Three individuals aged 35, 45, and 58 years recently developed Parkinson symptoms following COVID-19 infection, indicating that COVID-19 might increase risk of Parkinson’s disease (PD). PD is characterized by the depletion of brain neurons that produce the neurotransmitter dopamine, leading to symptoms like hand tremor, slow movement, stiffness, or loss of balance.
Two of the three individuals responded with reduced Parkinson symptoms after receiving traditional dopamine medication, and the third patient recovered spontaneously. In all three individuals, brain imaging revealed reduced function (similar to PD) of the nigrostriatal system, a set of brain neurons that synthesize and release dopamine.
Three explanations were proposed. First, vascular damage and increased blood clotting have been reported to develop in the brain with severe COVID-19 cases. This could damage the nigrostriatal system. Second, the inflammation caused by COVID-19 could trigger destruction of dopamine neurons. Third, the SARS-CoV-2 virus may directly infect brain neurons.
Although acute parkinsonism following COVID-19 infection appears to be rare, SARS-CoV-2 spread may lead to more patients developing PD later in life, especially because they will also have aged. Therefore, it is important to monitor large cohorts of patients affected by COVID-19 because of the initial infection’s drastic long-term implications.