Ictal Generalized EEG Attenuation (IGEA) and hypopnea in a child with occipital type 1 cortical dysplasia – Is it a biomarker for SUDEP?

An interesting association of ictal hypopnea and ictal generalized EEG attenuation (IGEA) as possible marker of sudden unexpected death in epilepsy (SUDEP) is reported. We describe a 5-years-old girl with left focal seizures with secondary generalization due to right occipital cortical dysplasia presenting with ictal hypopnea and IGEA. She had repeated episodes of the ictal apnoea in the past requiring ventilator support and intensive care unit (ICU) admission during episodes of status epilepticus. The IGEA lasted for 0.26-4.68 seconds coinciding with the ictal hypopnea during which both clinical seizure and electrical epileptic activity stopped. Review of literature showed correlation between post-ictal apnoea and post ictal generalized EEG suppression and increased risk for SUDEP. The report adds to the growing body of literature on peri-ictal apnea, about its association with IGEA might be considered as a marker for SUDEP. She is seizure free for 4 months following surgery.     

The association of cardiac asystole with partial seizures: does it result from ictal or interictal activity?

Bradycardia or asystole that occur during some seizures may be life threatening as a leading cause of SUDEP. A patient with right and left temporal lobe onset seizures and preceding bardycardia or asystole is presented. He had bilateral hippocampal atrophy on MRI. The unreliability of ictal bradycardia or asystole as a lateralizing sign in patients with partial epilepsy and the role of interictal autonomic activity in heart rate changes during seizures are discussed.     

Ictal asystole in temporal lobe epilepsy before and after pacemaker implantation.

Events of ictal bradycardia or asystole may be of relevance in epilepsy patients presenting with ictal falls, and are a potential contributor to SUDEP. The literature on ictal bradycardia or asystole is anecdotal and consists of case reports and small case series. There are no guidelines for the care of patients with ictal arrhythmias. Insertion of cardiac pacemakers may prevent life-threatening cardiac arrest, syncope and trauma.We report the case of a 41-year-old man who presented with refractory partial seizures resulting in syncope leading to severe head trauma, as the only ictal semiology. During presurgical video-EEG monitoring, two episodes of ictal bradycardia followed by asystole and syncope were recorded. A cardiac pacemaker was implanted. At the nine-month follow-up, the patient reported no overt seizures, syncopes or traumatic falls. Our case demonstrates that implantation of a cardiac pacemaker while continuing AEDs may render a patient free from ictal symptoms and prevent ictal syncope and subsequent trauma. [Published with video sequences].     

Serotonin reuptake inhibitors are associated with reduced severity of ictal hypoxemia in medically refractory partial epilepsy

Ictal respiratory dysfunction occurs in patients with epilepsy and may contribute to sudden unexplained death in epilepsy (SUDEP). Fluoxetine reverses respiratory arrest in a mouse model of epilepsy, suggesting that selective serotonin reuptake inhibitors (SSRIs) may reduce ictal respiratory dysfunction. Video–electroencephalography (EEG) and pulse oximetry data from 496 seizures in 73 consecutive patients with partial epilepsy was reviewed, including 87 seizures in 16 patients taking SSRIs (SSRI+) and 409 seizures in 57 patients not taking SSRIs (SSRI?). The proportion of ictal‐related oxygen desaturation <85% with partial seizures without secondary convulsions in SSRI+ patients was reduced relative to SSRI? patients (p = 0.011). There was no statistically significant difference in ictal oxygen desaturation for secondarily generalized convulsions. SSRIs are associated with reduced likelihood of ictal oxygen desaturation in patients with partial seizures.     

