Morphometric correlates of anomia in patients with small left temporopolar lesions

Visual object naming is a complex cognitive process that engages an interconnected network of cortical regions moving from occipitotemporal to anterior-inferior temporal cortices, and extending into the inferior frontal cortex. Naming can fail for diverse reasons, and different stages of the naming multi-step process appear to be reliant upon the integrity of different neuroanatomical locations. While the neural correlates of semantic errors have been extensively studied, the neural basis of omission errors remains relatively unspecified. Although a strong line of evidence supports an association between anterior temporal lobe damage and semantic errors, there are some studies suggesting that the anterior temporal lobe could be also associated with omissions. However, support for this hypothesis comes from studies with patients in whom damage affected extensive brain regions, sometimes bilaterally. Here, we availed of a group of 12 patients with epilepsy associated with a small lesion at the tip of the left temporal pole. Using an unbiased surface-based morphometry methodology, we correlated two morphological features with errors observed during visual naming. Analyses revealed a correlation between omission errors and reduced local gyrification index in three cortical clusters: one in the left anteromedial temporal lobe region (AMTL) and two in the left anterior cingulate cortex (ACC). Our findings support the view that regions in ACC and AMTL are critical structures within a network engaged in word selection from semantics.

Retrospective study of perampanel efficacy and tolerability in myoclonic seizures

OBJECTIVES

Perampanel is an antiepileptic drug (AED) approved for add-on treatment of focal seizures (with or without generalization) and primary generalized tonic-clonic (GTC) seizures. Our objective was to explore the effectiveness and tolerability of adjunctive perampanel in patients with drug-resistant myoclonic seizures, after failure of other AEDs.

MATERIALS AND METHODS

Retrospective, multicenter, observational study. Data were collected from individual patient clinical files and analysed using appropriate descriptive statistics and inferential analyses.

RESULTS

Data are reported for 31 patients with mean age 36.4 years, who had an average epilepsy duration of 18 years, previously taken an average of 5.03 AEDs, and were taking an average of 2.4 AEDs on perampanel initiation. Patients exhibited myoclonic, GTC, absence, tonic and focal seizures, and most had associated cognitive decline and/or ataxia. Median time on perampanel was 6 months, most common dose was 6 mg, and overall retention rate was 84%. The responder rate for myoclonic seizures was defined via reduction of days with myoclonic seizures per month. At 6 months, 15 (48.4%) of the 31 patients were classed as myoclonic seizure responders, 10 (32.3%) were myoclonic seizure free, and 39% saw improvements in functional ability. Of 17 patients with GTC seizures at baseline, 9 (53%) were responders at 6 months, and 8 (47.1%) were seizure free. The most frequent side effects were psychiatric disorders, instability, dizziness and irritability, and mostly resolved with dose reduction. Five patients discontinued perampanel due to side effects.

CONCLUSIONS

Perampanel caused clinically meaningful improvements in patients with drug-resistant myoclonic seizures. It was generally well tolerated, but psychiatric and neurological side effects sometimes required follow-up and dose reduction.

Specificity of electroclinical features in the diagnosis of ring chromosome 20

BACKGROUND

Ring chromosome 20 (R20) syndrome is a chromosomal disorder characterized mainly by drug-resistant frontal lobe seizures, recurrent nonconvulsive status epilepticus (NCSE), and typical EEG features. The aim of this study was to investigate if this triad is common and specific to all patients with R20.

METHODS

In this cross-sectional study (from 2000 to 2011), we selected patients who fulfilled at least two out of three criteria: drug-resistant frontal lobe seizures, recurrent NCSE, and characteristic electroencephalography (EEG) features. In all patients, diagnosis was based on karyotype analysis of at least 100 metaphases.

RESULTS

We identified 36 patients who met at least two of the selected criteria: six patients (16.7%) with R20 and 30 (83.3%) without R20 (non-R20). All patients with R20 met all three criteria. Eleven (36.7%) patients without R20, however, also displayed the full triad. In 19 patients without R20 (63.3%), one of the three clinical features was missing: frontal lobe seizures were not resistant to antiepileptic drugs (AED) in four (13.3%), recurrent NCSE was missing in six (20%), and nine (30%) patients did not have typical EEG features. Based on this data, specificity was 63.3%, positive predictive value was 35.3%, and sensitivity and negative predictive values were 100%. Additionally, a review of all publications describing the R20 phenotype revealed that 81.98% of patients with R20 display the full electroclinical triad.

CONCLUSIONS

In our study, all patients with R20 displayed the three electroclinical characteristics. This is in line with previous reports (presenting high sensitivity and negative predictive value). However, these features can also be observed in other epilepsies and are not specific to R20. Our findings suggest that in the presence of the full triad of symptoms, karyotype analysis focused on chromosome 20 should be conducted.

