Blog #113: Some Seizures Have Transient Residual Numbness/Weakness Lasting Hours or Days. “Did I Have a Stroke?”

Occasional convulsive seizures, non-convulsive seizures and the post-ictal state (the time after the visible seizure ends but the patient is still not back to normal) can have residual focal numbness or weakness that last minutes to hours or more after the event—unlike strokes these are not associated with demonstrable brain circulatory problems. This post-ictal phenomenon is referred to as a Todd’s Paralysis which can mimic strokes causing the patient to worry, “Am I having a stroke?” However, unlike most strokes, these worrisome symptoms soon dissipate. \

Transient ischemic attacks (TIAs) can cause these same symptoms. We use the term Todd’s Paralysis when the focal symptoms are due to seizures. TIAs are associated with brain circulation interruption and often predict a future stroke. These TIA symptoms can last minutes up to 24 hours and then disappear. But, if these focal symptoms occur and then disappear after a seizure we diagnose a “post-ictal phenomenon” or Todd’s Paralysis; this is not a stroke. 

How do the patient and the doctor differentiate the post-ictal focal numbness/weakness symptoms associated with an epileptic seizure from a true brain circulatory interruption causing a TIA or a stroke? The bedside medical evaluation sometimes leads to uncertainty. Often, rapidly obtaining an electroencephalogram (EEG) to diagnose seizures is not possible. Then how do we make an accurate diagnosis? We obtain a brain CT or MRI scan.

Fortunately, the CT scan is readily available and easy to do in Western countries. The radiologist performs a CT scan and then can inject a dye-like substance into a vein. The brain CT picture is again examined for perfusion or circulatory changes highlighted by the dye; it can differentiate seizure from TIA/stroke in those patients with symptoms suggestive of stroke with focal numbness and/or weakness and/or speech problems. Loss of consciousness is usually not associated with stroke or TIA.

No focal increased flow or perfusion in the brain cortex is seen if it’s a post-ictal state affecting one side of the face/body called “lateralizing signs.” This is how doctors can make this crucial diagnosis and reassure the patient no stroke happened.

The younger the patient with post-ictal lateralizing focal symptoms/signs that is not in the typical older-adult stroke population, the more reassured everyone can be that a permanent stroke is not occurring. A past history of Todd’s Paralysis, especially in younger people with epilepsy is also reassuring against stroke.

Migraine sometimes occurs without headache and it is another condition that can mimic clinical presentation of TIA / stroke. Brain scans are usually normal in migraine, abnormal in stroke. And migraine is a repetitive clinical situation which makes differentiating Todd’s Paralysis from TIAs and Stroke, easier. Recurrent migraine usually occurs at younger ages than stroke, too.

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.

Blog # 112: ADD SEIZURES TO RISKS ASSOCIATED WITH E-CIGARETTES AND VAPING?

     Neurology Today ¹ reported that the United States Food and Drug Administration (FDA) is collecting reports of seizures associated with e-cigarettes and vaping. E-cigarettes, also known electronic cigarettes, are handheld battery-powered vaporizers that simulate smoking but without burning tobacco. Using an e-cigarette is known as "vaping." Instead of cigarette smoke, the user inhales an aerosol, commonly called vapor. E-cigarettes typically have a heating element that atomizes a liquid solution called e-liquid.^[5] E-cigarettes are automatically activated by taking a puff; others turn on manually by pressing a button. E-cigarettes contain propylene glycol, glycerin, nicotine, flavorings, additives, and differing amounts of contaminants.

     Development of serious lung problems, including deaths, is currently featured in the news. Research has not yet identified the cause of the lung malady.

     The FDA announced that since 2010, one-hundred twenty-seven cases of seizures have been reported in otherwise healthy eighth to twelfth graders, young people who had no past history of seizures or epilepsy. This youthful age-group who vape is also vulnerable to new-onset epilepsy. University of Michigan researchers reported that in 2019, more than one-in-four 12^th graders reported having vaped in the past month. Some had seizures following first-time use of the product, even after just a few puffs or up to just one day after first use. Data, currently still sparse, is being collected and reporting by physicians and the public to the FDA is necessary. Cause and effect of the seizures is not yet established. Fainting and tremors have been reported following vaping, but a direct relationship has not been determined.

     Physicians’ concerns are that we don’t know what individuals are actually vaping into their lungs. Arsenic, lead, manganese, chromium and nickel are among chemicals and toxins found in the vaping products including some products containing a nicotine intake equivalent to smoking one pack of cigarettes. The neurological complaints are, to date, few compared with the lung problems. 

     Add seizures to the risks associated with e-cigarettes/vaping. 

1. Neurology Today Vol: 19. Issue 20, October 17, 2019, page 1.

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.

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.

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.

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.