Olfactory Information Processing and Temporal Lobe Epilepsy

Olfactory function in patients with and without temporal lobe resection

“…Their identification abilities, however, were impaired compared to the healthy individuals. This is in line with the results by Carroll et al [19], Martinez et al [7], and Eskenazi et al [4]. The missing difference between the patients and controls in odor thresholds was also described by Eskenazi et al [4] and Kohler et al [2].…”

Olfactory abnormalities in temporal lobe epilepsy

“…Previous studies have found impaired odor discrimination upon monorhinic [3] and birhinic administration [7,8,14] in patients with temporal and frontal lobe epilepsy, but not in patients with epilepsy arising from outside the fronto-temporal regions [14]. In addition, studies have shown impairment of olfactory identification [3] and discrimination [15] upon monorhinic presentation ipsilateral to the side of temporal lobectomy.…”

“…Olfactory sensitivity, assessed using detection or recognition threshold measurements, was usually reported to be in the normal range compared with healthy controls [3][4][5][6]. In contrast, a wide variety of tasks (for example, odour matching, discrimination, short and long term recognition, identification and naming) highlighted consistent deficits in higher olfactory functions [3][4][5][6][7][8][9]. Factors such as stimulation type (monorhinal or birhinal), stimulated nostril side (ipsi or controlaterally to the epileptogenic focus), and odorant nameability appeared to be determining factors in patient performance.…”

The Functional Neuroanatomy of Awareness: With a Focus on the Role of Various Anatomical Systems in the Control of Intermodal Attention

“…But they developed loss of discrimination between different stimuli. Temporal lobectomy (which included the uncus and amygdala) produced an ipsilateral defect whereas frontal lobectomy (especially R) produced a bilateral deficit (see also Carroll, Richardson, & Thompson, 1993;Bellas, Novelly, & Eskenaz, 1989). Price, Slotnick, and Revial, (1991) suggest that the dorsomedial thalamic nucleus (MD) (and associated cortex) is implicated in olfactory discrimination and complex learning whereas the hypothalamus mediates the autonomic and neuroendocrine aspects of olfactory-guided behaviors (e.g., feeding, aggression, reproduction).…”