Out-of-body experiences linked to neural instability and biases in body representation

Although out-of-body experiences (OBEs) are typically associated with migraine, epilepsy and psychopathology, they are quite common in healthy and psychologically normal individuals as well. However, they are poorly understood. A new study, published in the July 2011 issue of Elsevier's Cortex, has linked these experiences to neural instabilities in the brain's temporal lobes and to errors in the body's sense of itself — even in non clinical populations.

Dr Jason Braithwaite from the Behavioural Brain Sciences Centre, School of Psychology, University of Birmingham, has been investigating the underlying factors associated with the propensity for normal healthy individuals to have an OBE. As well as informing the scientific theories for how such hallucinations can occur, studying these unusual phenomena can also help us to understand how normal "in-the-body" mental processes work and why, when they break down, they produce such striking experiences.

Dr Braithwaite tested a group of individuals, including some "OBEers," for their predisposition to unusual perceptual experiences, and found that the OBEers reported significantly more of a particular type of experience: those known to be associated with neuroelectrical anomalies in the temporal lobes of the brain, as well as those associated with distortions in the processing of body-based information. The OBEers were also less skilled at a task which required them to adopt the perspective of a figure shown on the computer screen.

These findings suggest that, even in healthy people, striking hallucinations can and do occur and that these may reflect anomalies in neuroelectrical activity of the temporal lobes, as well as biases in "body representation" in the brain.


Journal Reference:

  1. Jason J. Braithwaite, Dana Samson, Ian Apperly, Emma Broglia, Johan Hulleman. Cognitive correlates of the spontaneous out-of-body experience (OBE) in the psychologically normal population: Evidence for an increased role of temporal-lobe instability, body-distortion processing, and impairments in own-body transformations. Cortex, 2011; 47 (7): 839 DOI: 10.1016/j.cortex.2010.05.002

New microsystem for better drug-testing

A University of Southampton nanoscientist is working on a new microsystem for more efficient testing of pharmaceutical drugs to treat diseases such as cystic fibrosis, MG (myasthenia gravis) and epilepsy.

Dr Maurits de Planque of ECS-Electronics and Computer Science at the University will develop a new method to investigate the ion channels that underlie these serious disorders and that are used to test the effectiveness of new drugs.

"At the moment, commercial testing of new drugs is carried out using ion channels in living cell membranes. This is a slow and difficult process, not least because producing too many channels actually kills the cells," said Dr de Planque

The researchers therefore plan to produce these ion channels without using cells, which is possible with so-called cell-free expression mixtures, and to insert the channels in a very stable artificial cell membrane which should enable faster, less expensive drug testing.

"Researchers have experimented with cell-free mixtures before, but they found that this method was not economical due to the amount of expensive biochemicals required," said Dr de Planque. "Our proposal to develop a new platform, which uses a couple of microlitres instead of millilitres, will be a very cost-effective way of doing this, particularly when the produced channel is directly inserted in a membrane for drug testing."

Dr de Planque is conducting this research over a two-year period in collaboration with biological scientists at the University of Southampton. He is Principal Investigator for the project: Microsystems for Coupled Expression and Electrophysiology of Ion Channels, which has been awarded a grant of £125,000 from the Engineering and Physical Sciences Research Council (EPSRC).

Master switch for adult epilepsy discovered

UC Irvine and French researchers have identified a central switch responsible for the transformation of healthy brain cells into epileptic ones, opening the way to both treat and prevent temporal lobe epilepsy.

Epilepsy affects 1 to 2 percent of the world's population, and TLE is the most common form of the disorder in adults. Among adult neurologic conditions, only migraine headaches are more prevalent. TLE is resistant to treatment in 30 percent of cases.

UCI neurologist and neuroscientist Dr. Tallie Z. Baram and her colleagues found that TLE manifests after a major reorganization of the molecules governing the behavior of neurons, the cells that communicate within the brain. These alterations often stem from prolonged febrile seizures, brain infections or trauma.

