Category-specific naming and recognition deficits in temporal lobe epilepsy surgical patients

Abstract

Objective-Based upon Damasio's "Convergence Zone" model of semantic memory, we predicted that epilepsy surgical patients with anterior temporal lobe (TL) seizure onset would exhibit a pattern of category-specific naming and recognition deficits not observed in patients with seizures arising elsewhere. Methods-We assessed epilepsy patients with unilateral seizure onset of anterior TL or other origin (n = 22), pre-or postoperatively, using a set of category-specific items and a conventional measure of visual naming (Boston Naming Test: BNT).Results-Category-specific naming deficits were exhibited by patients with dominant anterior TL seizure onset/resection for famous faces and animals, while category-specific recognition deficits for these same categories were exhibited by patients with nondominant anterior TL onset/resection. Patients with other seizure onset did not exhibit category-specific deficits. Naming and recognition deficits were frequently not detected by the BNT, which samples only a limited range of stimuli.Interpretation-Consistent with the "convergence zone" framework, results suggest that the nondominant anterior TL plays a major role in binding sensory information into conceptual percepts for certain stimuli, while dominant TL regions function to provide a link to verbal labels for these percepts. Although observed category-specific deficits were striking, they were often missed by the BNT, suggesting that they are more prevalent than recognized in both pre-and postsurgical epilepsy patients. Systematic investigation of these deficits could lead to more refined models of semantic memory, aid in the localization of seizures, and contribute to modifications in surgical technique and patient selection in epilepsy surgery to improve neurocognitive outcome. Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. NIH Public Access Author ManuscriptNeuropsychologia. Author manuscript; available in PMC 2009 April 1. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author ManuscriptKeywords semantic memory; temporal lobe epilepsy; category-specific deficits; epilepsy surgery; naming deficits While several models of semantic memory exist, most agree that the temporal lobes play an important role in supporting this cognitive construct (Caramazza & Shelton, 1998;H. Damasio, Tranel, Grabowski, Adolphs, & Damasio, 2004;Gainotti, 2006). Research suggesting a role for the temporal lobes in semantic memory includes a variety of studies demonstrating deficits in this area in patients with TL impairment (Bayles, Tomoeda, & Trosset, 1990;Chan et al., 1993;Garrard, Lam...

Optic Radiation Tractography and Visual Field Deficits in Laser Interstitial Thermal Therapy for Amygdalohippocampectomy in Patients with Mesial Temporal Lobe Epilepsy

“…Anterior temporal lobectomy is a well-established treatment for patients with drug-resistant MTLE [24,25,26,27] and results in 60-80% seizure freedom in selected patients [5,28,29], but is associated with adverse effects, such as cognitive impairments and focal neurological deficits [30,31,32,33,34,35,36]. Therefore, the balance of effectiveness and possible complications of open resection needs to be taken into account for patients with MTLE.…”

Neuropsychological Evaluation of the Epilepsy Surgical Candidate

“…A few studies demonstrate that left (dominant) TLE patients are impaired at naming famous faces (Drane, Ojemann, Aylward, et al, 2008 ;Glosser, Salvucci, & Chiaravalloti, 2003 ;Seidenberg, Griffi th, Sabsevitz, et al, 2002 ), and at least two of these studies suggest that these defi cits may be worse following ATL resection. Drane et al (Drane et al, 2008 ;Drane, Ojemann, Tranel, Ojemann, & Miller, 2004 ) recently extended these fi ndings to include other visually complex item categories (e.g., famous landmarks, animals) even when performance is completely normal on standard naming measures (e.g., BNT). They have argued that commonly used naming measures lack sensitivity to the specifi c item categories that appear the most affected by anterior TLE surgery, as such measures employ a restricted range of object type (i.e., mostly man-made objects).…”

“…For example, at least four studies demonstrate that postoperative right ATL patients exhibit recognition defi cits for famous faces when compared to controls (Drane et al, 2008 ;Glosser et al, 2003 ;Seidenberg et al, 2002 ). There is also evidence that recognition defi cits for animals and famous landmarks may occur in patients following nondominant resection as well and that even a sense of "familiarity" may be impaired in these individuals (Drane et al, 2004(Drane et al, , 2008. Patients with these defi cits have greater diffi culty recognizing familiar individuals, which may compromise social functioning.…”

“…Many of these cases appear to represent language reorganization that has occurred in individuals experiencing early-life injuries, although a few studies suggest there is likely a subset of patients with rare but naturally occurring atypical language lateralization (Drane, Ojemann, Ojemann, et al, 2009 ;Knecht, Jansen, Frank, et al, 2003 ). The possibility of atypical language lateralization must be borne in mind when analyzing neurocognitive data and making outcome predictions.…”

Language treatment prior to anterior temporal lobe surgery: Can naming skills be preserved?

“…In medically intractable epilepsy with unilateral temporal lobe onset, surgical removal of the anterior temporal lobe (ATL) is a highly effective treatment, with class I clinical evidence supporting its use in specific circumstances [3]. The ATL plays a critical role in the convergence of visual informa tion and proper nouns, and in the majority of individuals, resection is commonly associated with permanent difficul ties in the retrieval of proper names [4][5]. This problem is especially common in individuals undergoing surgery in the language-dominant hemisphere.…”