Seizures at stroke onset: A case-control study

PURPOSE

Seizures occurring at the immediate onset of a stroke, abbreviated "seizures at onset" (SaO), pose a diagnostic and therapeutic challenge for physicians. In this study, we report on the current clinical practice in managing stroke patients with SaO from a large tertiary stroke center in Germany.

METHODS

We selected all patients with SaO and acute ischemic or hemorrhagic stroke admitted to the Department of Neurology at the University Hospital of Cologne between 2019 and 01-01 and 2020-12-31. SaO patients were then compared to patients with acute ischemic or hemorrhagic stroke without SaO from the local stroke registry. Further, we compared SaO patients who received intravenous recombinant tissue-type plasminogen activator (rt-PA) and/or mechanical thrombectomy with matched controls.

RESULTS

Overall, 54 out of 2312 stroke patients (2.3 %) in the examined period presented with SaO. The most prevalent SaO semiology was focal to bilateral tonic-clonic (42.6 %). SaO was associated with hemorrhagic strokes and higher in-hospital mortality in all stroke patients. The rate of acute stroke therapy was not influenced by the occurrence of SaO. In patients that received acute stroke therapy, patients with SaO had higher scores on the National Institutes of Health Stroke Scale (NIHSS) and the modified Rankin Scale (mRS) at admission, and longer door-to-needle times for the administration of rt-PA, while none of the examined outcome parameters revealed a difference between patients with and without SaO after adjusting for potential confounders.

CONCLUSION

Data show that SaO is rare in stroke patients but associated with more extensive strokes.

Prognosis and management of acute symptomatic seizures: a prospective, multicenter, observational study

BACKGROUND

Acute symptomatic epileptic seizures are frequently seen in neurocritical care. To prevent subsequent unprovoked seizures, long-term treatments with antiseizure medications are often initiated although supporting evidence is lacking. This study aimed at prospectively assessing the risk of unprovoked seizure relapse with respect to the use of antiseizure medications. It was hypothesized that after a first acute symptomatic seizure of structural etiology, the cumulative 12-month risk of unprovoked seizure relapse is ≤ 25%.

METHODS

Inclusion criteria were age ≥ 18 and acute symptomatic first-ever epileptic seizure; patients with status epilepticus were excluded. Using telephone and mail interviews, participants were followed for 12 months after the acute symptomatic first seizure. Primary endpoint was the occurrence and timing of a first unprovoked seizure relapse. In addition, neuro-intensivists in Germany were interviewed about their antiseizure treatment strategies through an anonymous online survey.

RESULTS

Eleven of 122 participants with structural etiology had an unprovoked seizure relapse, resulting in a cumulative 12-month risk of 10.7% (95%CI, 4.7%-16.7%). None of 19 participants with a non-structural etiology had a subsequent unprovoked seizure. Compared to structural etiology alone, combined infectious and structural etiology was independently associated with unprovoked seizure relapse (OR 11.1; 95%CI, 1.8-69.7). Median duration of antiseizure treatment was 3.4 months (IQR 0-9.3). Seven out of 11 participants had their unprovoked seizure relapse while taking antiseizure medication; longer treatment durations were not associated with decreased risk of unprovoked seizure relapse. Following the non-representative online survey, most neuro-intensivists consider 3 months or less of antiseizure medication to be adequate.

CONCLUSIONS

Even in case of structural etiology, acute symptomatic seizures bear a low risk of subsequent unprovoked seizures. There is still no evidence favoring long-term treatments with antiseizure medications. Hence, individual constellations with an increased risk of unprovoked seizure relapse should be identified, such as central nervous system infections causing structural brain damage. However, in the absence of high-risk features, antiseizure medications should be discontinued early to avoid overtreatment.

Prehospital Levetiracetam Use in Adults With Status Epilepticus: Results of a Multicenter Registry

BACKGROUND AND PURPOSE

Status epilepticus (SE) is a neurological emergency due to prolonged seizure activity or multiple seizures without full recovery in between them. Prehospital SE management is crucial since its duration is correlated with higher morbidity and mortality rates. We examined the impact of different therapeutic strategies in the prehospital setting with a focus on levetiracetam.

METHODS

We initiated the Project for SE in Cologne, a scientific association of all neurological departments of Cologne, the fourth-largest city in Germany with around 1,000,000 inhabitants. All patients with an SE diagnosis were evaluated over 2 years (from March 2019 to February 2021) to determine whether prehospital levetiracetam use had a significant effect on SE parameters.

RESULTS

We identified 145 patients who received initial drug therapy in the prehospital setting by professional medical staff. Various benzodiazepine (BZD) derivatives were used as first-line treatments, which were mostly used in line with the recommended guidelines. Levetiracetam was regularly used (n=42) and mostly in combination with BZDs, but no significant additional effect was observed for intravenous levetiracetam. However, it appeared that the administered doses tended to be low.

CONCLUSIONS

Levetiracetam can be applied to adults with SE in prehospital settings with little effort. Nevertheless, the prehospital treatment regimen described here for the first time did not significantly improve the preclinical cessation rate of SE. Future therapy concepts should be based on this, and the effects of higher doses should in particular be reexamined.

Status epilepticus and benzodiazepine treatment: Use, underdosing and outcome - insights from a retrospective, multicentre registry

OBJECTIVE

To explore the reasons for and outcomes of non- or undertreatment with benzodiazepines (BZDs) in status epilepticus (SE).

METHODS

We retrospectively analysed all SE patients from the urban area of Cologne over two years.