Epidemiological profile of epilepsy in low income populations

Epilepsy is a global disease with an unequal distribution. About 80% of the affected individuals reside in low and middle income countries. The incidence and prevalence of epilepsy in low income populations is higher than in the rest of the world, this is partly explained by some risk factors such as head trauma, perinatal injury and CNS infections, which are more common in poor regions, especially in rural areas. Epilepsy is considered a treatable condition with high rates of therapeutic response. About three fourths of patients achieve control of the disease with the use of antiepileptic drugs, however, despite this benign prognosis, over 75% of patients from low income populations do not receive treatment at all. The cultural beliefs, the inequity in the distribution of public health services, the inadequate supply of antiepileptic drugs, the low number of neurologists involved in the attention of epilepsy, and the social stigma, are the main reasons that increase the treatment gap and the burden of disease in low income populations with epilepsy. We conducted a narrative review regarding the epidemiology of epilepsy in low income populations by searching PubMed, EMBASE, Google Scholar and thoroughly examining relevant bibliographies. This review aims to summarize the main epidemiological aspects of epilepsy in LMIC, emphasizing on incidence, prevalence, socio-demographic profile, TG, social stigma and QoL.

Lacosamide for refractory generalized tonic-clonic seizures of non-focal origin in clinical practice: A clinical and VEEG study

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7 of 9 patients with GGE reduced ≥ 50% their tonic–clonic seizure frequency on LCM.

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All 7 patients remained seizure free for > 1 year, and 2 of them for > 5 years.

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In 2 of the 9 patients, both with Juvenile Absence Epilepsy, absences aggravated.

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One aggravation consisted on a myoclonia and absence status, in a patient with no history of myoclonia.

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VEEG paralleled clinical improvement but didn't change in a case of absence worsening.

Subjective Evaluation of Mood and Cognitive Functions in a General Neurology Clinic: Patients versus Informants

Background and Purpose

We aimed to determine the correlation between subjective evaluations of mood and cognitive functions by patients and informants, and the findings of a battery of neuropsychological tests.

Methods

We analyzed 74 subjects recruited from a general neurology clinic, comprising 37 patients with cognitive complaints and 37 informants (either relatives or caregivers in close contact with the patients). Four ordinal scales concerning recent memory, verbal expression, initiative, and mood were correlated with the findings of a series of neuropsychological tests and questionnaires using the tau b coefficient.

Results

The scores for the patients on the scales were most strongly correlated with scores on the 15-item Geriatric Depression Scale (GDS-15), while the scores for the informants were most strongly correlated with scores on GDS-15, the Informant Questionnaire on Cognitive Decline, and the Functional Activities Questionnaire (FAQ). The most significant correlation was between the initiative scale from informants and FAQ (tau b=-0.591, p<0.001), and it was the only one that remained significant after correcting for multiple testing (p Holm=0.013).

Conclusions

Cognitive complaints from patients mainly reflect their mood, whilst informant reports mainly reflect both the functional ability and mood of the patients.

Differences in visual naming performance between patients with temporal lobe epilepsy associated with temporopolar lesions versus hippocampal sclerosis

OBJECTIVE

Naming difficulties are frequently observed in patients with temporal lobe epilepsy (TLE). Although damage/removal of regions of the anterior temporal neocortex including the temporal pole is considered critical for those difficulties, 1 relevant hypothesis proposes that hippocampal damage also has a role. Our aim was to better understand the specific involvement of temporal pole and hippocampus in visual object naming.

METHOD

We assessed 2 types of patients with TLE on a visual confrontation-naming task: patients with hippocampal sclerosis (HS; n = 16) and patients with a lesion on the tip of the temporal pole that spared the hippocampus entirely (n = 18). A common battery of verbal and nonverbal semantic tasks was administered and used as a semantic memory background. Control group were 20 matched healthy participants.

RESULTS

Patients with lesions on their temporal poles differed from patients with HS and control group on naming ability, proportion and rate of error type, and influence of concept familiarity. Of note, naming performance was not affected by hippocampal damage. Using a Bayesian model averaging approach, we found that the number of omission errors distinguished patients with temporal pole damage from patients with HS and controls. This differential pattern occurred despite similar impairment on the semantic memory background in both clinical groups.

