TU-159. Repetitive transcranial magnetic stimulation as a therapeutic approach in a case of NORSE

ABSTRACT

Introduction: Status epilepticus (SE) is a neurologic emergency with high-mortality rates that requires early diagnosis and prompt treatment to improve the patient's chances. A SE is called refractory (RSE) when seizures are uncontrollable despite intravenous (IV) benzodiazepine in addition to anti-epileptic drugs (AED). If seizures continue despite IV-AED and/or IV-anesthetics, that is designated as super-RSE (SRSE). Recently, new-onset RSE (NORSE) has been described. The current armamentarium of AEDs, immunomodulation-drugs and non-pharmacological therapies available, including neuromodulation techniques, has been used to treat RSE. Lately, the use, efficacy, and safety of repetitive-transcranial-magnetic-stimulation (rTMS) are well known. Method(s) In October 2020, a 23-year-old male with a low level of consciousness and clinical SE was admitted to an intensive care unit. A febrile peak, the previous week, was the only pertinent data. SARS-CoV2 test was negative, although it became positive a week later. While in the hospital, SE therapeutic protocol was followed (antivirals, antibiotics, and AEDs, anesthetics, including cortical electrical silence pentothal-induced, immunomodulation drugs (tocilizumab, anakinra), and ketogenic diet) without achieving seizure control. Despite the lack of continuous electroencephalography (EEG) monitorization, daily EEGs were recorded and a diffuse slow-wave cortical activity led the way to bihemispheric fronto-temporal (FT) seizures;left-FT SE was also registered. On the 49th day, the decision was made to administer rTMS. Previously, the epileptiform zone had been located in the right-FT region. He received ten sessions of low-frequency (1-Hz) rTMS in a middle point between C4/T4. No side effects were reported. Result(s) After the first sessions, the patient's level of consciousness improved, and the EEG showed progressive improvement of the cortical slowing and the epileptiform activity over the following days. By the time of discharge, EEG activity was almost normal with some epileptiform discharge still present on the EEG record. Conclusion(s) To our knowledge, a few case series have been published on the use of low-frequency rTMS as a therapeutic approach in SE. Low-frequency rTMS applied over the active epileptogenic focus may swap the cortical excitability toward an inhibitory direction by inducing synaptic plasticity through a long-term depression mechanism, which translates into SE suppression. We cannot confirm that rTMS was the only reason for the positive outcome in this particular patient. However, the outstanding improvement of the EEG activity since the administration of rTMS, accompanied by the progressive recovery of the level of consciousness, means that this technique should be taken into account as a potential therapeutic option in the early onset of SE given its efficacy, and its harmless characteristics. Copyright © 2022