T2 hyperintense signal in patients with temporal lobe epilepsy with MRI signs of hippocampal sclerosis and in patients with temporal lobe epilepsy with normal MRI

BackgroundIncreased MRI T2 signal is commonly present not only in the hippocampus but also in other temporal structures of patients with temporal lobe epilepsy (TLE), and it is associated with histological abnormalities related to the epileptogenic lesion.ObjectiveThis study aimed to verify the distribution of T2 increased signal in temporal lobe structures and its correlations with clinical characteristics of TLE patients with (TLE-HS) or without (TLE-NL) MRI signs of hippocampal sclerosis.MethodsWe selected 203 consecutive patients: 124 with TLE-HS and 79 with TLE-NL. Healthy controls (N = 59) were used as a comparison group/comparative group. T2 multiecho images obtained via a 3-T MRI were evaluated with in-house software. T2 signal decays were computed from five original echoes in regions of interest in the hippocampus, amygdala, and white matter of the anterior temporal lobe. Values higher than 2 standard deviations from the mean of controls were considered as abnormal.ResultsT2 signal increase was observed in the hippocampus in 78% of patients with TLE-HS and in 17% of patients with TLE-NL; in the amygdala in 13% of patients with TLE-HS and in 14% of patients with TLE-NL; and in the temporal lobe white matter in 22% of patients with TLE-HS and in 8% of patients with TLE-NL. Group analysis demonstrated a significant difference in the distribution of the T2 relaxation times of the hippocampus (ANOVA, p < 0.0001), amygdala (p = 0.003), and temporal lobe white matter (p < 0.0001) ipsilateral to the epileptogenic zone for patients with TLE-HS compared with controls but only for the amygdala (p = 0.029) and temporal lobe white matter (ANOVA, p = 0.025) for patients with TLE-NL compared with controls. The average signal from the hippocampus ipsilateral to the epileptogenic zone was significantly higher in patients with no family history of epilepsy (two-sample T-test, p = 0.005).ConclusionIncreased T2 signal occurs in different temporal structures of patients with TLE-HS and in patients with TLE-NL. The hippocampal hyperintense signal is more pronounced in patients without family history of epilepsy and is influenced by earlier seizure onset. These changes in T2 signal may be associated with structural abnormalities related to the epileptogenic zone or to the nature of the initial precipitating injury in patients with TLE.     

Distribution of regional gray matter abnormalities in a pediatric population with temporal lobe epilepsy and correlation with neuropsychological performance

ObjectiveThe goals of the work described here were to determine if hippocampal and extrahippocampal atrophy in children with temporal lobe epilepsy (TLE) follows a pattern similar to that in adult patients, and to assess the clinical and neuropsychological relevance of regional brain atrophy in pediatric TLE.MethodsChildren with symptomatic TLE (n = 14: 9 with mesial TLE due to hippocampal atrophy and 5 with TLE due to neocortical lesions), healthy children (n = 14), and 9 adults with mesial temporal lobe epilepsy (MTLE) were compared using voxel-based morphometry (VBM) of brain magnetic resonance imaging (MRI). The children underwent a comprehensive neuropsychological battery.ResultsChildren with MTLE with unilateral hippocampal atrophy (n = 9) exhibited a significant reduction in gray matter in the hippocampus ipsilateral to the seizure origin and significant atrophy in the ipsilateral cingulate gyrus and contralateral middle frontal lobe. Children with TLE (n = 14) exhibited a significant reduction in the gray matter of the ipsilateral hippocampus and parahippocampal gyrus. There was a correlation between gray matter volume in children with TLE and scores on several neuropsychological tests. Atrophy in pediatric patients with MTLE was less extensive than that in adults, and involved the hippocampi and the frontal cortex.ConclusionsSimilar to adult MTLE, pediatric MTLE is associated with hippocampal and extrahippocampal cell loss. However, children display less intense quantifiable gray matter atrophy, which affects predominantly frontal lobe areas. There was a significant association between volume of gray matter in medial temporal and frontal regions and scores on neuropsychological tests. In childhood, TLE and the concomitant cognitive/behavior disturbances are the result of a damaged neural network.     

