Frequent Cause Of Epilepsy Research Articles

Causes of Epilepsy in Elderly Patients Presenting in a Tertiary Care Hospital of Karachi

Background: Epilepsy is fairly a frequent occurrence in the elderly. It is commonly diagnosed after the episode of two or more unprovoked seizures. Unprovoked seizures in elderly are recurrent rather than younger individuals. This study was designed to estimate the concrete burden of frequent causes of epilepsy. Methods: A descriptive cross-sectional study with a total of 153 patients diagnosed case of epilepsy were included in this study at Jinnah Medical College Hospital from February 2018-August 2018. Mean was calculated for age, duration of disease of the patients. Causes of epilepsy, gender, and education was calculated and presented as percentages. Electrolyte readings were taken i.e., Sodium, Calcium and Magnesium levels and imaging was planned to rule out stroke, primary neurodegenerative disorders and tumors. Post stratification Chi square test was applied and p-value less than or equal to 0.05 was considered significant. Results: The mean age of the patients was 63.91±5.68 years and mean duration of the disease was 4.61± 1.07 months. The common causes of epilepsy were found to be cerebrovascular disease 56.9%, cryptogenic 54.2%, neurodegenerative disorder 20.3%, traumatic head injury 11.8%, metabolic abnormalities or electrolyte disturbances 10.5% and brain tumor 7.8%. Conclusion: Elderly patients with first seizure should present to a facility designed in a way that neurologist, cardiologist, rehabilitation and geriatrics work together to identify and treat the condition in a better way. Keywords: Epilepsy; Seizures; Cerebrovascular Disease; Neurodegenerative Disorder.

Epilepsy in NF1: a systematic review of the literature.

Epilepsy is one of the possible neurological manifestations of the neurofibromatosis type 1 (NF1) that represents the most common neurocutaneous disorder. We performed a systematic review of the literature on epilepsy associated with NF1 since 1995 in order to better define prevalence and describe type and causes of seizures. Data on type, nature of studies, number of patients, gender, and inheritance of NF1 were recorded as well as data on causes, type, EEGs, brain imaging, intellectual disability (ID), surgical treatment, and outcome of epilepsy. We identified a total of 141 references through the literature search of Pubmed and Embase. After screening, 42 records were identified, including 11617 individuals with NF1 (53% of males). Overall prevalence was estimated at 5.4% lifelong with values that seemed to be slightly lower in children, 3.7% (p 0.0016). Neither gender differences nor correlation with NF1 inheritance was found. Focal with or without bilateral tonic-clonic seizures were the most common seizure type encountered (60.9%). Structural causes were identified in half of cases (114/226). Low-grade gliomas were the most frequent associated lesions followed by mesial temporal sclerosis, malformation of cortical development, dysembryoplastic neuroepithelial tumor, and cerebrovascular lesions. In these cases, the surgical approach improved the epileptic outcome. Prevalence of epilepsy is higher in subjects with NF1 respect of the general population, with values apparently significantly lower in pediatric age. Brain tumors and cytoarchitectural abnormalities are the most frequent causes of epilepsy in this population, although many other brain complications should be taken in account.

Visual analysis of automated segmentation in the diagnosis of focal cortical dysplasias with magnetic resonance imaging

Focal cortical dysplasias (FCDs) are a frequent cause of epilepsy. It has been reported that up to 40% of them cannot be visualized with conventional magnetic resonance imaging (MRI). The main objective of this work was to evaluate by means of a retrospective descriptive observational study whether the automated brain segmentation is useful for detecting FCD. One hundred and fifty-five patients, who underwent surgery between the years 2009 and 2016, were reviewed. Twenty patients with FCD confirmed by histology and a preoperative segmentation study, with ages ranging from 3 to 43 years (14 men), were analyzed. Three expert neuroradiologists visually analyzed conventional and advanced MRI with automated segmentation. They were classified into positive and negative concerning visualization of FCD by consensus. Of the 20 patients evaluated with conventional MRI, 12 were positive for FCD. Of the negative studies for FCD with conventional MRI, 2 (25%) were positive when they were analyzed with automated segmentation. In 13 of the 20 patients (with positive segmentation for FCD), cortical thickening was observed in 5 (38.5%), while pseudothickening was observed in the rest of patients (8, 61.5%) in the anatomical region of the brain corresponding to the dysplasia. This work demonstrated that automated brain segmentation helps to increase detection of FCDs that are unable to be visualized in conventional MRI images.

