ETAS reduces wake time after sleep onset in healthy adults who are dissatisfied with their sleep: A randomized, placebo-controlled, double-blind crossover study.

Disorders of the nervous system encompass both the central nervous system (CNS) and peripheral nervous system (PNS), including their somatic and autonomic components, and often present with overlapping clinical features. While CNS disorders commonly manifest as headache, cognitive impairment, movement abnormalities, and gait disturbances, autonomic nervous system (ANS) involvement may result in cardiovascular, gastrointestinal, urogenital, and thermoregulatory dysfunction [,]. Emerging evidence highlights a close relationship between neurological and cardiovascular health, with both systems sharing common risk factors and pathophysiological mechanisms. Major neurological disorders, including stroke, epilepsy, Parkinson’s disease, multiple sclerosis, and Alzheimer’s disease, are frequently accompanied by cardiovascular comorbidities and varying degrees of autonomic dysfunction. These neurocardiac interactions may contribute to arrhythmias, impaired cardiac autonomic regulation, heart failure, and increased cardiovascular morbidity and mortality [-]. Headache and migraine are increasingly recognized as disorders involving complex interactions between central neural pathways and peripheral trigeminovascular and parasympathetic systems. More broadly, disturbances in sympathetic-parasympathetic balance are implicated in a range of neurological conditions and may predispose affected individuals to adverse cardiovascular outcomes. Acute neurological insults such as stroke can provoke neurohormonal activation, myocardial injury, and cardiac rhythm disturbances, whereas chronic neurological disorders and recurrent seizures are associated with persistent autonomic dysregulation and cardiovascular instability [,,]. The neurocardiac connection is further illustrated by primary autonomic disorders, including pure autonomic failure, postural orthostatic tachycardia syndrome (POTS), and related dysautonomias. These conditions commonly present with orthostatic intolerance, syncope, gastrointestinal and urogenital dysfunction, and disturbances of thermoregulation, all of which may be associated with increased cardiovascular risk and reduced quality of life [,]. Patients with epilepsy often exhibit altered autonomic regulation, reflected by abnormalities in heart rate variability (HRV) measures. These changes are commonly characterized by a relative increase in sympathetic activity and impaired autonomic balance. Growing evidence suggests that such HRV abnormalities may serve as indicators of autonomic dysfunction and have been associated with an increased risk of sudden unexpected death in epilepsy (SUDEP) [].