RESULTS

328 SE patients were eligible, and only 72% were initially treated with BZDs. Of these, only 21.6% were treated sufficiently with BZDs according to current guidelines. SE patients not initially treated with BZDs were significantly older, had less often known epilepsy, had a prolonged arrival time to the emergency room, and presented more often with a non-generalised convulsive semiology. Regarding adequate dosages, patients with a generalised convulsive SE seemed to benefit from a sufficient BZD dosing with significantly shortened mean ventilation duration (37.1 to 208 h), decreased mean intensive care unit (1.7 to 5 days) and in-hospital stay (4.1 to 8.8 days). In contrary, aggressive BZD treatment in non-generalised convulsive SE resulted in a longer inpatient stay (9.2 to 5.8 days) and lower favourable outcome rates at discharge (16% to 63%).

CONCLUSIONS

The current SE treatment guidelines for first-line BZD therapy in SE were violated in most patients. Sufficient BZD dosing was beneficial in generalised convulsive SE, but not in other forms of SE. SE semiology might be crucial for treatment decisions with BZDs. Further treatment evidence especially in non-generalised convulsive SE is urgently needed.

Glutamic acid decarboxylase antibody-associated neurological syndromes: Clinical and antibody characteristics and therapy response

BACKGROUND

Antibodies against glutamic acid decarboxylase (GAD-abs) at high serum levels are associated with diverse autoimmune neurological syndromes (AINS), including cerebellar ataxia, epilepsy, limbic encephalitis and stiff-person syndrome. The impact of low serum GAD-ab levels in patients with suspected AINS remains controversial. Specific intrathecal GAD-ab synthesis may serve as a marker for GAD-ab-associated nervous system autoimmunity. We present characteristics of a multicentric patient cohort with suspected AINS associated with GAD antibodies (SAINS-GAD+) and explore the relevance of serum GAD-ab levels and intrathecal GAD-ab synthesis.

METHODS

All patients with SAINS-GAD+ included in the registry of the German Network for Research on Autoimmune Encephalitis (GENERATE) from 2011 to 2019 were analyzed. High serum GAD-ab levels were defined as RIA>2000 U/mL, ELISA>1000 U/mL, or as a positive staining pattern on cell-based assays.

RESULTS

One-hundred-one patients were analyzed. In descending order they presented with epilepsy/limbic encephalitis (39%), cerebellar ataxia (28%), stiff person syndrome (22%), and overlap syndrome (12%). Immunotherapy was administered in 89% of cases with improvements in 46%. 35% of SAINS-GAD+ patients had low GAD-ab serum levels. Notably, unmatched oligoclonal bands in CSF but not in serum were more frequent in patients with low GAD-ab serum levels. GAD-ab-levels (high/low) and intrathecal GAD-ab synthesis (present or not) did not impact clinical characteristics and outcome.

CONCLUSIONS

Overall, immunotherapy in SAINS-GAD+ was moderately effective. Serum GAD-ab levels and the absence or presence of intrathecal GAD-ab synthesis did not predict clinical characteristics or outcomes in SAINS-GAD+. The detection of unmatched oligoclonal bands might outweigh low GAD-ab serum levels.

Super-refractory status epilepticus in adults

Introduction

Super-refractory status epilepticus (SRSE) represents the culmination of refractory status epilepticus (RSE) and carries a significant risk of poor neurological outcome and high mortality. RSE is not defined primarily by seizure duration, but by failure to respond to appropriate antiseizure treatment. SRSE is present when a RSE persists or recurs after more than 24 h of treatment with anesthetics. No evidence-based treatment algorithms can be provided for SRSE. Therefore, we propose a pragmatic standard operating procedure (SOP) for the management of SRSE that addresses the existing uncertainties in the treatment of SRSE and provides options for resolution and decision-making.

Comments

First, we recommend the assessment of persistent seizure activity and the evaluation of differential diagnoses to confirm correct diagnosis. Relevant differential diagnoses include psychogenic non-epileptic seizures, hypoxic, metabolic, or toxic encephalopathies, and tetanus. During SE or in severe encephalopathies, a so-called electroclinical ictal-interictal continuum may occur, which denotes an intermediate stage that cannot be defined with certainty as ictal or interictal by EEG and should not lead to harmful overtreatment. Because both prognosis and specific treatment options depend crucially on the etiology of SRSE, the etiological evaluation should be performed rapidly. When SRSE is confirmed, various pharmacological and non-pharmacological treatment options are available.

Conclusion

We provide a pragmatical SOP for adult people with SRSE.

A genome-wide association study in autoimmune neurological syndromes with anti-GAD65 autoantibodies

