Saturday, October 26, 2019

Blog #111: MY EPILEPSY IS CONTROLLED. WHY DO I HAVE OCCASIONAL THINKING BLANK OUTS?

   The brains of people with epilepsy are not the same as the brains of the general population. 

   A new study by Stanford University epilepsy specialists(1) found electrical activity in epilepsy patients’ brains which can explain brief lapses in thinking, perceiving and remembering even in those whose epilepsy seems to be well-controlled by medication.

   High-frequency oscillations (HFO) are subtle, transient brain recording signals that erupt up to 100 times per minute in people who do not have epilepsy. However, these HFO “buzzes” are abnormal if they occur with an onset of a seizure in epileptogenic areas of the epilepsy patient’s brain. The HFO buzzes are not abnormal if they occur in parts of the epilepsy patient’s brain that are not associated with their seizures.

   In their study, the Stanford researchers tested six patients with intractable seizures who had sensors implanted in their brains for consideration for possible epilepsy surgery. Cognitive challenges were presented to the patients for them to solve during periods when a buzz of epileptic activity was interfering with their brains’ normal processes. Several HFOs per minute were seen on EEGs but clinical seizures were undetectable to observing neurologists. The researchers suggest that these HFOs could explain cognitive complaints from otherwise “normal-appearing,” epilepsy patients whose epilepsy is “controlled.” If the HFO occurred milliseconds before a seizure-prone brain area began processing information the HFO seemed to affect cognition The HFOs lowered the accuracy and speed of the patient’s thinking, i.e., the response time, even though visible seizure activity was not observed.

   The explanation for this brief deterioration is that HFOs within that period interfere with high-frequency broadband events, or HFBs. These healthy brain events occur in brain areas that are not affected by the epilepsy focus. HFBs are associated with a brain circuit beginning to do something the brain is supposed to do, as processing visual information or recalling previous experiences. HFOs can disrupt healthy brain activity for up to one second even though clinical seizure activity is not apparent.

   A computer was trained to accurately distinguish between HFOs and HFBs. In all six patients studied, if a spontaneous HFO occurred within one second before a task-elicited HFB should have arisen, it disrupted, delayed, diminished and often completely extinguished the HFB. Testing at these times showed this event slowed responses, showed poorer recall and reduced confidence in answering memory-evoking questions.

   The important conclusion from this study is that the epileptic tissue’s performance was normal outside the window of the HFOs. For the majority of the time when seizure-prone brain tissue isn’t experiencing HFOs, the brain tissue worked well in these test patients. Researchers advised that prior to surgery for its removal, physicians should weigh that much of the time the epileptic focus that is seizure-controlled can still have significant cognitive abilities. Is surgery to remove it still the best treatment considering side-effects?

   Bruce Goldman, a science writer in the Office of Communications at Stanford University, reviewed the researchers’ scientific article.

1)      Liu S,  Parvizi J. Cognitive Refractory State Caused By Spontaneous Epileptic High-Frequency Oscillations In The Human Brain. Science Translational Medicine Vol. 11, Issue 514, 16 Oct 2019.

 


Lance Fogan, M.D. is Clinical Professor of Neurology at the David Geffen School of Medicine at UCLA. “DINGS” is his first novel. It is a mother’s dramatic story that teaches epilepsy, now available in eBook, audiobook and soft cover editions.

Thursday, September 26, 2019

Blog #110: SHE HAD A CONVULSIVE SEIZURE. DOES THAT MEAN SHE HAS EPILEPSY?


After a first-observed convulsion causing loss of consciousness with falling and shaking, it is natural to wonder, will the person have another convulsion? If so, when? Why did it happen? Is this epilepsy or just a seizure? These are questions patients, families and doctors must deal with.

Epilepsy is diagnosed when more than one seizure occurs if the seizure is not a “reactive” seizure. Reactive seizure are caused by some transient medical condition that can disappear such as infections, toxins and drugs, or temporary loss of a body organ function (e.g., liver, kidney, lung, etc.) that then heal and further seizures do not occur. When a second convulsion occurs, even if the first and this second seizure are separated by years, epilepsy is diagnosed. Epilepsy means recurrent seizures.

