evidence: Conclusion Our report shows that patients’ CSF may be devoid of viral particles even when they test positive for COVID-19 on a nasal swab. Whether SARS-CoV-2 is present in CSF may depend on the systemic disease severity and the degree of the virus’ nervous tissue tropism and should be examined in future studies. [...] Our second patient is a 62-year-old woman who had an acute-onset right hemiparesis and aphasia, and her CT angiogram revealed a left middle cerebral artery occlusion, for which she underwent mechanical thrombectomy with full recanalisation. She was discharged to rehabilitation in late March 2020, but 10 days after discharge, she returned with a change in mental status, and her head CT demonstrated haemorrhagic conversion with midline shift and obstructive hydrocephalus (figure 1D) requiring a decompressive hemicraniectomy and EVD placement (figure 1E). Postoperatively, the patient remained intubated due to poor mental status. As part of evaluation for tracheostomy, the patient underwent COVID-19 testing via a nasal swab, which was positive in the absence of overt symptoms, such as persistent fever or an ARDS-like picture on chest X-ray. Since the patient continued to have an EVD in place, CSF was sent for SARS-CoV-2 testing to rule out CNS involvement, and real-time PCR was negative on two consecutive samples. Of note, the patient was retested via nasal swab 4 days after her first positive result and her nasal swab was negative for COVID-19, indicating recovery. Individual patient consent was obtained for the publication of this report.