"This discovery marks a dramatic change in our understanding of how TLE comes about. Previously, it was believed that neurons died after damaging events and that the remaining neurons reorganized with abnormal connections," said Baram, the Danette Shepard Chair in Neurological Studies. "However, in both people and model animals, epilepsy can arise without the apparent death of brain cells. The neurons simply seem to behave in a very abnormal way."

To learn why, Baram's UCI team collaborated with a French group led by Christophe Bernard of the University of Marseille and Inserm. They focused on ion channels, molecules that straddle the boundaries of brain cells and govern how they fire and communicate among themselves.

Specifically, they explored an ion channel called HCN1 — which is suppressed in response to brain seizures, injuries and infections that lead to epilepsy — hoping to find the long-sought mechanism that triggers epileptic activity in previously normal brain cells.

In their study, which appears online in the Annals of Neurology, the researchers reveal that mechanism: The HCN1 channel gene and about three dozen other important genes are altered by a major cellular repressor called NRSF, which increases after events that give rise to epilepsy.

NRSF proteins work by attaching to the DNA of selected genes and shutting them down, causing neurons to fire abnormally and promoting the development of epilepsy. This was discovered when Baram and her colleagues prevented NRSF from linking to HCN1 and other NRSF-regulated genes, the development of epilepsy was markedly lessened.

This NRSF binding process is an example of epigenetics — enduring changes to gene expression without changes to the DNA sequence. Baram said the study is the first to show the significance of epigenetic mechanisms in the formation of epilepsy. The findings also point to NRSF having a larger role in influencing brain activity.

"NRSF operates like a master switch on many genes affecting neuron function," said Shawn McClelland, UCI researcher and study co-author. "And if its levels increase, it can provoke changes lasting for years."

"We're quite excited about this discovery," Baram said. "Understanding how previous brain infections, seizures or injuries can interact with the cellular machinery to cause epilepsy is a crucial step toward designing drugs to prevent the process. We don't want to just treat people with epilepsy. We hope to develop medicines that will prevent epilepsy from occurring — and influence the lives of millions of people around the globe."


Journal Reference:

  1. Shawn McClelland, Corey Flynn, Celine Dubé, Cristina Richichi, Qinqin Zha, Antoine Ghestem, Monique Esclapez, Christophe Bernard, Tallie Z. Baram. Neuron-restrictive silencer factor-mediated cyclic nucleotide gated channelopathy in experimental temporal lobe epilepsy. Annals of Neurology, 2011; DOI: 10.1002/ana.22479

Neuroscientists' discovery could bring relief to epilepsy sufferers; Computational model of epileptic seizures at molecular level

Researchers at the University of California, Riverside have made a discovery in the lab that could help drug manufacturers develop new antiepileptic drugs and explore novel strategies for treating seizures associated with epilepsy — a disease affecting about two million Americans.

Neurons, the basic building blocks of the nervous system, are cells that transmit information by electrical and chemical signaling. During epileptic seizures, which generally last from a few seconds to minutes and terminate spontaneously, the concentrations of ions both inside the neuron and the space outside the neuron change due to abnormal ion flow to and from neurons through ion "channels" — tiny gateways that are embedded to the surface of the neuron.

Ordinarily, intracellular (inside the cell) sodium concentration is low compared to extracellular sodium (the reverse is true of potassium). During seizure, however, there is a buildup of intracellular sodium, with sodium ions moving into neurons from the extracellular space, and potassium ions doing the opposite.

To understand exactly how neurons function during epileptic seizures, Maxim Bazhenov, an associate professor of cell biology and neuroscience, and Giri P. Krishnan, a postdoctoral researcher in his lab, developed and used realistic computer simulations in their analyses and found that while there is a progressive and slow increase in intracellular sodium during seizure, it is this accumulation of intracellular sodium that leads to the termination of the seizure.

"According to our model, sodium concentration reaches a maximum just before the seizure terminates," Bazhenov said. "After seizure initiation, this intracellular sodium buildup is required to terminate the seizure."

The researchers' computational model simulates the cortical network. (The cortex is the outer layer of the cerebrum of the mammalian brain. A sheet of neural tissue, it is often referred to as gray matter.) The model simulates neurons, connections between neurons, variable extracellular and intracellular concentrations for sodium and potassium ions and variable intracellular concentrations for chloride and calcium ions.

