging of Case nineten. a On admission, magnetic resonance imaging (FLAIR) shows abnormal signals in the left hippocampus, as indicated by the red arrow. b The patient was treated with gamma globulin and methylprednisolone. Following treatment, repeated magnetic resonance imaging shows the signal abnormality was alleviated. c-d Two months later, the patient developed severe memory deterioration. Magnetic resonance diffusion-weighted imaging shows that an enlargement of the lesion to also effect the right hippocampus, as indicated by the additional red arrow