Autoimmune neurological syndromes (AINS) with autoantibodies against the 65 kDa isoform of the glutamic acid decarboxylase (GAD65) present with limbic encephalitis, including temporal lobe seizures or epilepsy, cerebellitis with ataxia, and stiff-person-syndrome or overlap forms. Anti-GAD65 autoantibodies are also detected in autoimmune diabetes mellitus, which has a strong genetic susceptibility conferred by human leukocyte antigen (HLA) and non-HLA genomic regions. We investigated the genetic predisposition in patients with anti-GAD65 AINS. We performed a genome-wide association study (GWAS) and an association analysis of the HLA region in a large German cohort of 1214 individuals. These included 167 patients with anti-GAD65 AINS, recruited by the German Network for Research on Autoimmune Encephalitis (GENERATE), and 1047 individuals without neurological or endocrine disease as population-based controls. Predictions of protein expression changes based on GWAS findings were further explored and validated in the CSF proteome of a virtually independent cohort of 10 patients with GAD65-AINS and 10 controls. Our GWAS identified 16 genome-wide significant (P < 5 × 10-8) loci for the susceptibility to anti-GAD65 AINS. The top variant, rs2535288 [P = 4.42 × 10-16, odds ratio (OR) = 0.26, 95% confidence interval (CI) = 0.187-0.358], localized to an intergenic segment in the middle of the HLA class I region. The great majority of variants in these loci (>90%) mapped to non-coding regions of the genome. Over 40% of the variants have known regulatory functions on the expression of 48 genes in disease relevant cells and tissues, mainly CD4+ T cells and the cerebral cortex. The annotation of epigenomic marks suggested specificity for neural and immune cells. A network analysis of the implicated protein-coding genes highlighted the role of protein kinase C beta (PRKCB) and identified an enrichment of numerous biological pathways participating in immunity and neural function. Analysis of the classical HLA alleles and haplotypes showed no genome-wide significant associations. The strongest associations were found for the DQA1*03:01-DQB1*03:02-DRB1*04:01HLA haplotype (P = 4.39 × 10-4, OR = 2.5, 95%CI = 1.499-4.157) and DRB1*04:01 allele (P = 8.3 × 10-5, OR = 2.4, 95%CI = 1.548-3.682) identified in our cohort. As predicted, the CSF proteome showed differential levels of five proteins (HLA-A/B, C4A, ATG4D and NEO1) of expression quantitative trait loci genes from our GWAS in the CSF proteome of anti-GAD65 AINS. These findings suggest a strong genetic predisposition with direct functional implications for immunity and neural function in anti-GAD65 AINS, mainly conferred by genomic regions outside the classical HLA alleles.

CSF Findings in Acute NMDAR and LGI1 Antibody-Associated Autoimmune Encephalitis

Background and Objectives

CSF in antibody-defined autoimmune encephalitis (AE) subtypes shows subtype-dependent degrees of inflammation ranging from rare and often mild to frequent and often robust. AEs with NMDA receptor antibodies (NMDAR-E) and leucine-rich glioma-inactivated protein 1 antibodies (LGI1-E) represent opposite ends of this spectrum: NMDAR-E with typically frequent/robust and LGI1-E with rare/mild CSF inflammation. For a more in-depth analysis, we characterized CSF findings in acute, therapy-naive NMDAR-E and LGI1-E in a multicentric, retrospective, cross-sectional setting.

Methods

Eighty-two patients with NMDAR-E and 36 patients with LGI1-E from the GErman NEtwork for Research of AuToimmune Encephalitis (GENERATE) with lumbar puncture within 90 days of onset and before immunotherapy were included. CSF parameters comprised leukocytes, oligoclonal bands (OCBs), and CSF/serum ratios for albumin, immunoglobulin G (IgG), A (IgA), and M (IgM), the latter 3 converted to Z scores according to Reiber formulas. The MRZ reaction was tested in 14 patients with NMDAR-E and 6 patients with LGI1-E, respectively.

Results

CSF was abnormal in 94% of NMDAR-E but only in 36% of LGI1-E patients. Robust quantitative intrathecal immunoglobulin synthesis (IIS, IgG > IgM >> IgA) was characteristic for NMDAR-E, but absent in LGI-E. In NMDAR-E, CSF leukocytes were higher when IIS was present or more pronounced. In addition, in NMDAR-E, CSF leukocytes were lower and IIS occurred less often and if so to a lesser degree at older age. Patients with NMDAR-E with severe functional impairment more often had positive OCBs. In CSF obtained later than 3 weeks of onset, leukocytes were lower. In parallel, the correlation of leukocytes with IIS disappeared as IIS was partially independent of disease duration. The MRZ reaction was positive in 5 (36%) patients with NMDAR-E. All these associations were completely absent in LGI1-E. Here, younger patients showed more blood-CSF barrier dysfunction. In LGI1-E, but not in NMDAR-E, the blood-CSF barrier was more dysfunctional when CSF leukocytes were higher.

Discussion

NMDAR-E and LGI-E differ in their typical extent of CSF inflammation. In addition, the patterns formed by the different inflammatory CSF parameters and their relationship with disease severity, age, and disease duration are subtype-characteristic. Moreover, signs for multiple sclerosis-like chronic inflammation are present in a subgroup of patients with NMDAR-E. These CSF patterns might be markers for the different immunopathogeneses of LGI1-E and NMDAR-E.

Intrathecal Antibody Production Against Epstein-Barr, Herpes Simplex, and Other Neurotropic Viruses in Autoimmune Encephalitis

Background and Objectives

Neurotropic viruses are suspected to play a role in the pathogenesis of autoimmune diseases of the CNS such as the association between the Epstein-Barr virus (EBV) and multiple sclerosis (MS). A group of autoimmune encephalitis (AE) is linked to antibodies against neuronal cell surface proteins. Because CNS infection with the herpes simplex virus can trigger anti–NMDA receptor (NMDAR) encephalitis, a similar mechanism for EBV and other neurotropic viruses could be postulated. To investigate for previous viral infections of the CNS, intrathecally produced virus-specific antibody synthesis was determined in patients with AE.

Methods

Antibody-specific indices (AIs) against EBV and measles, rubella, varicella zoster, herpes simplex virus, and cytomegalovirus were determined in 27 patients having AE (anti-NMDAR encephalitis, n = 21, and LGI1 encephalitis, n = 6) and in 2 control groups comprising of 30 patients with MS and 21 patients with noninflammatory CNS diseases (NIND), which were sex and age matched.

Results

An intrathecal synthesis of antibodies against EBV was found in 5/27 (19%) patients with AE and 2/30 (7%) of the patients with MS. All these patients had also at least 1 additional elevated virus-specific AI. In contrast, in none of the patients with NIND, an elevated virus-specific AI was detected.

