Since the outbreak of Covid-19 in December 2019, the deadly respiratory virus, SARS-CoV-2 has gripped the world. With passing time, frequently increasing cases have been reporting more symptoms of Covid-19 along with its varying nature of presentation of these symptoms. It is expected that there could be a myriad of potential long-term symptoms of brain damage and cases of neurological and neuropsychiatric complications, secondary to SARS-CoV-2 infection, review report published in the Journal of Parkinson’s Disease.
The report furthers claims that this expected wave of neurological consequences of Covid-19 implicates a potential link of parkinsonism – combinational abnormal movements in Parkinson’s disease including tremor, slow movement, impaired speech or muscle stiffness – in patients with Covid-19.
Experts warn coronavirus may cause 'wave' of neurological conditions including Parkinson's disease – ABC News. Beauchamp, Leah C. et al. ‘Parkinsonism as a Third Wave of the COVID-19 Pandemic?’ 1 Jan. 2020 : doi 10.3233/JPD-202211 https://t.co/jRs7cLEYgS
— CCS Monash (@CCSMonash) September 22, 2020
In past outbreaks, numerous virus were found capable to invade brain cells, called neurotropic viruses, including polio virus, herpes simplex virus, influenza Type A virus, and all the previously reported coronaviruses. Therefore, it is crucial to understand the mechanism of viruses invading these brain cells. So far, extensively studied virus with better understanding of penetrating brain cells and the subsequent neurotropism (mechanism of virus invading brain cells), is influenza. Swine flu and avian flu have been reported to infect the mice model after entering through nasal passage. Importantly, there is a significant amount of data to support the speculation of SARS-CoV-2 virus being neurotropic.
It is clear from the detailed literature analysis that the potential effect of the novel coronavirus on the nervous system is overshadowed by the effects on respiratory system. Researchers from Melbourne, who reviewed the data, therefore propose that it is critical to screen Covid-19 patients after they have been recovered from convalescent plasma for potential long-term implications of neurological symptoms associated with the virus. Therefore, it is hypothesized based on the reviewed literature that Covid-19 virus enters the brain via nasal or stomach passage, thereby activates the subsequent cells that predispose them to enter brain cells, leading to lack of oxygen and chronic inflammation resulting in brain damage.
Till date, numerous data reports the incidence of brain damage symptoms. In China, from 214 hospitalized patients over 78 (36.4%) of Covid-19 patients exhibited neurological symptoms, such as, dizziness and headache. In another study from France, from 58 hospitalized patients up to 8 (13.8%) had brain damage symptoms while they were in ICU and up to 39 (67.2%) showed lethargy, sedation and involuntary/voluntary muscle damage. Similarly, in Spain, from 841 patients 483 (57.4%) demonstrated similar symptoms and in 197 dead people, 8 (4.1%) died of these symptoms.
“The virus can cause insult to brain cells, with potential for neurodegeneration to follow on from there,” said Professor Kevin Barnham from the Florey Institute of Neuroscience & Mental Health.
Therefore, it is imperative to acknowledge the presence of neurological symptoms due to the neurotropic potential of SARS-CoV-2. This review raises alarm of possible third wave, a silent wave of neurological symptoms that needs to be addressed as soon as possible.