Sandra Rose

SUDEP, suspected positional airway obstruction, and hypoventilation in postictal coma

Sudden unexpected death in epilepsy (SUDEP) is the leading cause of mortality in patients with chronic uncontrolled epilepsy. Despite intense interest in SUDEP from the medical and scientific communities in recent years, its etiologies are still largely unresolved. A 35‐year‐old woman had SUDEP after having a generalized seizure in the prone position. The cause of her death was likely asphyxia from the convergence of postictal coma and suspected positional airway obstruction and hypoventilation, rather than the commonly suspected periictal cardiac arrhythmia or central apnea. SUDEP may share a similar etiology with sudden infant death syndrome (SIDS) and is likely preventable, at least in a proportion of cases.

Association of prone position with sudden unexpected death in epilepsy

Editors’ Note: “Association of prone position with sudden unexpected death in epilepsy” raised several inquiries from our readers. Sethi suggests that since the pathogenesis of sudden unexpected death in epilepsy (SUDEP) is not yet elucidated, advising patients to sleep in the supine position, which risks aspiration, warrants careful consideration. Furthermore, based on their prior study, Lhatoo et al. believe that forced ictal version, rather than prone position, may be a SUDEP risk factor. Authors Tao et al. argue that supine sleeping can help prevent SUDEP and, although it could be associated with aspiration, babies seizing facedown risk suffocation. —Chafic Karam, MD, and Robert C. Griggs, MD

Interictal regional delta slowing is an EEG marker of epileptic network in temporal lobe epilepsy

Purpose:  Several studies have suggested that interictal regional delta slowing (IRDS) carries a lateralizing and localizing value similar to interictal spikes and is associated with favorable surgical outcomes in patients with temporal lobe epilepsy (TLE). However, whether IRDS reflects structural dysfunction or underlying epileptic activity remains controversial. The objective of this study is to determine the cortical electroencephalography (EEG) correlates of scalp‐recorded IRDS, in so doing, to further understand its clinical and biologic significances.

Tonic phase of a generalized convulsive seizure is an independent predictor of postictal generalized EEG suppression

To determine the incidence, duration, risk factors for, and clinical correlates of postictal generalized electroencephalography (EEG) suppression (PGES), and to further delineate the significance of PGES in the pathogenesis of sudden unexpected death in epilepsy (SUDEP).

Advances in Spike Localization with EEG Dipole Modeling

EEG interpretation by visual inspection of waveforms, using the assumption that activity at a given electrode is a representation of only the activity of the cortex immediately beneath it, has been the traditional form of EEG analysis since its inception. The relatively recent advent of digital EEG has allowed more advanced analysis of EEG data and has shown that the simple visual inspection described above is a simplistic form of analysis. This is especially true when one is attempting to localize an epileptogenic focus using EEG spikes or seizure onset data. Spatio-temporal analysis of scalp voltage fields has allowed for improved localization of likely cerebral origins of such waveforms. Equivalent dipole source modeling is one such technique and, although not perfect, provides improved characterization of spike and seizure sources as compared to previous methods when properly interpreted. The use of other modern techniques, such as 3D MRI reconstructions and realistic head models, can further improve accuracy of dipole localization and allow for the synthesis of EEG and imaging data, which may be invaluable, especially in cases of pre-surgical epilepsy evaluation.

Periictal autonomic dysfunction and generalized postictal EEG suppression in convulsive seizures arising from sleep and wakefulness

Sleep appears to be an independent risk factor of sudden unexpected death in epilepsy (SUDEP). We retrospectively determined the periictal electrophysiological characteristics of nocturnal and diurnal generalized convulsive seizures (GCSs) in 109 patients. Our data showed that preictal heart rate (HR) was significantly lower in 46 patients with nocturnal GCSs than in 63 patients with diurnal GCSs (p=0.002). However, there was no significant difference in postictal HR and respiratory rate (RR), total seizure duration, total convulsive phase, tonic phase, and clonic phase. Meanwhile, postictal generalized EEG suppression (PGES) was observed in 52.4% of the patients with diurnal GCSs and 67.4% of the patients with nocturnal GCSs. Duration of PGES was 38.2±17.3s in patients with diurnal GCSs and 49.5±21.7s in patients with nocturnal GCSs. There was also no significant difference in the prevalence (p=0.118) and duration (p=0.044, Bonferroni-corrected significant level: α=0.00625) of PGES in the two patient groups. Therefore, there is no clear evidence to attribute the SUDEP risk associated with sleep to postictal autonomic dysfunction and PGES, as compared to wakefulness.

Impact of periictal nurse interventions on postictal generalized EEG suppression in generalized convulsive seizures.

