Abstracts

Rationale: The temporal pole receives projections from multimodal sensory association regions and sends projections via the uncinate fasciculus to the ventromedial regions of the frontal lobe. It functions to couple appropriate emotional responses to highly processed sensory stimuli. Since this region is spared in patients who undergo a selective amygdalohippocampectomy (SAH) and is removed in patients who undergo a standard anterior temporal lobectomy (ATL), we postulated that patients with standard resections would have increased symptoms of depression, anxiety, or paranoia as compared to patients with selective resections. Methods: All patients with hippocampal sclerosis who underwent a standard temporal lobectomy and selective amygdalohippocampectomy from 1992 to 2004 were identified from the Dartmouth surgical database. Those patients who did not have both a pre- and one year post-surgical neuropsychological evaluation were excluded. Patients were compared with regard to seizure outcome and neuropsychological outcome. Results: 22 patients who underwent an ATL and 28 patients who underwent a SAH and who satisfied the inclusion and exclusion criteria were identified. Engel class Ia-d outcome at one year for ATL and SAH were 0.88 and 0.83 respectively (not significantly different). There was no significant effect of surgery type on verbal IQ, Boston Naming Test, verbal fluency, most measures of verbal and nonverbal memory (CVLT short delay, WMS Logical Memory immediate and delayed recall, WMS Visual Reproduction immediate and delayed recall, Beck Depression Inventory, the Spielberger Trait Anxiety Scale, or the Schizophrenia subscale of the Minnesota Multiphasic Personality Inventory (MMPI). Significant improvement was seen in both surgery types for Performance IQ, and State Anxiety. Significant decline in performance for for both surgery types was seen for CVLT Long Delay. For both groups, a trend toward better performance on Full Scale IQ and poor performance on CVLT Trials 1-5 was apparent post-surgically. Patients who underwent an ATL scored significantly higher on the MMPI Paranoia subscale than patients who underwent a SAH. Conclusions: Patients treated with ATL for refractory epilepsy with hippocampal sclerosis score significantly higher on the MMPI Paranoia subscale than patients treated with SAH. There was no significant difference between the two groups with respect to seizure outcome or performance on other neuropsychological and mood variables, including anxiety and depression. We postulate that the disconnection of temporal lobe and the frontal lobe by removal of the uncinate fasciculus during ATL may result in inappropriate emotional labeling of sensory stimuli as threatening, and thus to the possibility of increased incidence of paranoid thinking and development of post-surgical psychosis.