Characteristics of symptomatic epilepsy and other neurological disorders in children with lissencephaly

Brain malformations are one of the most frequent causes of epilepsy in childhood. In patients with malformations of the brain epilepsy is diagnosed in 75–80% of cases. Lissencephaly is a cortical malformation, which develops as a result of global violations of glial-neuronal migration. The probable cause of the deterioration is considered to be the “Transportation” function-specific astrocytes and radial glial fibers involved in the migration of germ cells. The absence of convolutions in the mature brain – morphological substrate is agyria full lissencephaly, the presence of only a single, rudimentary and thickened gyri (pachygyria) – incomplete lissencephaly. Clinical manifestations lissencephaly presented delayed psycho-motor development, spastic tetraplegia and intractable epilepsy. Materials and methods. To examine and compare the clinical, electrophysiological and neuroimaging results in children with symptomatic epilepsy with lissencephaly, to assess the effectiveness of antiepileptic therapy and to identify the frequency of drug-resistant forms of epilepsy. The study involved 22 patients with lissencephaly. In all the children studied anamnesis and neurological examinations were conducted and neuroimaging and electrophysiological studies were performed. Results. In neuroimaging examinations, pachygyria and agyria were equally identified. The preferential localization pachygyria was observed in the frontal region. In most cases, clinical examination revealed the presence of motor deficits, cognitive and behavioral disorders. The debut of seizures was observed significantly more often in the age of six months. In general, during the observation period focal seizures with secondary generalization like, with or without secondary generalization were more common. Neuroimaging and EEG correlation was noted in half of the children surveyed. Conclusions. In the treatment of epileptic seizures in patients valproate are used more often. The results of the study suggest that one of the common causes of severe forms of epilepsy in children is malformations of brain development, so their early diagnosis and adequate antiepileptic therapy correlated with the prevention pharmacoresistance, symptomatic epilepsy and disability in children.

Seizures After Intracerebral Hemorrhage: Incidence, Risk Factors, and Impact on Mortality and Morbidity.

Spontaneous intracerebral hemorrhage (ICH) is one of the most frequent causes of epilepsy in the United States. However, reported risk factors for seizure after are inconsistent, and their impact on inpatient morbidity and mortality is unclear. We aimed to study the incidence, risk factors, and impact of seizures after ICH in a nationwide patient sample. We queried the Nationwide Inpatient Sample for patients admitted to the hospital with a primary diagnosis of ICH between the years 1999 and 2011. Patients were subsequently dichotomized into groups of those with a diagnosis consistent with seizure and those without. Multivariate logistic regression was used to assess risk factors for seizure in this patient sample, and the association between seizures and mortality and morbidity. Logistic regression was then used for trend analysis of incidence of seizure diagnoses over time. We identified 220,075 patients admitted with a primary diagnosis of ICH. Of these, 11.87% had a diagnosis consistent with seizure. Factors associated with increased risk of seizure after ICH included higher categorical van Walraven score, encephalopathy, alcohol abuse, solid tumor, and prior stroke. Seizure was independently associated with decreased odds of morbidity (odds ratio [OR], 0.89; 95% confidence interval [CI], 0.86-0.92) and mortality (OR, 0.75; 95% CI, 0.72-0.77) in multivariate models controlling for existing comorbidities. Seizures after were associated with decreased mortality and morbidity despite attempts to correct for existing comorbidities. Continuous monitoring of these patients for seizures may not be necessary in all circumstances, despite their frequency.

