Neurological Disorders

Anti- NMDA Receptor Antibody Encephalitis: - A Review of Nine Patients with Clinical Presentation, Investigations, Treatment and Outcome in Singapore

Abstract

Sachdeva P, Rohit , Sharan P, Prakash K, Yip CW and See SJ

Objective: To report on epidemiology, clinical and laboratory features of patients diagnosed with anti-N-methyl-Daspartate receptor (NMDAR) encephalitis admitted to Singapore general hospital over the period of four years. This is the first study for the local population. Introduction: Anti –NMDA receptor encephalitis is a severe form of encephalitis that associates with antibodies against NMDA receptors resulting in a neuropsychiatric syndrome. It has been considered as a Paraneoplastic syndrome. Methods: Nine patients (6 female and 3 male) admitted to neurology unit from March 2010 to Oct 2013 were studied retrospectively. Diagnosis of anti-NMDA receptor antibody encephalitis was based on encephalitis plus positive CSF serology. Result: Younger age group affected more (range 16 to 65 years). Clinical presentation usually involves the triad of psychotic (100%); seizures (66%) and movement disorder (45%). Autonomic instability observed in two third (66%) of patients. Serum serology is positive only in 55% patients. CSF analysis was variable. MRI brain was largely unremarkable (77%). Tumour occurrence was seen in 66%; 83% in females, 33% in males. The outcome was favourable in two third patients with the best prognosis in female patients when the tumour was found and resected and worst in male patients with tumour unresected. Conclusion: Results are consistent with the current literature in terms of epidemiology, investigations and outcome. However, it requires the larger number of patients with longer follow-up to prove its association with a tumour in patients who has no evidence of malignancy at diagnosis.