Purpose Brain–computer interfaces (BCIs) offer a pathway to restore ambulation in indi-viduals with spinal cord injury (SCI). However, existing BCI systems for gait are unidirectional and lack sensory feedback. This study aimed to demonstrate that a bidirectional brain–computer interface (BDBCI) can simultaneously enable real-time brain-controlled walking and artificial leg sensation via electrical stimulation of the sensory cortex. Methods Epilepsy patients undergoing bilateral interhemispheric subdural electrocorticog-raphy (ECoG) implantation were recruited for this proof-of-concept study. Motor mapping identified electrodes in the leg motor cortex for decoding stepping intent, while sensory stimu-lation mapping determined stimulation sites in the somatosensory cortex to elicit artificial leg percepts. A custom embedded BDBCI decoded motor intent in real time to actuate a robotic gait exoskeleton (RGE) from ECoG signals and delivered leg swing sensory feedback via direct cortical stimulation. Performance was assessed through correlations between cued and decoded states, sensory reliability tasks, and control experiments. Results One subject was recruited and achieved a high decoding performance (ρ = 0.92 ± 0.04, lag of 3.5 ± 0.5 s) across 10 runs of operating the BDBCI-controlled RGE. Bilateral leg percepts were validated through a blind step-counting task (92.8% accuracy, p < 10−6). Control experiments verified that decoding was not affected by stimulation artifacts. No adverse events were reported. Discussion This study establishes the feasibility of an embedded system BDBCI for restor-ing both motor control and artificial sensation of walking. Leveraging interhemispheric leg sen-sorimotor cortices is safe and yields superior decoding compared to prior lateral brain convexity approaches. These findings provide a foundation for translating BDBCI technology into fully implantable systems for SCI patients with paraplegia.
BACKGROUND:Reviews of adverse events (AEs) in patients with cardiac implantable electronic devices (CIEDs) during catheter ablation predate newer devices, procedures, and ablation technologies (eg, pulsed field [PF], lattice-tip radiofrequency [RF]). OBJECTIVE:This study aimed to characterize AEs in contemporary patients with CIED undergoing ablation and identify implications for safer practice. METHODS:We analyzed 433 AEs from the US Food and Drug Administration's Manufacturer and User Facility Device Experience database and peer-reviewed literature (2020-2025), focusing on newer technologies. RESULTS:Ablation catheters or energy caused 97% of AEs (RF 89%; PF 8%). Mechanical interactions caused 32% of AEs (30% dislodgements). Electromagnetic interactions (68%) included myocardial thermal injury (34%), generator dysfunction (20%), oversensing (9%), and induction of ventricular fibrillation (5%). Interventions (generator/lead replacement/repositioning) occurred in 56% of cases. Thermal injury with loss of capture necessitated replacement or repositioning of 53 transvenous leads and 32 leadless pacemakers, often when ablation sites were ≥2 cm from tip electrodes. Lattice-tip RF near Biotronik implantable cardioverter-defibrillator leads induced 14 of 15 RF-related ventricular fibrillations. PF accounted for all 6 confirmed generator failures. No cryoablation AEs were reported. CONCLUSION:This first and largest comprehensive series of ablation-related complications in contemporary patients with CIED underscores the underappreciated risks of older technology and highlights novel risks of evolving technologies. A notable finding is that most threshold elevations requiring intervention occurred at ablation sites remote from CIED tip electrodes. More than 40% of AEs seemed largely preventable, suggesting gaps in procedural workflows. Our results suggest opportunities to improve clinical practices and CIED design to safeguard patients.
BACKGROUND:Hepatitis B surface antigen (HBsAg) can be derived from intrahepatic covalently closed circular DNA (cccDNA) and integrated hepatitis B virus (HBV) DNA (iDNA). OBJECTIVE:We evaluated the cccDNA and iDNA from liver tissues of 24 hepatitis B e antigen (HBeAg)(+) and 32 HBeAg(-) treatment-naïve chronic hepatitis B (CHB) participants in the North American Hepatitis B Research Network. DESIGN:For cccDNA analysis, DNA was heat-denatured and digested by plasmid-safe ATP-dependent DNase to remove relaxed circular DNA and iDNA before real-time polymerase chain reaction. For iDNA detection, total DNA was subjected to HBV hybridisation-targeted next generation sequencing assay for identification of the HBV-host junction sequences. Comparisons of HBV cccDNA and iDNA with other virological biomarkers were assessed. RESULTS:Intrahepatic cccDNA, serum HBV DNA, HBV RNA, hepatitis B core related antigen and quantitative hepatitis B surface antigen were higher in HBeAg(+) CHB. Intrahepatic hepatitis B core antigen staining was present in 87% HBeAg(+) but only 13% HBeAg(-) samples (p<0.0001). HBsAg staining was frequent in over 85% in both groups. 23 (95.8%) HBeAg(+) participants had ≤50% iDNA whereas 25 (78.1%) HBeAg(-) participants had >50% iDNA of total HBV DNA in their livers. For HBeAg(+) CHB, the iDNA integration sites were random with only 15.9% localised to the direct repeat 2 (DR2)-DR1 region. For HBeAg(-) CHB, 52.4% of the iDNA integrations were clustered at DR2-DR1. Microhomology-mediated end joining patterns of double-stranded linear DNA HBV integration was more frequent in HBeAg(+) livers. CONCLUSION:HBeAg(-) CHB was associated with high HBsAg staining concentration despite low cccDNA levels suggesting that iDNA was the primary source of HBsAg. The high frequency of DR2-DR1 iDNA distribution in HBeAg(-) CHB suggests the selection advantage and clonal expansion of this integrant in the natural history of CHB.
BACKGROUND:Prior reports of internal jugular vein (IJV) access for implantation of leadless pacemakers (LLPM) are primarily small series and for ventricular LLPM. OBJECTIVES:To describe outcomes of consecutive patients undergoing IJV access for both atrial and ventricular LLPM implantation. METHODS:This observational multicenter study included 32 consecutive patients (17 female; 69 ± 14 years; range 17-91) undergoing LLPM implantation via IJV access. Dual chamber LLPM was implanted in 16 patients, right ventricular (RV) only in 13, and right atrial (RA) only in 3. Electrical parameters were measured at implantation, 7-10 days post implantation, and at last follow-up (mean 215 ± 98 days). RESULTS:IJV access was successful in all patients. Mean procedure and fluoroscopy times were 82 ± 40 and 16 ± 9 min, respectively. RV implant required 1.3 ± 0.6 deployments with mean of 21 min and RA implant required 1.6 ± 0.9 deployments with mean of 31 min. Electrical parameters were excellent. Current of injury for the RA LLPM is the primary indicator of engagement of the atrial myocardium. Two device-related complications occurred without clinical sequelae; no late complications were observed. Fifteen patients were discharged the same day. CONCLUSIONS:IJV access for atrial and ventricular LLPM implantation is safe and effective across a broad age range and is an alternative to FV access, enabling same-day discharge and early ambulation. Elevated acute atrial capture thresholds with robust current of injury should not prompt repositioning, as thresholds significantly improve at early follow-up.
