Post-surgical heart rate variability in patients with brain tumor and epileptic seizures

Aim. To identify post-surgical perculiarities of heart rate variability in patients with brain tumors and symptomatic epilepsy.

Methods. The study group consisted of 85 patients (43 males and 42 females) aged 22 to 83 years admitted to neurosurgical department of Ryazan regional clinical hospital with brain tumor. The control group consisted of 20 relatively healthy individuals. The study group was divided into 2 subgroups of patients with brain tumor associated with symptomatic epilepsy and brain tumors without epileptic seizures. Five-minute ECGs in 3 functional probes (baseline, hyperventilation and post-hyperventilation) before and after craniotomy with tumor resection were recorded. The following statistical analysis of time and frequency parameters of heart rate variability was performed.

Results. Statistically significant differences in heart rate variability in pre- and post-surgical periods were found only in patients with epilepsy syndrome caused by brain tumor: mode increased by 11% in baseline and post-hyperventilation probes. Coefficient of variation and standard deviation were decreased by 29% in hyperventilation probe, index of centralization decreased by 60% in baseline probe and by 42% in post-hyperventilation probe. Statistically significant increase of high frequency power component by 46% was registered after surgical intervention in baseline probe and by 10% in post-hyperventilation probe. As opposed to this in the subgroup of patients with brain tumors and without epilepsy this parameter decresed by 10% in baseline probe.

Conclusion. The obtained results demonstrate significant post-surgical improvement of autonomic nervous system homeostasis and restoration of cardiovascular functional reserves in patients with brain tumor associated with epilepsy compared to those with no epileptic seizures.