Case report

A 64-year-old female was referred to the acute medical team in view of new onset confusion. Over 12 h, the patient had become confused and aggressive, necessitating admission. There were no preceding symptoms or recent medication alterations.

On admission, the patient was very agitated and had a Glasgow Coma Scale (GCS) of 9. There was no fever or meningism. An extensive macular and urticated eruption was noted. Neurological and general examinations were normal. Treatment with acyclovir and ceftriaxone was commenced empirically.

The following tests were normal: C-reactive protein, erythrocyte sedimentation rate, white cell count, serum electrolytes and full-body CT scan. MRI head was normal with no medial temporal lobe signal change. EEG showed generalised slowing without focal epileptiform activity. Cerebrospinal fluid (CSF) examination revealed an acellular, mildly raised protein (0.8 g/dl), and the polymerase chain reaction was negative for herpes simplex virus, varicella zoster virus and enterovirus. Urine, CSF and blood cultures yielded no growth. Autoimmune screen showed negative voltage gated potassium-channel antibodies (VGKCAb), N-methyl d-aspartate receptor antibodies, paraneoplastic antibodies (Hu, Yo, Ri, CRMP5 and Ma2), antinuclear antibodies, rheumatoid factor and positive cytoplasmic antinuclear neutrophil cytoplasmic antibodies but negative MPO and PR3 antigen tests.

On day 3 of admission, the patient suddenly deteriorated. The GCS dropped to 5, and temperature rose to 38.4°C. Intensive care unit (ICU) admission was necessary for intubation and …