Bazhenov explained that conventional antiepileptic drugs are commonly designed to target various sodium channels in order to reduce their activity.

"These drugs essentially slow down the intracellular build-up of sodium, but this only prolongs seizure duration," he said. "This is because seizure duration is affected by the rate of intracellular sodium accumulation — the slower this rate, the longer the seizure duration."

According to Bazhenov, targeting the sodium channels is not the best approach for drugs to take. He explained that even for drugs to increase the activity of the sodium channels (in order to reduce seizure duration) there is an undesirable effect: seizures become more likely.

"The drugs ought to be targeting other ion channels, such as those responsible for the buildup of intracellular chloride," he advises. "According to our model, restricting the chloride increase would lead to a faster termination of seizure and can even make seizures impossible."

Bazhenov and Krishnan's model also shows that the occurrence of seizures depends critically on the activity of ionic "pumps" — structures that are also embedded to the surface of neurons. These pumps help remove the sodium and chloride ions from inside the neurons and critically influence their concentrations in the brain.

Study results appear in the June 15 issue of The Journal of Neuroscience.

The research was supported by a grant to Bazhenov from the National Institutes of Health.

Epilepsy is a chronic neurological condition characterized by recurrent seizures — involuntary changes in body movement or function, sensation, awareness or behavior. The seizures are caused by abnormally excited electrical signals in the brain. It is estimated that about 10 percent of people will experience a seizure some time during their lifetime; about 3 percent will have had a diagnosis of epilepsy by age 80. Epilepsy cannot be transmitted from person to person. No definite cause for epilepsy has been identified.


Journal Reference:

  1. Giri P. Krishnan, Maxim Bazhenov. Ionic Dynamics Mediate Spontaneous Termination of Seizures and Postictal Depression State. The Journal of Neuroscience, 2011; 31 (24): 8870-8882 DOI: 10.1523/%u200BJNEUROSCI.6200-10.2011

Unique nerve-stimulation treatment proves effective against drug-resistant epilepsy, study suggests

Medications are the mainstay of treatment for epilepsy, but for a considerable number of patients — estimated to be as many as 1 million in the U.S. — drugs don't work. These patients suffer from a type of epilepsy known as refractory or drug-resistant epilepsy, in which drugs can't control their seizures.

But at an epilepsy conference last month, Dr. Christopher DeGiorgio, a UCLA professor of neurology, presented the results of a non-invasive, non-pharmaceutical treatment that shows promise in controlling seizures.

In his talk at the Antiepileptic Drug Trials XI Conference in Miami, Fla., DeGiorgio reported the results of a Phase 2 clinical trial of a new treatment called trigeminal nerve stimulation (TNS). He noted that 40 percent of the patients receiving TNS treatment experienced a significant improvement in seizure reduction.

The external stimulator, which is about the size of a large cell phone, attaches to a belt or can slip into a pocket. Wires from the stimulator are passed under the clothing and connected to conductive pads attached to the forehead. The electrodes, which can be covered by a cap or scarf, transmit a signal to the trigeminal nerve, which extends into the brain from the face and forehead and is known to play a role in seizure inhibition.

"TNS offers potential benefits — it can be delivered bilaterally (to both sides of the brain) and at high frequencies," DeGiorgio said. "Since the electrical energy does not travel directly into the brain, TNS provides a safe method of brain modulation."

The clinical trial showed that at the end of the 18-week study, 40 percent of patients receiving TNS experienced a significant improvement in seizure reduction, which is defined as a 50 percent or greater decrease in the frequency of seizures.

"We showed that TNS works well, under stringent clinical-trial conditions. The fact that 40 percent showed a clinically-meaningful response is exciting," DeGiorgio said.

These results confirm and extend the findings of DeGiorgio's positive Phase 1 trial in epilepsy, reported in 2009 in the journal Neurology.

