Episodes Of Nonconvulsive Status Epilepticus Research Articles

Power spectrum analysis and outcomes of non-convulsive status epilepticus: a single-center study.

Diagnosis of non-convulsive status epilepticus (NCSE) is challenging and outcomes during follow-up are not clear. This study aimed to conduct power spectrum analysis in NCSE and measure outcomes of patients. We searched continuous EEG monitoring (cEEG) recordings to identify patients of NCSE. An artifact-free cEEG epoch of continuous 60s was chosen for spectral power analysis. We also collected electronic medical records of the patients for extracting clinical information. Patients recruited were followed up at least every half a year. There were 48 patients with 64 independent NCSE episodes during different course of disease recruited in the study, with a mean age of 40.3 ± 19.1years (range, 12-72years), including 24 males (50%) and 24 females (50%). When the spectral power of 60s equaled to 11.30 μV2 for predicting impairment of consciousness, (sensitivity, specificity) = (0.979, 0.625). When the spectral power of 60s equaled to 52.70 μV2 for predicting myoclonic jerks, (sensitivity, specificity) = (0.783, 0.756). There were 27 patients (56.3%) followed up with a duration over 12months. Nineteen patients (70.4%) continued to have seizures. Eleven (40.7%) resisted to at least two kinds of appropriate anti-seizure medication at maximum tolerated levels. Five patients with prolonged NCSE suffered from loss of brain parenchymal volume on follow-up MRI scans. Spectral power analysis can be used to detect mental status and limb jerks. Early diagnosis and treatment of NCSE are important, which can influence outcomes of the patients during follow-up.

Non-convulsive status epilepticus in the setting of cannabidiol adjunctive therapy

Anti-seizure medications (ASMs) can cause non-convulsive status epilepticus (NCSE), but account for less than 5% of all NCSE cases. We present a 63-year-old, right-handed male with a history of intractable focal epilepsy since age seven years old, whose bouts of NCSE were triggered by cannabidiol (CBD) adjunctive therapy. His most common seizure types included focal myoclonic or tonic seizures with vocalization, usually with awakening, which occurred on a monthly basis despite the combination of tiagabine, perampanel, levetiracetam, lacosamide and clonazepam. After CBD was initiated, he began to exhibit episodes of prolonged confusion, at times with myoclonic or tonic seizures. Increasing CBD doses led to more frequent and prolonged episodes. The confusional episodes occurred predominantly in the morning, with spontaneous resolution by the afternoon. During one of these episodes, he was hospitalized, and NCSE was confirmed by video-EEG monitoring. CBD was withdrawn and the patient had no further episodes of NCSE. While CBD can cause NCSE, the medication interaction between CBD and tiagabine also needs to be considered.

Stimulus Induced Rhythmic, Periodic, or Ictal Discharges (SIRPIDs) and its Association with Non-convulsive Status Epilepticus in Critically Ill Patients.

Stimulus induced repetitive periodic or ictal discharges (SIRPIDs) are a commonly observed EEG pattern in critically ill patients. However, the epileptic significance of SIRPIDs remain unclear. We identified and reviewed 55 cases with SIRPIDs according to the ACNS criteria. SIRPIDs occurred after standardized painful stimuli during a standard 20-minute EEG. These cases were investigated regarding their relation to non-convulsive status epilepticus (NCSE) according to Salzburg Consensus Criteria and in-hospital mortality. In 37/55 patients (67.3%), SIRPIDs were associated with NCSE. In most patients (26/37 cases, 70.3%) with concurrent status epilepticus, SIRPIDs occurred after status epilepticus (on average 4.8 days later), but in 3/37 patients (8.1%) they were observed before a later status epilepticus. In four cases (4/37 cases, 10.8%), SIRPIDs appeared both before and after an episode of NCSE and in other four cases the two patterns coexisted in the same EEG. In 50% of the patients, status epilepticus was refractory, super-refractory or the patient died before its resolution. The overall mortality in the cohort was high at 58.2%. These findings corroborate the hypothesis that SIRPIDs might represent a state with increased epileptogenic potential, commonly co-occurring with NCSE. Furthermore, SIRPIDs are associated with therapy-refractory course of status epilepticus and high mortality.

