A 21-year-old Caucasian lady presented to the psychiatric ward with anxiety, agitation and an erratic speech pattern. She was treated for 'acute psychosis' with haloperidol. Two days later, she developed twitching of the eyelids with gaze fixed to the right upper quadrant. This was treated as oculogyric crisis secondary to haloperidol and treated with procyclidine. She was also commenced on olanzapine and sodium valproate. Apart from eating disorder, there was no past psychiatric illness or any family history.
For 2 weeks, she continued with pure psychiatric manifestations before developing pyrexia, tachycardia and cough. She was noted to have slow telegraphic speech and gegenhalten, but the rest of the neurological examination was normal. Soon after her conscious level dropped (Glasgow Coma Scale (GCS) 9), she was transferred to the high dependency unit with a diagnosis of aspiration pneumonia and Type 1 respiratory failure. Blood tests showed raised white blood cell (WBC) with neutrophilia and raised C-reactive protein (CRP). Chest X-radiograph was normal. Computed tomography (CT) of the head showed no abnormality, and a lumbar puncture showed a cerebrospinal fluid (CSF) WBC count of 38 (100% lymphocytes) with three red blood cells (RBCs), normal glucose and protein. Magnetic resonance imaging (MRI) of the brain was unremarkable. A transthoracic echocardiogram was normal. CT pulmonary arteriogram was suggestive of aspiration pneumonitis and features of mediastinal emphysema. Her breathing deteriorated requiring ventilation. She was given intravenous (IV) acyclovir and broad-spectrum antibiotics.
Three days later, she developed abnormal eye movements with divergence of both eyes, although pupils were equal and reactive. She had generalised hypertonia and hyper-reflexia with flexor plantar response bilaterally.
Further tests showed a weakly positive CSF polymerase chain reaction (PCR) for enterovirus but negative for herpes simplex virus, varicella zoster virus and cytomegalovirus. CSF angiotensin-converting enzyme, lactate, lactate dehydrogenase, virology and tests for tuberculosis, fungi and syphilis were negative. Monospot test for EBV was weakly positive. Thyroid functions, B12, ferritin, folic acid, autoimmune profile, HIV, antithyroid antibodies, T spot for tuberculosis, toxoplasma antibody, anti-voltage-gated potassium channel antibodies, antineuronal antibodies, anti-Purkinje antibody, cerebellar antibody and serological tests for syphilis were negative. Tumour markers were negative apart from Cancer Antigen (CA) 19-9 which was non-specifically raised at 62.8. Repeat CT and MRI of the head were normal. Electroencephalogram (EEG) showed runs of slow wave activity over both frontal areas consistent with encephalitis.
A diagnosis of a neuroinflammatory disorder was considered for which a 5-day course of IV 1 g methylprednisolone followed by oral prednisolone 60 mg once daily was given. She showed some improvement, and by the end of the third week of admission, she was alert but not following commands and had developed generalised rigidity and catatonia. She had a generalised tonic-clonic seizure following which she was treated with phenytoin. She had a tracheotomy as she remained ventilated. The results for anti-NMDA receptor antibody in the serum returned positive, and a diagnosis of 'Anti-NMDA receptor antibody-positive encephalitis' was made. Her CT of the abdomen and pelvis was normal, and fluorodeoxyglucose positron emission tomography (FDG-PET) of whole body showed no signs of malignancy.
She was given intravenous immunoglobulins (IVIGs) 0.4 mg/kg for 5 days and continued with oral steroids in a tapering dose through nasogastric tube, to which she responded slowly. Phenytoin was later changed to sodium valproate for its mood-stabilizing effect. The patient continued to improve. One week later, psychiatrist review documented delusional beliefs with persecutory paranoid ideation. She was given another dose of IVIG, IV methylprednisolone for 5 days.
She continued to improve in the rehabilitation unit with regular input from the multidisciplinary team of neurologist, psychiatrist, oncologist, dietician, physiotherapist and occupational therapists and was discharged home after 3 months. She made a full recovery, and all medications were successfully withdrawn. No malignancy was found in the 2-year follow-up.
We confirm that patient's consent to report the case has been obtained. Institutional approval is not required for reporting this case.