Characteristics of symptomatic epilepsy with schizencephaly

Objective: Study and compare the clinical and electrophysiological and neuroimaging findings in children with symptomatic epilepsy with schizencephaly. Methods: The study included 11 patients with schizencephaly. There are five boys (45.45%) and six girls (54.55%). Results: Compliance with focal changes in the EEG (electroencephalography) and localization revealed morphological changes in the group of children with schizencephaly is 80%. The clinical picture of epilepsy dominated by focal seizures in eight patients (72,72%), epileptic spasms – two patients (18,18%), focal with secondary generalization seizures – two (18,18%), atonic – one (9,09%). Simple focal seizures were observed in two boys (18.18%) and two girls (18.18%). Complex focal seizures recorded a boy (9.09%) and three girls (27.27%), focal seizures with secondary generalization – a boy (9.09%) and one girl (9.09%), epileptic spasms – a boy (9.09%) and one girl (9.09%). Seizures are not registered with one girl (9.09%). In the group of children with schizencephaly have four boys and four girls diagnosed with focal epilepsy (72.73%), one boy and one girl – focal epilepsy with secondary generalization (18.18%), one boy and one girl – multifocal (18 ,18%). Epileptic Encephalopathy – one girl (9.09%). Epilepsy is not diagnosed in one girl (9.09%). Eleven patients (100%) identified a variety of changes in neurological status. Severe motor impairment with the formation of palsy, a violation of the innervation of the bulbar group cranial nerves – in six patients (54.55%). Muscular hypotonia – two patients (18.18%). Eleven children of this group noted intellectual-mental disorders in varying degrees of severity (100%). In the treatment of epilepsy in nine patients (81.81%) with schizencephaly used valproate. Topiramate was used in two patients (18.18%) carboxamide derivatives, phenobarbital, hormones were used at least in one case (9,09%). Conclusion: Malformations of the brain are one of the frequent causes of epilepsy in children.

STXBP1 encephalopathy: A neurodevelopmental disorder including epilepsy.

To give a comprehensive overview of the phenotypic and genetic spectrum of STXBP1 encephalopathy (STXBP1-E) by systematically reviewing newly diagnosed and previously reported patients. We recruited newly diagnosed patients with STXBP1 mutations through an international network of clinicians and geneticists. Furthermore, we performed a systematic literature search to review the phenotypes of all previously reported patients. We describe the phenotypic features of 147 patients with STXBP1-E including 45 previously unreported patients with 33 novel STXBP1 mutations. All patients have intellectual disability (ID), which is mostly severe to profound (88%). Ninety-five percent of patients have epilepsy. While one-third of patients presented with Ohtahara syndrome (21%) or West syndrome (9.5%), the majority has a nonsyndromic early-onset epilepsy and encephalopathy (53%) with epileptic spasms or tonic seizures as main seizure type. We found no correlation between severity of seizures and severity of ID or between mutation type and seizure characteristics or cognitive outcome. Neurologic comorbidities including autistic features and movement disorders are frequent. We also report 2 previously unreported adult patients with prominent extrapyramidal features. De novo STXBP1 mutations are among the most frequent causes of epilepsy and encephalopathy. Most patients have severe to profound ID with little correlation among seizure onset, seizure severity, and the degree of ID. Accordingly, we hypothesize that seizure severity and ID present 2 independent dimensions of the STXBP1-E phenotype. STXBP1-E may be conceptualized as a complex neurodevelopmental disorder rather than a primary epileptic encephalopathy.

Approach to cortical dysplasia associated with glial and glioneuronal tumors (FCD type IIIb).

