The Heart-Brain Connection in Patients with Disorders of Consciousness
Recently, there has been a growing emphasis on better understanding how the brain-heart axis works and in which way the brain may influence cardiac performances both in physiological and in pathological conditions. A new research field, named as neurocardiology, investigates the whole spectrum of cardiac syndromes, which arise as a result of a widespread or a strategic brain injury in the absence of a real ischemic heart disease. Disorders of consciousness, such as coma, vegetative state and minimally conscious state, have been recently reported to be associated with multiple medical comorbidities, also including cardiovascular manifestations like arrhythmias, arterial hypertension, and conditions of myocardial stunning. There is growing evidence that such clinical events are the consequence of an autonomic imbalance within the autonomic nervous system, with the sympathetic activation outweighing the parasympathetic one. Either a widespread anoxic brain injury or a vascular/traumatic damage in specific cortical areas, which usually slow down the activity of the sympathetic branch, may produce a wide pattern of cardiac manifestations ultimately interfering with the prognosis of patients. Investigating the cardiac behavior in patients with disorders of consciousness is mandatory in order to avoid further medical complications, prevent the secondary injury occurring in the minutes to months following the primitive brain damage, and improve survival and long-term outcomes. Moreover, the study of the brain-heart interface offers a window for a better understanding of the natural history of disorders of consciousness and the identification of chances for recovery. This is because the heart behavior, with its physiological fluctuations, may represent an indirect sign of the residual complexity of cortical-subcortical networks responsible for consciousness recovery.
KeywordsComa Vegetative state Unresponsive wakefulness syndrome Minimally conscious state Comorbidities Heart
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