A 40-year-old man comes to the emergency department 30 minutes after experiencing a seizure. Over the past 3 months, the patient has had several episodes of brief twitching of the right hand, but today the abnormal movement gradually progressed to involve the entire right upper extremity, followed by shaking of the whole body for about a minute. He also lost consciousness and urinated involuntarily during the event. The patient feels groggy and has a mild headache. He has no other medical conditions but reports several concussions from playing football in college. Vital signs are within normal limits. Physical examination shows mild weakness of right hand grip but is otherwise normal. This patient's seizure presentation is most suggestive of which of the following etiologic processes?
A.Diffuse cerebral hypoperfusion
B.Focal structural abnormality
C.Genetic epilepsy syndrome
D.Neuroexcitatory substance use
E.Neuronal metabolic disturbance
