Understanding Blood Pressure
The Mechanics of Heartbeat and Blood Pressure
When the heart beats, it contracts and pushes blood through the arteries to the rest of the body. This action generates pressure within the blood vessels. The pressure in the arteries during heart contractions is referred to as systolic pressure, while the pressure when the heart is at rest between beats is known as diastolic pressure.
Blood pressure measurements are expressed as a fraction, with systolic pressure listed above diastolic pressure. A reading below 90 over 60 mm Hg is classified as low blood pressure, or hypotension. Although low blood pressure may appear favorable, it can pose serious risks, leading to symptoms such as fatigue, dizziness, nausea, and fainting. In extreme cases, hypotension can be life-threatening.
Blood Pressure and Epileptic Seizures
Autonomic dysregulation can occur during and following epileptic seizures, resulting in significant fluctuations in blood pressure. Cardiovascular collapse post-seizure can result in sudden, unforeseen death.
A Study on Epilepsy Surgery and Blood Pressure
Research Overview
A recent study published in JAMA Neurology investigated the connection between brain activity and blood pressure control. Researchers from University Hospital’s Cleveland Medical Center employed modern stereotactic techniques on 12 patients undergoing invasive electroencephalogram (EEG) studies as part of epilepsy surgery. The goal was to identify brain areas implicated in regulating blood pressure.
Among these patients, four had electrodes implanted in Brodmann area 25, located in the cerebral cortex. The research revealed that electrical stimulation in this area resulted in significant and consistent reductions in systolic blood pressure.
Significance of the Findings
The findings suggest that Brodmann area 25 plays a crucial role in lowering systolic blood pressure, which carries important clinical implications for individuals with epilepsy. However, the study’s limitations include its small sample size and focus on patients with intractable epilepsy.
Greater comprehension of the brain’s influence on blood pressure regulation could pave the way for treatments aimed at preventing cardiovascular collapse and reducing the risk of sudden death in those affected by epilepsy.
Reference
Lacuey, N., Hampson, J. P., Theeranaew, W., Zonjy, B., Vithala, A., Hupp, N. J., … & Lhatoo, S. D. (2017). Cortical Structures Associated with Human Blood Pressure Control. JAMA Neurology. doi:10.1001/jamaneurol.2017.3344