The role of hybrid FDG-PET/MRI on decision-making in presurgical evaluation of drug-resistant epilepsy

Background

When MRI fails to detect a potentially epileptogenic lesion, the chance of a favorable outcome after epilepsy surgery becomes significantly lower (from 60 to 90% to 20–65%). Hybrid FDG-PET/MRI may provide additional information for identifying the epileptogenic zone. We aimed to investigate the possible effect of the introduction of hybrid FDG-PET/MRI into the algorithm of the decision-making in both lesional and non-lesional drug-resistant epileptic patients.

Methods

In a prospective study of patients suffering from drug-resistant focal epilepsy, 30 nonlesional and 30 lesional cases with discordant presurgical results were evaluated using hybrid FDG-PET/MRI.

Results

The hybrid imaging revealed morphological lesion in 18 patients and glucose hypometabolism in 29 patients within the nonlesional group. In the MRI positive group, 4 patients were found to be nonlesional, and in 9 patients at least one more epileptogenic lesion was discovered, while in another 17 cases the original lesion was confirmed by means of hybrid FDG-PET/MRI. As to the therapeutic decision-making, these results helped to indicate resective surgery instead of intracranial EEG (iEEG) monitoring in 2 cases, to avoid any further invasive diagnostic procedures in 7 patients, and to refer 21 patients for iEEG in the nonlesional group. Hybrid FDG-PET/MRI has also significantly changed the original therapeutic plans in the lesional group. Prior to the hybrid imaging, a resective surgery was considered in 3 patients, and iEEG was planned in 27 patients. However, 3 patients became eligible for resective surgery, 6 patients proved to be inoperable instead of iEEG, and 18 cases remained candidates for iEEG due to the hybrid FDG-PET/MRI. Two patients remained candidates for resective surgery and one patient became not eligible for any further invasive intervention.

Conclusions

The results of hybrid FDG-PET/MRI significantly altered the original plans in 19 of 60 cases. The introduction of hybrid FDG-PET/MRI into the presurgical evaluation process had a potential modifying effect on clinical decision-making.

Trial registration

Trial registry: Scientific Research Ethics Committee of the Medical Research Council of Hungary. Trial registration number: 008899/2016/OTIG. Date of registration: 08 February 2016.

Status epilepticus 2020

Status epilepticus is the second most common neurological emergency with 15‒25% mortality rate. The principle of “time is brain” is also true for the treatment of status epilepticus: the earlier we start an adequate treatment, the more likely we are to stop progression. With treatment protocols based on high-level evidence, the progression of status epilepticus can be prevented in 75–90% of cases: we can avoid the induced coma or death. At the beginning of status epilepticus, parenteral benzodiazepine should be given immediately: intramuscular midazolam (0.2 mg/kg, max. 10 mg). In the case of easy veinous access, benzodiazepines can also be given intravenously. If the first benzodiazepine bolus does not stop the status epilepticus, we speak about established (benzodiazepine refractory) status epilepticus. In this case, a fast-acting non-benzodiazepine antiepileptic drug should be given: intravenous valproate (40 mg/kg, max. 3000 mg, within 10 minutes) or levetiracetam (60 mg/kg, max. 4500 mg, within 10 minutes). Refractory status epilepticus that persists for more than 1 hour and does not respond to either benzodiazepines or antiepileptics should be treated with general anesthesia (full narcosis). Induced coma can be achieved with fast-acting anesthetics, a combination of propofol with midazolam is the most frequently used one. Orv Hetil. 2020; 161(42): 1779–1786.