EKG abnormalities during partial seizures in refractory epilepsy

SUMMARY: PURPOSE: This study assessed the frequency and character of ictal cardiac rhythm and conduction abnormalities in intractable epilepsy. Sudden unexpected death in epilepsy (SUDEP) is a major cause of excess mortality in people with refractory epilepsy, and cardiac arrhythmias during seizures may be responsible. The frequency of cardiac abnormalities during seizures in patients with refractory epilepsy must be determined. METHODS: Fifty-one seizures in 43 patients with intractable partial epilepsy were analyzed prospectively from CCTV-EEG monitoring with one ECG channel. Arrhythmias, repolarization abnormalities, and PR and QTc intervals were determined for preictal (3 min), ictal, and postictal (3 min) periods for one or more seizures per patient. Parametric statistics were used for continuous variables, and nonparametric statistics were used for categoric variables. RESULTS: Of the patients, 39% had one or more abnormalities of rhythm and/or repolarization during or immediately after seizures. Abnormalities included asystole (one), atrial fibrillation (one), marked or moderate sinus arrhythmia (six), supraventricular tachycardia (one), atrial premature depolarizations (APDs; eight), ventricular premature depolarizations (VPDs; two), and bundle-branch block (three). Mean seizure duration was longer in patients with abnormalities than in those without (204 vs. 71 s; p < 0.001). Generalized tonic-clonic seizures were also associated with increased occurrence of ictal ECG abnormalities (p = 0.006) as compared with complex partial seizures. There were no clinically significant differences in mean preictal and ictal/postictal PR and QTc intervals. CONCLUSIONS: Cardiac rhythm and conduction abnormalities are common during seizures, particularly if they are prolonged or generalized, in intractable epilepsy. These abnormalities may contribute to SUDEP.     

Ictal asystole in a patient with posterior reversible encephalopathy syndrome (PRES) and seizures

We describe a case of ictal asystole in a patient with posterior reversible encephalopathy syndrome (PRES), which has never been described previously. Ictal asystole is rare and has possible serious medical consequences, including syncope, and may be a potential mechanism for sudden unexpected death in epilepsy (SUDEP). Awareness that PRES may be observed with recurrent ictal asystole may aid in the recognition and treatment of seizures in this condition and the prevention of asystole‐associated complications.     

Cardiac asystole in epilepsy: clinical and neurophysiologic features

PURPOSE: Cardiac asystole provoked by epileptic seizures is a rare but important complication in epilepsy and is supposed to be relevant to the pathogenesis of sudden unexplained death in epilepsy (SUDEP). We sought to determine the frequency of this complication in a population of patients with medically intractable epilepsy and to analyze the correlation between EEG, electrocardiogram (ECG), and clinical features obtained from long-term video-EEG monitoring. METHODS: Retrospective analysis of the clinical records of hospitalized patients from May 1992 to June 2001 who underwent long-term video-/EEG monitoring. RESULTS: Of a total of 1,244 patients, five patients had cardiac asystole in the course of ictal events. In these patients, 11 asystolic events, between 4 and 60 s long in a total of 19 seizures, were registered. All seizures had a focal origin with simple partial seizures (n = 13), complex partial seizures (n = 4), and secondarily generalized seizures (n = 2). One patient showed the longest asystole ever reported (60 s) because of a seizure. Cardiac asystole occurred in two patients with left-sided temporal lobe epilepsy (TLE) and in three patients with frontal lobe epilepsy (FLE; two left-sided, one bifrontal). Two patients reported previous cardiac disease, but only one had a pathologic ECG by the time of admission. Two patients had a simultaneous central ictal apnea during the asystole. None of the patients had ongoing deficits due to the asystole. CONCLUSIONS: These findings confirm that seizure-induced asystole is a rare complication. The event appeared only in focal epilepsies (frontal and temporal) with a lateralization to the left side. A newly diagnosed or known cardiac disorder could be a risk factor for ictal asystole. Abnormally long postictal periods with altered consciousness might point to reduced cerebral perfusion during the event because of ictal asystole. Central ictal apnea could be a frequent associated phenomenon.     