Epilepsy can be caused by brain injuries, strokes, tumors, infections, degenerative diseases such as Alzheimer’s disease, Multiple Sclerosis, Parkinson’s Disease, inherited conditions, and other diseases. Recognition of genetic causes of epilepsy is rising as science improves to identify abnormal genes. However, epilepsy is not common in families. Causes for approximately 50% of epilepsy cases are never found. Currently, onset of epilepsy is no longer most common in children, rather, it most commonly occurs in those over age 60. This is because we are living longer and we are susceptible to more insults to our brains.

One percent of the world-wide population has epilepsy. Approximately half of all people with epilepsy have their seizures controlled; these people can remain seizure-free if they are on the “best” anti-epilepsy drug (AED) at the “best” dosage for that individual. They must continue this medication as they are not cures. Finding this medication is a trial-and-error process of the patient working with doctors and the AEDs. Another 30% of epilepsy patients will have a seizure every few weeks to months; they have “incomplete” control. The remaining 20% of patients have “uncontrolled” epilepsy; they experience seizures each day or every few days despite taking AEDs. Epilepsy brain surgery is the most effective treatment to decrease or even cure epilepsy for people in whom no AED works. If the brain focus causing the epilepsy can be identified on various tests then attempting its surgical removal is deemed promising for marked improvement in epilepsy control or even cure.

Brain scans (to search for abnormal areas) and electroencephalograms (EEG) may identify a seizure-causing focus. Spinal taps (if infection or other brain conditions are suspected) and blood and urine tests to screen for other conditions also help doctors identify epilepsy causes.

EEGs are normal in half of all people with epilepsy because the test of multiple wires on the scalp is done for just an hour or so and the EEG abnormalities do not always occur during that time. Ambulatory EEGs (the person has EEG wires pasted on the scalp connected to a small recording device on their body as they carry out daily activities over 24 hours) may pick up abnormalities. More sophisticated testing in special labs can be done where EEGs and video cameras are used to capture abnormalities as the monitored-person lies in bed.

Pseudoseizures-involuntary, psychological, causes of “seizures”-are not rare and can complicate epilepsy diagnosis and treatment. See my past blogs on this subject at LanceFogan.com: blog #10 (March 23, 2011); Blog#49 (August 27, 2014); Blog #99 (October 26, 2018).

The diagnosis of epilepsy depends on the clinical history of searching for, and characterizing,  “spells” patients complain of along with the above testing which commonly are all normal. Ultimately, clinical judgment and the experience of your physician are crucial.




Lance Fogan, M.D. is Clinical Professor of Neurology at the David Geffen School of Medicine at UCLA. “DINGS” is his first novel. It is a mother’s dramatic story that teaches epilepsy, now available in eBook, audiobook and soft cover editions.

Monday, August 26, 2019

Blog # 109: ANOTHER STUDY SHOWS DOGS CAN SMELL WHEN SEIZURES ARE ABOUT TO BEGIN==MORE SAFETY


Researchers 1 find dogs can somehow detect a telltale scent linked to epileptic seizures. Can they be trained to warn owners when seizures are imminent? If so, this can add to the patient’s independence, confidence and safety in avoiding injury. They could then seek aid more expeditiously, too.

Dogs are known to detect odors of some cancers, diabetes and malaria. For example, the composition of exhaled breath is different in patients with lung cancer, inflammatory lung or liver disease, kidney dysfunction or diabetes.2
There is also anecdotal evidence they can sense that their owner may be about to have a seizure, though this was poorly understood until now.
Researchers in France used five dogs in a study to sniff out a scent specifically linked to a human seizure. They presented the dogs with a variety of smells taken from epileptic patients, including body odors emitted during calm activity, while exercising, and during an attack.
Three dogs identified the seizure scent 100 percent of the time, while two others sniffed out the right sample in two out of three challenges.
The results went beyond our expectations by showing that there is indeed a general odor of an epileptic seizure, the lead University of Rennes French researcher, Dr. Amelie Catala, said. We hope it will open new lines of research that could help anticipate seizures and thus get patients to seek security.
Dogs’ noses have evolved to be highly sensitive, and can detect specific organic compounds at a concentration of less than 0.001 parts per billion. The most sophisticated current electronic noses, meant to pick up potentially harmful odors that humans can't smell, have a detection threshold of around 300 parts per billion.