Discussion

Intrathecally produced antibodies against EBV can be found in patients with AE and MS but only together with antibodies against different neurotropic viruses. Evidence of these antibodies is the result of a polyspecific immune response similar yet distinct from MS response rather than an elapsed infection of the CNS.

Isoflurane in (Super-) Refractory Status Epilepticus: A Multicenter Evaluation

Background

We aimed to determine the association between seizure termination and side effects of isoflurane for the treatment of refractory status epilepticus (RSE) and super-refractory status epilepticus (SRSE) in neurointensive care units (neuro-ICUs).

Methods

This was a multicenter retrospective study of patients with RSE/SRSE treated with isoflurane for status epilepticus termination admitted to the neuro-ICUs of nine German university centers during 2011–2018.

Results

We identified 45 patients who received isoflurane for the treatment of RSE/SRSE. During isoflurane treatment, electroencephalograms showed no epileptiform discharges in 33 of 41 (80%) patients, and burst suppression pattern was achieved in 29 of 41 patients (71%). RSE/SRSE was finally terminated after treatment with isoflurane in 23 of 45 patients (51%) for the entire group and in 13 of 45 patients (29%) without additional therapy. Lengths of stay in the hospital and in the neuro-ICU were significantly extended in cases of ongoing status epilepticus under isoflurane treatment (p = 0.01 for length of stay in the hospital, p = 0.049 for length in the neuro-ICU). During isoflurane treatment, side effects were reported in 40 of 45 patients (89%) and mainly included hypotension (n = 40, 89%) and/or infection (n = 20, 44%). Whether side effects occurred did not affect the outcome at discharge. Of 22 patients with follow-up magnetic resonance imaging, 2 patients (9%) showed progressive magnetic resonance imaging alterations that were considered to be potentially associated with RSE/SRSE itself or with isoflurane therapy.

Conclusions

Isoflurane was associated with a good effect in stopping RSE/SRSE. Nevertheless, establishing remission remained difficult. Side effects were common but without effect on the outcome at discharge.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12028-021-01250-z.

Informed DEcision for cerebrospinal fluid analysis after epiLeptic seizures- the IDEAL-score: A development and validation study

BACKGROUND

This observational study was done to develop a score based on clinical predictors that enables a guided decision for the necessity of cerebrospinal fluid (CSF) analysis after first unprovoked epileptic seizures and to validate this score in a retrospective patient cohort.

METHODS

Clinical predictors were identified by two panels of epilepsy experts and selected according to content validity ratios. Based on these predictors a score was created and applied to a cohort of patients with first epileptic seizures.

RESULTS

The "IDEAL score" consists of 9 items (fever, prolonged disturbance of consciousness, headache, imaging results, cognitive dysfunction, status epilepticus, malignancy, autoimmune encephalitis symptoms) that are collected at two different time points (< 3 h [A-score]; > 3 h [B-score] after hospital admittance). A CSF analysis is recommended, if at least one clinical finding is present, either one of the items evaluated during the acute phase (A-score) or later in the diagnostic process (B-score). In 41 patients (13%) CSF analysis provided essential clues to the cause of the seizure. The combined IDEAL score reached a sensitivity of 98%, a specificity of 53%, a positive predictive value of 24% and a negative predictive value of 99% in this patient cohort.

CONCLUSIONS

A CSF analysis after first epileptic seizures provided decisive etiological findings in only 13% of all investigated patients. The IDEAL score offers clinicians a simple and easy-to-implement algorithm to assess the necessity of a CSF analysis, and to prevent unnecessary diagnostic procedures.

Can commercially available wearable EEG devices be used for diagnostic purposes? An explorative pilot study

Electroencephalography (EEG) is a core element in the diagnosis of epilepsy syndromes and can help to monitor antiseizure treatment. Mobile EEG (mEEG) devices are increasingly available on the consumer market and may offer easier access to EEG recordings especially in rural or resource-poor areas. The usefulness of consumer-grade devices for clinical purposes is still underinvestigated. Here, we compared EEG traces of a commercially available mEEG device (Emotiv EPOC) to a simultaneously recorded clinical video EEG (vEEG). Twenty-two adult patients (11 female, mean age 40.2 years) undergoing noninvasive vEEG monitoring for clinical purposes were prospectively enrolled. The EEG recordings were evaluated by 10 independent raters with unmodifiable view settings. The individual evaluations were compared with respect to the presence of abnormal EEG findings (regional slowing, epileptiform potentials, seizure pattern). Video EEG yielded a sensitivity of 56% and specificity of 88% for abnormal EEG findings, whereas mEEG reached 39% and 85%, respectively. Interrater reliability coefficients were better in vEEG as compared to mEEG (ϰ = 0.50 vs. 0.30), corresponding to a moderate and fair agreement. Intrarater reliability between mEEG and vEEG evaluations of simultaneous recordings of a given participant was moderate (ϰ = 0.48). Given the limitations of our exploratory pilot study, our results suggest that vEEG is superior to mEEG, but that mEEG can be helpful for diagnostic purposes. We present the first quantitative comparison of simultaneously acquired clinical and mobile consumer-grade EEG for a clinical use-case.