Focal epilepsy recruiting a generalised network of juvenile myoclonic epilepsy: a case report

We report a patient with juvenile myoclonic epilepsy who subsequently developed temporal lobe epilepsy, which gradually became clinically dominant. Video telemetry revealed both myoclonic seizures and temporal lobe seizures. The temporal lobe seizures were accompanied by a focal recruiting rhythm with rapid generalisation on EEG, in which the ictal EEG pattern during the secondary generalised phase was morphologically similar to the ictal pattern during myoclonic seizures. The secondary generalised seizures of the focal epilepsy responded to sodium valproate, similar to the myoclonic epilepsy. In this rare case of coexistent Juvenile Myoclonic Epilepsy and Temporal lobe epilepsy, the possibility of focal epilepsy recruiting a generalised epileptic network was proposed and discussed.     

Sudden unexpected death in epilepsy during cenobamate clinical development

Objective

We assessed mortality, sudden unexpected death in epilepsy (SUDEP), and standardized mortality ratio (SMR) among adults treated with cenobamate during the cenobamate clinical development program.

Methods

We retrospectively analyzed deaths among all adults with uncontrolled focal (focal to bilateral tonic–clonic [FBTC], focal impaired awareness, focal aware) or primary generalized tonic–clonic (PGTC) seizures who received ≥1 dose of adjunctive cenobamate in completed and ongoing phase 2 and 3 clinical studies. In patients with focal seizures from completed studies, median baseline seizure frequencies ranged from 2.8 to 11 seizures per 28 days and median epilepsy duration ranged from 20 to 24 years. Total person-years included all days that a patient received cenobamate during completed studies or up to June 1, 2022, for ongoing studies. All deaths were evaluated by two epileptologists. All-cause mortality and SUDEP rates were expressed per 1000 person-years.

Results

A total of 2132 patients (n = 2018 focal epilepsy; n = 114 idiopathic generalized epilepsy) were exposed to cenobamate for 5693 person-years. Approximately 60% of patients with focal seizures and all patients in the PGTC study had tonic–clonic seizures. A total of 23 deaths occurred (all in patients with focal epilepsy), for an all-cause mortality rate of 4.0 per 1000 person-years. Five cases of definite or probable SUDEP were identified, for a rate of .88 per 1000 person-years. Of the 23 overall deaths, 22 patients (96%) had FBTC seizures, and all 5 of the SUDEP patients had a history of FBTC seizures. The duration of exposure to cenobamate for patients with SUDEP ranged from 130 to 620 days. The SMR among cenobamate-treated patients in completed studies (5515 person-years of follow-up) was 1.32 (95% confidence interval [CI] .84–2.0), which was not significantly different from the general population.

Significance

These data suggest that effective long-term medical treatment with cenobamate may reduce excess mortality associated with epilepsy.     

Severe ictal hypoxemia following focal, subclinical temporal electrographic scalp seizure activity

Ictal hypoxemia has been reported in focal seizures and can be particularly severe during sustained seizure activity involving both hemispheres. Oxygen desaturations have been linked to sudden unexplained death in epilepsy (SUDEP). We report a 71-year-old patient with subclinical electrographic seizure discharges involving the left temporal lobe. Electrographic seizures were followed by apneas and severe oxygen desaturations below 70% SpO(2) even after cessation of electrographic scalp seizure activity, suggesting inhibition of respiratory brainstem centers outlasting neocortical seizure activity. Seizures led to disrupted night's sleep due to arousals. Our case illustrates that severe hypoxemia can occur in association with subclinical seizures involving the temporal lobe and after scalp EEG seizure activity has terminated. Electrographic seizures followed by hypoxemia, such as observed in our patient, could contribute to SUDEP without overt clinical seizure activity.     

Ictal asystole—Late manifestation of partial epilepsy and importance of cardiac pacemaker

Ictal asystole (IA) is a life-threatening complication of epilepsy and is a potential mechanism of sudden unexplained death in epilepsy (SUDEP). This entity has been proven by multiple case reports and small case series. The management of the patients with IA is still in early phase of discussion. We report a patient with medically intractable cryptogenic partial epilepsy for 27 years who presented with new onset drop attacks. During the epilepsy monitoring unit stay he was found to have a left fronto-temporal partial onset seizures which triggered brady-arrhythmia followed by asystole for 20 s. A cardiac pacemaker was implanted and the patient was followed for 2 years. He continued to have simple and complex partial seizures but did not have drop attacks anymore. He still occasionally feels the activation of his pacemaker during simple partial phase of his seizures but the characteristic loss of muscle tone never happened again which made him highly satisfied. Our case demonstrates that IA can even happen decades after the onset of epilepsy. Cardiac pacemaker should be considered in all patients with IA as it prevents ictal falls and possibly SUDEP.     