Hippocampal injury and learning deficits following non-convulsive status epilepticus in periadolescent rats

The effects of non-convulsive status epilepticus (NCSE) on the developing brain remain largely elusive. Here we investigated potential hippocampal injury and learning deficits following one or two episodes of NCSE in periadolescent rats. Non-convulsive status epilepticus was induced with subconvulsive doses of intrahippocampal kainic acid (KA) under continuous EEG monitoring in postnatal day 43 (P43) rats. The RKA group (repeated KA) received intrahippocampal KA at P43 and P44, the SKA group (single KA injection) received KA at P43 and an intrahippocampal saline injection at P44. Controls were sham-treated with saline. The modified two-way active avoidance (MAAV) test was conducted between P45 and P52 to assess learning of context-cued and tone-signaled electrical foot-shock avoidance. Histological analyses were performed at P52 to assess hippocampal neuronal densities, as well as potential reactive astrocytosis and synaptic dysfunction with GFAP (glial fibrillary acidic protein) and synaptophysin (Syp) staining, respectively. Kainic acid injections resulted in electroclinical seizures characterized by behavioral arrest, oromotor automatisms and salivation, without tonic-clonic activity. Compared to controls, both the SKA and RKA groups had lower rates of tone-signaled shock avoidance (p < 0.05). In contextual testing, SKA rats were comparable to controls (p > 0.05), but the RKA group had learning deficits (p < 0.05). Hippocampal neuronal densities were comparable in all groups. Compared to controls, both the SKA and RKA groups had higher hippocampal GFAP levels (p < 0.05). The RKA group also had lower hippocampal Syp levels compared to the SKA and control groups (p < 0.05), which were comparable (p > 0.05). We show that hippocampal NCSE in periadolescent rats results in a seizure burden-dependent hippocampal injury accompanied by cognitive deficits. Our data suggest that the diagnosis and treatment of NCSE should be prompt.

Automated Pupillometry for Assessment of Treatment Success in Nonconvulsive Status Epilepticus.

Altered pupillary function may reflect nonconvulsive status epilepticus (NCSE). Neurological pupil index (NPi) assessed by automated pupillometry is a surrogate marker of global pupillary function. We aimed to assess NPi changes in relation to NCSE treatment response. In this prospective observational study, serial automated pupillometry was performed in 68 NCSE episodes. In accordance with local standards, patients were treated with clonazepam (1-2mg), levetiracetam (40mg/kg), and lacosamide (5mg/kg) in a stepwise approach under continuous electroencephalography monitoring until NCSE was terminated. Patients with refractory NCSE received individualized regimens. NPi was assessed bilaterally before and after each treatment step. For statistical analysis, the lower NPi of both sides (minNPi) was used. Nonparametric testing for matched samples and Cohen's d to estimate effect size were performed. Principal component analysis was applied to assess the contribution of baseline minNPi, age, sex, and NCSE duration to treatment outcome. In 97.1% of 68 episodes, NCSE could be terminated; in 16.2%, NCSE was refractory. In 85.3% of episodes, an abnormal baseline minNPi ≤ 4.0 was obtained. After NCSE termination, minNPi increased significantly (p < 0.001). Cohen's d showed a strong effect size of 1.24 (95% confidence interval 0.88-1.61). Baseline minNPi was higher in clonazepam nonresponders vs. responders (p = 0.008), minNPi increased in responders (p < 0.001) but not in nonresponders. NCSE refractivity was associated with normal baseline minNPi (principal component analysis, component 1, 32.6% of variance, r = 0.78), male sex, and longer NCSE duration (component 2, 27.1% of variance, r = 0.62 and r = 0.78, respectively). Automated pupillometry may be a helpful noninvasive neuromonitoring tool for the assessment of patients with NCSE and response to treatment.

Clinical phenotypes within nonconvulsive status epilepticus.

