Over the summer, I was reading a book authored by Dr. Michael Trimble “Why Humans Like to Cry: Tragedy, Evolution, and the Brain.” For someone who is seeking to understand how psychogenic non-epileptic seizures occur, the research he discusses in the book is intriguing. The research he cites offers a sound and reasonable explanation of how these seizures are not consciously “faked” by the patients. It also offers an understandable explanation to the patients themselves who often state that they were not aware of any trigger or stress before the psychogenic seizure occurred.
In his book, Dr. Trimble begins by discussing the many emotions that humans are capable of feeling including primary emotions: fear, anger, happiness, sadness and disgust and social emotions: Shame, guilt, compassion, jealousy, awe, and revenge. He goes on to explain that events felt as emotions are triggered by external and internal bodily stimuli.
Now the book gets really interesting from a psychogenic non-epileptic seizures (PNES) perspective when he begins to talk about how there is a growing body of research that is showing that conscious awareness is not initially involved in the reactions our body has to these stimuli. He refers to the concept of NEUROPERCEPTION (electrical discharges are processed at a neuronal level) versus PERCEPTION (conscious awareness and recognition of the stimuli). He explains that neurons finish processing an event half a second before the information it processed reaches the conscious brain; this is called: Pre-attentive emotion processing. There are brain structures that are processing stimuli before any of this has reached awareness. In fact, emotional responses in the amygdala (brain structure involved in emotional and memory processing) can occur rapidly without conscious awareness, triggering responses that have not reached or been processed by the conscious mind. Therefore, a psychogenic non-epileptic seizure might easily be triggered without the person who suffers the seizure being aware of what triggered it.
Another great book is “Consciousness” by Stanislas Dehaene. In it, Dehaene details the subliminal processing/masking experiments along high resolution EEG which demonstrate at least 4 distinct markers of conscious perception. He likens all incoming stimuli to ocean waves with high power crests which dissipate to merely lap your feet at the shore, while the transition into conscious perception requires a particular synchrony, amplification, and specific anatomical geographcial spread of the brain waves generated by the stimuli which then trigger an avalanche in which the signals suddenly grow in power. He identified particular EEG signals (P3 waves, increased gamma freq, etc.) that marked the crossover from pre-conscious processing to conscious awareness. Most importantly, he noted evidence that the brain uses top-down processing to check and reinforce the validity of the bottom-up stimuli which would seem to account for the fact that observing a seizure in someone else is a variable/flag seen in NEAD patients. This includes evidence for preconscious semantic processing! Further, he briefly mentioned how subtle deficits in white matter connectivity (haven’t some been identified in NEAD?) can disrupt the functional connectivity and synchrony of brain wide networks. I am envisioning all kinds of subliminal masking experiments that could be done with NEAD patients to help identify their deficits. If only I had a lab, LOL! We’re definitely on the verge of medically defining this disorder.
This blog was recommended to me by a former colleague (and brilliant scientist I might add). It has inspired me to buy the Michael Trimble book. Trimble is an epilepsy authority, I have read a lot of his work on epilepsy and religious delusion and various papers he has written on PNES. The idea that the amygdala is an unconscious memory center is not new, and has been eloquently written about in Joseph Ledeouxs “the emotional brain.” Ledoux contrasts the conscious hippocampal memory system with the unconscious amygdala memory system. I have long thought that PNES was somehow related to amygdala dysfunction, or amygalar contributions to a broader dysfunction of the HPA axis, although this “dysfunction” has never been substantiated in any imaging or pathologic studies that I am aware of. It is worth noting that the development of the HPA axis is negatively impacted by childhood stress in ways that are idiosyncratic and can effect later stress responses in ways that are not fully understood.
What makes the differential diagnosis of mesial temporal lobe epilepsy and PNES so difficult is that both disorders may involve dysfunctional amygdala-hippocampal circuitry. Video-EEG, the gold standard, is not infallible. On at least two occasions, I have seen patients demonstrate non-epileptic seizures during their first video-EEG monitoring, and later show genuine Video-EEG confirmed seizures during a second admission. While this is extremely uncommon, it does not seem coincidental that such a high number (perhaps 10%) of individuals with temporal lobe epilepsy also have PNES.