Strategies for non‐EEG seizure detection and timing for alerting and interventions with tonic–clonic seizures

Sudden unexpected death in epilepsy (SUDEP) is a common cause of death in epilepsy and frequently occurs following generalized tonic–clonic seizures (GTCS). Non–electroencephalography (EEG) seizure detection systems using mobile sensor devices permit caregivers to assist patients during seizures and may reduce risks for complications of seizures such as injuries and SUDEP. We review changes in accelerometry, electrodermal activity, and heart rate associated with tonic–clonic seizures and their use in detection systems, including multimodal detectors. We reviewed current and past publications reporting data on linkage between GTCS, post‐ictal generalized EEG suppression (PGES), and ventilatory dysfunction. The timing and duration of postictal immobility and respiratory dysfunction associated with convulsions help identify which patients might benefit the most from seizure monitoring and from benchmarks for the timing of seizure detection, caregiver alerting, and interventions.     

Cardiac Effects of Seizures

Seizures frequently affect the heart rate and rhythm. In most cases, seizure-related cardiac changes are transient and do not appear to cause clinically significant abnormalities for the patient. Great interest in this area of research has been generated because of a possible connection with sudden unexpected death in epilepsy (SUDEP). While there are clear, but rare complications from seizure-related cardiac arrhythmias, such as ictal asystole that causes syncope, the overall risk of seizures on cardiac status and any potential connection between seizures and SUDEP still remain uncertain.     

Sudden unexpected death in epilepsy: a series of witnessed deaths

OBJECTIVES: Sudden unexpected death in epilepsy (SUDEP) represents a significant category of mortality in the population with chronic epilepsy. A consistent feature is that most of these deaths are unwitnessed. The aim was to identify witnessed deaths, examine the circumstances, and relate these findings to the proposed mechanisms for SUDEP. METHODS: During the course of case ascertainment for a control study on SUDEP, witnessed deaths were identified and the circumstances examined in detail. Cases were notified by coroners, neurologists, and bereaved families. The findings were related to the proposed mechanisms for SUDEP which include central and obstructive apnoea and cardiac arrhythmia. RESULTS: One hundred and thirty five SUDEP cases have been identified to date, of which 15 were witnessed deaths. Twelve deaths were associated with convulsive seizures, one collapse occurred 5 minutes after a generalised seizure, another collapse occurred after an aura and one patient died while in a probable post ictal state. Witnesses reported that 12 of the 15 cases experienced respiratory difficulty. CONCLUSIONS: Most sudden epilepsy deaths are unwitnessed. Where witnessed most occur in association with a seizure and respiratory compromise is a prominent feature. Positioning or stimulation of respiration may be important in the prevention of these deaths.     

SUDEP counseling: Where do we stand?

Sudden unexpected death in epilepsy (SUDEP) is the leading cause of epilepsy-related death in children and adults living with epilepsy. Several recent clinical practice guidelines have recommended that all individuals living with epilepsy and their caregivers be informed about SUDEP as a part of routine epilepsy counseling. Furthermore, several studies over the last two decades have explored the state of SUDEP counseling. Patients with epilepsy and their families want to be informed about the risk of SUDEP at or near the time of diagnosis, and preferably in person. Despite guideline recommendations, many pediatric and adult neurologists do not routinely inform individuals with epilepsy and their families about SUDEP. Some neurologists discuss SUDEP with only a subset of patients with epilepsy, such as those with risk factors like frequent generalized or focal to bilateral tonic–clonic seizures, nocturnal seizures, noncompliance, or medically refractory epilepsy. Proponents of routine SUDEP counseling argue that patients with epilepsy and their families have a “right to know” and that counseling may positively impact epilepsy self-management (i.e., behavioral modification and risk reduction). Some neurologists still believe that SUDEP counseling may cause unnecessary stress and anxiety for patients and their families (although this is erroneous) and that they also have a “right not to know.” This narrative review explores the current gaps in SUDEP counseling, patients' and caregivers' perspectives of SUDEP counseling, and SUDEP prevention.     