Interictal epileptic discharge correlates with global and frontal cognitive dysfunction in temporal lobe epilepsy

ObjectiveTemporal lobe epilepsy (TLE) with hippocampal sclerosis has widespread effects on structural and functional connectivity and often entails cognitive dysfunction. EEG is mandatory to disentangle interactions in epileptic and physiological networks which underlie these cognitive comorbidities. Here, we examined how interictal epileptic discharges (IEDs) affect cognitive performance.MethodsThirty-four patients (right TLE = 17, left TLE = 17) were examined with 24-hour video-EEG and a battery of neuropsychological tests to measure intelligence quotient and separate frontal and temporal lobe functions. Hippocampal segmentation of high-resolution T1-weighted imaging was performed with FreeSurfer. Partial correlations were used to compare the number and distribution of clinical interictal spikes and sharp waves with data from imagery and psychological tests.ResultsThe number of IEDs was negatively correlated with executive functions, including verbal fluency and intelligence quotient (IQ). Interictal epileptic discharge affected cognitive function in patients with left and right TLE differentially, with verbal fluency strongly related to temporofrontal spiking. In contrast, IEDs had no clear effects on memory functions after corrections with partial correlations for age, age at disease onset, disease duration, and hippocampal volume.ConclusionIn patients with TLE of long duration, IED occurrence was strongly related to cognitive deficits, most pronounced for frontal lobe function. These data suggest that IEDs reflect dysfunctional brain circuitry and may serve as an independent biomarker for cognitive comorbidity.     

Reduced Pumilio-2 expression in patients with temporal lobe epilepsy and in the lithium–pilocarpine induced epilepsy rat model

ObjectiveDrosophila Pumilio (Pum), a homolog of mammalian Pum2, plays an important role in translational regulation in the central nervous system (CNS), particularly for dendrite outgrowth and neuronal excitability. We investigated the expression pattern and cellular distribution of Pum2 in patients with drug-refractory temporal lobe epilepsy (TLE) and rats with lithium chloride–pilocarpine-induced epilepsy.MethodsReal-time quantitative PCR (RT-qPCR), Western blot, immunohistochemistry, and double-labeled immunofluorescence were utilized to determine the expression level and distribution of Pum2 in temporal neocortex tissues from patients with intractable TLE (n = 20) and patients with severe head trauma (n = 20) in addition to the hippocampus and adjacent cortex of rats with lithium chloride–pilocarpine-induced TLE and controls.ResultsPum2 was expressed in the cell bodies and dendrites of neurons but did not colocalize with glial fibrillary acidic protein-positive astrocytes or propidium iodide (PI) in nuclei. The expression of Pum2 was significantly reduced in patients and rats with TLE in comparison to controls (P < 0.05).ConclusionPum2 expression was less in patients with TLE and a rodent model of epilepsy, suggesting that decreased expression of Pum2 may be involved in the pathogenesis of TLE.     