Lamotrigine Induces Tremor among Epilepsy Patients Probably via Cerebellar Pathways

Lamotrigine, a frequently used antiepileptic drug, inhibits voltage-gated sodium-channels. By suppressing the release of glutamate and aspartate, lamotrigine acts as a membrane stabilizer, and it is also effective in bipolar disorder and migraine. However, lamotrigine is known to induce tremor among 4-10% of patients. We examined the lamotrigine-induced tremor in 28 epilepsy patients (age: 38.06 ± 13.56 years; 24 females and 4 males) receiving lamotrigine monotherapy and compared the data to 30 age- and sex-matched controls (age: 33.06 ± 10.71 years; 25 females and 5 males). Tremor was visually assessed by clinical tremor rating scales. Quantitative characteristics (intensity, center frequency and frequency dispersion) which are regularly used to differentiate various tremor syndromes were measured by validated, sensitive biaxial accelerometry in resting, postural and intentional positions. Regularity of repetitive finger and hand movements and reaction time were also determined. Data were statistically analyzed. Clinical tremor rating scales detected pathological tremor in three patients (10%), while accelerometry revealed tremor in seven patients (25%). Center frequency of patients with pathological tremor was similar to controls, but the frequency dispersion was significantly lower and tremor intensity was significantly higher in both postural and intentional positions. Rhythmic movements and reaction time were normal. Our results show that objective measurements detect pathological intention tremor in 25% of epilepsy patients receiving lamotrigine monotherapy. Quantitative characteristics suggest the involvement of the cerebellum in the pathomechanism of lamotrigine-induced tremor. Determining the parameters of drug-induced tremor syndromes might help to understand the complex action of tremor generator networks.

[Assessment of health related quality of life among epileptic patients in the context of coping strategies and subjective disease perception]

Background and purpose

Psychosocial condition and life quality of epileptic patients are greatly determined by the existence of the disease-related comorbid disorders, like depression, anxiety, and the subjective disease perception, as well as the neuropsychological consequences of the seizures.It has been examined in patients living with epilepsy how subjective disease perception and coping strategies influence life quality, comorbid depression and the condition of anxiety.

Methods

Study patients were asked to fill in a self-completion questionnaire, which examined their psychosocial condition (HADS, Beck Depression Scale), life quality (Qolie-31), coping strategies (FKV-LIS), and subjective disease perception (IPQ-R), as well as sociodemographic and disease variables. The subjects of the study: the data of epileptic patients between the age of 18 to 70 was recorded. Patients were selected from the adult outpatients of a national centre, a regional hospital and two private health care centres located in Budapest.

Results

Based on the multiple regression analysis. Beck's depression (b coefficient=-0.351, t=-4.703, p<0.001**). Depressive coping strategy (FKV Dep) (b coefficient = -0.235, t=-3.123, p=0.002**). Subjective health perception (b coefficient =0.232. t=3.643, p<0.001**). Sex (women; b coefficient =-0.162, t=-3.008, p=0.003**). IPQ consequences (b coefficient =-0.161, t=-2.572, p=0.012*). Active coping strategy (FKV Act; b coefficient =0.146, t=2.572, p=0.012*). Type of seizure (b coefficient =-0.138, t=-2.527, p=0.013*), and Sleep quality (b coefficient =-0.125, t=-1.995, p=0.049) explain some 75.6% of the variance of life quality's total score (model3: F=33.333, p<0.001**. adjusted R2=0.733).

Conclusion

Among the factors of the subjective disease perception (IPQ-R), the physical, mental and social consequences play the most important role. Similarly, the impact of negative emotional representation, as well as the erratic nature of the seizures are decisive. Emotional representation, cyclicity and disease coherence have an important role in coping with disease-related negative emotions.

Factors affecting quality of life in Hungarian adults with epilepsy: A comparison of four psychiatric instruments

PURPOSE

We investigated the impact of 19 factors on life quality in Hungarian patients with epilepsy. Wellbeing was evaluated by several inventories to investigate the impact of factors in more detail.

METHODS

A cross-sectional study was performed in 170 patients. Wellbeing was evaluated with the WHO-5 Well-being Index (WHOQOL-5), Diener Satisfaction with Life Scale (SwLS), and the Quality of Life in Epilepsy-31 Questionnaire (Qolie-31). We investigated their association with demographic characteristics, general health status, epilepsy, and its treatment. The impact of these factors on illness perception (Illness Perception Questionnaire, IPQ) was also studied.