Successful Treatment of Myasthenia Gravis Following PD-1/CTLA-4 Combination Checkpoint Blockade in a Patient With Metastatic Melanoma

Currently, the blockade of certain immune checkpoints such as the cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and programmed cell death-1 (PD-1) using checkpoint inhibitors is standard of care in patients with metastatic melanoma, especially with BRAF wild-type. However, several checkpoint inhibitor-related complications have been reported, including severe adverse events in the central and peripheral nervous system. In particular, in the recent past, the occurrence of myasthenia gravis following checkpoint inhibitor monotherapy, particularly nivolumab or ipilimumab, has been reported. In contrast, reports on PD-1/CTLA-4 combination blockade—usually with fatal clinical outcome—are scarce. We here report a case with combination immune checkpoint blockade-related myasthenia gravis with favorable clinical outcome.

New onset status epilepticus in older patients: Clinical characteristics and outcome

PURPOSE

We here evaluated (1) the differential characteristics of status epilepticus (SE) in older (≥60 years) compared to younger adults (18-59 years). In particular, we were interested in (2) the proportion and characteristics of new onset SE in patients with no history of epilepsy (NOSE) in older compared to younger adults, and (3) predictive parameters for clinical outcome in older subjects with NOSE.

METHODS

We performed a monocentric retrospective analysis of all adult patients (≥18years) admitted with SE to our tertiary care centre over a period of 10 years (2006-2015) to evaluate clinical characteristics and short-time outcome at discharge.

RESULTS

One-hundred-thirty-five patients with SE were included in the study. Mean age at onset was 64 years (range 21-90), eighty-seven of the patients (64%) were older than 60 years. In 76 patients (56%), SE occurred as NOSE, sixty-seven percent of them were aged ≥60 years. There was no age-dependent predominance for NOSE. NOSE was not a relevant outcome predictor, especially regarding age-related subgroups. Older patients with NOSE had less frequently general tonic clonic SE (GTCSE; p=0.001) and were more often female (p=0.01). Regarding outcome parameters and risk factors in older patients with NOSE, unfavourable outcome was associated with infections during in-hospital treatment (0.04), extended stay in ICU (p=0.001), and generally in hospital (p<0.001).

CONCLUSION

In our cohort, older patients represented the predominant subgroup in patients with SE. Older patients suffered more often from non-convulsive semiology and had a less favourable short-time outcome. NOSE was not a predictive outcome parameter in older patients. Data suggest that avoiding infections should have a priority because higher infection rates were associated with unfavourable outcome.

Suspected new-onset autoimmune temporal lobe epilepsy with amygdala enlargement

OBJECTIVE

Recent reports define temporal lobe epilepsy with amygdala enlargement (TLE-AE) as a distinct electroclinical syndrome comparable to TLE with hippocampal sclerosis. In this retrospective observational study, we present the largest consecutive series of patients with new-onset TLE-AE to date and describe clinical characteristics and seizure outcome, and we aim to explore underlying autoimmune mechanisms within this syndrome.

METHODS

We reviewed all consecutive patients between 2004 and 2014 at our tertiary epilepsy center at the University of Bonn, Germany, with new-onset (<5 years) TLE-AE, negative serum antibody (ab) test results, and with available follow-up data for at least 12 months.

RESULTS

We identified 40 patients (23 male) with TLE-AE with a median age at epilepsy onset of 51 years (range 10-73) and a median disease duration of 11 months (range 0.5-55) at first presentation. At follow-up, 50% of the entire cohort achieved seizure freedom. Of interest, patients with remittent features of AE at follow-up (N = 24) had a superior outcome compared to those with stable magnetic resonance imaging (MRI) features of AE (N = 16): 17 (71%) of 24 were seizure-free for at least 6 months compared to 3 (19%) of 16, respectively (p = 0.003). MRI volumetry confirmed significantly enlarged amygdalae in TLE-AE in relation to healthy controls, and additionally showed significantly greater volume reductions in patients with remittent AE compared to those with stable AE.

SIGNIFICANCE

TLE-AE is a clinical syndrome beginning mostly in middle age, and in addition to its known association with ab-positive limbic encephalitis, it occurs in an ab-negative condition. Remission of AE in the course of the disease could be identified as a predictor for a favorable clinical outcome and is suspicious of an autoimmune etiology, although we could not confirm this hypothesis unequivocally with currently available noninvasive diagnostic tools.

Distinct white matter integrity in glutamic acid decarboxylase and voltage-gated potassium channel-complex antibody-associated limbic encephalitis

OBJECTIVE

Autoantibodies against glutamic acid decarboxylase (GAD) and the voltage-gated potassium channel (VGKC) complex are associated with distinct subtypes of limbic encephalitis regarding clinical presentation, response to therapy, and outcome. The aim of this study was to investigate white matter changes in these two limbic encephalitis subtypes by means of diffusion tensor imaging (DTI).

METHODS

Diffusion data were obtained in 14 patients with GAD antibodies and 16 patients with VGKC-complex antibodies and compared with age- and gender-matched control groups. Voxelwise statistical analysis was carried out using tract-based spatial statistics. The results were furthermore compared with those of 15 patients with unilateral histologically confirmed hippocampal sclerosis and correlated with verbal and figural memory performance.

RESULTS

We found widespread changes of fractional anisotropy and all diffusivity parameters in GAD-associated limbic encephalitis, whereas no changes were found in VGKC-complex-associated limbic encephalitis. The changes observed in the GAD group were even more extensive when compared against those of the hippocampal sclerosis group, although the disease duration was markedly shorter in patients with GAD antibodies. Correlation analysis revealed areas with a trend toward a negative correlation of diffusivity parameters with figural memory performance located mainly in the right temporal lobe in the GAD group as well.

