Abstracts

Rationale: EEG reactivity has been studied and increasingly utilized for post cardiac arrest prognostication in recent years, absence of EEG background reactivity was found to be accurately associated with poor clinical outcome and death, particularly when combined with the presence of myoclonus, absence of hypothermia and absence of underlying toxic etiology, with poor outcome in 100% of cases in some studies, we report 2 rare cases with malignant EEG patterns, lack of reactivity and seizures with EEG reactivity reemergence 3 days later and a favorable clinical outcome. Methods: Case one: a 49-year-old female was undergoing mechanical ventilation and continuous EEG monitoring following cardiac arrest and subsequent generalized tonic-clonic seizure activity for 3 minutes and myoclonic jerks, the patient was reported to be apneic, hypoxic and pulseless with the return of spontaneous circulation achieved after 10 minutes of CPR. She was found to have PE for which she received TPA. Pupils were 3 mm in size and sluggishly reactive with absent brain stem reflexes including cough, gag reflex and oculocephalic reflex. EEG showed low voltage background with lack of reactivity and generalized spike and slow wave discharges that required IV Propofol. She was also treated with high dose IV levetiracetam and lacosamide, she did not undergo hypothermia treatment, no metabolic or toxic etiology was found, 3 days later EEG improved with treatment and EEG reactivity reemerged. She remained in ICU for 17 days and required tracheostomy and PEG tube insertion, the patient subsequently improved and she had an MRS of 1, six months later when assessed in the Neurology outpatient clinic.Case two: 67-year-old female with extensive cardiac history who had brief witnessed seizure activity without regaining of consciousness, she was found pulseless and had CPR for 15 minutes before the return of spontaneous circulation. EEG showed a highly malignant pattern. lack of reactivity, Generalized Periodic discharges GPDs and burst suppression were noted in the context of anoxic brain injury. She was treated with IV Levetiracetam and Lacosamide. 3 days later EEG reactivity was noted, the prognosis was thought to be poor initially, but the patient improved dramatically and had a good clinical recovery. Results: These 2 patients had re-emergence of EEG reactivity and a good clinical outcome despite early seizures and lack of EEG reactivity until 3 days post cardiac arrest. Conclusions: Although lack of EEG reactivity in the context of anoxic brain injury has been associated with poor prognosis, this finding cannot be consistently relied upon to guide decisions about prognostication and withdrawal of care, EEG reactivity may reemerge later on and patients may improve clinically. Funding: No funding