RESULTS

The four measures correlated highly significantly. In addition, the predictive power of factors was comparable with the four inventories as evaluated by Multiple Regression. Factors explained 52%, 41%, 63% and 46% in the variance of WHOQOL-5, SwLS, Qolie-31, and IPQ scores, respectively. However, associations with particular factors were instrument-specific. The WHOQOL-5 was associated with factors indicative of general health. SwLS scores were associated with health-related and several demographic factors. Neither showed associations with epilepsy-related factors. All four categories of factors were associated with Qolie-31 and IPQ scores. Factors had an additive impact on IPQ, but not on Qolie-31.

SIGNIFICANCE

Our findings reveal interactions between the method of life quality assessment and the factors that are identified as influencing life quality. This appears to be the first study that analyses the factors that influence illness perception in epilepsy patients, and suggests that the IPQ may become a valuable tool in epilepsy research.

[The role of zonisamide in the treatment of women with epilepsy]

The antiepileptic drugs can effect fertility, development of gynecological diseases and occurence of sexual problems. They can cause a number of "cosmetic" problem and also influence the selection of safe contraceptive method. Many antiepileptic drugs can cause congenital malformations or affect the new-born child's psychomotor and cognitive development, therefore during pregnancy should be treated with extreme caution in women with epilepsy. Most types of epilepsies accompany the patient through their whole life. Women spend almost the third of their lives after menopause and - due to the formation of associated diseases as well - this period is also special. According to the 2013 recommendation of International League Epilepsy (ILAE), zonisamide is one of the first-line antiepileptic drugs in focal epilepsy. In my review I discuss women's epilepsy in the viewpoint of the application of zonisamid.

[Survey of adults living with epilepsy in Hungary: health-related quality of life and costs]

BACKGROUND AND PURPOSE

Disease burden of epilepsy in Hungary is underexplored. The aim of our study was to assess the quality of life and costs of adults with epilepsy.

METHODS

Cross-sectional questionnaire survey was performed in two hospital based outpatient neurology centres involving consecutive patients with epilepsy. Demography, clinical characteristics, health status (EQ-5D) and health care utilisation in the past 12 months were surveyed. Cost calculation was performed from the societal perspective.

RESULTS

Altogether 100 patients (women 58%) were involved, their mean age was 37.6 (SD = 12.5) years. Disease duration was 15.0 (SD = 12.1) years on average and 22 (22%) patients were disability pensioners. The EQ-5D score was mean 0.83 (SD = 0.24) which is significantly lower than the age-matched population norm (p = 0.017). Pain/discomfort and anxiety/depression are the most problematic health dimensions. The annual cost per patient was mean 2421 (SD = 3249) Euros (679 397 SD = 911 783 HUF; conversion: 1 Euro = 280.6 HUF), distribution between direct medical, direct non-medical and indirect costs was 33%, 18% or 49%. Patients with seizure in the past 12 months have higher cost on avergare than the asymptomatic subsample (3119 vs. 988 Euros/patient/year; 935 481 vs. 277 209 HUF/patient/year).

CONCLUSION

Adults with epilepsy have significantly worse health status by the EQ-5D than the gender and age matched Hungarian general population. Disease related costs are significant especially in cases with seizure, productivity loss related costs are dominant. Our study provides basic data for clinical and sustainable health care financing decisions.

[Critical analysis of types and objectives of phamacological trials]

Antiepileptic drug randomized controlled trial (RCT) design has been criticized in the near past. Designs emphasize conventions and regulations more than clinical aspects. In the new study that scrutinized RCT patient recruitment has also raised important ethical issues. The time has come when changes in RCT design seem imperative.

