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Rafi, P.

Publications and source records attributed to Rafi, P..

2 recordsLinked to original sources

Phase-dependent closed-loop intersectional short-pulse stimulation reduces seizure duration: From computational modeling to clinical application

Drug-resistant epilepsy affects one-third of patients with persistent seizures despite optimal therapy. Intersectional short-pulse (ISP) stimulation is a novel transcranial electrical stimulation technique designed to deliver temporally precise, spatially targeted modulation of pathological brain activity. Here, we combined computational modeling with measurements in a rat epilepsy model and in patients with epilepsy to map the relationship between stimulation phase and seizure attenuation. In silico simulations of epileptiform networks showed that ISP stimulation significantly shortened seizure duration, with efficacy strongly depending on the phase of delivery. Phase-targeted stimulation during the rising phase and around the peaks (~45-90{degrees}) of the seizure oscillations led to the greatest reduction in seizure length. In rodents, ISP decreased seizure duration by 42.4% and shortened generalized seizure segments by 58.3%. In humans, stimulation reduced seizure length by 60.9% compared to control seizures. Phase dependence was evident across models and species, with a prominent efficacy window in the rising-to-peak portion of the ictal oscillation and model-specific secondary windows. These findings show that phase-targeted ISP can substantially shorten seizures and support phase-resolved stimulation as a precision-neuromodulation approach for epilepsy.

neuroscience↗

Non-vectorial Integration of Intersectional Short-Pulse Stimulation Enables Enhanced Deep Brain Modulation and Effective Seizure Control

Transcranial electrical stimulation (TES) holds promise to treat neurological disorders, but its efficacy is limited by poor spatial focality and depth of penetration. Here, we examined the potential utility of Intersectional Short-Pulse (ISP) stimulation of deeper brain penetration. Using computational modeling and in vivo patch-clamp recordings in rats, we demonstrate that neurons integrate ISP-induced electric fields in a non-vectorial manner. This mechanism allows ISP to overcome some limits of conventional TES, achieving spatially limited stimulation across cortical and subcortical structures. In a rat model of temporal lobe epilepsy, closed-loop ISP stimulation significantly outperformed conventional TES in reducing seizure duration and severity. ISP reduced hippocampal seizure duration by 49% and 41% compared to sham stimulation and conventional TES and significantly reduced motor seizure severity. Our findings demonstrate that ISP stimulation can rapidly terminate hippocampal seizures, offering a potential new approach for non-invasive neuromodulation with applications across diverse neurologic and psychiatric disorders.

neuroscience↗