The study aimed to identify distinct phenotypes within nonconvulsive status epilepticus (NCSE). Consecutive episodes of NCSE in patients at least 14 years old were included. The level of consciousness was assessed through the Glasgow Coma Scale (GCS). Etiology of NCSE was defined as symptomatic (acute, remote, progressive) or unknown. Electroencephalographic (EEG) recordings were searched for lateralized periodic discharges (LPDs), generalized sharply and/or triphasic periodic potentials (GPDs), and spontaneous burst suppression (BS). According to treatment response, NCSE was classified as responsive, refractory, or superrefractory. Average linkage hierarchical cluster analysis was performed with Pearson correlation as similarity measure. Two hundred twenty‐nine episodes of NCSE were included. Three clusters were identified. The first cluster linked GCS score 3–8, presence of spontaneous BS on EEG, acute symptomatic etiology, and treatment superrefractoriness. The second cluster gathered GCS score 9–12, presence of LPDs or GPDs on EEG, unknown etiology, and treatment refractoriness. The third cluster associated GCS score 13–15, absence of LPDs, GPDs, and spontaneous BS on EEG, and progressive and remote symptomatic etiology with treatment responsiveness. Phenotyping the heterogeneity of NCSE into electroclinical clusters can contribute to understanding correlations between pathologic and clinical domains, assessing the intrinsic severity of NCSE episodes, and estimating the likelihood of treatment responsiveness.

Cortical responsive neurostimulation in a baboon with genetic generalized epilepsy

ObjectiveTo evaluate the efficacy of cortical responsive neurostimulation (CRN) in a male baboon with epilepsy and with genetic generalized epilepsy (GGE), as well as the alteration of seizure patterns and their circadian rhythms due to treatment. MethodsThe baboon was implanted with two subdural frontoparietal strips, bridging the medial central sulci bilaterally. Electrocorticography (ECoG) data were downloaded daily during a three-month baseline, then every 2–3 days over a five-month treatment period. Long episodes, reflecting ictal or interictal epileptic discharges, were also quantified. ResultsTwenty-three generalized tonic-clonic seizures (GTCS) and 2 episodes of nonconvulsive status epilepticus (NCSE) were recorded at baseline (median 8 events/month), whereas 26 GTCS were recorded under treatment (median 5/month). Similarly, daily indices of long episodes decreased from 0.46 at baseline to 0.29 with treatment. Ictal ECoG patterns and the circadian distribution of GTCS were also altered by RNS therapy. SignificanceThis case study provides the proof-of-concept for RNS therapy in the baboon model of GGE. Cortical responsive neurostimulation (CRN) demonstrated a 38% median reduction in GTCS. Distinct ictal patterns were identified, which changed over the treatment period; the circadian pattern of his GTCS also shifted gradually from night to daytime with treatment. Future studies targeting the thalamic nuclei, or combining cortical and subcortical sites, may further improve detection and control of GTCS as well as other generalized seizure types. More broadly, this study demonstrates opportunities for evaluating seizure detection as well as chronic therapeutic interventions over long term in the baboon.

Benefits, safety and outcomes of long-term video EEG monitoring in pediatric patients.

To investigate benefits of in-hospital, long-term video EEG monitoring (LVEM) for pediatric patients, from a therapeutic perspective and from the perspectives of patients and their families. A monocentric retrospective cohort study was conducted. Patients aged 0-18 years who underwent LVEM for epilepsy surgery eligibility, epilepsy syndrome clarification, or medication adjustment were evaluated regarding paroxysmal event type, change in seizure frequency and patients' benefits using a standardized evaluation protocol. A total of 163 (88 boys and 75 girls, mean age 10.9 years) pediatric patients underwent 178 LVEM sessions, with a mean duration of 5.4 days. The rate of habitual event detection was 69.1%. Epilepsy diagnosis was confirmed in 147 patients and excluded in 16 patients (9.8%). LVEM results altered the diagnosis of 37.4% of patients. Diagnosis remained unchanged in 49.1% of patients and was specified in 13.5% of patients. Epilepsy surgery was performed in 32 patients, and 64% of epilepsy patients deemed ineligible for epilepsy surgery underwent medication adjustments. Patients or their families found LVEM helpful in 75% of cases. Significant seizure reductions and improvements in the disease course were reported by 45% of epilepsy patients. Three episodes of non-convulsive status epilepticus occurred, representing 1.7% of admissions and 1.9% of patients diagnosed with epilepsy, while no injuries were observed. LVEM is beneficial for pediatric patients from both a medical perspective and from the perspective of patients and their families, even if patients are ineligible for epilepsy surgery. LVEM is well-tolerated with a low risk of status epilepticus and injuries.

