Clinico-Laboratory Profile of Autoimmune Encephalitis Amongst Children at Tertiary Care Hospital

Abstract

Introduction: The causes of encephalitis in children are numerous and is often thought to be mediated by infections, commonly viral. Children with acute encephalitis often undergo extensive testing for infectious etiologies without discovery of a causative agent. In the past 10 years growing number of non-infectious causes like autoimmune encephalitis have been identified making them one of the important causes of encephalitis in children. Hence, we planned this study.Aims and objectives of The Study: To study the clinical and laboratory profile of children with autoimmune encephalitis.Material and methods: This prospective observational study on clinical and laboratory profiles of children with autoimmune encephalitis was conducted from October 2018 to April 2020 at Indira Gandhi Institute of child health, Bengaluru. Children 1year to 18years of age attending a tertiary care super specialty children hospital who fulfil the diagnostic criteria of possible autoimmune encephalitis were considered. History clinical examination and laboratory investigations were carried out with a pre-designed proforma after obtaining the consent from the care givers. Study population were treated with the first, second- and third-line immunotherapy and followed up for 6 months.
Results: Out of 30 cases of suspected autoimmune encephalitis, 9 (30%) were serologically confirmed anti-NMDAR encephalitis and 21(70%) are seronegative. 15(50%) were males and 15 (50%) were females. Clinical symptoms were insidious in onset in 23(76%) children. Mean age of onset of symptoms was 6 y. various clinical features seen were seizures 24 (80%), movement disorders 15(50%), speech disturbances 19(63%) and psychiatric symptoms 10 (33%). sleep disturbances 7(23%) and autonomic dysfunction 3(10%). One child had preceding herpes simplex viral (HSV) encephalitis. MRI Brain was abnormal in 14(46%), cerebral atrophy in 2(14%), cystic lesion in temporal horn in 1(7%), diffusion restriction in bilateral frontal lobe in 1(7%), hyperintense signal changes in thalamus in 2(14%) and periventricular white matter signal changes in 8(57%). EEG was abnormal in 16(53%). 13 (43%) had CSF lymphocytic pleocytosis. out of 30 cases of autoimmune encephalitis 12 cases responded to iv methylprednisolone,8 cases each to IVIG and rituximab. Out of 30 cases 4 required mechanical ventilation among which 2cases were seropositive and 2 cases were seronegative AIE. Among 30 cases, 25 cases (83%) improved among which 17 cases were seronegative, and 8cases were seropositive. 3 cases left against medical advice and two children expired due to ventilator associated pneumonia each being seropositive and seronegative. Cases were followed up for 6 months. Mean duration of hospital stay was found to be 15 days. Screening for tumors was done in all and was found to be negative. Early diagnosis and initiation of immunosuppressive therapy has shown that 16(53%) cases had partial improvement, 9(30%) cases had full improvement. Hence timely initiation of immunosuppressive therapy has shown reduction in severity of the disease and improves the overall outcome of the disease. Conclusion: Clinical history and examination play an important role in diagnosis of autoimmune encephalitis. laboratory evidence of CSF analysis, autoantibody panel in serum and CSF, MRI brain as imaging modality further strengthens the diagnosis of autoimmune encephalitis. Early diagnosis and timely intervention is essential for long term outcome. However, it is never too late for diagnosing and treating this entity.