COVID-19-induced gastrointestinal autonomic dysfunction: A systematic review

Figure 3 Mechanism of autonomic dysfunction induced by coronavirus disease 2019. The exact mechanism is not clear but could be due to the direct viral invasion of the brainstem affecting the dorsal vagal complex located in the medulla oblongata, due to the resultant cytokine storm-induced sympathetic stimulation, due to the hypoxia resulting from the lung injury causing sympathetic stimulation and parasympathetic depression, due to the down-regulation of angiotensin-converting enzyme 2 receptors causing excess angiotensin II, or as a complication of various medications used to treat coronavirus disease 2019 patients, particularly those requiring intensive care.