SIGNIFICANCE

The present study provides further evidence that, depending on the associated antibody, limbic encephalitis features clearly distinct imaging characteristics by showing widespread white matter changes in GAD-associated limbic encephalitis and preserved white matter integrity in VGKC-complex-associated limbic encephalitis. Furthermore, our results contribute to a better understanding of the specific pathophysiologic properties in these two subforms of limbic encephalitis by revealing that patients with GAD antibodies show widespread affections of white matter across various regions of the brain. In contrast to this, the inflammatory process seems to be more localized in VGKC-complex-associated limbic encephalitis, primarily affecting mesiotemporal gray matter.

Serum from a Patient with GAD65 Antibody-Associated Limbic Encephalitis Did Not Alter GABAergic Neurotransmission in Cultured Hippocampal Networks

Background

Glutamate decarboxylase is an intracellular enzyme converting glutamate into GABA. Antibodies (abs) to its isoform GAD65 were described in limbic encephalitis and other neurological conditions. The significance of GAD65 abs for epilepsy is unclear, but alterations of inhibitory GABAergic neurotransmission may be involved. Here, we investigated the effects of the serum of a female patient suffering from GAD65 ab-associated LE on GABA_A currents in cultured hippocampal networks.

Methods

Spontaneous or evoked post-synaptic GABA_A currents were measured in cultured hippocampal neurons prepared from embryonic mice after 11–21 days in vitro using the patch-clamp technique in the whole-cell mode after incubation with serum of a healthy control or the LE-patient at a final concentration of 1% for 5–8 h.

Results

Properties of miniature inhibitory post-synaptic currents were not different in cultures treated with control and LE-serum. Likewise, paired-pulse ratio of evoked GABA_A currents as a measure of release probability was not different in both conditions. Evoked GABA_A currents were significantly depressed during 10 Hz stimulation without significant differences between control and LE-serum treated cultures.

Conclusion

In our experimental paradigms, serum of a patient with confirmed GAD65 ab-associated LE had no apparent effect on GABAergic neurotransmission in murine-cultured hippocampal networks. These results challenge the view that the presence of GAD65 abs invariably compromise inhibitory network function.

Supratentorial white matter blurring associated with voltage-gated potassium channel-complex limbic encephalitis

INTRODUCTION

Limbic encephalitis (LE) associated with voltage-gated potassium channel-complex antibodies (VGKC-LE) is frequently non-paraneoplastic and associated with marked improvement following corticosteroid therapy. Mesial temporal lobe abnormalities are present in around 80 % of patients. If associated or preceded by faciobrachial dystonic seizures, basal ganglia signal changes may occur. In some patients, blurring of the supratentorial white matter on T2-weighted images (SWMB) may be seen. The purpose of this study was to evaluate the incidence of SWMB and whether it is specific for VGKC-LE.

METHODS

Two experienced neuroradiologists independently evaluated signal abnormalities on FLAIR MRI in 79 patients with LE while unaware on the antibody type.

RESULTS

SWMB was independently assessed as present in 10 of 36 (28 %) compared to 2 (5 %) of 43 non-VGKC patients (p = 0.009). It was not related to the presence of LGI1 or CASPR2 proteins of VGKC antibodies. MRI showed increased temporomesial FLAIR signal in 22 (61 %) VGKC compared to 14 (33 %) non-VGKC patients (p = 0.013), and extratemporomesial structures were affected in one VGKC (3 %) compared to 11 (26 %) non-VGKC patients (p = 0.005).

CONCLUSION

SWMB is a newly described MRI sign rather specific for VGKC-LE.

Features of scalp EEG in unilateral mesial temporal lobe epilepsy due to hippocampal sclerosis: Determining factors and predictive value for epilepsy surgery

OBJECTIVE

To investigate determining factors of the ictal scalp EEG pattern at seizure onset and its predictive value for postsurgical outcome in people with unilateral MTLE due to hippocampal sclerosis (MTLE-HS).

METHODS

Review of consecutive people with chronic MTLE-HS undergoing presurgical video-EEG telemetry. Exclusion criteria were additional epileptogenic lesions or seizure generators or compromised EEG traces at seizure-onset. Mixed linear or logistic regression models were used.

RESULTS

Inclusion of 63 patients with 219 seizures with a favorable outcome (no seizures or auras only) in 43 patients at last follow-up. Rhythmic activity at seizure-onset (RA) had a frequency of 4.7±1.5/s (range 1-8/s), mostly localized in the anterior temporal region. Postsurgical seizure outcome was not associated with any clinical or electrophysiological feature. RA in the delta-band was more often observed with shorter epilepsy duration (p=0.002).

CONCLUSIONS

RA on scalp EEG gets faster with increasing epilepsy duration, possibly via time-dependent alterations of epileptogenic networks. Neither the frequency of RA nor other EEG-features appeared to predict postsurgical seizure outcome.

SIGNIFICANCE

The results challenge the view that if patients with apparent MTLE display RA in the delta-band, seizure-onset in neocortical structures rather than in temporo-mesial tissue should be considered and further investigations should be prompted.

Automated volumetry of the mesiotemporal structures in antibody-associated limbic encephalitis

OBJECTIVE

Limbic encephalitis (LE) is an autoimmune mediated disease leading to temporal lobe epilepsy, mnestic and psychiatric symptoms. In recent years, several LE subforms defined by serum antibody findings have been described. MRI usually shows volume changes of the amygdala and hippocampus. However, studies quantifying longitudinal volume changes in the acute disease stage are lacking.

METHODS

The aim of this retrospective observational study was to evaluate and quantify these volume changes by applying a fully automated volumetric approach to serial MRIs of 28 patients with antibody-associated LE. The results were compared with those of 28 age-matched and gender-matched healthy controls and analysed separately for the different antibody profiles and correlated with clinical parameters. Antibody profile analyses were exploratory due to the relatively small sample sizes.