In addition, the researchers found that the TNS treatment also improved the mood of the participants. Since depression is a common problem in people with epilepsy, this finding could have significant impact on the quality of life of people who suffer from the disorder.

DeGiorgio, lead inventor of TNS, was the principal investigator for the Phase 2 study, which was conducted at Olive View-UCLA Medical Center and the University of Southern California.

"I'm encouraged to see that our non-invasive and safe approach to neuromodulation compares favorably to pharmaceutical and surgically implanted-device therapies of drug-resistant epilepsy," he said.

The research was funded by the Epilepsy Therapy Project; the Epilepsy Foundation; Boston Scientific; and the Milken Family Foundation. UCLA's Office of Intellectual Property executed an exclusive worldwide license for TNS with NeuroSigma, Inc., a Los Angeles-based medical technology company. DeGiorgio is a consultant with NeuroSigma but has no equity interest in the company.

Prenatal use of newer antiepileptic drugs not associated with increased risk of major birth defects, study finds

Use of newer-generation antiepileptic drugs, which are also prescribed for bipolar mood disorders and migraine headaches, during the first trimester of pregnancy was not associated with an increased risk of major birth defects in the first year of life among infants in Denmark, according to a study in the May 18 issue of JAMA. Older-generation antiepileptic drugs are associated with an increased risk of birth defects.

"Epilepsy during pregnancy is a therapeutic challenge. Since the 1990s, the number of licensed antiepileptic drugs has substantially increased, but safety data on first-trimester use of newer-generation antiepileptic drugs and birth defects are limited," according to background information in the article.

Ditte Molgaard-Nielsen, M.Sc., and Anders Hviid, M.Sc., Dr.Med.Sci., of the Statens Serum Institut, Copenhagen, Denmark, conducted a study to analyze the association between the use of lamotrigine, oxcarbazepine, topiramate, gabapentin, and levetiracetam (newer-generation antiepileptic drugs) during the first trimester of pregnancy and the risk of any major birth defects. The study included data on 837,795 live-born infants in Denmark from January 1996 through September 2008. Individual-level information on dispensed antiepileptic drugs to mothers, birth defect diagnoses, and potential confounders (factors that can influence outcomes) were ascertained from nationwide health registries.

Among the live births included in the study (837,795), 19,960 were diagnosed with a major birth defect (2.4 percent) during the first year of life. Among 1,532 pregnancies exposed to lamotrigine, oxcarbazepine, topiramate, gabapentin, or levetiracetam at any time during the first trimester, 49 infants were diagnosed with a major birth defect (3.2 percent) compared with 19,911 infants (2.4 percent) among 836,263 unexposed pregnancies. After adjusting for various factors, the authors found that exposure to lamotrigine, oxcarbazepine, topiramate, gabapentin, or levetiracetam at any time during the first trimester was not associated with an increased risk of major birth defects. Gabapentin and levetiracetam exposure during the first trimester was uncommon.

The prevalence odds ratios for any major birth defects after exposure to any newer-generation antiepileptic drugs during the first trimester were not statistically different for mothers with epilepsy, mood affective disorder or migraine, or without a diagnosis.

"Our study, to our knowledge, is the largest analytic cohort study on this topic and provides comprehensive safety information on a class of drugs commonly used during pregnancy. The use of lamotrigine and oxcarbazepine during the first trimester was not associated with moderate or greater risks of major birth defects like the older-generation antiepileptic drugs, but our study cannot exclude a minor excess in risk of major birth defects or risks of specific birth defects. Topiramate, gabapentin, and levetiracetam do not appear to be major teratogens [an agent that can cause malformations in an embryo or fetus], but our study cannot exclude minor to moderate risks of major birth defects," the authors conclude.


Journal Reference:

  1. D. Molgaard-Nielsen, A. Hviid. Newer-Generation Antiepileptic Drugs and the Risk of Major Birth Defects. JAMA: The Journal of the American Medical Association, 2011; 305 (19): 1996 DOI: 10.1001/jama.2011.624

Common genetic cause of autism and epilepsy discovered

Researchers from the CHUM Research Centre (CRCHUM) have identified a new gene that predisposes people to both autism and epilepsy.

