Search

Anterior temporal lobe resection is an effective treatment for refractory temporal lobe epilepsy. The structural consequences of such surgery in the white matter, and how these relate to language function after surgery remain unknown. We carried out a longitudinal study with diffusion tensor imaging in 26 left and 20 right temporal lobe epilepsy patients before and a mean of 4.5 months after anterior temporal lobe resection. The whole-brain analysis technique tract-based spatial statistics was used to compare pre- and postoperative data in the left and right temporal lobe epilepsy groups separately. We observed widespread, significant, mean 7%, decreases in fractional anisotropy in white matter networks connected to the area of resection, following both left and right temporal lobe resections. However, we also observed a widespread, mean 8%, increase in fractional anisotropy after left anterior temporal lobe resection in the ipsilateral external capsule and posterior limb of the internal capsule, and corona radiata. These findings were confirmed on analysis of the native clusters and hand drawn regions of interest. Postoperative tractography seeded from this area suggests that this cluster is part of the ventro-medial language network. The mean pre- and postoperative fractional anisotropy and parallel diffusivity in this cluster were significantly correlated with postoperative verbal fluency and naming test scores. In addition, the percentage change in parallel diffusivity in this cluster was correlated with the percentage change in verbal fluency after anterior temporal lobe resection, such that the bigger the increase in parallel diffusivity, the smaller the fall in language proficiency after surgery. We suggest that the findings of increased fractional anisotropy in this ventro-medial language network represent structural reorganization in response to the anterior temporal lobe resection, which may damage the more susceptible dorso-lateral language pathway. These findings have important implications for our understanding of brain injury and rehabilitation, and may also prove useful in the prediction and minimization of postoperative language deficits.

Summary: Introduction: Medial temporal lobe epilepsy (mTLE) is the most common refractory focal epilepsy in adults. Around 30%‐40% of patients have prominent memory impairment and experience significant postoperative memory and language decline after surgical treatment. BDNF Val66Met polymorphism has also been associated with cognition and variability in structural and functional hippocampal indices in healthy controls and some patient groups. Aims: We examined whether BDNF Val66Met variation was associated with cognitive impairment in mTLE. Methods: In this study, we investigated the association of Val66Met polymorphism with cognitive performance (n = 276), postoperative cognitive change (n = 126) and fMRI activation patterns during memory encoding and language paradigms in 2 groups of patients with mTLE (n = 37 and 34). Results: mTLE patients carrying the Met allele performed more poorly on memory tasks and showed reduced medial temporal lobe activation and reduced task‐related deactivations within the default mode networks in both the fMRI memory and language tasks than Val/Val patients. Conclusions: Although cognitive impairment in epilepsy is the result of a complex interaction of factors, our results suggest a role of genetic factors on cognitive impairment in mTLE. [ABSTRACT FROM AUTHOR]

Objective.—To evaluate the efficacy of topiramate in the treatment of migraine aura. Antiepileptic drugs may be useful in migraine prevention through such mechanisms as acting directly on the nociceptive system or by modulating the biochemical phenomena of aura. Topiramate acts directly on N-methyl- d-aspartate and amino-3-hydroxy-5-methylisoxazole-4-propionic acid/kainate glutamate receptors and modulates calcium ion channel activity by inhibiting high-voltage–activated L-type calcium ion channels. Methods.—Twelve patients with migraine with aura were enrolled in an open-label study and treated with topiramate for 6 months. The dose of topiramate was increased weekly by 25 mg up to a daily dose of 100 mg after 4 weeks. Results.—In all 12 patients after 6 months of treatment, topiramate did not statistically influence aura frequency ( P= .317) or duration ( P= .480) compared with baseline. Mild to moderate side effects were observed, but they did not interfere with treatment. Consistent with previous observations, migraine frequency as well as headache intensity and duration improved statistically significantly. Conclusion.—Topiramate is not effective in preventing migraine aura. [ABSTRACT FROM AUTHOR]