Brain tumors are a frequent cause of epilepsy in the pediatric population. The last International League Against Epilepsy (ILAE) classification of focal cortical dysplasias (FCDs) includes a subgroup consisting of tumors with surrounding dysplastic abnormalities (FCD type IIIb). Although its pathogenesis is still unclear, it has several clinical and therapeutic (surgical) implications. A number of benign tumors (such as dysembryoplastic neuroepithelial tumors and gangliogliomas) frequently present with medically refractory epilepsy associated with cortical dysplasia. In such cases, planning of surgical resection needs to take into consideration not only the tumor but also the whole area of epileptogenicity. The use of intraoperative electrocorticography recordings is reported to result in better postoperative outcomes, since they help delineate the abnormal cerebral cortex that needs to be resected to provide seizure freedom to patients. Clinical, radiological, and pathological features are also discussed herein.

Estimating blur at the brain gray-white matter boundary for FCD detection in MRI.

Focal cortical dysplasia (FCD) is a frequent cause of epilepsy and can be detected using brain magnetic resonance imaging (MRI). One important MRI feature of FCD lesions is the blurring of the gray-white matter boundary (GWB), previously modelled by the gradient strength. However, in the absence of additional FCD descriptors, current gradient-based methods may yield false positives. Moreover, they do not explicitly quantify the level of blur which prevents from using them directly in the process of automated FCD detection. To improve the detection of FCD lesions displaying blur, we develop a novel algorithm called iterating local searches on neighborhood (ILSN). The novelty is that it measures the width of the blurry region rather than the gradient strength. The performance of our method is compared with the gradient magnitude method using precision and recall measures. The experimental results, tested on MRI data of 8 real FCD patients, indicate that our method has higher ability to correctly identify the FCD blurring than the gradient method.

Clinical analysis of catastrophic epilepsy in infancy and early childhood: Results of the Far-East Asia Catastrophic Epilepsy (FACE) study group

Purpose: We studied children younger than 6years old who developed catastrophic epilepsy and were registered in the FACE study group to clarify their clinical characteristics and prevalence of seizure as well as epilepsy types. Subjects: Subjects were prospectively recruited from children with epilepsy who satisfied the following criteria and underwent intensive examination between 2009 and 2012 in 14 collaborative centers: (1) younger than 6years old and (2) more than 10 seizures/month refractory to all available medical treatments including ACTH therapy, leading to significant psychosocial morbidity. Methods: We analyzed epilepsy onset age, predominant seizure type, etiology, neuropsychological findings, and syndromic classification according to the pre-determined registration format. Results: A total of 314 children were enrolled in this study. Epilepsy onset age in 239 cases (80%) was younger than 12months. The most frequent seizure type was epileptic spasms (ES), followed by generalized tonic seizures (GTS), which accounted for 42% and 20%, respectively. West syndrome (WS) was the most frequent epileptic syndrome and accounted for 37%, followed by unclassified epilepsy at 21%, neocortical epilepsy at 19%, Lennox–Gastaut syndrome at 12%, Dravet syndrome at 4%, Rasmussen syndrome at 2%, and others. The two most frequent causes of epilepsy were cortical dysplasia and chromosomal anomalies, as shown in 16% and 6%, respectively. However, the etiology of nearly one half of all patients remained unknown. Psychomotor development was already worse than a moderate degree in 62% of subjects at the first examination. Conclusion: The highest proportion of catastrophic epilepsy was WS and its related syndromes featuring ES and GTS, followed by neocortical epilepsy, whose psychomotor development was significantly retarded at examinations.