Everyday nonconvulsive status epilepticus episodes in a 12-year-old girl with pharmacoresistant epilepsy of unknown etiology admitted for presurgical evaluation

Everyday nonconvulsive status epilepticus episodes in a 12-year-old girl with pharmacoresistant epilepsy of unknown etiology admitted for presurgical evaluation

Epilepsy in spinocerebellar ataxia type 8: a\xa0case report

BackgroundSpinocerebellar ataxia type 8 is an uncommon genetic condition and presents with gait disturbances, ataxia, dysarthria, nystagmus, and cognitive and psychiatric abnormalities. Seizures are extremely uncommon in the spinocerebellar ataxias and have been reported only once before in a patient with spinocerebellar ataxia type 8. This case report highlights the need to evaluate spells in patients with a known neurodegenerative or genetic disease to exclude seizures, and it stresses the importance of timely diagnosis and therapy.Case presentationThe patient was a 22-year-old Caucasian woman with known spinocerebellar ataxia 8 since age 10 years. She was admitted to our hospital with new-onset left hemiparesis and encephalopathy in addition to chronic occurrence of multiple spells of confusion and oromanual automatisms with postictal lethargy. Testing confirmed that she was having recurrent seizures with episodes of nonconvulsive status epilepticus. Urgent treatment with antiepileptic therapy was initiated; her seizures resolved shortly thereafter, and her mental status improved. Her left hemiparesis has improved; she remains seizure-free; and she has returned to her baseline antiepileptic medications following physical therapy.ConclusionsSeizures have been reported extremely rarely in association with spinocerebellar ataxia 8, but they must be considered in the differential diagnosis of patients with spells of altered awareness, especially in those with a known neurodegenerative or genetic condition. Clinicoradiological correlation with symptoms can help expedite diagnosis and treatment. Expert consultation with epileptologists at the earliest signs can help establish the diagnosis quickly, minimize morbidity, and enhance recovery.

Anticonvulsive effect of anterior thalamic deep brain stimulation in super-refractory status epilepticus crucially depends on active stimulation zone—A single case observation

Super-refractory status epilepticus has a high mortality, and its treatment remains a challenge for clinical epileptologists. Deep brain stimulation (DBS) is successfully used in pharmacotherapy-resistant epilepsy andlargerstudies showed significant seizure reduction byhigh frequency stimulation in the anterior nucleus of the thalamus (ANT) [1]. Furthermore, several case reports indicate that DBS is also effective in the management of status epilepticus. In a recent, very comprehensive publication, Lehtimaki et al. reported resolution of a super-refractory non-convulsive status epilepticus with continuous high-frequency stimulation of the centromedian thalamic nucleus [2]. Other groups found beneficial effects in the centromedian thalamus and recently also in the ANT in generalized or focal status epilepticus [3]. These cases emphasize the feasibility to interact with and eventually disrupt ongoing cortical epileptic activity by DBS. Here we report a case of a patient with multiple episodes of nonconvulsive status epilepticus who was sucessfully treated with bilateral ANT-DBS.

The development of the expressive speech after surgery in Broca ’s area in two-year-old child: А case report

The case history of a two-year-old child with meningo-angiomotosis of the left frontal lobe is described in this article. The special features of the clinical manifestations were two episodes of nonconvulsive status epilepticus and absence of seizures between these episodes. The diagnosis was suspected at the age of 14 months after magnetic resonance imaging investigation. The presurgical investigation/diagnostics before the neurosurgery and the neurosurgery were performed in the Department for Children’s Neurology of Schoen Klinik Vogtareuth (Germany). The results of electroencephalographic video monitoring over 7 days showed derangements in the left fronto-central and temporo-parietal regions. The repeated magnetic resonance imaging showed no progression of tumor growth. At the age of 2 years and 4 months the girl had been operated. A subtotal lobectomy was carried out. The patient showed a positive trend of speech development after the operation. The question of a lateralization of speech center after surgery in Broca’s area is debated in this article.

