Abstracts

Rationale: The subtle and sometimes atypical semiology of seizures in the elderly are confounded by coexisting conditions that complicate the clinical diagnosis of epilepsy. The diagnostic yield of routine EEG for epilepsy diminishes with age. Reports on the value of VEEG in the elderly have seldom addressed the diagnostic characteristics of new-onset “elder spells." Methods: A retrospective analysis was performed on patients 60 years and older who underwent inpatient long-term VEEG monitoring at the Strong Epilepsy Center, University of Rochester, NY from 1999 to 2008 and whose spells began after the age of 60 years. Prior routine EEG findings, treatment history, psychosocial evaluation and VEEG diagnoses were tabulated and compared to a group of elderly patients who underwent VEEG evaluation for events beginning prior to the age of 60 years. Results: A total of 69 patients were identified whose spells in question began after the age of 60. The average age was 70 years (range 60-92), and 52% were male. Diagnostic events were recorded in 63 patients, and interictal findings sufficient for diagnosis in an additional two patients for a total diagnostic yield of 94%. 24 patients (35%) were diagnosed with epilepsy on the basis of recorded seizures (22 patients) or newly identified interictal discharges (2 patients). 14 patients (20%) had psychogenic nonepileptic attacks (PNEA). 23 patients (33%) were classified as having other nonepileptic events, 4 patients (6%) with mixed epileptic-nonepileptic events, and 4 (6%) were indeterminate. Epileptic seizures were temporal in 50% and focal-onset extratemporal in 29%. 71% of patients with PNEA had a history of abuse or relevant psychosocial stressors, and 79% were taking antiseizure medications. The identification of “other nonepileptic” spells led to treatable diagnoses in 75% of cases. Prior routine EEG showed interictal epileptiform discharges in only 33% of our patients with new onset epilepsy. Routine EEG findings such as wickets, BETS and SREDA had erroneously been interpreted as “epileptiform” in 27% of patients with PNEA. Compared to 70 patients 60 years or older who underwent VEEG monitoring for “elder spells” with an onset prior to the age of 60, patients with new onset spells were more likely to experience “other nonepileptic” events (33% vs. 4%) and less likely to have epileptic seizures (35% vs. 67%). Conclusions: These results confirm a broad differential diagnosis of new-onset “elder spells” in patients over 60 years, and highlight the prevalence of non-psychogenic nonepileptic events. A comprehensive diagnostic approach, utilizing VEEG, cardiac monitoring, hemodynamic testing, and intensive psychosocial evaluation can effectively identify treatable conditions responsible for new-onset spells in the elderly.