Led by the neurologist Dr. Patrick Cossette, the research team found a severe mutation of the synapsin gene (SYN1) in all members of a large French-Canadian family suffering from epilepsy, including individuals also suffering from autism. This study also includes an analysis of two cohorts of individuals from Quebec, which made it possible to identify other mutations in the SYN1 gene among 1% and 3.5% of those suffering respectively from autism and epilepsy, while several carriers of the SYN1 mutation displayed symptoms of both disorders.

"The results show for the first time the role of the SYN1 gene in autism, in addition to epilepsy, and strengthen the hypothesis that a deregulation of the function of synapse because of this mutation is the cause of both diseases," notes Cossette, who is also a professor with the Faculty of Medicine at the Université de Montréal.

He adds that "until now, no other genetic study of humans has made this demonstration."

The different forms of autism are often genetic in origin and nearly a third of people with autism also suffer from epilepsy. The reason for this comorbidity is unknown. The synapsin gene plays are crucial role in the development of the membrane surrounding neurotransmitters, also referred to as synaptic vesicles. These neurotransmitters ensure communication between neurons. Although mutations in other genes involved in the development of synapses (the functional junction between two neurons) have previously been identified, this mechanism has never been proved in epilepsy in humans until the present study.

The results of the present study were published in the latest online edition of Human Molecular Genetics. They provide the key to a common cause of epilepsy and autism and will make it possible to gain a better understanding of the pathophysiology of these devastating diseases that seriously perturb brain development. They will also contribute to the development of new treatment strategies.

Facts and figures relating to autism and epilepsy in Canada

Invasive development disorders, also called the autism spectrum, include five diagnoses: autism, the most well known; RETT syndrome; childhood disintegrative disorder; Asperger syndrome; and unspecified pervasive developmental disorder. It is estimated that 60 to 70 people (including 10 children) out of every 10,000 people are affected by pervasive development disorders in Canada.

Epilepsy affects around 85 out 10,000 people in Canada. There are several kinds of epileptic seizures and syndromes.

About the study

SYN1 loss-of-function mutations in ASD and partial epilepsy cause impaired synaptic function. Anna Fassio, Lysanne Patry, Sonia Congia, Franco Onofi, Amélie Piton, Julie Gauthier, Davide Pozzi, Mirko Messa, Enrico Defranci, Manuela Fadda, Anna Corradi, Pietro Baldelli, Line Lapointe, Judith St-Onge, Caroline Meloche, Laurent Mottron, Flavia Valtorta, Dang Khoa Nguyen, Guy A. Rouleau, Fabio Benfenati. Human Molecular Genetics.


Journal Reference:

  1. A. Fassio, L. Patry, S. Congia, F. Onofri, A. Piton, J. Gauthier, D. Pozzi, M. Messa, E. Defranchi, M. Fadda, A. Corradi, P. Baldelli, L. Lapointe, J. St-Onge, C. Meloche, L. Mottron, F. Valtorta, D. K. Nguyen, G. A. Rouleau, F. Benfenati, P. Cossette. SYN1 loss-of-function mutations in ASD and partial epilepsy cause impaired synaptic function. Human Molecular Genetics, 2011; DOI: 10.1093/hmg/ddr122

Potassium channel gene modifies risk for epilepsy

Vanderbilt University researchers have identified a new gene that can influence a person's risk for developing epilepsy. The findings, reported in the March 29 Proceedings of the National Academy of Sciences, could improve molecular diagnostic tools and point to novel therapeutic targets for epilepsy.

The gene, KCNV2, codes for a unique type of potassium channel, a protein that participates in the electrical activity of nerve cells. Disturbed electrical activity in the brain — and resulting seizures — are hallmarks of epilepsy, a group of disorders that affects about 1 percent of the world's population.

A number of genetic mutations that cause inherited epilepsies have been identified. But the clinical severity of inherited epilepsies varies widely — from mild childhood seizures that resolve with age to severe lifelong seizures — even in individuals who have the same single-gene mutation, said Jennifer Kearney, Ph.D., assistant professor of Medicine in the Division of Genetic Medicine.