Relationship between Status Epilepticus Severity Score and etiology in adult NCSE patients.

Nonconvulsive status epilepticus (NCSE) is a heterogeneous, severe neurological disorder of different etiologies. In this study, the outcomes of NCSE episodes was assessed in a large series of adult patients. Our objective was to evaluate relationship between Status Epilepticus Severity Score (STESS) and etiology and the role of etiological factors on predicting the outcomes. In this retrospective study, the medical records of 95 patients over 18 years of age who were diagnosed with NCSE between June 2011 and December 2015 were reviewed. Their treatment and follow-up for NCSE was performed at the Epilepsy Unit in Department of Neurology, Antalya Research and Training Hospital. Etiological factors thought to be responsible for NCSE episodes as well as the prognostic data were retrieved. The etiological factors were classified into three groups as those with a known history of epilepsy (Group 1), primary neurological disorder (Group 2), or systemic/unknown etiology (Group 3). STESS was retrospectively applied to patients. There were 95 participants, 59 of whom were female. Group 1, Group 2, and Group 3 consisted of 11 (7 female), 54 (33 female), and 30 (19 female) patients, respectively. Of the 18 total deaths, 12 occurred in Group 2, and 6 in Group 3. The negative predictive value for a STESS score of ≤ 2 was 93.88% (+LR 2.05 95% CI: 1.44-2.9 and -LR 0.3 95% CI 0.10-0.84 ) in the overall study group. While the corresponding values for Group 1 (patients with epilepsy), Group 2 (patients with primary neurological disorder), and group 3 (patients with systemic or unknown etiology) were 100%, 92.59% (+LR 2.06 95%CI: 1.32-3.21 and -LR 0.28 95% CI 0.08-1.02 ) 83.33% (+LR 1.14 95%CI: 0.59-2.9 and -LR 0.80 95% CI 0.23-2.73). This study included the one of the largest patients series ever reported in whom STESS, a clinical scoring system proposed for use in patients with status epilepticus, has been implemented. Although STESS appeared to be quite useful for predicting a favorable outcome in NCSE patients with epilepsy and primary neurological disorders, its predictive value in patients with systemic or unknown etiology was lower. Further prospective studies including larger NCSE samples are warranted.

Diazepam for outpatient treatment of nonconvulsive status epilepticus in pediatric patients with Angelman syndrome

Nonconvulsive status epilepticus (NCSE) is present in multiple pediatric neurogenetic syndromes with epileptic encephalopathies. While intravenous (IV) medications are used inpatient for treatment of critical illness-related NCSE, there is no consensus on treatment of ambulatory NCSE. Up to 50% of patients with Angelman syndrome (AS) have NCSE with myoclonic or atypical absence status. Here we report our experience in pediatric patients with AS and NCSE treated outpatient with a tapering course of oral diazepam. We conducted a chart review of 104 patients seen in the Angelman Syndrome Clinic at Massachusetts General Hospital from January 2008 to March 2017, who met the criteria. Response to treatment was defined as cessation of NCSE symptoms with electroencephalogram (EEG) confirmation when possible. Twenty-one patients with NCSE were identified, and 13 patients (9 male) with 25 episodes of NCSE were included. Mean age at NCSE episode was 5years 4months (15months–12years). Six patients had one episode of NCSE, and 7 patients had recurrent episodes (mean: 2.7; range: 2–4). Median diazepam treatment was 6days (4–12days), with a mean dose of 0.32mg/kg/day divided over 2–3 administrations, decreased every 2days. Nine episodes required multiple courses; however, oral diazepam alone was ultimately successful in 80% (20/25) of NCSE episodes. Oral diazepam was well-tolerated with no major side effects. A short course of oral diazepam is well-tolerated and effective in patients with AS who have ambulatory NCSE. It may be considered prior to escalating to inpatient care in AS and possibly other epilepsy syndromes.

Prognostic factors of status epilepticus in adults.

