trancing, entoptic phemomena and nosebleeds

[Math Is Hard]

I am studying the practice of trancing in the religious ceremonies of certain cultures, and I became curious about some of the perceptual and physical experiences that occur during the trance state. The first stage features entoptic phenomena - the shaman experiences brightly lit patterns during the first phase of altered consciousness. My teacher said this is not unlike what you might see when pressing on the corner of your eye. All I really know is that the effects are produced by the central nervous system, but I wonder what triggers this.

I have also read that nosebleeds are a very common occurrence during the trance state. I was very curious about that. I have seen people undergo the trance state and films and they sometimes shake violently. Do you think the nosebleed is related to that?

[selfAdjoint]

People who suffer from migrane headaches also experience bright lines and patterns generated by the CNS; you might look that up and see if they've localized the source.

[Math Is Hard]

Thanks, SA. I am not finding as much information as I had hoped, but maybe when I get back to work I can go into some medical databases and see if I can find more.

The occurence of entoptic phenomena at the onset of migraines seems to be very well documented, but I haven't found any studies yet about what the specific relationship is - other than a few references to the stress on the CNS from the pain.

Just out of curiosity, I did a search on migraines and nosebleeds and I found a message board for migraine sufferers and some were reporting nosebleeds during the attacks. They were unsure, however, if the nosebleed might have been caused by their migraine control medication.

My understanding is that migraine pain is caused by vasodilation in the cranial blood vessels. Perhaps this could somehow be related to blood vessels breaking in the nasal passages.

I can't help but wonder if these people who are trancing are inducing a type of migraine. Yet, they don't seem to report pain during the trance. Of course, if they are in a deep hypnotic state it is possible that they are separated from an awareness of the pain.