The range of clinical severity "tells us that there are other factors that contribute," she said. "We think that susceptibility and resistance genes that are inherited in addition to the primary mutation are probably a major factor."

Identifying susceptibility and resistance genes may suggest new targets for drugs that fine-tune neuronal excitability, rather than dampening it completely as many current antiepileptic drugs do, Kearney said.

The investigators began to look for these types of "modifier" genes after they made a curious observation in a mouse model of epilepsy — that epilepsy severity depended on the genetic background strain of the mice.

They were studying mice with an epilepsy-causing gene mutation in a sodium channel, a protein that is important for neuronal excitability. The mice had spontaneous, progressive seizures and a reduced lifespan. But when the researchers "moved" the gene mutation into mice with a different genetic background (using breeding strategies), the epilepsy became less severe: the mice developed seizures later and had improved survival.

Using genetic strategies, the investigators zeroed in on two chromosome regions that influenced the difference in epilepsy severity in the two mouse strains. In one of these regions, the mouse Kcnv2 gene (the mouse equivalent of the human KCNV2 gene) appeared to be the strongest candidate gene, based on its potential for altering electrical activity in neurons.

The current report demonstrates that increased expression of the mouse Kcnv2 gene — not changes in its coding sequence — is associated with more severe epilepsy in the susceptible mouse strain. Increasing Kcnv2 expression in the resistant mouse strain caused these mice to develop more severe symptoms, supporting the gene's contribution as an epilepsy modifier.

The investigators then screened 209 pediatric epilepsy patients for variations in KCNV2 and found two different variations in two unrelated patients.

Colleagues in the laboratory of Alfred George Jr., M.D., director of the Division of Genetic Medicine, conducted electrophysiology studies in cells to examine how the two variations affected the function of the potassium channel. They found that both variations suppressed a type of potassium current that normally dampens excitability in neurons.

"The mutations make a neuron more excitable, so you could have longer periods of excitation and also repetitive excitation (that leads to seizures)," Kearney said.

The team plans to screen additional patients with epilepsy to assess the incidence of variations in KCNV2. They are also collaborating with Dave Weaver, Ph.D., director of the Vanderbilt High-Throughput Screening Facility, to find compounds that target the potassium channel and may be useful therapeutics for epilepsy.

Kearney said that understanding how genes such as KCNV2 modify the clinical severity of epilepsy is important for molecular diagnostics and genetic counseling. Patients may currently learn that they have an epilepsy-causing gene mutation, but because clinical severity varies, their prognosis may not be clear.

"We need to understand how all of these different gene interactions impact the final clinical disorder to improve risk assessment and disease management in epilepsy," Kearney said.

The National Institutes of Health supported the research.


Journal Reference:

  1. B. S. Jorge, C. M. Campbell, A. R. Miller, E. D. Rutter, C. A. Gurnett, C. G. Vanoye, A. L. George, J. A. Kearney. Voltage-gated potassium channel KCNV2 (Kv8.2) contributes to epilepsy susceptibility. Proceedings of the National Academy of Sciences, 2011; 108 (13): 5443 DOI: 10.1073/pnas.1017539108

Epilepsy and coordination disorders: Important role for the cerebellum

Hereditary diseases such as epilepsy or various coordination disorders may be caused by changes in nerve cells of the cerebellum, which do not set in until after birth. This is reported by Bochum's neuroscientists in the Journal of Neuroscience. The team of Prof. Dr. Stefan Herlitze, the Chair of the Department of Zoology and Neurobiology at RUB, showed that the diseases broke out in mice if, a week after birth, they eliminated a particular protein in the cerebellum which regulates the influx of ions into nerve cells. "It's the first time that we have gained an insight into the origin of these diseases" said Prof. Herlitze. "We can now start conducting research to develop new therapeutic approaches."