Status epilepticus (SE) can lead to sequelae or even death. Identifying characteristics associated with poor outcome is crucial in guiding patient treatment. Based on our retrospective patient cohorts, potential prognostic factors were analysed. Patients consecutively treated for refractory convulsive status epilepticus (CSE) between 2001 and 2010 and non-convulsive status epilepticus (NCSE) between 2004 and 2009 were studied. Outcome was compared to prognostic variables. Index SE episodes were used for the statistical analyses. Crosstabs and independent samples t-test were applied. Due to sample size, logistic regression was performed for the combined groups. In total, 50% (9/18) of index refractory CSE and 42% (16/38) of index NCSE episodes led to sequelae. Refractory CSE requiring narcosis for >20hours was associated with poor outcome (p=0.05). De novo presentation (p=0.0001), long-lasting SE (>2hours) (p=0.014), age >65 years (p=0.002), and refractory SE (p=0.047) were predictors of poor outcome following NCSE. Based on logistic regression for combined refractory CSE and NCSE, de novo presentation was identified as the strongest predictor of sequelae. Older age and de novo SE are predictors of sequelae following NCSE. Prolonged SE is a risk factor for poor outcome, both for refractory CSE and NCSE. Aggressive initial treatment to terminate seizures during the early phase is therefore essential.

Color density spectral array of bilateral bispectral index system: Electroencephalographic correlate in comatose patients with nonconvulsive status epilepticus

Purposeto describe the characteristics of the color density spectral array (CDSA) of bilateral bispectral index (b-BIS) monitoring system in patients with comatose nonconvulsive status epilepticus (NCSE). We hypothesized that CDSA could be helpful for monitoring NCSE in critically subjects if continuous EEG (cEEG) is not available. Methodswe retrospectively analyzed comatose patients admitted to our neurological intensive care unit (NICU) from 2011 to 2014 with a diagnosis of definitive NCSE that underwent b-BIS monitoring for at least 24h to guide anesthetic sedation. Clinical, electroencephalography and neuroimaging findings were analyzed. Moreover, all parameters from the b-BIS data including the CDSA were reviewed during periods of NCSE (NCSE pattern) and profound sedation (sedation pattern). Results15 NCSE patients were included. The delay from the diagnosis of NCSE to the onset of b-BIS monitoring was 8 (0.5–31)h and total time of b-BIS monitoring 7.8±6.5 days. CDSA during NCSE pattern was characterized by continuous or intermittent red and dark red tones, spectral edge frequency (SEF) in the delta-theta range, with or without asymmetry and BIS number trend with significant variability. In contrast, CDSA during sedation revealed predominance of orange, yellow, green and occasionally blue tones, SEF in the alpha-beta range, absence of asymmetry and stability of BIS number. Conclusionsb-BIS monitoring system and, in particular, CDSA used by nonexpert NICU personnel may be helpful to follow-up episodes of NCSE, to detect recurrences of nonconvulsive seizures (NCSzs), and to monitor profound anesthetic therapy in comatose patients when cEEG is not available.

Outcomes in pediatric patients with nonconvulsive status epilepticus.

Recognition of nonconvulsive status epilepticus (NCSE) is gaining increasing attention in the assessment and evaluation of critically ill pediatric patients. The underlying cause of NCSE is often the most important factor in determining outcome. However, there is a growing body of literature suggesting that electrical seizure burden in NCSE also contributes to unfavorable outcomes. Determination of impact of NCSE on outcome based on current evidence involves consideration of heterogeneous study settings, study populations, and process of care and outcome measures. In addition, the lack of data on neurocognitive function prior to episodes of NCSE as well as limited long-term neurocognitive assessment data confines precise conclusions about neurocognitive changes. This article is part of a Special Issue entitled "Status Epilepticus".

