Abstracts

Rationale: Although seizure like states (pseudo-seizures) may result from organic pathological events, such as cardiac arrhytmias, most have a psychological etiology. There have been reports of hypo-perfusion in SPECT suggesting the presence of functional brain abnormalities in these patients, but its true occurrence and relevance is unknown. We report the incidence of this finding in our medically intractable epilepsy population, diagnosed with pseudoseizures.Methods: The charts of patients admitted to the Level IV epilepsy monitoring unit at OU Medical Center from March 1995 to February 2006 were reviewed for history and physical, MRI, SPECT and video EEG reports. The occurrence of pseudoseizures was documented by the absence of appropriate EEGchanges during the events. True seizures were defined as events with epileptiform discharges in EEG. Events were sub-classified as psychogenic, organic, and those co-existing with epilepsy.Results: 1648 admissions were reviewed and 465 (28.2%) had pseudoseizures. 137 (29.5%)were males and 328 (70.5%) were females. 388 (83.4%) were considered psychogenic, 77 (16.6%) were organic or co-existed with epilepsy. Out of the 388 wit psychogenic events, 217 had inter-ictal SPECT available. Of those, 179 (82.5%) showed hypo-perfusion in the temporal region. Perfusional changes were noted in frontal 32 (14.7%), parietal 11 (5.1%) and occipital 3 (1.4%) regions as well.Conclusions: Temporal lobe hypo-perfusion was the most common finding (83.4%) in the inter-ictal SPECT of patients with pseudoseizures. The hypo-perfusion in these patients could not be explained by underlying brain lesions as evidenced by MRI. We postulate that the high incidence of temporal hypo-perfusion is significant and could be mechanistically related to the repression of traumatic experiences, since the temporal lobe is the pathway for memory-retrieval mechanisms.