Abstracts

RATIONALE: The nature and scope of psychogenic non-epileptic seizures (PNES)in later life is unknown. Aside from isolated case reports, no literature exists regarding PNES in older adults, suggesting such events are likely under-recognized in this population. We describe demographic, clinical, EEG, MRI and social features of a sample of 16 older adults diagnosed with PNES via inpatient video-EEG (v-EEG) monitoring.
METHODS: Computerized databases were searched for all patients 60 years and older who underwent inpatient v-EEG monitoring between 1995 and 2000 at the Mayo Clinic Hospitals in Arizona and Florida. Only patients with v-EEG evidence of PNES were included in this study. Patients with v-EEG confirmation of epileptic seizures (ES) during this period were employed in comparative analyses.
RESULTS: Of 509 cases monitored between 1995 and 2000, 77 (15%) were age 60 and older (mean age=70.2, range=60-86 years). Psychogenic NES was documented in 16 patients (21%; 8 male, 8 female). Epilepsy was confirmed in 41 patients (53%; 24 male, 17 female).
Psychogenic NES and ES groups did not differ in age (mean age = 69.3 and 68.8, respectively). The frequency of pre-admission AED treatment was equivalent between groups but did differ by gender in patients with PNES; all male patients but only 63% of female patients were admitted on AEDs. Clinical groups also did not differ with respect to number of event-related injuries, marital or driving status.
Among PNES patients, 12 (75%) had abnormal MRI findings, which was not statistically different from the occurrence of imaging abnormalities in ES patients (83%). Leukoariosis was the most frequent structural finding, documented in 7 PNES patients (44%). Abnormal outpatient EEGs were more common in ES vs. PNES patients, yet occurred in one-third of psychogenic casesas well (73% vs. 31%, respectively).
Primary clinical characteristics of PNES were as follows: 4 patients had multiple symptoms and an equal number had tremor or focal movements (25% in each category), 3 reported an alteration in consciousness or memory of events (19%), 2 had falls and 2 had convulsions (12.5% in each category), and 1 patient (6%) experienced episodic dizziness/syncope.
CONCLUSIONS: As with younger adults, inpatient v-EEG recording is a valuable tool for identifying psychological imitators of epilepsy in late life. Abnormal EEGs and MRIs were common in this patient sample. Clinical characteristics of spells were nonspecific. Given varied risks associated with under-recognition of PNES, such findings underscore the utility of v-EEG monitoring in diagnostic workups of older adults.