Lateralized periodic discharges associated with status epilepticus in the first year after stroke

Backgrand

Lateralized periodic discharges (LPDs) are infrequent electroencephalograph (EEG) findings, and may present in ictal or interictal form. They are regarded as potential electrophysiologic signs of convulsive or nonconvulsive status epilepticus (NCSE). We report four patients who presented with NCSE and one who presented with convulsive status epilepticus in the postictal period, characterized by LPDs in EEG recordings in the first year after stroke.

Material and methods

We prospectively evaluated patients who clinically presented with status epilepticus associated LPDs between March 2014 and March 2015. We investigated patients that presented with a new stroke occurrence. We excluded the other LPD etiologies.

EEG studies of five patients (two men) who were admitted to our emergency unit with confusion, three of whom had visual symptoms; four were treated for NCSE as diagnosed with LPDs. The fifth patient had convulsive status epilepticus with LPD in the postictal period.

Results and Discussion

None of the five patients, who were aged between 68 and 92 years, showed any etiologic factor other than a history of cerebrovascular disease (CVD). Magnetic resonance imaging studies of the patients revealed old infarcts and transitional diffusion restrictions. The clinical and EEG findings decreased substantially upon antiepileptic drug treatment. Herein, we illustrate the first patient who had confusion, visual hallucinations, and ictal and interictal LPD in her consecutive EEGs.

Conclusions

CVDs may pave the way for LPDs in patients with a history of stroke because CVDs cause structural brain damage. Patients who present with a similar clinical profile and imaging signs of stroke should be checked for NCSE, particularly in the presence of LPDs in EEGs.