Background: Temporal lobe epilepsy (TLE) can lead to structural brain abnormalities, with thalamus atrophy being the most common extratemporal alteration. This study used probabilistic tractography to investigate the structural connectivity between individual thalamic nuclei and the hippocampus in TLE., Methods: Thirty-six TLE patients who underwent pre-surgical 3 Tesla magnetic resonance imaging (MRI) and 18 healthy controls were enrolled in this study. Patients were subdivided into TLE with HS (TLE-HS) and MRI-negative TLE (TLE-MRneg). Tractography and whole brain segmentation, including thalamus parcellation, were performed to determine the number of streamlines per mm 3 between the thalamic nuclei and hippocampus. Connectivity strength and volume of regions were correlated with clinical data., Results: The volume of the entire thalamus ipsilateral to seizure onset was significantly decreased in TLE-HS compared to controls (Mann-Whitney-U test: p FDR < 0.01) with the anterior thalamic nuclei (ANT) as important contributor. Furthermore, decreased ipsilateral connectivity strength between the hippocampus and ANT was detected in TLE-HS (p FDR < 0.01) compared to TLE-MRneg and controls which correlated negatively with the duration of epilepsy (ρ = -0.512, p = 0.025) and positively with seizure frequency (ρ = 0.603, p = 0.006). Moreover, ANT volume correlated negatively with epilepsy duration in TLE-HS (ρ = -0.471, p = 0.042)., Conclusions: ANT showed atrophy and decreased connectivity in TLE-HS, which correlated with epilepsy duration and seizure frequency. Understanding the dynamics of epileptogenic networks has the potential to shed light on surgery-resistant epilepsy and refine the selection process for ideal neurosurgical candidates, consequently enhancing post-surgical outcomes., (© 2025 The Author(s). European Journal of Neurology published by John Wiley & Sons Ltd on behalf of European Academy of Neurology.)

Objective: Epilepsy surgery is the recommended treatment option for patients with drug-resistant temporal lobe epilepsy (TLE). This method offers a good chance of seizure freedom but carries a considerable risk of postoperative language impairment. The extremely variable neurocognitive profiles in surgical epilepsy patients cannot be fully explained by extent of resection, fiber integrity, or current task-based functional MRI (fMRI). In this study, the authors aimed to investigate pathology- and surgery-triggered language organization in TLE by using fMRI activation and network analysis as well as considering structural and neuropsychological measures., Methods: Twenty-eight patients with unilateral TLE (16 right, 12 left) underwent T1-weighted imaging, diffusion tensor imaging, and task-based language fMRI pre- and postoperatively (n = 15 anterior temporal lobectomy, n = 11 selective amygdalohippocampectomy, n = 2 focal resection). Twenty-two healthy subjects served as the control cohort. Functional connectivity, activation maps, and laterality indices for language dominance were analyzed from fMRI data. Postoperative fractional anisotropy values of 7 major tracts were calculated. Naming, semantic, and phonematic verbal fluency scores before and after surgery were correlated with imaging parameters., Results: fMRI network analysis revealed widespread, bihemispheric alterations in language architecture that were not captured by activation analysis. These network changes were found preoperatively and proceeded after surgery with characteristic patterns in the left and right TLEs. Ipsilesional fronto-temporal connectivity decreased in both left and right TLE. In left TLE specifically, preoperative atypical language dominance predicted better postoperative verbal fluency and naming function. In right TLE, left frontal language dominance correlated with good semantic verbal fluency before and after surgery, and left fronto-temporal language laterality predicted good naming outcome. Ongoing seizures after surgery (Engel classes ID-IV) were associated with naming deterioration irrespective of seizure side. Functional findings were not explained by the extent of resection or integrity of major white matter tracts., Conclusions: Functional connectivity analysis contributes unique insight into bihemispheric remodeling processes of language networks after epilepsy surgery, with characteristic findings in left and right TLE. Presurgical contralateral language recruitment is associated with better postsurgical language outcome in left and right TLE.

The aim of this study was an analysis of the localizing and lateralizing value of clinical symptoms in frontal lobe epilepsy. Nineteen patients with medically refractory seizures originating from the frontal lobe were examined retrospectively, seven of these patients underwent subsequent neurosurgical removal of the epileptogenic zone. The predominant clinical symptoms were clonic (53%) and tonic motor phenomena (89%). Dystonic posturing (32%) and postictal paresis (37%) occurred frequently, indicating a seizure onset in the contralateral hemisphere. Head version contralateral to the seizure onset zone, as demonstrated in 53% of the patients, was a reliable lateralizing sign, whereas early head and eye turning (11%) had no lateralizing significance. 37% of the patients showed ictal vocalisation, another 37% presented with automatisms--so called hypermotor seizures should be considered as a special subtype. An aura was present in 26% of the patients--in most cases as a somatosensory manifestation or a feeling of dizziness, especially with seizures originating from the supplementary motor area (SMA) or the precentral area. Secondary generalization and seizure series occurred frequently. Unilateral automatisms, head version, tonic phenomena, dystonic posturing, unilateral grimacing, postictal paresis and unilateral clonic movements could be identified as reliable lateralizing signs. We conclude that the analysis of clinical symptoms plays an important role in presurgical epilepsy diagnosis.