CONCLUSION

Current findings provide evidence that temporal pole damage produces or contributes to naming impairment in TLE, while also suggesting that the hippocampus is not critical for naming. They also highlight the importance of error-type analysis when evaluating visual naming in TLE. (PsycINFO Database Record

Mild Malformation of Cortical Development with Oligodendroglial Hyperplasia in Frontal Lobe Epilepsy: A New Clinico-Pathological Entity

The histopathological spectrum of human epileptogenic brain lesions is widespread including common and rare variants of cortical malformations. However, 2-26% of epilepsy surgery specimens are histopathologically classified as nonlesional. We hypothesized that these specimens include also new diagnostic entities, in particular when presurgical magnetic resonance imaging (MRI) can identify abnormal signal intensities within the anatomical region of seizure onset. In our series of 1381 en bloc resected epilepsy surgery brain specimens, 52 cases could not be histopathologically classified and were considered nonlesional (3.7%). An increase of Olig2-, and PDGFR-alpha-immunoreactive oligodendroglia was observed in white matter and deep cortical layers in 22 of these patients (42%). Increased proliferation activity as well as heterotopic neurons in white matter were additional histopathological hallmarks. All patients suffered from frontal lobe epilepsy (FLE) with a median age of epilepsy onset at 4 years and 16 years at epilepsy surgery. Presurgical MRI suggested focal cortical dysplasia (FCD) in all patients. We suggest to classify this characteristic histopathology pattern as "mild malformation of cortical development with oligodendroglial hyperplasia (MOGHE)." Further insights into pathomechanisms of MOGHE may help to bridge the diagnostic gap in children and young adults with difficult-to-treat FLE.

Altered brain rhythms and functional network disruptions involved in patients with generalized fixation-off epilepsy

Generalized Fixation-off Sensitivity (CGE-FoS) patients present abnormal EEG patterns when losing fixation. In the present work, we studied two CGE-FoS epileptic patients with simultaneous EEG-fMRI. We aim to identify brain areas that are specifically related to the pathology by identifying the brain networks that are related to the EEG brain altered rhythms. Three main analyses were performed: EEG standalone, where the voltage fluctuations in delta, alpha, and beta EEG bands were obtained; fMRI standalone, where resting-state fMRI ICA analyses for opened and closed eyes conditions were computed per subject; and, EEG-informed fMRI, where EEG delta, alpha and beta oscillations were used to analyze fMRI. Patient 1 showed EEG abnormalities for lower beta band EEG brain rhythm. Fluctuations of this rhythm were correlated with a brain network mainly composed by temporo-frontal areas only found in the closed eyes condition. Patient 2 presented alterations in all the EEG brain rhythms (delta, alpha, beta) under study when closing eyes. Several biologically relevant brain networks highly correlated (r > 0.7) to each other in the closed eyes condition were found. EEG-informed fMRI results in patient 2 showed hypersynchronized patterns in the fMRI correlation spatial maps. The obtained findings allow a differential diagnosis for each patient and different profiles with respect to healthy volunteers. The results suggest a different disruption in the functional brain networks of these patients that depends on their altered brain rhythms. This knowledge could be used to treat these patients by novel brain stimulation approaches targeting specific altered brain networks in each patient.

Statin adherence and LDL cholesterol levels. Should we assess adherence prior to statin upgrade?

BACKGROUND

Adherence to statin therapy has been shown to be suboptimal. In statin-treated patients with residual elevated low density lipoprotein cholesterol (LDL-C) levels the physician must decide whether to switch to a more potent statin or try and achieve better adherence. We examined the association between adherence and LDL-C within low, moderate and high intensity statin groups in a "real world" setting.

METHODS

We assessed annual adherence by the mean MPR (Medication Possession Ratio = number of purchased/prescribed daily doses) in unselected patient group. Statins were stratified (ACC/AHA Guideline) into low, moderate and high intensity groups. The impact of adherence on LDL levels was assessed by LOESS (locally weighted scatter plot smoothing).

RESULTS

Out of 1183 patients 173 (14.6%) were treated with low, 923 (78.0%) with moderate and 87 (7.4%) with high intensity statins. Statin intensity was inversely associated with adherence (MPR 77±21, 73±22 and 69±21% for low, moderate and high intensity respectively, p=0.018). Non-adjusted LDL levels decreased with higher adherence: a 10% adherence increase resulted in LDL decrease of 3.5, 5.8 and 7.1mg/dL in low, moderate and high intensity groups. Analysis of the adherence effect on LDL levels adjusted for age, DM and ischemic heart disease showed that MPR above 80% was associated with an additional decrease in LDL levels only in the high intensity group.

CONCLUSIONS

Increased adherence to statins beyond an MPR of 80% improves LDL levels only among patients given high intensity therapy. Switching from lower to higher intensity therapy may be more effective than further efforts to increase adherence.

Differential diagnosis of degenerative dementias using basic neuropsychological tests: multivariable logistic regression analysis of 301 patients

BACKGROUND

The validity of neuropsychological tests for the differential diagnosis of degenerative dementias may depend on the clinical context. We constructed a series of logistic models taking into account this factor.

