Abstracts

Rationale: Super refractory status epilepticus (SRSE) is associated with high morbidity and mortality. Semiology effects outcomes. Treatment options are limited with most evidence being anecdotal. The utility of surgical treatment and neuromodulation therapy for status epilepticus treatment is unclear. Few case reports described use of neuromodulation devices in treatment of SRSE. We report a single case of focal SRSE treated with responsive neuro stimulation (RNS) which is instructive for this challenging disease.

Methods: A 24-year-old female with refractory focal epilepsy with seizures of neocortical onset presented with frequent breakthrough seizures that evolved into SRSE refractory to several antiseizure medications (ASMs) (perampanel, clobazam, lacosamide, clonazepam, phenobarbital, Ativan, valproic acid) and sedatives including pentobarbital, propofol and ketamine. Seizure semiology was left facial (occasional left hand) twitch with or without altered awareness but frequent evolution to bilateral tonic-clonic activity. Scalp electroencephalogram (EEG) infrequently showed activity in the right frontocentral region but most seizures had poorly formed EEG changes involving the bilateral frontal regions. Magnetic resonance imaging (MRI) brain showed congenital absence of right caudate with diffuse right frontal cortical abnormality. Positron emission tomography (PET) brain during seizure period showed increased FDG uptake correlating to the right lateral motor cortex. Autoimmune work-up was negative. Invasive monitoring localized seizure onset zone to the right lateral motor cortex corresponding to the face region (FIGURE) and additional areas with infrequent independent seizures. For SRSE, she underwent placement of RNS device with paddle leads targeting the lateral motor and premotor cortex along with resection of other zones. Multiple subpial transection was the favored surgical strategy; however, due to left MCA infarct during burst suppression, RNS was chosen over resection. Pathology showed focal cortical dysplasia and heterotopia.

Results: Scalp EEG was resumed after surgery. RNS device system was turned ON immediately after placement with detection and stimulation parameters set to mimic seizure offset pattern based on live electrocorticography (EcoG; FIG.). Postoperatively, antiseizure medications were continued and sedation (propofol) was gradually weaned over a 10-day period with simultaneous optimization of RNS parameters periodically to maximize detection and treatment. At 3 weeks post-implantation she was free of disabling generalized convulsions with termination of status epilepticus but continued to have brief focal motor seizures. The RNS therapy indirectly helped improve the drug-induced encephalopathy although she continued several ASMs. RNS parameters continue to be optimized with a goal of meaningful seizure reduction to facilitate wakefulness and rehabilitation.

Conclusions: SRSE is an uncommon neurological emergency with often poor outcomes. Usual treatment options include ASMs and sedatives. RNS may be a treatment option for select patients with SRSE with networks involving eloquent cortex.

Funding: Please list any funding that was received in support of this abstract.: None.