An Unusual Case of Blackout in a COVID-19 Patient: COVID-19 Brain Fog.

This case report highlights a unique case of brain fog in a COVID-19 patient suggesting COVID-19's neurotropic nature. COVID-19 is associated with a long-COVID syndrome that presents with cognitive decline and fatigue. Recent studies show the emergence of a novel syndrome known as post-acute COVID syndrome or long COVID, which constitutes a variety of symptoms that continue for four weeks following the onset of a COVID-19 diagnosis. Numerous post-COVID patients experience both short and long-lasting symptoms affecting several organs, including the brain, which includes being unconscious, bradyphrenia, or amnesia. This long COVID status comprises of "brain fog", which, coupled with neuro-cognitive effects, has a significant role in prolonging the recovery phase. The pathogenesis of brain fog is currently unknown. One of the leading causes might be the involvement of neuroinflammation due to mast cells stimulated by pathogenic and stress stimuli. This in turn, triggers the release of mediators that activate microglia, causing inflammation in the hypothalamus. Its ability to invade the nervous system through trans-neural or hematogenous mechanisms is possibly the chief cause behind the presenting symptoms. This case report highlights a unique case of brain fog in a COVID-19 patient suggesting COVID-19's neurotropic nature and how it may lead to neurologic complications such as meningitis, encephalitis, and Guillain-Barré syndrome.