Postsurgical outcome in patients with auditory auras and drug-resistant epilepsy

PurposeWe assessed whether patients with auditory auras have similar outcomes after epilepsy surgery as patients without auditory auras, and hypothesized that patients with non-dominant hemisphere foci might fare better after temporal lobe surgery than patients with dominant resections.MethodsIn this retrospective study, outcome after temporal resection was assessed for patients with drug-resistant epilepsy. Preoperative demographic data, clinical data, and surgical outcome were prospectively registered in a database from 1986 through 2016. Seizure outcome was classified as either seizure-free or relapsed.ResultsData were available in 1186 patients. Forty five patients (3.8%) reported auditory auras; 42 patients (93%) had temporal lobe epilepsy (TLE), and three patients (7%) had extratemporal epilepsy. Since most patients with auditory auras had TLE and in order to have comparable groups, we selected 41 patients with auditory auras and compared them with patients without auditory auras who had temporal lobe resections (767 patients). There were no significant demographic or clinical differences between TLE patients with auditory auras and those without. Patients who had auditory auras were more likely to relapse after temporal lobe surgery than those without (p = 0.03). Among patients who had auditory auras and temporal lobe surgery, side of surgery was not related to postoperative outcome (p = 0.3).ConclusionAuditory auras are rare among patients with drug-resistant TLE. The presence of an auditory aura in a patient with drug-resistant TLE carries a worse prognosis for a postoperative seizure free outcome and this is not related to the side of surgery.     

White matter integrity correlates with depressive symptomatology in temporal lobe epilepsy

RationaleWhite matter abnormalities occur in both temporal lobe epilepsy (TLE) and depression, but there is limited research examining the depression–white matter association in depressed individuals with TLE. This study examined the relationship between white matter integrity (WMI) and depression including the influence of age at seizure onset, in adults with TLE, TLE and depression, and depression only.MethodsThirty-one adults were in one of three groups: TLE without depression (TLE; n = 11), TLE with depression (TLE + DEP; n = 9), and depression without TLE (DEP; n = 11). Participants completed structured interviews for depression diagnosis and severity. White matter integrity was estimated based on fractional anisotropy (FA) calculated in frontotemporolimbic (FTL) and non-FTL regions in the JHU DTI atlas.ResultsIn adults with TLE (n = 20), depressive symptomology was significantly correlated with FA in non-FTL regions and trended toward significance in FTL regions. These associations were found in FTL (statistically significant) and non-FTL (trended toward significance) regions in participants with childhood seizure onset but not in those with adolescent/adult seizure onset.ConclusionsCurrent results suggest that WMI, within FTL and non-FTL regions, are associated with depressive symptomology in adults with TLE. This association may be most notable in those with childhood-onset epilepsy. These findings could have important implications for the conceptualization and clinical care of neuropsychiatric comorbidities in TLE.     

The effects of temporal lobe epilepsy on scene encoding

Forty-four patients with temporal lobe epilepsy (TLE) (25 left) and 40 healthy control participants performed a complex visual scene-encoding fMRI task in a 4-T Varian scanner. Healthy controls and left temporal lobe epilepsy (LTLE) patients demonstrated symmetric activation during scene encoding. In contrast, right temporal lobe (RTLE) patients demonstrated left lateralization of scene encoding which differed significantly from healthy controls and LTLE patients (all p ≤ .05). Lateralization of scene encoding to the right hemisphere among LTLE patients was associated with inferior verbal memory performance as measured by neuropsychological testing (WMS-III Logical Memory Immediate, p = 0.049; WMS-III Paired Associates Immediate, p = 0.036; WMS-III Paired Associates Delayed, p = 0.047). In RTLE patients, left lateralization of scene encoding was associated with lower visuospatial memory performance (BVRT, p = 0.043) but improved verbal memory performance (WMS-III Word List, p = 0.049). These findings indicate that, despite the negative effects of epilepsy, memory functioning is better supported by the affected hemisphere than the hemisphere contralateral to the seizure focus.     

Memory for public events in patients with unilateral temporal lobe epilepsy

Memory for public events (PEs) was assessed as a marker of remote declarative memory in 36 patients with temporal lobe epilepsy (TLE) and compared with that of 19 patients with extra-TLE (ETLE), 17 patients with idiopathic generalized epilepsy (IGE), and 23 healthy volunteers. Verbal IQ, inventory-based evidence of depression, handedness, onset of illness, disease duration, and medication were obtained. Memory for PEs was reduced in all patient groups (TLE, P < 0.0001; ETLE, P = 0.009; IGE, P = 0.008). The TLE group showed reduced memory for PEs compared with the other patients with epilepsy (P = 0.001). A time gradient was observed, with worse memory for PEs of the 1990s and for PEs that occurred after onset of illness. Our data support the key role of the temporal lobe in remote declarative memory. With patients with TLE remembering fewer PEs from the period after onset of epilepsy, the deficits can be partly attributed to unsuccessful consolidation rather than retrieval difficulties alone.     