PCDH19 mutation in Japanese females with epilepsy

To determine the significance of PCDH19 mutations in Japanese females with epilepsy and to delineate their phenotypes. PCDH19 sequencing analysis was performed in 116 females with various epilepsies, including 97 with Dravet syndrome (83.6%). They were referred for SCN1A analysis, and 52 carried SCN1A mutations. Seven heterozygous mutations in exon 1 were identified in 7 patients (6.0%): 2 frameshift, 2 nonsense, and 3 missense mutations. One patient was a monozygotic twin, and her sister with mild phenotype carried the same mutation. The main clinical features among these 8 patients included early seizure onset (≤25 months of age), seizure clusters (7/8), fever-associated seizures (7/8), single seizure type (6/8), and late deterioration of intellect (5/8). Seizure durations were generally up to a few minutes, and only one patient developed status epilepticus once. The main seizure types were generalized tonic-clonic (4/8), tonic (3/8) and focal seizures, with (2/8) or without secondary generalization (3/8). Myoclonic, atonic and absence seizures were extremely rare. Two patients had Dravet syndrome (25%), and this proportion was significantly smaller than that in the total subjects (p<0.01). PCDH19 mutation is a relatively frequent cause of epilepsy in Japanese females. Dravet syndrome was rare in our cohort.

Privacy and Security Issues in Cerebrovascular Diseases Data Research

The cerebrovascular diseases research are based on real patient’s data received from a collaborating centre. The goal of research is to take advantage of heterogeneous medical data relationships. Medical data relationships leads to get more data mining facilities in studying of dependencies and crucial values of parameters in a huge volume of real imaging examinations with clinical and therapeutic data. There are lot of difficulties and security issues when providing research on medical data. All real patient’s identifiers must be removed for privacy reasons. A research team does not necessity know the patient identity information. We keep limited characteristics only and can be accessible to patient’s medical doctors. These characteristics are useful to provide us analysis and statistics results. The aggregated results are publicly available. The goal of research is to take advantage of heterogeneous medical data relationships. Medical data relation-ships leads to get more data mining facilities in studying of dependencies and crucial values of parameters in a huge volume of the real imaging examinations with clinical and therapeutic data. The cerebrovascular diseases research is based on real patient’s data received from a collaborating centre. There are lot of difficulties and security issues to be solved in medical data research. All data used for research must be de-identified before we can use them. The experimental database concept was first announced in [17]. The knowledge base and de-identified real patient data can be used in a practical education and as a diagnostic tool. Stroke is one of the leading causes of morbidity and mortality worldwide [7]. Large differences in incidence, prevalence and mortality have been noted between Eastern and Western Europe. This has been attributed to differences in risk factors, with higher levels of hypertension and other risk factors resulting in more severe stroke in Eastern Europe [2]. Notable regional variations have also been found within Western Europe. Stroke is the most important cause of morbidity and long term disability in Europe, and demographic changes will result in an increase in both incidence and prevalence. It is also the second most common cause of dementia, the most frequent cause of epilepsy in the elderly, and a frequent cause of depression. [1, 12, 15] In the European Union countries, the female and male mortality rates on cerebrovascular diseases are almost the same among persons aged 85 and over. The lowest rates are recorded in France, Slovakia, the Netherlands. The highest rates are recorded in Portugal, Greece, Latvia and the Czech Republic. The rate in the Czech Republic being 2.8 times higher than the European average. [11] The cerebrovascular diseases are the second most frequent cause of death in the Czech Republic. Cancer incidence and mortality are two to three times greater in the Czech Republic than in other developed countries in Europe. [9, 19]

Epilepsy Aspects and EEG Patterns in Neuro-Metabolic Diseases

Neurometabolic diseases (NMD) are a frequent cause of epilepsy in children. Epilepsy is more frequently part of a complex clinical picture than a predominant symptom and may be of different types and various EEG patterns. The primary goal of this article is, departing from a large personal series, to describe the seizure type, EEG patterns and response to antiepileptic drugs in NMD and to discuss clinical value of epilepsy type in the setting of specific NMD. We found epilepsy was associated to NMD in 43.1%. Disorders of energy metabolism were the most frequent cause of epilepsy (61.3%). We observed generalized epilepsy in 75% of the patients with partial epilepsy in 25%. EEG was abnormal in only 71% of cases with variable patterns. Resistance to antiepileptic drugs was observed in 75% of cases. Valproate acid was incriminated in seizure worsening in 22.7% of the patients, all of them affected by mitochondriopathies.