Defective calcium channels as a cause of disease

Various forms of epilepsy, coordination disturbances (ataxias) and migraines are caused by mutations in the so-called P/Q-type calcium channel that controls the influx of calcium ions into the nerve cells of the brain. Dr. Melanie Mark from Prof. Herlitze's team developed an animal model in which this calcium channel could be deactivated at any time in a brain region of choice. The researchers focused on specific cells in the cerebellum (Purkinje cells) that coordinate the movements of the body. "The calcium channel is actually present throughout the entire brain," explains Dr. Mark. "It is the first time that we have been able to show that the diseases can be triggered by dysfunctional signal processing originating in the cerebellum."

Through cooperation to a new therapy

With the aid of the new mouse model, the so-called Purky mouse, Prof. Herlitze's team is now investigating the molecular basis of the diseases caused by changes in the P/Q-type calcium channel, in order to develop new therapeutic approaches. In cooperation with Prof. Dr. Timmann-Braun of the University Clinic in Essen and Prof. Dr. Klockgether of the University Clinic in Bonn, Bochum's neuroscientists want to compare their studies in the mouse model with results from patient studies. "We especially hope to help children suffering from absence epilepsy, i.e. epilepsy associated with a disturbance of consciousness," says Prof. Herlitze.


Journal Reference:

  1. M. D. Mark, T. Maejima, D. Kuckelsberg, J. W. Yoo, R. A. Hyde, V. Shah, D. Gutierrez, R. L. Moreno, W. Kruse, J. L. Noebels, S. Herlitze. Delayed Postnatal Loss of P/Q-Type Calcium Channels Recapitulates the Absence Epilepsy, Dyskinesia, and Ataxia Phenotypes of Genomic Cacna1A Mutations. Journal of Neuroscience, 2011; 31 (11): 4311 DOI: 10.1523/JNEUROSCI.5342-10.2011

Epilepsy-linked memory losss worries more patients than doctors

Patients with epilepsy worry more than their physicians do about the patients' potential memory loss accompanying their seizure disorder, according to a recent study.

In a survey, patients with epilepsy as a group ranked memory loss as their second-most important concern on a list of 20 potential medical or social concerns. Memory loss as a concern came in 12th in the frequency of responses among concerns recorded by physicians and nurse practitioners who completed the same survey.

Patients and practitioners agreed overall on three of the top five concerns: having a seizure unexpectedly, the legal right or ability to drive and seizures not being controlled. Practitioners ranked problems with medication side effects as their second-highest concern, and patients ranked being a burden to their family as their fifth-highest concern.

Both groups agreed that having a seizure unexpectedly was the No. 1 concern. Almost three-fourths of practitioners and just over half of patients ranked unexpected seizures as their biggest worry.

"In a lot of cases, there was a fair amount of overlap, but the thing that the patients had on their radar screen that practitioners didn't was the memory issue. Memory was a concern for a larger percentage of the patients than we had anticipated," said James McAuley, associate professor of pharmacy practice and neurology at Ohio State University and lead author of the study.

"Indirectly, we address memory concerns in the clinic by addressing seizures. But we don't typically sit down with a patient and say, 'Tell me about your memory.' This has heightened the awareness of our clinicians and should serve as a wake-up call to all practitioners treating people with epilepsy."

The National Institutes of Health describes epilepsy as a brain disorder affecting an estimated 2 million Americans in which clusters of nerve cells in the brain signal abnormally, causing strange sensations, emotions and behavior or sometimes convulsions, muscle spasms and loss of consciousness. In about 80 percent of patients, seizures can be controlled with medication or surgery.

The study is published in a recent issue of the journal Epilepsy & Behavior.

McAuley and colleagues collected survey responses from 257 patients seen in Ohio State's outpatient epilepsy clinic between March 2009 and February 2010, as well as from five clinicians — four physicians and a nurse practitioner — who treated those patients. McAuley practices in the clinic as a drug therapy adviser and did not participate in the survey.

The questionnaire listed 20 potential concerns of patients with epilepsy. These included the highest concerns generally agreed upon by all respondents, as well as a host of others: holding down a job or achieving desired education and employment goals, mood issues, medical costs, treatment by others and sexual health.