Our clinical experience with zonisamide in resistant generalized epilepsy syndromes

PURPOSE

Zonisamide is licensed in the European Union for adjunctive therapy for partial epilepsy, but its efficacy in generalized epilepsy was less explored.

METHODS

This prospective observational study included 47 patients (mean age 29 years, range 3-50) with different resistant generalized epilepsy syndromes: idiopathic generalized syndromes (IGE) 15 patients, (juvenile myoclonic epilepsy four, absence epilepsy four, myoclonic absence two, unclassified IGE five), progressive myoclonic epilepsy type 1 (PME1) four, severe myoclonic epilepsy of infancy (SMEI) three, borderline SMEI three, Lennox-Gastaut syndrome/secondary generalized epileptic encephalopties 23 patients. All patients were followed up for at least six months. The mean dose given was 367 mg/day (range 100-600 mg/day), the patients received at least one and no more than two concomitant AE. Response was defined as more than 50% seizure reduction or seizure freedom.

RESULTS

The best effect was achieved in PME one, all the patients were responders. Myoclonic seizures were reduced 80%, none of the patients had generalized tonic clonic (GTC) seizures. In two of the four patients all other antiepileptics were tapered of (including piracetam), so they were GTC seizure and almost myoclonia free on zonisamide only. Responder rates were in GEFS +/- SME 62.5%, in resistant IGE 62.5%, and in epileptic encephalopathies 33.3% patients. Tolerance after initial efficacy developed in six patients. Adverse effects were mild: weight loss, somnolence and confusion were repeatedly reported. Three patients reported cognitive improvement.

CONCLUSION

Clinical benefit of a broad spectrum antiepileptic zonisamide extends across seizure types, ages and epilepsy syndromes. The efficacy in PME proved to be excellent.

Dynamic changes of CB1-receptor expression in hippocampi of epileptic mice and humans

The endocannabinoid system plays a central role in retrograde synaptic communication, and controls both glutamatergic and gamma-aminobutyric acid (GABA)ergic transmission via type 1 cannabinoid (CB1) receptor. Both in sclerotic human hippocampi and in the chronic phase of pilocarpine-induced epilepsy in mice with sclerosis, CB1-receptor-positive interneuron somata were preserved both in the dentate gyrus and in the CA1 area, and the density of CB1-immunostained fibers increased considerably in the dentate molecular layer. This suggests that, although CB1 receptors are known to be reduced in density on glutamatergic axons, the CB1-receptor-expressing GABAergic axons sprout, or there is an increase of CB1-receptor levels on these fibers. The changes of CB1 immunostaining in association with the GABAergic inhibitory system appear to correlate with the severity of pyramidal cell loss in the CA1 subfield. These results confirm the involvement of the endocannabinoid system associated with GABAergic transmission in human temporal lobe epilepsy (TLE), as well as in the chronic phase of the pilocarpine model in mice. Pharmacotherapy aimed at the modulation of endocannabinoid-mediated retrograde synaptic signaling should take into account the opposite change in CB1-receptor expression observed on glutamatergic versus GABAergic axon terminals.