RESULTS

We found distinct volumetric and clinical courses depending on the associated antibody. While LE associated with voltage-gated potassium channel-complex antibodies (VGKC-LE) showed highly significant larger volumes of both the amygdala and the hippocampus within the first 12 months after disease onset, LE associated with glutamic acid decarboxylase antibodies (GAD-LE) only displayed greater amygdala volumes at this disease stage. Both subgroups showed a reduction of the amygdala and hippocampus volumes during follow-up with higher volume changes in VGKC-LE.

CONCLUSIONS

These differences in the volumetric evolution corresponded to distinct clinical courses in terms of a more severe initial symptomatology regarding seizure, mnestic and psychiatric disturbances in VGKC-LE, which improved rapidly, corresponding to the evolution of the volumetric changes. In contrast to this, patients with GAD-LE were less severely affected at disease onset, showing a more unmodulated and chronic disease course during follow-up.

Neuropsychological outcome after epilepsy surgery in patients with bilateral Ammon's horn sclerosis

Object

The purpose of this study was to retrospectively assess the objective and subjective neuropsychological outcome after epilepsy surgery in patients with bilateral Ammon's horn sclerosis (AHS).

Methods

Memory and executive functions were evaluated at baseline and at follow-up in 11 surgically treated patients and compared with 8 pharmacologically treated patients with temporal lobe epilepsy and bilateral AHS. The median follow-up duration was 16 months in the surgically treated patients and 80.5 months in the pharmacologically treated group. Subjective outcome was evaluated by questionnaires and included mood, quality of life, subjective memory, and activities of daily living.

Results

At the follow-up assessment, 82% of the surgically treated patients as opposed to 0% of the nonsurgery patients were seizure free. In the surgical group, nonverbal memory performance did not change significantly in any patient after surgery, but there was a floor effect in 55% of the surgical patients. Regarding verbal memory, 9% of the surgical patients improved while 73% declined, despite severe impairments already evident at baseline. In the nonsurgery control group, 13% of the patients declined in nonverbal memory (floor effect in 63%) and 25% declined in verbal memory (floor effect in 25%) at follow-up. None of the controls improved at follow-up. Executive functions remained unchanged on an impaired level in both groups. At follow-up, the patient groups did not differ significantly with respect to mood, quality of life, subjective memory, or activities of daily living. However, in most aspects, surgically treated patients reported a slightly better subjective outcome than pharmacologically treated patients and a significantly improved quality of life.

Conclusions

These results suggest that beyond benefits concerning seizure control, surgically treated patients with bilateral AHS, despite already poor baseline performance, are still at risk for severe postoperative decline in memory. In the light of predominantly minor benefits on a subjective level, the findings put the overall outcome of epilepsy surgery in bilateral AHS patients into perspective.

Surgical Resection Can Be Successful in a Large Fraction of Patients With Drug-Resistant Epilepsy Associated With Multiple Cerebral Cavernous Malformations

BACKGROUND:

Multiple cerebral cavernous malformations (mCCMs) are known as potentially epileptogenic lesions. Treatment might be multimodal. Management of patients with mCCMs and epilepsy is challenging.

OBJECTIVE:

To evaluate (1) algorhythmic therapeutic sequences in patients with epilepsy associated to mCCMs, (2) whether there are predictive parameters to anticipate the development of drug-resistant epilepsy, and (3) seizure after epilepsy surgery compared to conservatively-treated drug-resistant patients.

METHODS:

All inpatients and outpatients with epilepsy associated to mCCMs from 1990 to 2010 and follow-up &gt;12 months available were retrospectively analyzed.

RESULTS:

Twenty-three patients matched inclusion criteria. Epilepsy became drug-resistant in 18/23 (78%) patients. No predictors were found for development of drug-resistant epilepsy. Median follow-up for both groups was 7.8 years. Nine patients did not qualify for surgical therapy and were treated conservatively. One patient of this cohort (11%) was seizure-free (International League Against Epilepsy [ILAE] class 1). Surgical treatment was performed in 9 patients; 7/9 (78%) of these patients were seizure-free (ILAE class 1) after epilepsy surgery for at least 12 months compared with 1/9 patients in the non-operated group. In 7/9 cases (78%) the largest CCM was resected. In 8/9 (89%) not all CCMs were resected.

CONCLUSION:

After initial diagnosis of epilepsy associated to mCCMs, a primary conservative approach is reasonable. Surgical treatment can be successful in a large fraction of cases with drug-resistant epilepsy where an epileptogenic lesion is identified. Cases where surgery is not undertaken are likely to remain intractable.

Incidence and mechanisms of cardiorespiratory arrests in epilepsy monitoring units (MORTEMUS): a retrospective study

BACKGROUND

Sudden unexpected death in epilepsy (SUDEP) is the leading cause of death in people with chronic refractory epilepsy. Very rarely, SUDEP occurs in epilepsy monitoring units, providing highly informative data for its still elusive pathophysiology. The MORTEMUS study expanded these data through comprehensive evaluation of cardiorespiratory arrests encountered in epilepsy monitoring units worldwide.

METHODS

Between Jan 1, 2008, and Dec 29, 2009, we did a systematic retrospective survey of epilepsy monitoring units located in Europe, Israel, Australia, and New Zealand, to retrieve data for all cardiorespiratory arrests recorded in these units and estimate their incidence. Epilepsy monitoring units from other regions were invited to report similar cases to further explore the mechanisms. An expert panel reviewed data, including video electroencephalogram (VEEG) and electrocardiogram material at the time of cardiorespiratory arrests whenever available.

