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De novo mutations in voltage- and ligand-gated channels have been associated with an increasing number of cases of developmental and epileptic encephalopathies, which often fail to respond to classic antiseizure medications. Here, we examine two knock-in mouse models replicating de novo sequence variations in the human HCN1 voltage-gated channel gene, p.G391D and p.M153I (Hcn1G380D/+ and Hcn1M142I/+ in mouse), associated with severe drug-resistant neonatal- and childhood-onset epilepsy, respectively. Heterozygous mice from both lines displayed spontaneous generalized tonic–clonic seizures. Animals replicating the p.G391D variant had an overall more severe phenotype, with pronounced alterations in the levels and distribution of HCN1 protein, including disrupted targeting to the axon terminals of basket cell interneurons. In line with clinical reports from patients with pathogenic HCN1 sequence variations, administration of the antiepileptic Na+ channel antagonists lamotrigine and phenytoin resulted in the paradoxical induction of seizures in both mouse lines, consistent with an impairment in inhibitory neuron function. We also show that these variants can render HCN1 channels unresponsive to classic antagonists, indicating the need to screen mutated channels to identify novel compounds with diverse mechanism of action. Our results underscore the necessity of tailoring effective therapies for specific channel gene variants, and how strongly validated animal models may provide an invaluable tool toward reaching this objective., This work was supported by grants from the German Research Foundation (DFG, FOR 2715) (IS63/10-1/2) and CRC 1451 (project ID 431549029-B01) to DI; Telethon award GGP20021 to AMo; NIH grants NS106983, NS109366, and NS123648 to SAS; NIH CCSG grant NCI 5P30CA013696-44 and the Columbia Precision Medicine Initiative for the generation of mouse models of human disease.

Background and Purpose: The impact of statins on hematoma characteristics, perihemorrhagic edema (PHE), cardiovascular events, seizures, and functional recovery in patients with intracerebral hemorrhage (ICH) is insufficiently studied. Methods: Patients with ICH of the prospective UKER-ICH (Universitätsklinikum Erlangen Cohort of Patients With Spontaneous Intracerebral Hemorrhage) study (URL: https://www.clinicaltrials.gov ; Unique identifier: NCT03183167) were analyzed by multivariable regression modeling and propensity score matching, and PHE volumes were volumetrically assessed. Outcomes comprised hematoma characteristics, the impact of continuation, discontinuation, and initiation of statins on peak PHE extent, and the influence of statin treatment on the occurrence of seizures, cardiovascular adverse events, and functional recovery after ICH. Results: A total of 1275 patients with ICH with information on statin treatment were analyzed. Statin treatment on hospital admission (21.7%) was associated with higher rates of lobar versus nonlobar ICH (odds ratio, 1.57 [1.03–2.40]; P =0.038). Initiation of statins after ICH was associated with increased peak PHE (β=0.12, SE=0.06, P =0.008), whereas continuation versus discontinuation of prior statin treatment was not significantly associated with edema formation ( P >0.10). There were no significant differences in the incidence of remote symptomatic seizures according to statin exposure during follow-up (statins: 11.5% versus no statins: 7.8%, subdistribution hazard ratio: 1.15 [0.80–1.66]; P =0.512). Patients on statins revealed less cardiovascular adverse events and more frequently functional recovery after 12 months (functional recovery: 57.7% versus 45.0%, odds ratio 1.67 [1.09–2.56]; P =0.019). Conclusions: Among statin users, lobar ICH occurs more frequently as compared with nonstatin users. While continuation of prior statin treatment appears to be safe regarding PHE formation, the initiation of statins during the first days after ICH may increase PHE extent. However, statins should be initiated thereafter (eg, at hospital discharge) to prevent cardiovascular events and potentially improve functional recovery.

To determine long-term seizure outcome, use of antiseizure medication (ASM) and seizure recurrence risk after its withdrawal in patients with autoimmune encephalitis (AE) due to neuronal surface and GAD antibodies.In patients from a specialized AE outpatient clinic, we assessed seizure manifestation, ASM and immunotherapy at onset of AE as well as seizure occurrence, development of autoimmune-associated epilepsy (AAE) and use of ASM in the long-term. Data were collected from patients via telephone interviews and medical records.Out of 94 AE patients, 75 were analyzed; 47 patients had NMDAR, 17 LGI1, 7 GAD, 3 CASPR2 and 1 mGluR5 antibodies. Fifty-three of the 75 patients (71 %) experienced seizures, all of which for the first time occurred at AE onset. After a median follow-up of 6 years (range, 1-15), 47 of the 53 AE patients had 1-year terminal seizure remission, median duration of terminal seizure freedom was 5 years. Rate of 1-year terminal seizure remission was significantly higher in patients with neuronal surface antibodies (NMDAR 97 %, LGI1 93 %, CASPR2 100 %) compared to patients with GAD antibodies (20 %, p < 0.001). In seizure-free patients, ASM was withdrawn after 13 months (median) without any relapse seizures.Seizures are common in most forms of AE manifesting at disease onset in all cases. However, the development of AAE is rare and typically occurs in patients with GAD antibodies. Thus, in most AE cases with neuronal surface antibodies, ASM can be withdrawn after the acute phase of AE with low risk of seizure relapse.