METHODS

We retrospectively analyzed the demographic and neuropsychological data of 301 patients with probable Alzheimer's disease (AD), frontotemporal degeneration (FTLD), or dementia with Lewy bodies (DLB). Nine models were constructed taking into account the diagnostic question (eg, AD vs DLB) and subpopulation (incident vs prevalent).

RESULTS

The AD versus DLB model for all patients, including memory recovery and phonological fluency, was highly accurate (area under the curve = 0.919, sensitivity = 90%, and specificity = 80%). The results were comparable in incident and prevalent cases. The FTLD versus AD and DLB versus FTLD models were both inaccurate.

CONCLUSION

The models constructed from basic neuropsychological variables allowed an accurate differential diagnosis of AD versus DLB but not of FTLD versus AD or DLB.

Aphasic seizures in patients with temporopolar and anterior temporobasal lesions: a video-EEG study

Studies of patients with temporal lobe epilepsy provide few descriptions of seizures that arise in the temporopolar and the anterior temporobasal brain region. Based on connectivity, it might be assumed that the semiology of these seizures is similar to that of medial temporal lobe epilepsy. However, accumulating evidence suggests that the anterior temporobasal cortex may play an important role in the language system, which could account for particular features of seizures arising here. We studied the electroclinical features of seizures in patients with circumscribed temporopolar and temporobasal lesions in order to identify specific features that might differentiate them from seizures that originate in other temporal areas. Among 172 patients with temporal lobe seizures registered in our epilepsy unit in the last 15 years, 15 (8.7%) patients had seizures caused by temporopolar or anterior temporobasal lesions (11 left-sided lesions). The main finding in our study is that patients with left-sided lesions had aphasia during their seizures as the most prominent feature. In addition, while all patients showed normal to high intellectual functioning in standard neuropsychological testing, semantic impairment was found in a subset of 9 patients with left-sided lesions. This case series demonstrates that aphasic seizures without impairment of consciousness can result from small, circumscribed left anterior temporobasal and temporopolar lesions. Thus, the presence of speech manifestation during seizures should prompt detailed assessment of the structural integrity of the basal surface of the temporal lobe in addition to the evaluation of primary language areas.

Network reconfiguration and working memory impairment in mesial temporal lobe epilepsy

Mesial temporal lobe epilepsy (mTLE) is the most prevalent form of focal epilepsy, and hippocampal sclerosis (HS) is considered the most frequent associated pathological finding. Recent connectivity studies have shown that abnormalities, either structural or functional, are not confined to the affected hippocampus, but can be found in other connected structures within the same hemisphere, or even in the contralesional hemisphere. Despite the role of hippocampus in memory functions, most of these studies have explored network properties at resting state, and in some cases compared connectivity values with neuropsychological memory scores. Here, we measured magnetoencephalographic responses during verbal working memory (WM) encoding in left mTLE patients and controls, and compared their effective connectivity within a frontotemporal network using dynamic causal modelling. Bayesian model comparison indicated that the best model included bilateral, forward and backward connections, linking inferior temporal cortex (ITC), inferior frontal cortex (IFC), and the medial temporal lobe (MTL). Test for differences in effective connectivity revealed that patients exhibited decreased ipsilesional MTL-ITC backward connectivity, and increased bidirectional IFC-MTL connectivity in the contralesional hemisphere. Critically, a negative correlation was observed between these changes in patients, with decreases in ipsilesional coupling among temporal sources associated with increases contralesional frontotemporal interactions. Furthermore, contralesional frontotemporal interactions were inversely related to task performance and level of education. The results demonstrate that unilateral sclerosis induced local and remote changes in the dynamic organization of a distributed network supporting verbal WM. Crucially, pre-(peri) morbid factors (educational level) were reflected in both cognitive performance and (putative) compensatory changes in physiological coupling.

Validation of the Spanish version of the Neurological Disorders Depression Inventory for Epilepsy (NDDI-E)

INTRODUCTION

To translate and validate into Spanish (Spain) the screening instrument of major depressive episodes (MDEs), Neurological Disorders Depression Inventory in Epilepsy (NDDI-E), in patients with epilepsy.

METHODS

A total of 121 outpatients, aged 18 years and older, with a diagnosis of epilepsy were included. The diagnosis of a current major depressive episode (MDE) was established with the Mini International Neuropsychiatric Interview (MINI).

RESULTS

A diagnosis of current MDE was established in 20% of the patients with the MINI. Receiver operator characteristics (ROC) analysis showed an area under the curve of 0.89, with an internal consistency of 0.78. At a cutoff score >13, 22% of patients were considered to suffer from MDE with the NDDI-E (sensitivity: 84%; specificity: 78%; positive predictive value: 64.7%; and negative predictive value: 92.2%).

DISCUSSION

The Spanish-Spain version of the NDDI-E appears to be a good screening instrument to identify MDE.