One final thought on the often debated “conscious versus unconscious” production of PNES. This is a dichotomy that is untenable. Rarely do you see a PNES that is blatantly and unmistakably fabricated or one that is generated with no patient awareness whatsoever. PNES exist on a continuum with “fully conscious generation” and “fully unconsious generation” representing the polar extremes. The majority of the 100 or so PNES that I have witnessed fall somewhere on one side or the other of this “conscious/unconscious” continuum with very few representing one of these poles.
You are correct that the many patients have both epileptic seizures and NEAD (PNES) but that does not mean that the vEEG tests failed. The vEEG can clearly discern abnormal cortical discharges which is the medical definition of “seizure”. Ideally, a patient will undergo a series of EEGs, neuropsychological evaluations, and treatment options (CBI, meds, etc.) to ascertain the nature of their symptoms. This takes time. NEAD is a complex condition and patients with epilepsy are not immune to developing psychiatric/emotional disorders as well. I think that it’s important realize that the vEEG is the gold standard for a reason and that a negative EEG is still a valuable data point in diagnosis which should not be dismissed because it only captured an NEAD event during a particular test, in a patient who may also have epileptic events at other times.
Dx:2011 after being misdiagnosed several times. Then was refered to as having pseudo seizures. I was hospitalized. During my 3 day stay i was traumatized by being told that I was faking by an RN, because i had never urinated on myself. Then I was told that my hair had to be shaved on my head because their EEG machine was outdated and fitted like a cap . I have very long locs down to my buttucks. To cna’s came to my hosp. Rm. W/ lrg. Sissors. To cut my hair. I refused. They sent me to another hoapital 2hrs. Away frm my hm twn. My fam was worried. Once i arrived at this alledged more sofiticated hospital, no one could figure out what was my DX: especially because my speech became like Aphasia. For those 3-4 days w/o returning. EEG NORMAL. MRI OF BRAIN , NORMAL. AS OF NOW PERIODICALLY I STILL SUFFER W/ APHASIA, PNES. MEDS CONSIST OF . BENZODIAZAPINES, TOPIRAMATE, NEURONTIN, & ANTI- DEPRESSANTS.. I SUFFER W/ SEVERE HEAD ACHES. NOTHNG IS BEING DONE FOR ME. SLEEP PATTERN IS IRREGULAR. CHRONIC FATIGUE. THERES NO HOPE, OR HELP,AWAITING DISABILITY,. PYCH EVAL. NOV.7TH
Thanks for all the science backed posts. This really begins to explain why the seizures seem to start at times almost like a reflex similar to a sneeze. This kind of information is so helpful to understanding the seizures in the right perspective.
Thank you Kristine, for that excellent book recommendation.
I have not read the book but the argument as presented is not convincing. The fact that some processes occur below conscious awareness does not prove that PNES is unconscious. Drane and Williamson showed that about 56% of PNES cases failed the WMT and had a mean profile similar to simulators. True seizure cases failed much less often. This phenomenon (WMT failure) is probably a reflection of conscious choices to exaggerate impairment.
One of my PNES cases was given a 50-50 forced choice visual perception task and she got it wrong 20 times in a row. She then stated “I am not faking” and promptly had a pseudo-seizure. This looked very much like consciously controlled behaviour.
The simplest hypothesis is that such faking of cognitive impairment and the production of pseudo-seizures are both under voluntary control. One neurologist argued with me that failure on the WMT effort subtests in fibromyalgia cases is also “unconscious”. However, our paper in the Journal of Rheumatology showed that 40% of fibromyalgia cases claiming disability money failed the WMT. Those with no claim failed in only 4% of cases and those with rheumatoid arthritis did not fail at all. I doubt that the unconscious mind is so directly controlled by the potential for monetary gain.
