Autonomic Dysfunction Contributes to Impairment of Cerebral Autoregulation in Patients with Epilepsy

Abstract

Patients with epilepsy frequently experience autonomic dysfunction and impaired cerebral autoregulation. The present study investigates autonomic function and cerebral autoregulation in patients with epilepsy to determine whether these factors contribute to impaired autoregulation. A total of 81 patients with epilepsy and 45 healthy controls were evaluated, assessing their sudomotor, cardiovagal, and adrenergic functions using a battery of autonomic nervous system (ANS) function tests, including the deep breathing, Valsalva maneuver, head-up tilting, and Q-sweat tests. Cerebral autoregulation was measured by transcranial Doppler examination during the breath-holding test, the Valsalva maneuver, and the head-up tilting test. Autonomic functions were impaired during the interictal period in patients with epilepsy compared to healthy controls. The three indices of cerebral autoregulation—the breath-holding index (BHI), an autoregulation index calculated in phase II of the Valsalva maneuver (ASI), and cerebrovascular resistance measured in the second minute during the head-up tilting test (CVR2-min)—all decreased in patients with epilepsy. ANS dysfunction correlated significantly with impairment of cerebral autoregulation (measured by BHI, ASI, and CVR2-min), suggesting that the increased autonomic dysfunction in patients with epilepsy may augment the dysregulation of cerebral blood flow. Long-term epilepsy, a high frequency of seizures, and refractory epilepsy, particularly temporal lobe epilepsy, may contribute to advanced autonomic dysfunction and impaired cerebral autoregulation. These results have implications for therapeutic interventions that aim to correct central autonomic dysfunction and impairment of cerebral autoregulation, particularly in patients at high risk for sudden, unexplained death in epilepsy.

The Association of Nocturnal Seizures and Interictal Cardiac/Central Autonomic Function in Frontal Lobe Epilepsy: Heart Rate Variability and Central Autonomic Network Analysis

“…1 , 53 Frequent seizure is a risk factor of SUDEP and is associated with autonomic dysfunction. 3 HRV was observed to be lower in the refractory TLE group than in normal controls but not in those with well-controlled TLE. 54 In our study, more severe autonomic dysfunction developed in the NFLE group than in the DFLE group, although there was no significant difference in total seizure frequency between the two groups.…”

“…1 , 2 Autonomic dysfunction is a risk factor for mortality and morbidity in people with epilepsy and is closely related to Sudden Unexpected Death in Epilepsy (SUDEP). 3 SUDEP is a prevalent cause of death in epilepsy, accounting for up to 17% of all deaths in epilepsy. 4 Although the pathophysiology of SUDEP is still uncertain, autonomic dysfunction is presumed to play an important role.…”

Breath-Hold-Triggered BOLD fMRI in Drug-Resistant Nonlesional Focal Epilepsy—A Pilot Study

“…reported 81 individuals with epilepsy in which they assessed cerebral autoregulation by TCD during breath-hold maneuvers, among others. They noted a decrease in breath-holding index, autoregulation, and cerebrovascular resistance, each correlating with several measures of autonomic function, suggesting that autonomic dysfunction in individuals with epilepsy may contribute to dysregulation of cerebral blood flow [ 17 ]. More generally, Dono et al.…”

Use of Hypoxic Respiratory Challenge for Differentiating Alzheimer’s Disease and Wild-Type Mice Non-Invasively: A Diffuse Optical Spectroscopy Study

“…Monitoring the cerebrovascular reactivity (CVR) caused by supplying breathing gas or using specific breathing methods is another approach to investigating various brain diseases, including migraine [ 14 ], traumatic brain injury [ 15 ], epilepsy [ 16 ], and cerebral small vessel disease [ 17 ]. In the meantime, some animal studies have used breathing gas challenges supplying 100% O 2 gas or carbogen gas (95% O 2 gas balanced by 5% CO 2 gas) to differentiate between 3xTg, a type of AD animal model, and wild-type (WT) animals [ 18 , 19 ].…”