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Temporal Lobe Seizures

  1. Jun 5, 2004 #1

    Ivan Seeking

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    Alright Zooby you peaked my interest about something the other day. In the thread where I mentioned driving while sleep deprived, I said that a loud buzzing sound kept waking me up. Now I know that this sound was not externally produced, and you mentioned that TLS's can cause this. So I wanted to explore this issue a bit.

    I remember when we were talking about my experiences with meditation, that is when I practiced a technique that is supposed to enable astral projection, not that I ever claimed to have left my body mind you, but I did experience something common to other practioners of this form of meditation. I was acutely aware of a deep, deep darkening in my minds eye. I felt and heard an intense rushing with the sensation of extreme upward acceleration. The sound was also pronounced.

    So first, you seem to feel that this rushing or roaring sound is typical of TLS's? How certain are you that this is an if and only if - iff - bit of logic? In other words, we know that someone having a TLS may hear a rushing sound, how certain are we that this works the other way to a significant degree? If we hear an intense rushing sound we are likely having a TLS?

    Next, I find the suggestion very interesting [seemingly unlikely] that we might be able to induce a TLS simply by concentrating. I can tell you that my form of meditation mostly involved a focused exclusion of sensory input. The techique is to rid ones mind completely of any external sensation. A strange sense of extreme weight slowly consumes the body as one becomes deeply immersed in this state. It is as if gravity has increased four or five times. Truely! Then, at the deepest level the extreme sense of acceleration came on slowly at first, and then very quickly. Inky blackness seemed to consume my vision even though my eyes were already closed and I was in bed in a dark room. I was then involuntarily catapulted to my feet from a nearly dead- sleep-like state. This was a fear reaction. I was suddenly terrified of what was happening to me. Are any of these sensations also indications of a TLS?

    I know that my experience is the normal one. This is to be expected but I didn't know this until later. So, if this is a TLS, it is something that apparently most people can learn to do at will. To me that would be quite amazing.
    Last edited: Jun 5, 2004
  2. jcsd
  3. Jun 5, 2004 #2
    The sudden loud buzzing sound is definitly on the list of simple partial seizure symptoms. All simple partials are not necessarily temporal lobe, however. You should bear the distinction in mind. Simple partials can happen anywhere in the brain.

    The rushing sound isn't necessarily the same thing as the buzzing sound. In this case there is also the possiblity something in the ears is involved. Not that I can think of anything, but I don't know much about ear conditions. I have run into mention of ear conditions recently that I'd never heard of, so there are probably many, many others I haven't and never will.

    The first time you told the story I wasn't clear that the fear you felt was in response to what was happening. I was under the impression it was fear with no known cause. Sudden fear when you can't figure out what it is you're afraid of, would be a simple partial. In your case it seems an obvious panic reaction to the freaky sensations. I didn't understand the first time.

    Recall that a seizure is the hypersynchronous firing of neurons. Thinking, on a purely biological level, is just a firing of neurons. The question is what it might take to push the normal firing of neurons to the exited hypersynchronous level. Any intense concentration such as you practised over time would train the neurons to get closer and closer to that intensity. Then, say, we come to a day in your life when your natural chemical inhibitors are on the low side, or the exiters are on the high side, and you cross the threshold. It is an avalanche or cascade situation. Every neuron that is repeatedly firing acts to entrain the neurons around it into firing at the same frequency. They are not supposed to be firing except when incited by neurotransmitters. Instead they are getting pushed into firing by the EM signals from neurons in their proximity, but to which they have no direct connection.

    That is only a crude picture of what goes on. But I hope you get the picture that when your brain seizes it is doing what it is already doing anyway, that is: neurons are firing. During a seizure the rhythm of the firing takes on a life of its own, the firing in any given individual neuron is too intense, and neaby circuits get caught up in the action.

    A couple months ago I was trying to find out exactly what is going on when one individual neuron is seizing. I have a complicated paper that explains it. To understand it I had to stop and backtrack and find out in better detail what is going on when it fires normally. That was so fascinating I got distracted by that research and never got back to the seizing neuron. I know that it starts firing repeatedly with no proper signal to fire, and that it also fires more intensly than normally, but I didn't go back and sort out what actually gets it started doing that.

    You could read up on it and grasp it pretty easily, because the chemistry is basic. It's all mineral ions. Not one compound. It's a matter of getting the picture of the unfamiliar mechanism, and the sequence of events. Neurons are something like leyden jars: there is a voltage between the outside and inside. When a neuron "fires" the outside charge moves inside the cell. Then these little pumps go to work and pump the charge back to the outside, and it is ready to fire again. Then there is this very cool process called "saltatory firing" which allows the impulse to travel down the very long axons to the next neuron.
  4. Jun 5, 2004 #3
    Stuff about seizure classifications:

    When the word "lobe" is used in naming a kind of seizure (temporal lobe seizure, frontal lobe seizure, occipital lobe seizure, parietal lobe seizure) the point is to name the location of the seizure focus. It says nothing specific about what symptoms a person might experience.

    A more informative classification is one that tells the degree to which a person's consciousness is impaired. Here you have either:

    1. Simple Partial = no impairment of consciouness at all

    2. Complex partial = pronounced defect of consciousness, but not unconscious

    3. Generalized = totally unconscious

    This second set of classifications says nothing at all about the specific location of the seizure, or the symptoms, they just characterize the level of consciousness involved.

    So, whenever I speak about simple partial seizures, all I am refering to are those in which there is no impairment of consciousness at all.

    The buzzing noise strikes me as a parietal lobe sort of symptom. I haven't happened to come across a localization of this particular symptom like I have for many others. Anyway, when the term "simple partial" is used it absolutely does not automatically mean "temporal lobe".
    Last edited: Jun 5, 2004
  5. Jun 6, 2004 #4

    Ivan Seeking

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    Still, what about the issue of potential causes? Are you saying that you don't know of any other causes, or is the sound of buzzing or rushing considered nearly diagnostic for SPS's; like a constant HF ringing is for tinnitus?
  6. Jun 7, 2004 #5
    I am definitly not saying it is considered nearly diagnostic of SPS's. It is on many lists of simple partial symptoms. I have no idea how many other lists it is on.

    If you google permutations of that symptom you may come up with two, ten, or a hundred conditions it is associated with. I don't know, I haven't tried.
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