Neural correlates of verbal semantic memory in patients with temporal lobe epilepsy

Functional imaging data suggest that the core network engaged in verbal semantic memory (SM) processing encompasses frontal and temporal lobe structures, with a strong left lateralization in normal right handers. The impact of long term temporal lobe epilepsy (TLE) on this network has only partly been elucidated. We studied verbal SM in 50 patients with chronic, intractable TLE (left TLE = 26, right TLE = 24) and 35 right handed normal controls using a verbal fMRI semantic decision paradigm. All patients had language lateralized to the left hemisphere, as verified by the intracarotid amobarbital procedure. Within and between group analyses showed remarkable, group-specific activation profiles. The control group activated frontal and temporal areas bilaterally, with a strong left predominance. Left TLE patients showed a shift of activations of left frontal and medial temporal areas to homologous regions in the right hemisphere. Furthermore, left TLE subjects utilized subcortical structures such as the thalamus and putamen to accomplish the verbal SM task. Contrastively, the activation pattern of right TLE patients resembled that of normal controls, but exhibited ‘hypofrontality’ with a shift from frontal to posterior regions in the temporal, parietal and occipital lobe. Our results show that chronic epileptic activity originating from temporal seizure foci is associated with an alteration of neural circuits which support semantic language processing and that side of seizure focus has a specific impact on the resulting activation network. These findings presumably result from morphological changes and from functional reorganization which are both inherent to chronic TLE.     

Is there a creative functional paradoxical facilitation in juvenile myoclonic epilepsy?

ObjectiveIn patients with juvenile myoclonic epilepsy (JME), a specific personality profile suggestive of frontal lobe dysfunctions has been described. From a neurobiological point of view, the frontal lobe seems to be crucial for creative processes, although the exact role remains unclear. The theory of creative paradoxical functional facilitation (PFF) assumes that disinhibited frontal lobe function can enhance creative abilities. The aim of the current study was to explore our hypothesis that JME is associated with higher artistic creativity based on the theory of PFF.MethodsWe assessed 25 patients with JME aged 18 to 40 years in regard to neuropsychological creativity testing. Results were compared with those of 25 age-, sex-, and level of education-matched healthy control subjects (HC) and patients with temporal lobe epilepsy (TLE). Creative abilities were assessed using two validated and standardized tests: 1) nonverbal: the incomplete figure task of Torrance Test of Creative Thinking and 2) verbal: verbal creativity test. Additionally, a basic assessment of fluid intelligence (test for problem solving) and frontal lobe function (trail-making test) was administered to all participants.ResultsVerbal creativity was impaired in both groups with epilepsy compared with that in HC (specific score: JME vs. HC, p = 0.008; TLE vs. HC, p = 0.003). In regard to nonverbal creative abilities, both groups with epilepsy exhibited fair performance. Level of fluid intelligence was even in all groups (p = 0.433). Only patients with JME showed deficits in the frontal lobe test of psychomotor speed (time in seconds: 67.7 JME vs. 54.6 TLE vs. 52.8 HC; p = 0.045).ConclusionsOverall, our study did not reveal increased creativity in JME. The current findings provide insights into creative abilities in two different epilepsy syndromes. Knowledge on specific neuropsychological strengths or deficits in patients with epilepsy may be useful for treatment or counseling.     

