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A seizure is basically a synchronized firing of neurons as opposed to the more common unsynchronized firing taking place during normal neural activities. However, I am uncertain if the exact technical definition of a seizure restricts this synchronized nerve activity to the brain only .

I wonder whether a wave of synchronized firing can propagate up to or occur in the area of brain controlling the blood pressure level and hence affect the blood pressure of the individual going through a seizure? Or can the impact of a seizure propagate to other areas and hence affect other functions like cardio-vascular system and hence the blood pressure? Or can neurons connected to heart, but not necessarily present in brain, exhibit synchronization as in a seizure and thereby affect the blood pressure of an individual undergoing seizure?

Summarizing my question is: can seizures affect blood pressure?

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Yes, seizures can affect autonomic function including blood pressure. Such symptoms can even result in death. Note though that not all seizures are the same: there are many different types with many different causes, and they can affect different parts of the brain. There can also be different effects before, during, and post-seizure.

The effects described seem to be more related to overall discharge rates rather than synchronous firing in the periphery per se. The autonomic nervous system does not directly control heart rate, for example, but rather modulates the rate. The heart beat or vasculature would not entrain to any sort of seizure activity, for example, because the neurotransmitters involved in autonomic regulation of heart rate and blood pressure are comparatively slow-acting relative to the rate of seizure activity (essentially those functions are taking a moving average of neural input, rather than responding specifically to each impulse).

The relationship between autonomic function and seizures need not be unidirectional, either; circulatory changes can also be triggers for seizures.

References


Devinsky, O. (2004). Effects of seizures on autonomic and cardiovascular function. Epilepsy currents, 4(2), 43-46.

Nei, M. (2009). Cardiac effects of seizures. Epilepsy currents, 9(4), 91-95.

Penfield, W., von Sántha, K., & Cipriani, A. (1939). Cerebral blood flow during induced epileptiform seizures in animals and man. Journal of Neurophysiology, 2(4), 257-267.

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  • $\begingroup$ Thanks a lot . Does this kind of synchronous firing occur in neurons in any other part of the body ,other than the brain ? $\endgroup$ – Eddie Dorphy Sep 22 '17 at 17:16
  • $\begingroup$ The brain has some network architecture that isn't really found elsewhere. You could possible make some analogies with fibrillation in the heart, but the actual structure and causes are completely different. In other nervous tissue like that of the gut, a particular synchronous rhythmic pattern is important for gut motility and digestion, and you can certainly have cramping that occurs with overly synchronous activation along a stretch of gut tissue, but again, the networks aren't constructed the same as in the brain so I think it would be a distant analogy at best. $\endgroup$ – Bryan Krause Sep 22 '17 at 18:14
  • $\begingroup$ So no known cases where a synchronous oscillation of brain propagates to other neural networks ? $\endgroup$ – Eddie Dorphy Sep 22 '17 at 20:55
  • $\begingroup$ I'd hesitate to say "no known cases" - that's a pretty big leap that I can't make (hard to prove a negative), certainly you can have rhythmic clonic muscle activity in seizures, so does that count? It just isn't how the CNS is coupled with autonomic functions that makes me think it's unlikely you would have that sort of propagation. Like if you were driving a car and rhythmically pump the gas quickly, the car is going to speed up fairly continuously, because the engine doesn't respond immediately to the accelerator press and the velocity doesn't respond immediately to the engine. $\endgroup$ – Bryan Krause Sep 22 '17 at 21:30

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