When the virus hits suddenly: COVID-19 mimicking a subarachnoid haemorrhage-a case report and concise review of the literature.

We report a clinical case, where COVID-19 presented with a thunderclap headache and collapse, but no fever or respiratory symptoms on initial presentation. The patient was worked up for a possible spontaneous subarachnoid haemorrhage (SAH), but had a normal CT brain and normal lumbar puncture and then very rapidly deteriorated with worsening respiratory failure and COVID-19 pneumonitis. We discuss the current evidence of neurological involvement by SARS-COV-2 and the proposed pathophysiological mechanisms underlying these presentations.