Abstracts

Rationale: The non-convulsive nature of seizures in the elderly often makes correct diagnosis difficult; many patients are initially misdiagnosed as having dementia or stroke. Senile physiological changes in cerebral blood flow and metabolism, neurotransmitter activity, and the brain reaction to epilepsy may clinically affect the postictal period. We hypothesize that the clinical presentation of postictal states in geriatric onset epilepsy (GOE; age of onset 55 years or older) differs from non-GOE (age of onset less than 55 years).Methods: Upon IRB approval of this study, we retrospectively obtained the list of all patients in our university outpatient practice age 65 years or older at our institution between January 2012-July 2014 with the probable diagnosis of seizure and epilepsy utilizing ICD-codes 345/780. 431 patients were identified and screened for eligibility. Patients with unconfirmed diagnosis of epilepsy, psychogenic non-epileptic seizures, syncope, vertigo, transient ischemic attack, who were not on antiepileptic drugs and who had a follow-up period less than 30 days were excluded. Age of onset of seizures was identified, and 236 eligible patients were stratified into GOE and non-GOE groups. Detailed collection of demographic and clinical data including postictal duration and type (confusion vs. fatigue) were performed using witness reports from patients’ medical records.Results: Mean postictal duration was noted for 34 patients: in the GOE group (n= 24) (943.2 ± 283.8 minutes) it was longer than in the non-GOE group (n=10) (191 ± 439.7 minutes). Postictal symptomatology was described in 84 patients: 92% of GOE patients presented with confusion compared to 72% of non-GOE patients (p < 0.05), the second most common presentation was fatigue in both groups. Postictal periods following secondarily generalized seizures were longer than those following complex partial seizures in GOE (1238 ± 468 minutes vs. 787 ± 549 minutes) and non-GOE groups (369 ± 224 minutes vs. 102 ± 272 minutes) (p value < 0.05 for both groups).Conclusions: Significantly longer postictal periods of confusion, being the most common presentation in GOE lend themselves to the misdiagnosis of dementia or stroke. While seizures that secondarily generalize lead to longer postictal periods in both GOE and non-GOE, even partial onset seizures in GOE have longer symptomatic postictal periods. Thus highlighting the diagnostic challenge of this vulnerable elderly population poses to the clinician.