http://wordmemorytest.com/DISCUSSIONS/Fibromyalgia_disability_SVT_failure_J_Rheumatology.pdf
WOW! Your really comparing apples and oranges here. I have been diagnosed with fibro and continued to FIGHT for 10yrs to maintain a job, I had not ever even heard the word fibromyalgia until I was diagnosed. Now, 10yrs later I “pass out” at work for 15mins only to become aware that I was on the floor but unable to respond to anyones commands. I have since 6mos later been diagnose with PNES, again, I had never heard of it before now. For you to suggest that people are faking is irresponsible! You obviously have very little to no idea what you are talking about. I have no doubt that there are people who try to fake things to get disability, but for people to post such things as your post, it just infuriates me!! When I tell someone I am diagnosed fibro I always say, “I was diagnosed BEFORE the Lyrica commercials”, simply because of people like you who may think I would be faking!!! Dr. Myers, thank you, thank you, thank you!!! You are a life saver to many!!! As if depression, anxiety, PTSD, and sexual abuse survivor wasn’t enough, now my integrity is judged as well. But thanks to you Dr. Myers, my illness is validated!
After reading a bit of the article that you are referring to, and being diagnosed with fibro, I can now say that I am even more shocked than I was in my previous comment! To think that one person, or 69 which is the case of the article, would respond in the same way simply because they have the same illness is ridiculous! Fibro has many of the same characteristics, but is very different for many of the people who have it. I myself can not tell you from day to day how I will feel tomorrow, some days are good and some are bad, and I have gotten progressively worse! My specialist told me that fibro wasn’t a progressive illness, I beg to differ, I have done nothing but gotten progressively worse since my diagnoses! And I can tell you that most people who suffer from fibro would like nothing more than to have a test that says, THERE!! There it is, you have fibromyalgia!!! It is BEYOND frustrating being looked at as lazy, or faking!! To have a test would be validation! But, with the complexities of the brain and central nervous system I doubt there will be one in my lifetime. I only WISH I was faking, then I wouldn’t have had to leave my dream job!!
Paul, Drane and Williamson’s 2006 article cannot be mentioned without also mentioning Dodrill’s 2008 article that showed that Drane’s results could not be replicated and rather seemed the result in great part of super-selection.
I will include the abstract below.
And as for the one PNES case you had with the 20 failures, I have to say that this sounds like an outlier since in over ten years I have never seen something like that on malingering testing in our PNES patients. It is unfortunate that this was your one experience with this patient group.
Epilepsia. 2008 Apr;49(4):691-5. Epub 2007 Dec 6.
Do patients with psychogenic nonepileptic seizures produce trustworthy findings on neuropsychological tests?
Dodrill CB.
Author information
Abstract
Drane et al. (2006) has recently raised the possibility that patients with psychogenic nonepileptic seizures (PNES) may make poor effort in taking neuropsychological tests in comparison with patients with epilepsy (ES). Therefore, findings previously reported with PNES patients may be in error, especially with regard to tests of mental abilities. Using the same measure of effort used by Drane et al. (2006) but with more broadly selected patients, this paper attempts to replicate their findings with new samples of ES (n = 65) and PNES (n = 32) cases. However, their findings could not be replicated, and no differences in test taking effort could be demonstrated across the groups. The highly selected samples of Drane et al. (2006) appear to be responsible for their results, and neuropsychological findings with PNES patients appear to be as trustworthy as those with ES patients.
Lorna,
I am especially excited about this research which is consistent with other studies that are being done around the world. It has to do with the mind brain connection. Dr. Jon Stone from the UK states, on his web site Neurosymptoms.com, that you cannot separate the mind from the brain. He equates our condition to a software and a hardware problem similar to a virus on your computer. We do not have a “disease” that can be quantified by examinations of the brain any more than an x ray could show you a virus in the operating system of a computer. He has an exelent part of his site where he answers the question It’s not all “in your mind”.
My daughter has had psychogenic nonepileptic seizures for 7 years. She was diagnosed at an epilepsy center in Phila. She has 2 to 3 per day but they come at the exact same time daily. I was wondering if Dr. Myers had ever heard of this. If you pat her she stays calm and wakes up in ten minutes with no recollection of the event. She gets what she calls a heartbeat 20 minutes before and then 10 minutes before. She is seeing a therapist for 2 sessions per week.