Abstracts

Rationale: Assessment of outcomes of laser-induced thermal ablation in treatment of refractory epilepsy and neurocognitive comorbidities symptomatic to cortical dysplasias unamenable to conventional surgery.Methods: A 17-year-old boy developed episodic visual hallucinations, alteration of consciousness, urinary incontinence, inattention, fear, stress, worsening anxiety and obsessive compulsive disorder (OCD) without academic decline. Long-term video EEG monitoring (LTM) revealed focal rhythmic left posterior temporal, parietal, occipital spikes with visual hallucinations, indicative of seizures. Brain MRI revealed polymicrogyria in the left parieto-occipital cortex. Despite initial response to valproic acid and diazepam, he had a relapse in 2 to 4 weeks. PET CT revealed decreased FDG uptake mainly in left medial temporal-occipital region. MEG revealed left occipital epileptic focus. Given proximity to eloquent visual cortex, patient underwent MRI-guided thermal laser ablation of the focal cortical dysplasia. Following immediate seizure freedom, he had mild relapse due to a small residual lesion. Following repeat laser ablation of the residual lesion, patient had gradual improvement without further events or epileptic EEG abnormalities. A 15-year-old boy with autism spectrum disorder, neurocognitive difficulties, anxiety, OCD and intractable epilepsy due to left temporal open-lip schizencephaly, underwent LTM, revealing partial seizures (left temporal, parietal spikes), and decreased left temporal FDG uptake on PET-CT. Sequential laser-ablation of the schizencephalic cortex was performed, post-procedure MRI confirming ablation of the dysplastic cortex. A 16 year-old boy with intractable partial epilepsy (right central, parietal spikes), due a right parietal cortical dysplasia with corraborative PET-CT, underwent MRI-guided laser ablation of the dysplastic cortex, with post-procedure MRI confirming complete ablation. A 9-year-old boy with refractory partial epilepsy (left temporal spikes), electrical status epilepticus of sleep, neurocognitive/motor delays, symptomatic to septo-optic dysplasia, bilateral temporal lobe schizencephaly, diminished left anterior temporal metabolic activity on PET-CT, underwent MRI-guided laser ablation of the dysplastic cortex with complete ablation confirmed by MRI.Results: All 4 patients have been seizure free (between 4 and 30 months up to present time depending on their intervention date) with significant behavioral and cognitive improvement without significant neurological deficits.Conclusions: Favorable acute, mid/long term outcomes provide further evidence for safety and efficacy of MRI-guided thermal laser ablation as a promising novel technology that may revolutionize epilepsy surgery with elimination of perioperative risks encountered with conventional surgical techniques in cortical dysplasias, particularly those in difficult to reach anatomical regions, that are unamenable to excision with conventional neurosurgical techniques.