Laminar analysis of slow wave activity in humans

Brain electrical activity is largely composed of oscillations at characteristic frequencies. These rhythms are hierarchically organized and are thought to perform important pathological and physiological functions. The slow wave is a fundamental cortical rhythm that emerges in deep non-rapid eye movement sleep. In animals, the slow wave modulates delta, theta, spindle, alpha, beta, gamma and ripple oscillations, thus orchestrating brain electrical rhythms in sleep. While slow wave activity can enhance epileptic manifestations, it is also thought to underlie essential restorative processes and facilitate the consolidation of declarative memories. Animal studies show that slow wave activity is composed of rhythmically recurring phases of widespread, increased cortical cellular and synaptic activity, referred to as active- or up-state, followed by cellular and synaptic inactivation, referred to as silent- or down-state. However, its neural mechanisms in humans are poorly understood, since the traditional intracellular techniques used in animals are inappropriate for investigating the cellular and synaptic/transmembrane events in humans. To elucidate the intracortical neuronal mechanisms of slow wave activity in humans, novel, laminar multichannel microelectrodes were chronically implanted into the cortex of patients with drug-resistant focal epilepsy undergoing cortical mapping for seizure focus localization. Intracortical laminar local field potential gradient, multiple-unit and single-unit activities were recorded during slow wave sleep, related to simultaneous electrocorticography, and analysed with current source density and spectral methods. We found that slow wave activity in humans reflects a rhythmic oscillation between widespread cortical activation and silence. Cortical activation was demonstrated as increased wideband (0.3-200 Hz) spectral power including virtually all bands of cortical oscillations, increased multiple- and single-unit activity and powerful inward transmembrane currents, mainly localized to the supragranular layers. Neuronal firing in the up-state was sparse and the average discharge rate of single cells was less than expected from animal studies. Action potentials at up-state onset were synchronized within +/-10 ms across all cortical layers, suggesting that any layer could initiate firing at up-state onset. These findings provide strong direct experimental evidence that slow wave activity in humans is characterized by hyperpolarizing currents associated with suppressed cell firing, alternating with high levels of oscillatory synaptic/transmembrane activity associated with increased cell firing. Our results emphasize the major involvement of supragranular layers in the genesis of slow wave activity.

Interhemispheric propagation of seizures in mesial temporal lobe epilepsy

OBJECTIVES

To investigate interhemispheric propagation of mesial temporal lobe epilepsy seizures in patients undergoing long-term video-EEG monitoring with combined scalp and foramen ovale electrodes.

AIM OF THE STUDY

To reveal possible interhemispheric propagation patterns in mesial temporal lobe epilepsy, to improve presurgical evaluation of temporal epileptic patients.

METHODS

Sixty-five seizures from 20 patients were analyzed. We defined two contralateral seizure propagation patterns: Type I for those seizures that spread to the contralateral foramen ovale electrodes earlier than to the contralateral scalp electrodes, and type II for the opposite.

PARTICIPANTS

Twenty drug resistant epileptic patients were investigated in frame of their presurgical evaluation.

RESULTS

The majority of seizures (80%) were classified as type I. Inter-foramen ovale electrode propagation time was significantly shorter for type I compared to type II seizures. Ninety percent of patients had either type I or type II seizures only. Patients with type I seizures significantly more often had mesiotemporal structural alterations evident on magnetic resonance imaging scans, and became more often seizure-free after surgery compared to patients with type II seizures whose surgical outcome was less favorable or surgery could not be indicated because of independent bilateral ictal seizure-onset.

CONCLUSIONS

The two types of contralateral propagation patterns we are describing seem to represent two subtypes of mesial temporal lobe epilepsy with different morphological and prognostic features. The predominance of type I over type II seizures together with shorter propagation times for type I seizures indicate a role of a more direct and dominant interhemispheric pathway in mesial temporal lobe epilepsy.

[Supplementary sensory-motor seizures--symptomatology, etiology, and surgical management with illustrative case reports]

In the past decade, owing to the advance of epilepsy surgery, growing knowledge has accumulated on the role of the supplementary motor area, described by Penfield and coworkers in the early fifties, in movement regulation and on the characteristics of seizures involving this area. In the Hungarian neurological literature this topic--despite its neurophysiological and practical clinical importance--has been hardly touched. The authors, based on their own experience obtained from surgeries performed within the framework of the "Co-operative Epilepsy Surgery Program", describe the electrophysiological features of this area, its role in movement regulation and the symptoms of epileptic seizures stemmed from or spread onto this area. Using cases as illustrations, they demonstrate the reasoning and various algorithms of the multidisciplinary examination necessary to explore the seizure onset zone and the pathways of seizure spread. Details of the surgical solution are also described.