An edit published in the British Medical Journal has stated that Covid impacts the central nervous system (CNS) which may lead to neurological disorders including stroke and isolated psychiatric syndromes.
According to the edit, some patients with covid-19 have been reported to develop various CNS abnormalities with potentially serious and long term consequences, including stroke and isolated psychiatric syndromes.
The BMJ has said that in laboratory studies, Covid is neurotropic (replicating in neurons) and has the potential to enter the CNS via angiotensin converting enzyme 2 receptors in the olfactory bulb. Whether this happens in clinical populations is unclear.
It has pointed out that postmortem studies show evidence of cerebral inflammation, and neuroimaging studies detect leukoencephalopathy and microbleeds in critically ill patients.
“While viral RNA is typically absent from the cerebrospinal fluid and postmortem brain samples, antibodies to SARS-CoV-2 have been identified in cerebrospinal fluid. Other mechanisms causing CNS dysfunction include cytokine driven inflammatory responses and wider systemic effects such as endotheliopathy, breakdown of the blood-brain barrier, and clotting abnormalities,” it reads.
Additional biological mechanisms, including autoimmunity, may be relevant to psychiatric disorders, as well as the psychological trauma of life threatening illness and pandemic related socioeconomic stressors. The relative contributions of these mechanisms to neuropsychiatric complications remain largely unknown.
As per the edit, in Covid, delirium is the most common acute neuropsychiatric syndrome and may be the sole presenting feature of covid-19 in older adults and those with dementia. Delirium is associated with poorer outcomes and is especially prevalent among patients requiring intensive care, where cognitive and behavioural abnormalities have been reported in one third of patients after discharge.
It has recommended that screening for delirium should be considered in acute cases, particularly in older adults or those with pre-existing dementia, along with close monitoring for longer term adverse outcomes such as cognitive impairment.