Catala said that while dogs had been shown previously to be able to sniff out chronic diseases, this experiment showed they could potentially diagnose acute health episodes that last just a few minutes. This constitutes a first proof that, despite the variety of seizures and individual odors, seizures are associated with olfactory characteristics. These results open a large field of research on the odor signature of seizures. Further studies will aim to look at potential applications in terms of anticipation of seizures.
The study of odors by the use of dogs constitutes a fast, low-cost, non-invasive, and effective screening method of diseases that can be difficult to identify normally, she said.


1. Catalia A, Grandgeorge M, Schaff J-, et.al. Dogs demonstrate the existence of an epileptic seizure odor in humans Scientific Reports volume 9, Article number: 4103 (2019)

2. Buszewski B., Kesy M., Ligor, T.  Human exhaled air analytics: biomarkers of diseases. Biomed. Chromatogr. BMC 21, 553–566 (2007).

 
Lance Fogan, M.D. is Clinical Professor of Neurology at the David Geffen School of Medicine at UCLA. “DINGS” is his first novel. It is a mother’s dramatic story that teaches epilepsy, now available in eBook, audiobook and soft cover editions.

Thursday, July 25, 2019

Blog #108: SUDEP—SUDDEN DEATH IN EPILEPSY―OCCURS IN ALL TYPES OF EPILEPSIES



            SUDEP, sudden death in epilepsy, has an incidence of 1-2 cases per 1,000 patients with epilepsy per year.1
            The recent tragic death of Cameron Boyce, a popular 20 year-old Disney star, has brought SUDEP and epilepsy to the public eye.
            A study reviewed 237 SUDEP cases between October 2011 and June 2017 in the North American SUDEP Registry. Subjects were ages 1-70 years, the median age was 26. Women made up 38% of the study population.2  Researchers found that night sleep, usually considered the usual situation related to SUDEP deaths, is not necessarily the most common time when SUDEP occurs. Many patients in this registry died during daytime. Additionally, the mechanism of death may not be due to an obstruction of the airways but more likely is related to cardio-respiratory phenomena.
            The study showed all ages and all epilepsy severeties are affected by SUDEP; it is not restricted to chronic poorly-controlled epilepsies. Anybody with epilepsy can experience SUDEP including patients with well-controlled or benign epilepsies, i.e., those with centrotemporal EEG spikes (the Rolandic Epilepsies that primarily occur during sleep and not while awake). The reported lifetime number of generalized tonic-clonic grand mal seizure counted in the study population ranged from zero to more than 500.
            The most notable observation in the study was that a majority of these deaths occurred in people who did NOT take their last dose of antiseizure medication. This presents a chance to minimize the risk of SUDEP. Take your medications as prescribed!
            Physicians need to discuss the risk of SUDEP with their patients, emphasizing the importance of never skipping an antiseizure medication dose. If your doctor doesn’t bring SUDEP up, YOU, the patient, should ask about it. Minimize alcohol and, additionally, get enough sleep.
            Epilepsy surgery can be curative of epilepsy if you are a candidate. Discuss this option with your doctor. The shorter time interval between the onset of your epilepsy and the epilepsy surgery can achieve better results from surgery.3


1)      Thurman DJ, Hesdorffer DC, French JA. Sudden unexpected death in epilepsy: assessing the public health burden. Epilepsia 2014;55: 1479-85.
2)      Verducci C, Hussain F, Donner E et. al. SUDEP in the North American SUDEP Registry: the full spectrum of epilepsies. Neurology 2019;93:e226-e236.
3)      Bjelivi J, Olsson I, Malmgren K, et. al. Epilepsy duration and seizure outcome in epilepsy surgery. Neurology 2019;93:e159-e166.



Lance Fogan, M.D. is Clinical Professor of Neurology at the David Geffen School of Medicine at UCLA. “DINGS” is his first novel. It is a mother’s dramatic story that teaches epilepsy, now available in eBook, audiobook and soft cover editions.