Discussion:
We are reporting, a case with unilateral, isolated abducens nerve palsy in a patient with no known prior co-morbidities, and a mild COVID-19 pneumonia.
Unilateral abducens palsy is the most common type of isolated ocular motor nerve palsies possibly due its small size and long course1,4, this also hold true for post COVID-19 infection. A workup to exclude more serious causes such as increased intracranial pressure, stroke, infectious causes, and cerebral vein thrombosis, with stroke and CVT being more suspected than usual in patients with COVID-19, especially with the increasing reports about the thrombogenic potential of the virus1,5. While the neurological manifestations of COVID-19 are still being explored, it seems to be more frequent in severe COVID-19 pneumonia unlike our case which was mild. Furthermore, the acellular, aseptic CSF seen in our case is similar to what Gutierrez et al.1,6 has reported although the difference that our patient had no ageusia or anosmia .
Neurological injury has been previously described in SARs-CoV and MERS-CoV patients1,7. The mechanism of injury is postulated to be through either widespread inflammation, or direct viral invasion of the neuroepithelium and gaining access the central nervous system through the olfactory nerve and olfactory bulb, (anosmia is present in up to 60% of the cases)1,8 , or piggybacking on retrograde axonal transport through other cranial nerves1,9.