FINDINGS

147 (92%) of 160 units responded to the survey. 29 cardiorespiratory arrests, including 16 SUDEP (14 at night), nine near SUDEP, and four deaths from other causes, were reported. Cardiorespiratory data, available for ten cases of SUDEP, showed a consistent and previously unrecognised pattern whereby rapid breathing (18-50 breaths per min) developed after secondary generalised tonic-clonic seizure, followed within 3 min by transient or terminal cardiorespiratory dysfunction. Where transient, this dysfunction later recurred with terminal apnoea occurring within 11 min of the end of the seizure, followed by cardiac arrest. SUDEP incidence in adult epilepsy monitoring units was 5·1 (95% CI 2·6-9·2) per 1000 patient-years, with a risk of 1·2 (0·6-2·1) per 10,000 VEEG monitorings, probably aggravated by suboptimum supervision and possibly by antiepileptic drug withdrawal.

INTERPRETATION

SUDEP in epilepsy monitoring units primarily follows an early postictal, centrally mediated, severe alteration of respiratory and cardiac function induced by generalised tonic-clonic seizure, leading to immediate death or a short period of partly restored cardiorespiratory function followed by terminal apnoea then cardiac arrest. Improved supervision is warranted in epilepsy monitoring units, in particular during night time.

FUNDING

Commission of European Affairs of the International League Against Epilepsy.

Focal cortical dysplasia type IIIc associates with multiple cerebral cavernomas

The distinction of isolated malformations and combined lesions constitutes a major novelty in the 2011 consensus classification of the International League against Epilepsy (ILAE) for focal cortical dysplasias (FCD). Cortical lamination abnormalities together with vascular lesions are subsumed as FCD IIIc. Little is known regarding frequency and etiology of this entity. Here, we systematically evaluated biopsy specimens from 72 drug-refractory epilepsy patients with cerebral cavernous malformations (CCM) regarding presence of associated FCD. Due to a non-perpendicular orientation of the cortical structures or absence of sufficient cortical tissue adjacent to the vascular lesion 25 samples were not classifiable. In the remaining 47 cases FCD IIIc was rare (4.3%), but significantly increased in patients with multiple CCM (28.6%; p<0.05 vs. single CCM). Association of FCD IIIc with multiple CCM may argue against FCD IIIc as an acquired lesion.

Quantitative FLAIR analysis indicates predominant affection of the amygdala in antibody-associated limbic encephalitis

PURPOSE

Limbic encephalitis is an autoimmune-mediated disease leading to temporal lobe epilepsy, mnestic deficits, and affective disturbances. Magnetic resonance imaging (MRI) usually shows signal and volume changes of the temporomesial structures. However, these abnormalities may be subtle, thereby hampering the diagnosis by conventional visual assessment. In the present study we evaluated the diagnostic value of a fully automated MRI postprocessing technique in limbic encephalitis and hippocampal sclerosis.

METHODS

The MRI postprocessing was based largely on a recently described method allowing for an observer-independent quantification of the fluid-attenuated inversion recovery (FLAIR) signal intensities of amygdala and hippocampus. A 95% confidence region was calculated from the FLAIR intensities of 100 healthy controls. We applied this analysis to the MRI data of 39 patients with antibody-associated limbic encephalitis and 63 patients with hippocampal sclerosis. Moreover, the results were compared to those of visual assessment by an experienced neuroradiologist.

KEY FINDINGS

The method detected limbic encephalitis and hippocampal sclerosis with a high sensitivity of 85% and 95%, respectively. The detection rate of the automated approach in limbic encephalitis was significantly superior to visual analysis (85% vs. 51%; p = 0.001), whereas no statistically significant difference for the detection rate in hippocampal sclerosis was found. Patients with limbic encephalitis had significantly higher absolute intensity values of the amygdala and a significantly higher percentage fell outside of the amygdalar confidence region compared to those with hippocampal sclerosis (79% vs. 27%; p < 0.001), whereas we found opposite results in the hippocampal analysis (38% vs. 95%; p < 0.001).

SIGNIFICANCE

The FLAIR analysis applied in this study is a powerful tool to quantify signal changes of the amygdala and hippocampus in limbic encephalitis and hippocampal sclerosis. It significantly increases the diagnostic sensitivity in limbic encephalitis in comparison to conventional visual analysis. Furthermore, the method provides an interesting insight into the distinct properties of these two disease entities on MRI, indicating a predominant affection of the amygdala in limbic encephalitis, whereas the affection of the hippocampus is far less pronounced when compared to hippocampal sclerosis.

Neuropsychological course of voltage-gated potassium channel and glutamic acid decarboxylase antibody related limbic encephalitis

BACKGROUND AND PURPOSE

Autoantibodies (abs) to glutamic acid decarboxylase (GAD) and to voltage-gated potassium channels (VGKC) induce distinct courses of limbic encephalitis, related to MRI findings, seizure outcome and cognition.

METHODS

A detailed analysis of the cognitive course of the two forms is presented, spanning a median time interval of 28 months, including parameters of attention, learning and memory in 15 VGKC-ab-positive and 16 GAD-ab-positive patients.

RESULTS

In both groups, the initially significantly impaired attention performance recovered to a putatively premorbid level. In VGKC patients the partially severely impaired learning and memory performance improved under treatment but remained subnormal at last follow-up. By contrast, GAD-ab-positive patients had initially less impaired learning and memory scores but did not show an improvement under treatment.

CONCLUSIONS

The results provide evidence of distinct relations between inductive processes and cognitive outcome in VGKC-ab-positive and GAD-ab-positive subforms of limbic encephalitis, which possibly depend on differences in pathogenic molecular mechanisms and affected cerebral loci.