Faculty Bibliography

OBJECTIVE:Incomplete resection of neocortical epileptogenic foci correlates with failed epilepsy surgery in children. We often treat patients with neocortical epilepsy with a staged approach using invasive monitoring to localize the focus, resect the seizure onset zone, and, in select cases, post-resection invasive monitoring (PRM). We report the technique and the outcomes of children treated with staged surgery including PRM. METHODS:We retrospectively reviewed the charts of pediatric patients with neocortical epilepsy who underwent resective surgery with PRM. RESULTS:We identified 71 patients, 5 patients with MRI-negative epilepsy and 66 patients with MRI-identified neocortical lesions; 64/66 (97%) patients had complete lesionectomy. In 61/71 (86%) patients PRM was associated with positive outcomes. Those findings were: 1) clinical seizures with electrographic involvement at resection margins (47%); 2) subclinical seizures and interictal discharges at resection margins (29%); and 3) clinical and subclinical seizures revealing a new epileptogenic focus (20%). In 55/71 (77%) patients, PRM data led to additional resection (re-resection; RR). Six additional patients had no further resection due to overlap with eloquent cortex. Histopathology showed tuberous sclerosis complex (TSC; n = 46), focal cortical dysplasia (FCD; n = 16)), gliosis (n = 4), tumors (n = 4), and Sturge-Weber syndrome (n = 1). There were no major complications. Seizure-free outcome in children with TSC was 63% at 1-year follow-up and 56% at 2-year follow-up. In FCD, seizure freedom after 1 and 2 years was 85%. SIGNIFICANCE/CONCLUSIONS:Post-resection monitoring may provide additional information about the extent of the epileptogenic zone, such as residual epileptogenic activity at the margins of the resection cavity, and may unmask additional seizure foci. This method may be especially useful in achieving long-term stable seizure-free outcome.

The running-down phenomenon refers to 2 analogous but distinct entities that may be seen after epilepsy surgery. The first is clinical, and denotes a progressive diminution in seizures after epilepsy surgery in which the epileptogenic zone could not be completely removed (Modern Problems of Psychopharmacology 1970;4:306, Brain 1996:989). The second is electrographic, and refers to a progressive deactivation of a secondary seizure focus after removal of the primary epileptogenic zone. This progressive decrease in epileptiform activity may represent a reversal of secondary epileptogenesis, where a primary epileptogenic zone is postulated to activate epileptiform discharges at a second site and may become independent.³ The electrographic running-down phenomenon has been reported in only limited numbers of patients, using serial postoperative routine scalp electroencephalography (EEG) (Arch Neurol 1985;42:318). We present what is, to our knowledge, the most detailed demonstration of the electrographic running-down phenomenon in humans, made possible by chronic electrocorticography (ECoG). Our patient's left temporal seizure focus overlapped with language areas, limiting the resection to a portion of the epileptogenic zone, followed by implantation of a direct brain-responsive neurostimulator (RNS System, NeuroPace Inc.) to treat residual epileptogenic tissue. Despite the limited extent of the resection, the patient remains seizure-free more than 2 years after surgery, with the RNS System recording ECoG without delivering stimulation. We reviewed the chronic recordings with automated spike detection and inspection of electrographic episodes marked by the neurostimulator. These recordings demonstrate progressive diminution in spiking and rhythmic discharges, consistent with an electrographic running-down phenomenon.

Structural and functional elements of biological systems are highly conserved across vertebrates. Many neurological and psychiatric conditions affect both humans and animals. A cross-species approach to the study of brain and behaviour can advance our understanding of human disorders via the identification of unrecognized natural models of spontaneous disorders, thus revealing novel factors that increase vulnerability or resilience, and via the assessment of potential therapies. Moreover, diagnostic and therapeutic advances in human neurology and psychiatry can often be adapted for veterinary patients. However, clinical and research collaborations between physicians and veterinarians remain limited, leaving this wealth of comparative information largely untapped. Here, we review pain, cognitive decline syndromes, epilepsy, anxiety and compulsions, autoimmune and infectious encephalitides and mismatch disorders across a range of animal species, looking for novel insights with translational potential. This comparative perspective can help generate novel hypotheses, expand and improve clinical trials and identify natural animal models of disease resistance and vulnerability.