Social cognition in temporal lobe epilepsy: A systematic review and meta-analysis

ObjectiveThere is increasing evidence suggesting that social cognitive abilities are impaired in temporal lobe epilepsy (TLE), the most common form of focal epilepsies.MethodsIn this meta-analysis, 31 studies investigating theory of mind (ToM) and facial emotion recognition performances of 1356 patients with TLE (351 postsurgery) and 859 healthy controls were included.ResultsPatients with TLE had significant deficits in ToM (d = 0.73–0.89) and recognition of facial emotions. There were no significant differences in severity of social cognitive deficits between patients with TLE with or without medial temporal lobectomy. Earlier onset of seizures was associated with ToM impairment. Right-sided TLE was associated with more severe deficits in recognition of fear, sadness, and disgust.ConclusionsSocial cognitive information processing is impaired in TLE, and the potential role of these deficits in functional impairment needs to be further investigated.     

Ictal body turning in focal epilepsy

Despite the explanations of many lateralization findings, body turning in focal epilepsy has been rarely investigated. One of the aims of this study was to evaluate the role of ictal body turning in the lateralization of focal epilepsies. The records of 263 patients with focal epilepsy (temporal lobe epilepsy (TLE), n = 178; extratemporal lobe epilepsy (ETLE), n = 85) who underwent prolonged video-EEG monitoring during presurgical epilepsy evaluation were reviewed. Preoperative findings (TLE, n = 16; ETLE, n = 6) and postoperative outcomes (TLE, n = 7) of patients with focal epilepsy with ictal body turning were assessed. For the evaluation of ictal body turning, two definitions were proposed. Nonversive body turning (NVBT) was used to denote at least a 90° nonforced (without tonic or clonic component) rotation of the upper (shoulder) and lower (hip) parts of the body around the body axis for a minimum of 3 s. Versive body turning (VBT) was used to denote at least a 90° forced (with tonic or clonic component) rotation of the upper (shoulder) and lower (hip) parts of the body around the body axis for a minimum of 3 s. Nonversive body turning was observed in 6% (n = 11) of patients with TLE and 2% (n = 2) of patients with ETLE. For VBT, these ratios were 5% (n = 8) and 7% (n = 6) for patients with TLE and ETLE, respectively. Nonversive body turning was frequently oriented to the same side as the epileptogenic zone (EZ) in TLE and ETLE seizures (76% and 80%, respectively). If the amount of NVBT was greater than 180°, then it was 80% to the same side in TLE seizures. Versive body turning was observed in 86% of the TLE seizures, and 55% of the ETLE seizures were found to be contralateral to the EZ. When present with head turning, NVBT ipsilateral to the EZ and VBT contralateral to the EZ were more valuable for lateralization. In TLE seizures, a significant correlation was found between the head turning and body turning onsets and durations. Our study demonstrated that ictal body turning is a rarely observed but reliable lateralization finding in TLE and ETLE seizures, which also probably has the same pathophysiological mechanism as head turning in TLE seizures.     

Doublecortin (DCX) immunoreactivity in hippocampus of chronic refractory temporal lobe epilepsy patients with hippocampal sclerosis

IntroductionStatus epilepticus increases the production of new neurons (hippocampal neurogenesis) and promotes aberrant migration. However chronic experimental models of epilepsy and studies performed in human epilepsy showed controversial results suggesting a reduction in hippocampal neurogenesis in late stages of the disease. Doublecortin (DCX) has been validated to determine alterations in the production of new neurons in the human hippocampus.ObjectivesDetermine DCX expression in human hippocampal sclerosis (HS) from patients who underwent epilepsy surgery for refractory temporal lobe epilepsy (TLE).MethodsHippocampal sections of 9 patients with HS and TLE who underwent surgery, were processed using immunoperoxidase for DCX. Archival material from 5 normal post-mortem hippocampus were simultaneously processed.ResultsSignificantly lower staining intensity was observed in DCX-positive neurons localized in dentate gyrus (DG) and in CA1 of epileptic hippocampus; lower DCX reactive area was observed in pyramidal layers of CA1; and a reduced in the mean number of DCX-positive neurons were determined in DG compared to normal hippocampus (p < 0.05).ConclusionsThis study found a decrease in DCX expression in hippocampus of patients with HS and chronic and refractory TLE suggesting alterations in NG and hippocampal synaptogenesis with potential cognitive and emotional repercussion.     

