By Hai H. Hoang, MD
Assistant Professor of Clinical Neurology, Weill Cornell Medical College
Rau A, Gonzalez-Escamilla G, Schroeter N, et al. Inflammation-triggered enlargement of choroid plexus in subacute COVID-19 patients with neurological symptoms. Ann Neurol 2024; Jun 27. doi: 10.1002/ana.27016. [Online ahead of print].
The choroid plexus is a network of capillaries whose main role involves facilitating cerebrospinal fluid production and the exchange of nutrients and waste products between the central nervous system and the bloodstream. Immune cells are present near the choroid plexus. Enlargement of the choroid plexus has been noted in patients with multiple sclerosis.
The authors of this study hypothesized that there likely is enlargement of the choroid plexus in patients with COVID-19 infections. They examined the choroid plexus volumes in a cohort of subacute COVID-19 patients with neurologic symptoms compared to patients with encephalopathy triggered by an infection other than COVID-19 (control patients).
The study included 28 patients with COVID-19. Compared to the control patients, patients with COVID-19 had significantly larger choroid plexus volumes. This study demonstrates that patients with COVID-19 infection are very similar to patients with multiple sclerosis, who also were found to have an enlarged choroid plexus. The significance of this finding is uncertain.
In addition to impaired barrier function, inflammatory activation of choroid plexus cells may contribute to the development of neurological symptoms in patients with COVID-19 and also may play a role in the neurological symptoms associated with long-COVID.
COMMENTARY
This study is one of many that have been published and which tries to identify the pathological mechanisms of patients with neurologic sequelae from COVID-19, or long-COVID. Although a post-viral inflammatory syndrome is what is broadly considered to be the underlying driver for long-COVID, researchers have found it difficult to objectively quantify the various inflammatory mechanisms by which inflammation causes damage to the brain.
This study does add to the growing literature but falls short because it does not suggest any clinical implications or possible treatments for patients based on its findings. Ideally, researchers in this field might take this study and identify mechanisms by which the choroid plexus can be modified or regulated and see if this is a potential mechanism for future therapeutics.