Post-Traumatic Epilepsy: Review

Post traumatic epilepsy is defined by recurrent seizures secondary to brain injury following head trauma and represent the most frequent cause of epilepsy in young adults. Most post traumatic epilepsies start within two years from trauma, but in some cases may present several years after the brain injury. Severe traumatic brain injuries tend to correlate with an increased risk of developing early and late post-traumatic seizures. A cranial trauma creates a potentially epileptogenic brain damage through a number of different mechanisms. Several structural, physiological and biochemical modifications occur in a brain after a head injury that promote oxidative stress mechanisms and excitotoxic mechanisms. Current evidence shows that prophylactic use of antiepileptic drugs prevent the occurrence of early post-traumatic seizure but does not influence the incidence of post-traumatic epilepsy. Some authors propose treatment with antioxidant drugs in acute phase of severe traumatic brain injuries in order to prevent early tissue changes established in the traumatized tissue.

Mutations and deletions in PCDH19 account for various familial or isolated epilepsies in females

Mutations in PCDH19, encoding protocadherin 19 on chromosome X, cause familial epilepsy and mental retardation limited to females or Dravet-like syndrome. Heterozygous females are affected while hemizygous males are spared, this unusual mode of inheritance being probably due to a mechanism called cellular interference. To extend the mutational and clinical spectra associated with PCDH19, we screened 150 unrelated patients (113 females) with febrile and afebrile seizures for mutations or rearrangements in the gene. Fifteen novel point mutations were identified in 15 female patients (6 sporadic and 9 familial cases). In addition, qPCR revealed two whole gene deletions and one partial deletion in 3 sporadic female patients. Clinical features were highly variable but included almost constantly a high sensitivity to fever and clusters of brief seizures. Interestingly, cognitive functions were normal in several family members of 2 families: the familial condition in family 1 was suggestive of Generalized Epilepsy with Febrile Seizures Plus (GEFS+) whereas all three affected females had partial cryptogenic epilepsy. These results show that mutations in PCDH19 are a relatively frequent cause of epilepsy in females and should be considered even in absence of family history and/or mental retardation. © 2010 Wiley-Liss, Inc.

Experiencia de cinco años en una unidad de epilepsia pediátrica

The epilepsy monitoring unit is a space inside a hospital, which objective is to reproduce epileptic seizures in order to better study of an epileptic patient. We have analysed data from all the patients admitted to our pediatric epilepsy unit in the last 5 years. 191 patients have been admitted in our unit, and we have obtained seizures in 186 admissions (monitoring efficacy, 85.9%). In this report we summarize characteristics of these children, type of seizures and treatment. The most frequent cause of epilepsy in our series is cortical development malformation. Patients are often late in their admission, with a median time of 3 to 4 years from epileptic onset to admission in the epilepsy unit. After the study, 22 patients underwent functional epilepsy surgery, all of them with excellent results, 9 patients underwent vagal nerve stimulator implantation and in 66 patients their previous pharmacological treatment was modified. The efficacy of our monitoring unit is similar to previously published, 85.9%. After the admission, we have changed diagnose in 57% of the patients and pharmacological treatment in 29%. We recommend the study in a monitoring epilepsy unit of every patient with refractory epilepsy, meaning an epilepsy that does not respond to 2-3 different appropriate treatments.

