Smith, Kelsey M.

AbstractThe aim of this study is to report three cases of epilepsy with eyelid myoclonia (EEM) with CHD2 pathogenic variants. A database of 134 patients with EEM evaluated at Mayo Clinic sites was searched to identify patients with CHD2 variants. The medical records of those identified were reviewed to describe their presentation, treatment, and clinical course. Three patients (2 males, 1 female) with EEM were found to harbor de novo CHD2 pathogenic variants (c.2636C>T p.(Ala879Val), c.3734delA p. (Lys1245Asnfs*4), and c.3896delTinsCG p. (Val1299Alafs*5)). All three patients had comorbid autism spectrum disorder (ASD), intellectual disability (ID), and attention deficit disorder (ADHD). Eyelid myoclonia was a prominent seizure type that persisted in the three patients despite trials of multiple antiseizure medications. Generalized tonic–clonic seizures occurred in two of the patients but were controlled with antiseizure medications. Genetic testing should be considered in patients presenting with EEM, especially when ADHD, ID, ASD, and drug‐resistant seizures are present. Further understanding of the relationship between CHD2 variants and epileptogenesis may provide important insights into the pathogenesis of EEM.

AbstractEpilepsy associated with high‐titer glutamic acid decarboxylase 65 (GAD65) IgG is often refractory to immunotherapies and antiseizure medication. This study sought to determine the efficacy of vagus nerve stimulation (VNS) and surgical resection in patients with drug‐resistant epilepsy associated with GAD65‐IgG. We retrospectively identified 15 patients with drug‐resistant epilepsy and high serum GAD65 antibody titers (>20 nmol·L−1) who underwent VNS implantation (n = 6), surgical resection (n = 7), or both (n = 2). A responder to VNS was defined as someone with a ≥50% reduction in seizure frequency, and a favorable surgical outcome was defined as Engel I–II. Of the eight patients who underwent VNS implantation, three (37.5%) were initially responders, but this was not sustained in two. Of the nine patients who underwent surgical resection, three (33.3%) had a favorable outcome; however, only one patient was seizure‐free at last follow‐up. Pathology was available in six patients, and only one had evidence of inflammation; this patient had seizure onset 1 year prior to surgery. Favorable seizure outcome correlated with older age at time of resective surgery, with a trend favoring later age of seizure onset. Taken together, surgical resection and VNS implantation may have limited efficacy in this patient population but can be considered in carefully selected cases.

AbstractWith the discovery of an expanding number of neural autoantibodies, autoimmune etiologies of seizures have been increasingly recognized. Clinical phenotypes have been identified in association with specific underlying antibodies, allowing an earlier diagnosis. These phenotypes include faciobrachial dystonic seizures with LGI1 encephalitis, neuropsychiatric presentations associated with movement disorders and seizures in NMDA‐receptor encephalitis, and chronic temporal lobe epilepsy in GAD65 neurologic autoimmunity. Prompt recognition of these disorders is important, as some of them are highly responsive to immunotherapy. The response to immunotherapy is highest in patients with encephalitis secondary to antibodies targeting cell surface synaptic antigens. However, the response is less effective in conditions involving antibodies binding intracellular antigens or in Rasmussen syndrome, which are predominantly mediated by cytotoxic T‐cell processes that are associated with irreversible cellular destruction. Autoimmune encephalitides also may have a paraneoplastic etiology, further emphasizing the importance of recognizing these disorders. Finally, autoimmune processes and responses to novel immunotherapies have been reported in new‐onset refractory status epilepticus (NORSE) and febrile infection‐related epilepsy syndrome (FIRES), warranting their inclusion in any current review of autoimmune‐associated seizure disorders.

Purpose: Temporal encephaloceles are a cause of drug-resistant temporal lobe epilepsy; however, their relationship with epileptogenesis is unclear, and optimal surgical resection is uncertain. EEG source localization (ESL) may guide surgical decision-making. Methods: We reviewed patients at Mayo Clinic Rochester with drug-resistant temporal lobe epilepsy and temporal encephaloceles, who underwent limited resection and had 1-year outcomes. EEG source localization was performed using standard density scalp EEG of ictal and interictal activity. Distance from dipole and standardized low-resolution brain electromagnetic tomography (sLORETA) solutions to the encephalocele were measured. Concordance of ESL with encephalocele and surgical resection was compared with 1-year surgical outcomes. Results: Seventeen patients met criteria. The mean distances from ESL results to encephalocele center for dipole and sLORETA analyses were 23 mm (SD 9) and 22 mm (SD 11), respectively. Ten patients (55.6%) had Engel I outcomes at 1 year. Dipole-encephalocele distance and sLORETA-encephalocele distance were significantly longer in patients with Engel I outcome and patients whose encephalocele was contained by sLORETA had worse outcome as well; however, multiple logistic regression analysis found that only containment of encephalocele by the sLORETA current density was significant (P < 0.05), odds ratio 0.12 (95% confidence interval [0.021, 0.71]). Conclusions: EEG source localization of scalp EEG localizes near encephaloceles, however, typically not in the encephalocele itself; this may be due to scalp EEG sampling propagated activity or alternatively that the seizure onset zone extends beyond the herniated cortex. Surprisingly, we observed increased ESL to encephalocele distances in patients with excellent surgical outcomes. Larger cohort studies including intracranial EEG data are needed to further explore this finding.

AbstractThe objective of this study was to determine seizure control in women with epilepsy (WWE) undergoing assisted reproductive technology (ART). Through retrospective chart review, WWE undergoing ART were identified. Demographics and details regarding epilepsy type, seizure control, and ART procedures were extracted. Seizure frequency prior to and during ART were compared. We identified 12 WWE, who underwent 29 embryo transfers, resulting in 16 pregnancies and 10 live births. Nine women were seizure‐free at least 2 years before fertility treatment, including three with resolved epilepsy. Seven were on antiseizure medications throughout fertility treatment and pregnancy, with only one on polytherapy. Eleven (all with controlled epilepsy or epilepsy in remission) remained seizure‐free throughout fertility treatment. One woman with drug‐resistant epilepsy continued to have seizures throughout fertility treatment and pregnancy without an exacerbation of seizure frequency. There was no increased seizure frequency associated with fertility treatment and subsequent pregnancy in this small series of WWE. Although this study was statistically underpowered, our results provide some preliminary evidence that ART might not pose a threat to seizure control, but larger, confirmatory studies are necessary.