The localizing value of ictal EEG in focal epilepsy.

OBJECTIVE: To investigate the lateralization and localization of ictal EEG in focal epilepsy. METHODS: A total of 486 ictal EEG of 72 patients with focal epilepsy arising from the mesial temporal, neocortical temporal, mesial frontal, dorsolateral frontal, parietal, and occipital regions were analyzed. RESULTS: Surface ictal EEG was adequately localized in 72% of cases, more often in temporal than extratemporal epilepsy. Localized ictal onsets were seen in 57% of seizures and were most common in mesial temporal lobe epilepsy (MTLE), lateral frontal lobe epilepsy (LFLE), and parietal lobe epilepsy, whereas lateralized onsets predominated in neocortical temporal lobe epilepsy and generalized onsets in mesial frontal lobe epilepsy (MFLE) and occipital lobe epilepsy. Approximately two-thirds of seizures were localized, 22% generalized, 4% lateralized, and 6% mislocalized/lateralized. False localization/lateralization occurred in 28% of occipital and 16% of parietal seizures. Rhythmic temporal theta at ictal onset was seen exclusively in temporal lobe seizures, whereas localized repetitive epileptiform activity was highly predictive of LFLE. Seizures arising from the lateral convexity and mesial regions were differentiated by a high incidence of repetitive epileptiform activity at ictal onset in the former and rhythmic theta activity in the latter. CONCLUSIONS: With the exception of mesial frontal lobe epilepsy, ictal recordings are very useful in the localization/lateralization of focal seizures. Some patterns are highly accurate in localizing the epileptogenic lobe. One limitation of ictal EEG is the potential for false localization/lateralization in occipital and parietal lobe epilepsies.     

A case of sudden unexpected death in epilepsy 3 years after the onset of acute encephalitis with refractory, repetitive partial seizures

Acute encephalitis with refractory, repetitive partial seizures (AERRPS) is a peculiar form of encephalitis mainly affecting children. Although not usually lethal, we report a case of sudden unexpected death in epilepsy (SUDEP) 3 years after the onset of AERRPS. A 6-year-old boy was admitted to our hospital because of fever and extremely refractory partial and secondary generalized seizures with delirium and psychiatric change. The seizures were highly resistant to anticonvulsants and suppressed only by large dose intravenous administration of midazolam. Seven months after the onset, the seizures were ameliorated by treatment with potassium bromide and clorazepate. After the acute phase, the patient developed complex partial seizures that tended to present with cyanosis. At the age of 10, he was found lying prone in respiratory arrest with facial pallor. Although he regained cardiac function after being taken to our emergency room, the patient died 12 days later. Six SUDEP cases after the onset of AERRPS, including this one, have been reported to date. Since epilepsy following AERRPS is one of the risk factors of SUDEP, clinicians should consider SUDEP to be a rare but high risk syndrome in AERRPS-afflicted children.     