Different presurgical characteristics and seizure outcomes in children with focal cortical dysplasia type I or II

Cortical dysplasia (FCD) is a frequent cause of epilepsy in childhood. Two major pathological variants are distinguished, FCD type I and II. The aim of the study was to characterize differences between FCD type I and II with respect to imaging and EEG findings, clinical and neuropsychological presentations, and surgical outcome. Forty children with refractory epilepsy and histopathologically confirmed FCD were retrospectively analyzed. FCD type I was identified in 24 and FCD type II in 16 patients. Characteristic MRI abnormalities in FCD type I included subtle white matter signal changes and regional reduction of the white matter volume. Typical MRI findings in FCD type II were increased cortical thickness, transmantle sign, gray-white matter junction blurring, fluid-attenuated inversion recovery (FLAIR) and proton density (PD) gray matter signal changes as well as T1w, and PD white matter signal changes. Continuous EEG slowing was significantly more common in patients with FCD type I. Children with FCD type I presented with lower levels of intelligence and were suffering more often from maladaptive behavior and behavioral disorders. Surgical outcome was significantly worse in the FCD type I group (seizure freedom was achieved in 21% FCD type I patients and in 75% FCD type II subjects, p < 0.001). Clinically important differences were found in children with distinct histopathological subtypes of FCD. Due to prominent neuropsychological deficits and worse seizure outcome, treatment strategies in FCD type I are more challenging than previously reported and these children should be recognized and specifically addressed within the incoherent group of patients with malformative brain disorders.

Cortical malformations: a frequent cause of epilepsy in children.

In this review, a simplified scheme for classification of cortical malformations is introduced and illustrated based on the work of Barkovich et al. [8]. Detailed MRI studies identify cortical malformations as a major cause of epilepsy in children. Two aspects that are becoming increasingly important for the paediatrician are emphasised. First, knowledge of the genetic background of cortical malformations is necessary for appropriate genetic counselling. Although the majority of cortical malformations occur sporadically, recent studies have shown a familial pattern in specific epilepsy syndromes associated with cortical malformations. Second, the epilepsy becomes refractory to the common anti-epileptic drugs in many patients with cortical malformations so that epilepsy surgery should be considered. In this respect, the paediatrician can play a pivotal role in referring candidate patients for further specialised assessment. The input of the paediatrician will become crucial to link clinical, genetic and neuro-imaging data in children with the great variety of possible cortical malformations.

Crisis epilépticas de comienzo tardío y enfermedad vascular cerebral

Stroke is the most frequent cause of epilepsy in adults, specially in those over 60 years old. Our aim was to analyze the etiologic relevance of stroke among the different etiologies of late onset seizures and to evaluate the clinical characteristics of the subgroup of patients with late onset seizures associated to stroke. Patients aged over 20 who were admitted to the Neurology or Neurosurgery departments in our hospital for a first-ever seizure over a period of five years were identified retrospectively. The total number of patients included was 248. The most frequent etiologies were stroke (26.2%), tumors (26.2%), unknown (24.6%) and chronic alcohol intake (18.5%). Stroke was the most frequent etiology in patients over 60 (50%). Five of the 65 patients with stroke related seizures had suffered an intracranial hemorrhage and the rest had ischemic lesions. Seven patients had clinically silent infarctions. Seizures were generalized in 60% of the cases. Nearly in all the patients lesions were placed close to the cortex and mainly in carotid artery territory. Late onset seizures are due to a lesion in the brain in an important number of cases. Stroke is the most prevalent cause and this prevalence increases with age. A complete diagnostic procedures is warranted in this patients.

Changes in the threshold of pentylenetetrazol-induced seizures in cats with a chronic granuloma in brain amygdala

A parenchymal brain granuloma is the final consequence of a localized inflammatory reaction against an infectious agent, particularly parasites. In humans, these lesions are frequent causes of epilepsy. We studied the pattern of seizures induced by pentylenetetrazol (PTZ) in cats with a chronic granuloma induced 1 year earlier by injection of silicates into the brain amygdala. Compared with controls, the seizure threshold to myoclonic seizures was significantly decreased in cats with granuloma, while the threshold for tonic-clonic seizures was not altered. Thus, the difference in PTZ doses between the initial and final components of the seizure became significantly enlarged ( P<0.001). Our results indicate that a granulomatous lesion in amygdala facilitates the generation and propagation of myoclonic seizures, whereas other components of PTZ-induced seizures are not affected.