Impaired cerebral blood flow networks in temporal lobe epilepsy with hippocampal sclerosis: A graph theoretical approach

Graph theory is an emerging method to investigate brain networks. Altered cerebral blood flow (CBF) has frequently been reported in temporal lobe epilepsy (TLE), but graph theoretical findings of CBF are poorly understood. Here, we explored graph theoretical networks of CBF in TLE using arterial spin labeling imaging. We recruited patients with TLE and unilateral hippocampal sclerosis (HS) (19 patients with left TLE, and 21 with right TLE) and 20 gender- and age-matched healthy control subjects. We obtained all participants' CBF maps using pseudo-continuous arterial spin labeling and analyzed them using the Graph Analysis Toolbox (GAT) software program. As a result, compared to the controls, the patients with left TLE showed a significantly low clustering coefficient (p = 0.024), local efficiency (p = 0.001), global efficiency (p = 0.010), and high transitivity (p = 0.015), whereas the patients with right TLE showed significantly high assortativity (p = 0.046) and transitivity (p = 0.011). The group with right TLE also had high characteristic path length values (p = 0.085), low global efficiency (p = 0.078), and low resilience to targeted attack (p = 0.101) at a trend level. Lower normalized clustering coefficient (p = 0.081) in the left TLE and higher normalized characteristic path length (p = 0.089) in the right TLE were found also at a trend level. Both the patients with left and right TLE showed significantly decreased clustering in similar areas, i.e., the cingulate gyri, precuneus, and occipital lobe. Our findings revealed differing left–right network metrics in which an inefficient CBF network in left TLE and vulnerability to irritation in right TLE are suggested. The left–right common finding of regional decreased clustering might reflect impaired default-mode networks in TLE.     

Auditory temporal processing in patients with temporal lobe epilepsy

ObjectiveAuditory temporal processing is the main feature of speech processing ability. Patients with temporal lobe epilepsy, despite their normal hearing sensitivity, may present speech recognition disorders. The present study was carried out to evaluate the auditory temporal processing in patients with unilateral TLE.Materials and methodsThe present study was carried out on 25 patients with epilepsy: 11 patients with right temporal lobe epilepsy and 14 with left temporal lobe epilepsy with a mean age of 31.1 years and 18 control participants with a mean age of 29.4 years. The two experimental and control groups were evaluated via gap-in-noise and duration pattern sequence tests. One-way ANOVA was run to analyze the data.ResultsThe mean of the threshold of the GIN test in the control group was observed to be better than that in participants with LTLE and RTLE. Also, it was observed that the percentage of correct responses on the DPS test in the control group and in participants with RTLE was better than that in participants with LTLE.ConclusionPatients with TLE have difficulties in temporal processing. Difficulties are more significant in patients with LTLE, likely because the left temporal lobe is specialized for the processing of temporal information.     

Multiple hippocampal transections for intractable hippocampal epilepsy: Seizure outcome