Intravenous anesthesia in treatment of nonconvulsive status epilepticus: Characteristics and outcomes

ObjectiveTo determine factors associated with continuous anesthetic drug (IVAD) use in nonconvulsive status epilepticus (NCSE). MethodsRetrospective cohort study of patients who met clinical and EEG criteria of NCSE from 2009 to 2014 at a tertiary academic medical center. Patients were categorized according to IVAD use. Outcome variables were response to treatment and in-hospital death. We used descriptive analyses for baseline characteristics and outcome variable differences among patients who did and did not receive IVAD. ResultsForty-three patients had a total of 45 NCSE episodes. IVAD was used in 69% of the episodes. Patients treated with IVAD were younger (53.1±14.1 vs 64.1±13.3, p=0.019). The episodes treated with IVAD occurred more frequently in patients with an acute neurologic pathology (58% vs 21%, p=0.024) and those presenting in a coma (39% vs 7%, p=0.030). NCSE resolved in 74% of the patients who received IVAD. Duration of NCSE did not differ significantly by treatment group. There were total 13 in-hospital deaths: ten in IVAD users vs three in the no-IVAD group (p>0.05). Only one in-hospital death appeared to be a direct consequence of IVAD use. Mortality was more common among episodes that were not treated according to the published status epilepticus treatment guidelines compared to the episodes where guidelines were followed. ConclusionOur findings showed that factors such as younger age, acute neurologic pathology and coma at presentation were associated with IVAD use in patients with NCSE. These factors should be controlled in the future outcome and effectiveness studies to determine the effect of IVAD use on outcome of NCSE.

Ring Chromosome 20 Syndrome and Epilepsy

The ring chromosome 20 [r(20)] syndrome is a chromosomal disorder, characterized by refractory epilepsy, mild-to-moderate intellectual disability, and behavioral anomaly. In spite of structural chromosomal aberrations, malformations are often not recognized. In addition, neurological anomalies and abnormalities in brain magnetic resonance imagings are usually not detected. The epilepsy is refractory and mainly presents as atypical absence seizures or nocturnal frontal lobe seizures, with frequent episodes of nonconvulsive status epilepticus in typical cases. Ictal electroencephalograms performed during nonconvulsive status epilepticus episodes typically record spike wave discharges, superimposed with 2- to 3-Hz rhythmic slow waves predominantly in the frontal lesion. Since the r(20) syndrome was initially reported as a genetic syndrome in 1976, over 60 cases have been published to date. Most cases are sporadic, except four familial cases that have been previously reported. This syndrome is diagnosed only by karyotyping. Since epilepsy is the only symptom in most patients, genetic testing and diagnosis are usually delayed. In addition, patients usually exhibit mosaicism in lymphocytes, and the proportion of lymphocytes with the r(20) varies. Although some studies have evaluated the relationship between the phenotype and the proportion of lymphocytes with the r(20), no significant relationship has emerged. Ring chromosomes are usually formed by the fusion of each 20p and 20q telomere and cause the loss of both telomeres. Therefore, the r(20) syndrome is thought to be caused by haploinsufficiency of genes located on the telomeric regions of chromosome 20. However, in spite of showing typical symptoms of the r(20) syndrome, a patient in whom telomeres were not deleted has also been reported. Moreover, apart from the genes located on chromosome 20, two genes associated with epilepsy, KCNQ2 and CHRNA4, have also been located at p13ter and 13qter. Hence, the mechanism underlying seizure disorders in r(20) syndrome remains unknown. This review discusses the current knowledge about the genetic etiology of r(20) syndrome.

Ring 17 syndrome: first clinical report without intellectual disability.

Ring chromosomes are rare abnormalities caused by the fusion of the telomeric regions. Three-ring chromosome syndromes (Cr 20, Cr 17 and Cr 14) cause epilepsy with variable phenotypes. In ring 17 patients with mild phenotype, some authors have shown an epilepsy syndrome similar to that of ring 20. We report the first case of a girl with ring chromosome 17 and a normal neurological and general cognitive profile. She had had, from 9 years old, focal pharmacoresistant epilepsy associated with episodes of non-convulsive status epilepticus with mainly autonomic features. Cytogenetic analysis revealed an abnormal karyotype characterised by the presence of de novo ring chromosome 17 in 19% of metaphases. The array CGH (100KB) did not show any genetic deletion. The clinical and epilepsy phenotype was, to a certain degree, similar to that of ring 20 syndrome.