Short duration of focal onset awareness and impaired awareness seizure are characteristic features of epilepsy in elderly patients

PURPOSE: Diagnosing epilepsy in the elderly population can be difficult due to mimicking symptoms. Furthermore, epileptic symptoms can also be masked by various symptoms. We hypothesized that elderly patients with epilepsy exhibit specific clinical features among the various symptoms. PATIENTS AND METHODS: From 2009 to 2017, 177 patients who were older than 65 years were referred to our epilepsy center. Out of this group, the onset of symptoms occurred after reaching the age of 50 years in 152 of the patients, who were additionally being treated at our clinic. We divided their symptoms in accordance with their consciousness levels, which were defined as follows: full wakefulness level I, impaired awareness level II, and loss of consciousness level III. We also classified the duration of the symptoms as <10 seconds, ≥10 seconds but <1 minute, ≥1 minute but <5 minutes, ≥5 minutes but <10 minutes, ≥10 minutes but <1 hour, and ≥1 hour. RESULTS: Among the 152 patients analyzed (mean age 72.9 years, standard deviation 6.71, range 65–92), 84 patients had epilepsy (epilepsy group) while 68 did not exhibit epilepsy (nonepilepsy group). For the consciousness levels, there were more level I patients in the nonepilepsy vs epilepsy group (P<0.028), with symptom duration lasting <1 minute (sensitivity 0.857, specificity 1) in the epilepsy group. In contrast, there were more level II patients in the epilepsy vs the nonepilepsy group (P=0.015), with the duration of symptoms lasting <1 minute (sensitivity 0.8125, specificity 0.930) in the epilepsy group. For the level III consciousness, convulsions were more commonly seen in the epilepsy group (P=0.044). CONCLUSION: Symptoms that last <1 minute with awareness and impaired awareness might be epileptic in the elderly population.