The International League Against Epilepsy/American Epilepsy Society (ILAE/AES) Joint Translational Task Force created the TASK3 working groups to create common data elements (CDEs) for various aspects of preclinical epilepsy research studies, which could help improve standardization of experimental designs. This article concerns the parameters that can be measured to assess the physiologic condition of the animals that are used to study rodent models of epilepsy. Here we discuss CDEs for physiologic parameters measured in adult rats and mice such as general health status, temperature, cardiac and respiratory function, and blood constituents. We provide detailed CDE tables and case report forms (CRFs), and with this companion manuscript we discuss the monitoring of different aspects of physiology of the animals. The CDEs, CRFs, and companion paper are available to all researchers, and their use will benefit the harmonization and comparability of translational preclinical epilepsy research. The ultimate hope is to facilitate the development of biomarkers and new treatments for epilepsy.

Depression is a common comorbidity in people with epilepsy (PWE) that negatively affects self-management and a variety of health outcomes. Suicidal ideation is also more common among PWE than the general population. We examined correlates of depressive symptoms and suicidal ideation in adults using pooled data from epilepsy self-management studies conducted by sites in the Centers for Disease Control and Prevention (CDC) Research Center's Managing Epilepsy Well (MEW) Network that assessed depression severity with the 9-item Patient Health Questionnaire (PHQ-9). Of the 770 subjects in the analysis (mean age 42.4 ± 13.0 years), the mean total PHQ-9 score was 9.4 ± 6.6 and 334 subjects (43.4%) had moderate to severe depressive symptoms (PHQ-9 ≥ 10). Only ongoing seizures and low education were associated with moderate-severe depressive symptoms in multiple logistic regression analysis. Suicidality (PHQ-9, item 9 score ≥ 1) was endorsed by 155 subjects (20.1%). Only nonsuicidal depressive symptoms were associated with suicidality in multiple variable logistic regression analysis. We show in this large and regionally diverse dataset that both depression and suicidal ideation are common among PWE enrolled in self-management studies. Future studies are needed to examine whether suicidality exists independently of other depressive symptoms in some populations with epilepsy and investigate other correlates of suicidality that may inform screening practices.

OBJECTIVE:Both drowning and sudden unexpected death in epilepsy (SUDEP) are diagnoses of exclusion with predominantly nonspecific autopsy findings. We hypothesized that people with epilepsy found dead in water with no clear sign of submersion could be misdiagnosed as SUDEP. METHODS:All reported seizure-related deaths undergoing medicolegal investigation in three medical examiner's offices (New York City, Maryland, San Diego County) over different time periods were reviewed to identify epilepsy-related drownings and SUDEPs. Drowning cases that fulfilled inclusion criteria were divided into two groups according to the circumstances of death: definite drowning and possible drowning. The SUDEP group included two sex- and age (±2 years)-matched definite SUDEP/definite SUDEP plus cases for each drowning case. RESULTS:Of 1346 deaths reviewed, we identified 36 definite (76.6%) and 11 possible drowning deaths (23.4%), most of which occurred in a bathtub (72.3%). There were drowning-related findings, including fluid within the sphenoid sinuses, foam in the airways, clear fluid in the stomach content, and lung hyperinflation in 58.3% (21/36) of the definite drowning group, 45.5% (5/11) of the possible drowning group, and 4.3% of the SUDEP group (4/92). There was no difference in the presence of pulmonary edema/congestion between the definite drowning group, possible drowning group, and SUDEP group. The definite drowning group had a higher mean combined lung weight than the SUDEP group, but there was no difference in mean lung weights between the possible drowning and SUDEP groups or between the possible drowning and definite drowning groups. SIGNIFICANCE/CONCLUSIONS:No distinguishable autopsy finding could be found between SUDEPs and epilepsy-related drownings when there were no drowning-related signs and no clear evidence of submersion. SUDEP could be the cause of death in such possible drowning cases. As most drowning cases occurred in the bathtub, supervision and specific bathing precautions could be effective prevention strategies.