A 31-year-old patient named Y who was born and raised in Guatemala presents to the Emergency Department after being found by having a generalized tonic-clonic seizure. Y had never before had seizures, including during childhood. Preceding this event, Y had not been experiencing constitutional symptoms, and has been active with exercise and work at their office job without difficulty. Brain imaging with an MRI is performed and is shown below
What of the following is the next best appropriate step after initial laboratory evaluation?