PurposeThe purpose of this study was to evaluate the seizure outcomes after transverse multiple hippocampal transections (MHTs) in 13 patients with intractable TLE.MethodsThirteen patients with normal memory scores, including 8 with nonlesional hippocampi on MRI, had temporal lobe epilepsy (TLE) necessitating depth electrode implantation. After confirming hippocampal seizure onset, they underwent MHT. Intraoperative monitoring was done with 5–6 hippocampal electrodes spaced at approximately 1-cm intervals and spike counting for 5–8 min before each cut. The number of transections ranged between 4 and 7. Neuropsychological assessment was completed preoperatively and postoperatively for all patients and will be reported separately.ResultsDuration of epilepsy ranged between 5 and 55 years. There were no complications. Intraoperatively, MHT resulted in marked spike reduction (p = 0.003, paired t-test). Ten patients (77%) are seizure-free (average follow-up was 33 months, range 20–65 months) without medication changes. One of the 3 patients with persistent seizures had an MRI revealing incomplete transections, another had an additional neocortical seizure focus (as suggested by pure aphasic seizures), and the third had only 2 seizures in 4 years, one of which occurred during antiseizure medication withdrawal. Verbal and visual memory outcomes will be reported separately. Right and left hippocampal volumes were not different preoperatively (n = 12, p = 0.64, Wilcoxon signed-rank test), but the transected hippocampal volume decreased postoperatively (p = 0.0173).ConclusionsMultiple hippocampal transections provide an effective intervention and a safe alternative to temporal lobectomy in patients with hippocampal epilepsy.     

Epilepsy duration impacts on brain glucose metabolism in temporal lobe epilepsy: Results of voxel-based mapping

Objective[¹⁸F]Fluorodeoxyglucose positron emission tomography ([¹⁸F]FDG-PET) is a valuable method for detecting focal brain dysfunction associated with epilepsy. Evidence suggests that a progressive decrease in [¹⁸F]FDG uptake occurs in the epileptogenic cortex with an increase in the duration of epilepsy. In this study, our aim was to use statistical parametric mapping (SPM) to test the validity of this relationship in a retrospective study of patients with temporal lobe epilepsy (TLE).Methods[¹⁸F]FDG-PET scans of 46 adult patients with pharmacoresistant unilateral TLE (25 RTLE and 21 LTLE) were subjected to SPM analysis.ResultsForty-six patients were diagnosed with nonlesional TLE, 16 of whom had hippocampal sclerosis (HS). The average duration of epilepsy was 17.4 ± 12.3 years (3–46 years), <5 years in 10 patients and ?10 years in 30 patients. Visual analysis of [¹⁸F]FDG-PET scans revealed hypometabolism in the epileptogenic temporal cortex in 31 (67%) patients. After SPM analysis of all [¹⁸F]FDG-PET images, hypometabolism was unilateral and reported in lateral and mesial structures of the epileptogenic temporal cortex in addition to the ipsilateral fusiform and middle occipital gyrus. Subsequent analysis revealed that temporal lobe hypometabolism was present only in patients with longer epilepsy duration (?10 years) in parahippocampal gyrus, uncus, and middle and superior temporal gyrus (P < 0.05 corrected). Epilepsy duration was inversely correlated with decreased glucose uptake in the inferior temporal gyrus, hippocampus, and parahippocampal gyrus of the epileptogenic temporal cortex (P < 0.05). Age at seizure onset did not affect the correlation between epilepsy duration and glucose uptake except in the inferior temporal gyrus (P < 0.05).ConclusionVoxel-based mapping supports the assertion that glucose hypometabolism of the epileptogenic temporal lobe cortex and other neighboring cortical regions increases with longer epilepsy duration in TLE.     

