Long COVID (L-C19) leads to significant consequences and affects the quality of life of patients and their families as well. Thus, the most common neurological symptoms are headache, brain fog, sleep disturbances, chronic fatigue, forgetfulness, and even more serious conditions, such as balance disorders, anxiety, and depression. Headache is the earliest and most common symptom of L-C19 and is sometimes accompanied by vomiting or nausea. Patients often report difficulties with concentration and learning and a reduced efficiency in daily activities. Even though this disorders may be caused by an acute illness, biochemical changes caused by SARS-CoV-2 in the nervous system can be an important factor. L-C19 also affects the peripheral nerves, leading to paraesthesia, muscle aches, and weakness throughout the body. The duration of these symptoms is often unknown, and the treatment is predominantly symptom-based and difficult to predict. Other dysfunctions may include dysautonomia, a condition affecting the autonomic nervous system, responsible for regulating automatic processes such as heart rate, blood pressure, and digestion. This disruption may lead to symptoms like dizziness and fatigue, is often accompanied by neuropsychiatric challenges, and can alter cerebral blood flow, contributing to light-headedness, trouble focusing, and emotional instability. Furthermore, the SARS-CoV-2 virus may disrupt mitochondrial function, an important component of cellular energy production. Mitochondrial dysfunction can manifest as fatigue, cognitive challenges, and mood disorders, given the brain's sensitivity to shifts in energy metabolism.
Acknowledgement: This work was supported by a grant of the Ministry of Research, Innovation and Digitization, under the Romania’s National Recovery and Resilience Plan Funded by the EU "Next Generation EU” program, project "Artificial intelligence-powered personalized health and genomics libraries for the analysis of long-term effects in COVID-19 patients (AI-PHGL-COVID)", number 760073/23.05.2023, code 285/30.11.2022, within Pillar III, Component C9, Investment 8.