Epileptic activity in neurological deterioration after ischemic stroke, a continuous EEG study

Despite improvement in acute stroke care, almost 40% of patients with ischemic stroke present neurological deterioration. Neurological deterioration is associated with higher death and dependency rates. Neurological deterioration mechanisms are unknown, and half of neurological deterioration remains unexplained. We postulate that a substantial proportion of neurological deterioration in ischemic stroke is associated with periodic discharges/non-convulsive seizures that negatively impact the recovery of ischemic stroke and worsen symptoms.Retrospective review of 24 h continuous EEG monitoring (cEEG) performed for neurological deterioration in the stroke unit of a tertiary academic centre.Eighty-one patients were included. cEEG detected epileptic activities in 44% of cases (Non-convulsive seizures/non-convulsive status epilepticus: 10/81 (12%), periodic discharges: 17/81 (21%) and sporadic epileptiform discharges in 14/81 (17%)). The proportion of patients who did not receive recanalization therapy was significantly higher in the NCSE/NCSz/PDs group than in the group devoid of NCSE/NCSz/PDs: 17/22 (77%) vs 13/59 (22%); p < 0,001. Treatment of Non-convulsive seizures /non-convulsive status epilepticus and periodic discharges was followed by EEG improvement in respectively 7/8 and 10/16 of treated patients.Non-convulsive seizures /non-convulsive status epilepticus /periodic discharges are associated to neurological deterioration after ischemic stroke.Treatment of Non-convulsive seizures /non-convulsive status epilepticus and periodic discharges, if such patterns are detected, could help prevent adverse metabolic consequences of epileptic activities on ischemic brain tissue.