RESUMO
BACKGROUND: Focal cortical dysplasias (FCD) represent highly intrinsically epileptogenic lesions that require complete resection for seizure control. Resection of pure motor strip FCD can be challenging. Effective control of postoperative seizures is crucial and extending the boundaries of resection in an eloquent zone remains controversial. OBSERVATIONS: The authors report a 52-year-old right-handed male with refractory epilepsy. The seizure phenotype was a focal crisis with preserved awareness and a clonic motor onset of right-hemibody. Epilepsy surgery protocol demonstrated a left pure motor strip FCD and a full-awake resective procedure with motor brain mapping was performed. Further resection of surgical boundaries monitoring function along intraoperative motor tasks with no direct electrical stimulation corroborated by intraoperative-neuromonitorization was completed as the final part of the surgery. In the follow-up period of 3-years, the patient has an Engel-IB seizure-control with mild distal lower limb palsy and no gate compromise. LESSONS: This report represents one of the few cases with pure motor strip FCD resection. In a scenario similar to this case, the authors consider that this variation can be useful to improve seizure control and the quality of life of these patients by extending the resection of a more extensive epileptogenic zone minimizing functional damage.
RESUMO
BACKGROUND: Magnetic stimulation of the facial nerve has been tested in preclinical studies as a new, non-invasive emergency treatment of ischemic stroke that acts by increasing cerebral blood flow (CBF). The objective of the studies reported herein was to identify minimal stimulation parameters that increase CBF in large animals and then test those stimulation parameters in healthy volunteers for safety, tolerability, and effectiveness at increasing CBF. This translational research is necessary preparation for clinical studies in ischemic stroke patients. METHODS: Initial experiments in anesthetized Yorkshire pigs were undertaken in order to identify the lowest stimulus power and duration that increase CBF. A full 3 × 3 factorial design was used to evaluate magnetic stimulation of the facial nerve at various stimulation powers (1.3, 1.6, and 1.9 Tesla field strength at coil surface) and for various durations (2, 3.5, and 5 min). CBF was measured with contrast MRI perfusion imaging and the internal carotid arteries were assessed with MR angiography. Magnetic facial nerve stimulation with parameters identified in the pig study was then applied to 35 healthy volunteers. Safety was assessed with adverse event reports and by medical examination. Tolerability was defined as each volunteer's ability to withstand at least 2 min of stimulation. Volunteers could determine the maximum power of stimulation they received during a ramp-up period. RESULTS: In pigs, unilateral facial nerve stimulation increased CBF by as much as 77% over pre-stimulation baseline when administered across a range of 1.3-1.9 Tesla power and for 2- to 5-min duration. No clear dose-response relationship could be observed across this range, but lower powers and durations than these were markedly less effective. The effect of a single stimulation lasted 90 min. A second stimulation delivered 100 min after the first stimulation sustained the increased CBF without evidence of tachyphylaxis. In human, bilateral facial nerve stimulation caused only non-serious adverse events that were limited to the 2-min stimulation period. Tolerability was greatly improved by gentle encouragement from the study staff, which enabled most volunteers to tolerate 1.6-1.8 Tesla of stimulation power. CBF measures taken approximately 10 min after stimulation demonstrated on average a 32 ± 6% increase in CBF, with ≥ 25% increases in CBF occurring in 10 of the 31 volunteers who had adequate CBF measurements. CONCLUSIONS: The minimal effective stimulation parameters defined by increased CBF, as identified in the pig study, translated into safe, tolerable, and effective stimulation of healthy volunteers. These results support the future development and evaluation of non-invasive facial nerve stimulation for the emergency treatment of ischemic stroke. Trial Registration retrospectively registered with clinicaltrials.gov NRV_P1_01_15 on June 6, 2017.