Respiratory changes with seizures in localization‐related epilepsy: Analysis of periictal hypercapnia and airflow patterns

Purpose: The rate of sudden unexpected death in epilepsy (SUDEP) approaches 9 per 1,000 patient‐years in patients with refractory epilepsy. Respiratory causes are implicated in SUDEP. We reported that ictal hypoxemia occurs in one‐third of seizures in localization‐related epilepsy. We now report on respiratory changes in the ictal/postictal period including changes in end‐tidal CO₂ (ETCO₂) that correlate directly with alveolar CO₂, allowing a precise evaluation of seizure‐related respiratory disturbances. Methods: One hundred eighty‐seven seizures were recorded in 33 patients with localization‐related epilepsy, with or without secondarily generalized convulsions, undergoing video‐electroencephalography (EEG) telemetry with recording of respiratory data. Results: The ictal/postictal ETCO₂ increase from baseline was 14 ± 11 mm Hg (11, ?1 to 50) [mean ± standard deviation (SD) (median, range)]. ETCO₂ peak was at or above 50 mm Hg with 35 of 94 seizures, 60 mm Hg with 15, and 70 mm Hg with five seizures. Eleven of the 33 patients had seizures with ETCO₂ elevation above 50 mm Hg. The duration of ictal/postictal ETCO₂ increase above baseline was 424 ± 807 s (154, 4 to 6225). The duration of ictal apnea was 49 ± 46 s (31, 6–222); most ictal apneic events were central. Oxygen desaturation to 60% or less occurred with 10 seizures, including five that did not progress to generalized convulsions. Respiratory rate and amplitude increased postictally. The peak ictal ETCO₂ change and duration of change were not associated with apnea duration or seizure duration. Peak ETCO₂ change was significantly associated with contralateral seizure spread. Conclusions: Severe and prolonged increases in ETCO₂ occur with seizures. Postictally, respiratory effort is not impaired. Ictally triggered ventilation–perfusion inequality from pulmonary shunting or transient neurogenic pulmonary edema may account for these findings.     

Ictal kissing in a patient with right frontal lobe epilepsy

When performing pre‐surgical evaluation of patients with refractory epilepsy, the analysis of seizure semiology is one of the key elements used to generate a hypothesis about the location of the epileptogenic zone. Ictal kissing is a very rarely observed ictal automatism described in patients with temporal lobe epilepsy. We present a 62‐year‐old man who was referred to our epilepsy centre for comprehensive evaluation. During prolonged video‐EEG monitoring, six focal‐onset hyperkinetic seizures were registered. In five seizures, the patient repeatedly produced sonorous kisses “into the air”. Initial ictal EEG pattern consisted of rhythmic theta or alpha activity at the right fronto‐polar and fronto‐medial electrodes. MRI depicted focal cortical dysplasia located in the right prefrontal medial cortex. This case suggests that ictal kissing can also occur in the setting of right frontal lobe epilepsy; we therefore believe that this observation expands the anatomo‐clinical correlation for this rare ictal automatism. [Published with video sequences].     

Seizure anticipation by patients with focal and generalized epilepsy: a multicentre assessment of premonitory symptoms

PURPOSE: To assess subjective seizure anticipation in patients with focal and generalized epilepsy. METHODS: Five hundred consecutively recruited out-patients (251 male, 249 female, mean age 38.1 year) from three German tertiary epilepsy referral centres filled out questionnaires regarding subjective anticipation of seizures by at least 30 min and to timing and semiologic characteristics of their premonitory symptoms versus those of ictal phenomena. Patients were not regarded as having prodromi if the semiology of symptoms reported long before a seizure was identical to auras. RESULTS: 6.2% of patients reported that they were able to anticipate seizures. Premonitory symptoms were classified as stereotyped in all but one patient. An intraindividual semiologic analysis showed that the majority of these patients had symptoms, which were distinct from ictal experiences during auras. Seizure anticipation was reported both by patients with focal and idiopathic generalized epilepsy. The median estimated time interval between occurrence of premonitory symptoms and seizure onset was 90 min. CONCLUSIONS: This study gives evidence that both patients with focal and idiopathic generalized epilepsy may subjectively anticipate the occurrence of epileptic seizures. Premonitory symptoms are distinct from auras in terms of semiology and time of occurrence. The lower percentage of patients regarded as having premonitory symptoms as compared to some earlier reports may be related to stricter criteria and to the exclusion of auras, which could directly evolve into seizures, and other ictal events. Premonitory symptoms occur at similar periods prior to seizures as anticipatory EEG-changes have been reported using methods from time series analysis.