Epilepsy and restless legs syndrome

ObjectiveRestless legs syndrome (RLS) is a common neurological movement disorder occurring in approximately 10% of the general population. The prevalence of moderately severe RLS is 2.7% overall (3.7% for women and 1.7% for men). Epilepsy is also a common neurological disorder with significant associated morbidity and impact on quality of life. We evaluated the severity and frequency of primary RLS in patients with localization-related temporal lobe epilepsy (TLE) and investigated the role of prodromal RLS symptoms as a warning sign and lateralizing indicator.MethodsAll epilepsy patients seen in the outpatient clinic were screened for movement disorders from 2005 to 2015. Ninety-eight consecutive patients with localization-related TLE (50 right TLE and 48 left TLE) who met inclusion criteria were seen in the outpatient clinic. The control group consisted of 50 individuals with no history or immediate family history of epilepsy.Each patient was evaluated with the International Restless Legs Study Group (IRLSSG) questionnaire, NIH RLS diagnostic criteria, ferritin level, and comprehensive sleep screening including polysomnography. Furthermore, patients with obstructive sleep apnea or a definite cause of secondary restless legs syndrome such as low serum ferritin or serum iron levels were also excluded from the study.ResultsThere was a significant association between the type of epilepsy and whether or not patients had RLS χ² (1) = 10.17, p < .01, using the χ² Goodness of Fit Test. Based on the odds ratio, the odds of patients having RLS were 4.60 times higher if they had right temporal epilepsy than if they had left temporal epilepsy, serving as a potential lateralizing indicator. A prodromal sensation of worsening RLS occurred in some patients providing the opportunity to intervene at an earlier stage in this subgroup.SignificanceWe identified frequent moderate to severe RLS in patients with epilepsy. The frequency of RLS was much more common than would typically be seen in patients of similar age. The restlessness was typically described as moderately severe. The RLS symptoms were more common and somewhat more severe in the right TLE group than the left TLE group.     

Facial emotion perception in patients with epilepsy: A systematic review with meta-analysis

Facial emotion perception is a fundamental social competency relying on a specialised, yet distributed, neural network. This review aimed to determine whether patients with epilepsy have facial emotion perception accuracy impairments overall, or for a subset of emotions (anger, disgust, happiness, sadness, fear, and surprise), and the relationship to epilepsy type, demographic/treatment variables, and brain organisation. Database searches used PRISMA guidelines with strict inclusion/exclusion criteria. Thirty included studies assessed patients with temporal lobe (TLE; n = 709), frontocentral (FCE; n = 22), and genetic generalised (GGE; n = 48) epilepsy. Large deficits emerged in patients with epilepsy compared to controls (n = 746; Hedges’ g = 0.908–1.076). Patients with TLE were significantly impaired on all emotions except surprise; patients with GGE were significantly impaired in anger, disgust, and fear perception. Meta-regression of patients with TLE revealed younger age at testing was associated with lower accuracy. This review provides evidence for marked global deficits of emotion perception in epilepsy, with differential emotion-specific impairment patterns in patients with TLE and GGE.     

Psychiatric disorders in temporal lobe epilepsy: An overview from a tertiary service in Brazil

PurposeTo evaluate the frequency and intensity of psychiatric disorders in a group of temporal lobe epilepsy (TLE) patients from a tertiary-care center.MethodsClinical and sociodemographic data of 73 patients were collected and a neuropsychiatric evaluation was performed with the following instruments: Mini-Mental State Examination (MMSE), structured clinical interview (MINI-PLUS), Hamilton Anxiety Scale (HAM-A), Hamilton Depression Scale (HAM-D), Brief Psychiatric Rating Scale (BPRS).ResultsPatients with TLE showed a high frequency of lifetime psychiatric disorders (70%), the most frequent being mood disorders (49.3%). At assessment, 27.4% of the patients were depressed and 9.6% met criteria for bipolar disorder. Nevertheless, depression had not been properly diagnosed nor treated. Anxiety disorders were also frequent (42.5%), mainly generalized anxiety disorder (GAD) (21.9%). Obsessive compulsive disorder (OCD) was present in 11.0% and psychotic disorders in 5.5% of the sample. Patients with left mesial temporal sclerosis (LMTS) exhibited more psychopathologic features, mainly anxiety disorders (p = 0.006), and scored higher on HAM-A and HAM-D (p < 0.05 in both).ConclusionTLE is related to a high frequency of psychiatric disorders, such as anxiety and depression, which are usually underdiagnosed and undertreated. Damage to the left mesial temporal lobe, seen in LMTS, seems to be an important pathogenic lesion linked to a broad range of psychopathological features in TLE, mainly anxiety disorders. The present study prompts discussion on the recognition of the common psychiatric disorders in TLE, especially on the Brazilian setting.