Research reportHemispheric lateralization and language skill coherence in temporal lobe epilepsy☆
Section snippets
Participants
Participants were all diagnosed with medial TLE (n = 124; 53 males, 71 females) and underwent pre-surgical evaluation at the Thomas Jefferson Comprehensive Epilepsy Center (see Sperling et al., 1992) for a description of the surgical algorithm; see also (Tracy and Shah, 2008). Participants included adolescents and adults between the ages of 14 and 63 (mean = 38.06, SD = 11.49), in a consecutive series dating back approximately 5 years. All participants were free of additional significant medical,
Results
Regarding rates of atypicality, fifty of the total sample of 124 patients (40.3%) showed atypical representation of at least one language skill. Twenty of these 50 patients (40% or 16.1% of the total sample) were atypical for just one language skill. Ten of the 50 patients (20% or 8.1% of the total sample) showed atypical representation of two language skills. Overall, thirty of these patients (60% or 24.2% of the entire sample) showed atypicality for more than one language skill.
Discussion
The rates of atypical language representation in our TLE sample are slightly lower than those previously reported in the literature (Rasmussen and Milner, 1977, Springer et al., 1999, Rausch and Walsh, 1984, Strauss and Wada, 1983, Risse et al., 1997, Helmstaedter et al., 1997, Loring et al., 1990). Taking the skills individually, our rate of atypicality for reading was 25.8%, naming 22.6%, comprehension 19.4%, repetition 16.9%, and speech 14.5%. A total of 50 patients (40.3%) showed
References (32)
- et al.
Quantitative fMRI assessment of the differences in lateralization of language-related brain activation in patients with temporal lobe epilepsy
NeuroImage
(2003) - et al.
Atypical hemispheric language dominance in left temporal lobe epilepsy as a result of the reorganization of language functions
Epilepsy and Behavior
(2003) - et al.
Patterns of language dominance in focal left and right hemisphere epilepsies: relation to MRI findings, EEG, sex and age of onset of epilepsy
Brain and Cognition
(1997) - et al.
Right hemisphere language mapping in patients with bilateral language
Epilepsy and Behavior
(2005) - et al.
Quantitative and qualitative evaluation of patterns of cerebral language dominance
Brain and Language
(1994) - et al.
Cerebral language lateralization: evidence from intracarotid amobarbital testing
Neuropsychologia
(1990) - et al.
Abnormalities of language networks in temporal lobe epilepsy
NeuroImage
(2007) - et al.
A reconsideration of bilateral language representation based on the intracarotid amobarbital procedure
Brain and Cognition
(1997) - et al.
FMRI-determined language lateralization in patients with unilateral or mixed language dominance according to the Wada test
NeuroImage
(2002) - et al.
Productive and perceptive language reorganization in temporal lobe epilepsy
NeuroImage
(2005)
Reorganization of language-related neuronal networks in patients with left temporal lobe epilepsy – an fMRI study
European Journal of Neurology
Functional MRI of language processing: dependence on input modality and temporal lobe epilepsy
Epilepsia
Contrasting acute and slow-growing lesions: a new door to brain plasticity
Brain
Functional MRI lateralization of memory in temporal lobe epilepsy
Neurology
Anterior temporal language areas in patients with early onset temporal lobe epilepsy
Annals of Neurology
Memory lateralization in medial temporal lobe epilepsy assessed by functional MRI
Epilepsia
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2021, NeuroImageCitation Excerpt :Fernandez et al., 2003, Szaflarski et al., 2017) Given the high congruency between fMRI and invasive intracarotid sodium amobarbital testing, fMRI serves as a valuable non-invasive means of identifying the dominant hemisphere for language in preoperative evaluations. ( Ishikawa et al., 2017, Tracy et al., 2009) Overall, current clinical practices commonly utilize fMRI to help refine clinical decisions that are based on a synthesis of multimodal information acquired during the preoperative evaluation. Network analyses of whole-brain structural connectivity can be applied at local and global scales through the application of graph theory metrics, (He and Evans, 2010, Rubinov and Sporns, 2010) which have been used to explore the structural connectivity relationships and potential perturbations within disease states. (
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2017, CortexCitation Excerpt :Additionally, an important aspect is to elaborate models of efficient reorganization in patients (associated with behavioral recovery in cases of language deficit) and understand how the demographic and pathological factors, such as the age at seizures onset (ASO), duration of illness, type of lesion (EZ) and hemispheric and regional location of the epileptic lesion e.g., (Adcock et al., 2003; Backes et al., 2005; Brázdil et al., 2005; Hamberger, 2007; Janszky et al., 2003; Karunanayaka, Kim, Holland, & Szaflarski, 2011; Pataraia et al., 2004; Rausch & Walsh, 1984; Staudt et al., 2002; Tracy et al., 2009; Vargha-Khadem et al., 1997; Yuan et al., 2006), frequently studied in isolation, modulates the language representation and HSL. Only a few studies proceeded to a combined evaluation of these factors (Helmstaedter et al., 1997; Saltzman-Benaiah, Scott, & Smith, 2003; Tracy et al., 2009). Considering the effects of these variables on language network representation in healthy participants and in patients, one can describe different “scenarios” of functional reorganization resulting from the interaction between modulatory variables.
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Functional MRI and neuropsychological evidence for language plasticity before and after surgery in one patient with left temporal lobe epilepsy
2012, Epilepsy and BehaviorCitation Excerpt :The improvement in phonological processing was also supported by the behavioral performance assessed with fMRI. In the present study, different patterns of reorganization were observed according to language operation [45] and language regions [9,16]. Our results were consistent with those reported by other studies, suggesting various regional plasticity patterns and more interhemispheric reorganization in temporal than frontal regions [10,21].
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Disclosure: This research was supported, in part, by NIH grant NIH R21NS056071-01A1 awarded to Dr. Joseph Tracy. The authors report no conflicts of interest.