OBJECTIVES The objective of this study was to determine the impact of periictal nurse interventions on postictal generalized EEG suppression (PGES) in generalized convulsive seizures (GCS). METHODS We retrospectively reviewed the video-EEG recordings of patients during long-term video-EEG monitoring. We compared the duration of seizures, seizure phases (tonic, clonic, and tonic-clonic phases), and the occurrence and duration of postictal generalized EEG suppression (PGES) in patients with and without periictal interventions (e.g., oxygen administration, suctioning, and repositioning). Statistical analyses were performed to determine the association between the seizure-related variables and the periictal interventions. RESULTS A total of 109 patients with 150 GCS were included in the study. Periictal interventions were provided in 122 GCS, of which, ictal administration of oxygen was provided in 29 GCS. The duration of PGES was significantly shortened in GCS with interventions when compared with those without interventions (p=0.003). However, the ictal administration of oxygen, assessed as an independent variable, did not influence the occurrence or duration of PGES. CONCLUSION Periictal interventions significantly shortened the duration of PGES, and may, as a consequence, reduce the risk of SUDEP. However, ictal administration of oxygen did not influence the occurrence or duration of PGES.

Stereotactic EEG-guided laser interstitial thermal therapy for mesial temporal lobe epilepsy

Objective To determine the outcomes of combined stereo-electroencephalography-guided and MRI-guided stereotactic laser interstitial thermal therapy (LITT) in the treatment of patients with drug-resistant mesial temporal lobe epilepsy (mTLE). Methods We prospectively assessed the surgical and neuropsychological outcomes in 21 patients with medically refractory mTLE who underwent LITT at the University of Chicago Medical Center. We further compared the surgical outcomes in patients with and without mesial temporal sclerosis (MTS). Results Of the 21 patients, 19 (90%) underwent Invasive EEG study and 11 (52%) achieved freedom from disabling seizures with a mean duration of postoperative follow-up of 24±11 months after LITT. Eight (73%) of 11 patients with MTS achieved freedom from disabling seizures, whereas 3 (30 %) of 10 patients without MTS achieved freedom from disabling seizures. Patients with MTS were significantly more likely to become seizure-free, as compared with those without MTS (P=0.002). There was no significant difference in total ablation volume and the percentage of the ablated amygdalohippocampal complex between seizure-free and non-seizure-free patients. Presurgical and postsurgical neuropsychological assessments were obtained in 10 of 21 patients. While there was no group decline in any neuropsychological assessment, a significant postoperative decline in verbal memory and confrontational naming was observed in individual patients. Conclusions MRI-guided LITT is a safe and effective alternative to selective amygdalohippocampectomy and anterior temporal lobectomy for mTLE with MTS. Nevertheless, its efficacy in those without MTS seems modest. Large multicentre and prospective studies are warranted to further determine the efficacy and safety of LITT.

Antiglutamic acid decarboxylase 65 (GAD65) antibody-associated epilepsy

Glutamic acid decarboxylase (GAD) antibody-associated encephalitis causes both acute seizures and chronic epilepsy with predominantly temporal lobe onset. This condition is challenging in diagnosis and management, and the incidence of GAD antibody (Ab)-related epilepsy could be much higher than commonly believed. Imaging and CSF evidence of inflammation along with typical clinical presentations, such as adult onset temporal lobe epilepsy (TLE) with unexplained etiology, should prompt testing for the diagnostic antibodies. High serum GAD Ab titer (≥2000U/mL or ≥20nmol/L) and evidence of intrathecal anti-GAD Ab synthesis support the diagnosis. Unlike other immune-mediated epilepsies, antiglutamic acid decarboxylase 65 (GAD65) antibody-mediated epilepsy is often poorly responsive to antiepileptic drugs (AEDs) and only moderately responsive to immune therapy with steroids, intravenous immunoglobulin (IVIG), or plasma exchange (PLEX). Long-term treatment with more aggressive immunosuppressants such as rituximab (RTX) and/or cyclophosphamide is often necessary and may be more effective than current immunosuppressive approaches. The aim of this review is to review the physiology, pathology, clinical presentation, related ancillary tests, and management of GAD Ab-associated autoimmune epilepsy by searching the keywords and to promote the recognition and the initiation of proper therapy for this condition.

Homonymous hemianopsia after MR-guided stereotactic laser amygdalohippocampectomy

Magnetic resonance-guided laser interstitial thermal therapy (LITT) is a minimally invasive technique that can create lesions in the mesial temporal structures with little damage to surrounding tissues. Early data suggest that LITT is associated with favorable surgical outcomes and superior preservation of cognitive function in patients with mesial temporal lobe epilepsy [1–4]. Therefore, LITT is a promising alternative to traditional anterior temporal lobectomy and selective