Respondents were asked to scan the entire list of 20 concerns and rank only their top five concerns in order from highest to lowest. The researchers documented both the frequency of responses as well as the ranks of the concerns based on their average overall scores.

The study revealed two gaps between how the two groups thought about the disorder: Patients as a group were far more concerned about memory loss than were practitioners, and practitioners demonstrated more concern about unexpected seizures than did patients.

"The mantra in our clinic is, 'No seizures, no side effects,' so uncontrolled seizures are seen as a medical concern by practitioners," McAuley said. "Patients tend to not want to have seizures because of the social stigma. An interesting point in this context is that we believe in the clinic that if we can improve seizures, we will improve memory."

In all, 71 percent of practitioners listed an unexpected seizure as their top concern, compared to 51 percent of patients. Forty-two percent of patients listed memory among their top five concerns, compared to only 21 percent of practitioners.

McAuley said that people with epilepsy know that cognition can be an issue for patients over time. There are generally four ways that memory can be affected by epilepsy: medication side effects, uncontrolled seizures, the effects of the disease itself on the brain, and associated mood disorders such as depression and anxiety.

He said that memory loss in epilepsy patients tends to be accompanied by awareness of the forgetfulness. For example, patients might know they went out to lunch a few days ago, but cannot remember what they ate.

Research has shown that drugs specifically designed to improve memory, such as those for patients with dementia, have not been effective in patients with epilepsy — this is probably because the medications act on a completely different part of the brain, McAuley noted.

Patients with epilepsy who require multiple drugs to control their seizures are at higher risk of suffering side effects as a result of the combined drugs, he added. About 15 drugs compose the arsenal of medications available to treat the disorder.

For these reasons, McAuley said, practitioners strive to prescribe medications at dose levels that can control seizures while also minimizing side effects — a sometimes daunting task. The most common side effect associated with these drugs is sleepiness, he said. This can occur with medicines designed to dampen excitation in the affected area of the brain.

"If you overshoot the dampening by applying more brake than gas, then there is a potential that the patient may be tired," he said.

Some antiepileptic medicines can also cause weight gain or weight loss.

The questionnaire's demographic data showed that 57 percent of respondents, or 147 patients, had had seizures within the last six months. Only two overall responses differed significantly based on these characteristics: Patients with controlled seizures were more likely to report the legal right or ability to drive as one of their top concerns as compared with patients with uncontrolled seizures, and patients with uncontrolled seizures were more likely to report a lack of seizure control as a concern than were patients whose seizures were controlled.

McAuley noted that he was surprised to find that the strong concern about memory crossed over both groups of patients.

"I would have anticipated that if patients are doing well, they are not worried about memory, driving, or loved ones having to take care of them because they are doing OK," he said. "That also tells us that even though they're doing OK, they know that because of the unexpected nature of seizures that it could happen tomorrow, next week or two years from now. So I guess there is still underlying anxiety that seizures may return."

The researchers concluded that overall, practitioners are aware of their patients' concerns, memory notwithstanding. Patients' five most frequent concerns matched the seven most frequent concerns listed by practitioners.

The scientists plan to delve more deeply into this area of research by exploring what causes are behind memory problems that patients do report.

"We'll try to differentiate the cause of the memory problem and that will help guide us to either increase medication doses to get better control of seizures, decrease doses to eliminate side effects, or use an antidepressant to address mood," McAuley said. "It's quite a murky area and our goal is to learn more by dissecting the reasons for memory loss."

This work was funded in part by an Undergraduate Research Scholarship from Ohio State's College of Pharmacy.

Co-authors included John Elliott, Sheri Hart, Lucretia Long, J. Layne Moore and Bassel Shneker of Ohio State's Department of Neurology and Sonia Patankar of the College of Pharmacy.


Journal Reference:

  1. James W. McAuley, John O. Elliott, Sonia Patankar, Sheri Hart, Lucretia Long, J. Layne Moore, Bassel F. Shneker. Comparing patients’ and practitioners’ views on epilepsy concerns: A call to address memory concerns. Epilepsy & Behavior, 2010; 19 (4): 580 DOI: 10.1016/j.yebeh.2010.09.001