Clinical evaluation and noninvasive electroencephalography. Preoperative evaluation

Epilepsy surgery has been shown to be a safe and effective alternative to antiepileptic drug therapy for many patients with medical refractory partial seizure disorders. Surgical treatment should be considered when the patients experience and impairment in the quality of life related to the seizures, medical therapy, or both. Surgically remediable epileptic syndromes include medical temporal lobe epilepsy and lesional epilepsy. A comprehensive presurgical evaluation is performed to identify appropriate candidates for epilepsy surgery.     

Anesthetic implications of epilepsy, status epilepticus, and epilepsy surgery

Epilepsy is a clinical paroxysmal disorder of recurring seizures, excluding alcohol or drug withdrawal seizures or such recurring exogenous events as repeated insulin-induced hypoglycemia. Epilepsy has a profound impact on each individual diagnosed with this disease. Seizures have been and are thought to arise as a result of abnormalities in (a) neural circuits, (b) excitation/inhibition balance, (c) potassium, and (d) genetic abnormalities. Therapy for epilepsy is either medical, entailing the use of a variety of antiepileptic drugs, or surgical. An urgent approach to seizure control is indicated when status epilepticus occurs. When all standard therapy fails, general anesthesia can be used to control status epilepticus. Surgery is an option in the treatment of epilepsy and requires extensive preoperative evaluation. The primary concerns for the neuroanesthesiologist anesthetizing the patient with epilepsy are the capacity of anesthetics to modulate or potentiate seizure activity and the interaction of anesthetic drugs with antiepileptic drugs. Proconvulsant and anticonvulsant properties have been reported for nearly every anesthetic. If seizure spikes are to be evoked during seizure surgery, then light anesthesia with a proconvulsant anesthetic is used. Conscious analgesia can be used for awake seizure surgery. However, if electrocorticography is not planned, then a general anticonvulsant anesthetic maintenance regimen is used. The latter technique also may be useful in patients whose anesthetic management is complicated by an incidental history of epilepsy.     

Prognostic factors for seizure recurrence after withdrawal of antiepileptic drugs in patients with neurocysticercosis

We tapered antiepileptic drugs in 40 patients with epilepsy due to neurocysticercosis who had been free of seizures for 2 years. All patients previously received a course of albendazole that resulted in complete destruction of brain cysts. We followed the patients prospectively from the time of diagnosis until 12 months after antiepileptic drug withdrawal. We evaluated the following prognostic factors for seizure recurrence: sex, number of seizures before control, type of seizures, number of parenchymal brain cysts before albendazole therapy, EEG findings, and CT findings after albendazole therapy. In the univariate analysis of prognostic factors for seizure recurrence, the development of brain calcifications caused by albendazole was the only factor associated with a significantly higher rate of relapse (p = 0.004). The multivariate analysis showed that patients who had both recurrent seizures and multiple brain cysts also had a higher risk of relapse than those with single seizures or single cysts (p = 0.05). This study suggests that the prognosis of epilepsy due to neurocysticercosis is not as benign as previously thought. Patients with residual calcifications and those with both recurrent seizures and multiple cysts before albendazole therapy have the highest rate of relapse after withdrawal of antiepileptic drugs.     

Short-term perioperative anticonvulsant prophylaxis for the surgical treatment of low-risk patients with intracranial aneurysms

The long-term use of anticonvulsant medication to prevent postoperative seizures in patients with aneurysms has been accepted medical practice for many years. The low incidence of seizures in more recent aneurysm series makes it appropriate to re-evaluate the use of prophylactic anticonvulsants to prevent postoperative epilepsy, especially in patients at low risk of seizure disorders. On the basis of preoperative presentation, we categorized 387 of the 420 craniotomies for aneurysms over a 4-year period to be at low risk of seizure. Postoperative anticonvulsant medication in this group was restricted to an average of 3 days. A retrospective analysis of the incidence of early postoperative seizures and late postoperative seizure disorders was performed in the populations of patients with ruptured aneurysms and with unruptured aneurysms with an average follow-up of 2.4 years. The overall seizure rate in the study group was 5.4%. Patients with ruptured aneurysms had an early postoperative seizure rate of 1.5% and a long-term seizure disorder rate of 3.0%. Early and long-term seizure rates for unruptured aneurysms were 2.6 and 4.4%, respectively. No patients who had early seizures went on to develop epilepsy, and all seizure disorders were well controlled once anticonvulsants were begun. These data support the idea that anticonvulsant medication may be safely restricted to the immediate perioperative period for most patients with aneurysms.     

Effect of anticysticercal treatment on the prognosis of epilepsy in neurocysticercosis: a pilot trial

Epilepsy secondary to active or inactive neurocysticercosis (NCC) is a major public health problem in Latin American countries. In an open-label pilot trial, we evaluated and followed (mean = 13 months) 16 patients with epilepsy resulting from active NCC which was treated with anticisticercal (ACC) drugs. These patients were aged 12-68 years with confirmed active NCC and seizures not controlled by adequate antiepileptic drug (AED) therapy. Patients were treated with albendazole or praziquantel (ALB and PZQ, ACC drugs) and AED monotherapy. The number of NCC cysts was markedly reduced by ACC therapy. Thirteen patients remained seizure-free and 2 had only one seizure during follow-up. Our data suggest a positive effect of ACC treatment on the prognosis of epilepsy caused by active NCC, but a prospective, double-blind, controlled study with long-term follow-up must be performed to determine whether ACC therapy improves long-term seizure control.     

Neurochemical coding in the myenteric plexus of the upper gastrointestinal tract of hibernating hamsters

PURPOSE: To study the impact of epilepsy and its treatment on people with epilepsy in Europe. We therefore aimed to collect data from as many countries as possible. METHODS: Clinical and demographic details and information about psychosocial functioning was collected using self-completed questionnaires mailed to members of epilepsy support groups. RESULTS: Quality of life data was collected from >5,000 patients living in 15 countries in Europe. Over a third of all respondents had frequent seizures, and a fifth believed that their seizures were not well enough controlled by antiepileptic medication. Reported levels of side effects from medication were high. A significant number of respondents reported changing their medication because of side effects or poor control. Respondents reported that epilepsy and its treatment had a significant impact on a number of different aspects of their daily lives. Half of all respondents felt stigmatised by their epilepsy. There were significant differences by seizure type and frequency in the way respondents scored on measures of the perceived impact of their condition, the stigma associated with it and their health status as measured by a generic scale, the SF36. CONCLUSIONS: This study confirms the findings of previous smaller-scale studies that reducing side effects and achieving better control of seizures are key to improving the quality of life of people with epilepsy, as is reducing the stigma and handicap associated with it.     

Medical causes of seizures

Seizures are commonly encountered in patients who do not have epilepsy. Factors that may provoke such seizures include organ failure, electrolyte imbalance, medication and medication withdrawal, and hypersensitive encephalopathy. There is usually one underlying cause, which may be reversible in some patients. A full assessment should be done to rule out primary neurological disease. Treatment of seizures in medically ill patients is aimed at correction of the underlying cause with appropriate short-term anticonvulsant medication. Phenytoin is ineffective in the management of seizures secondary to alcohol withdrawal, and in those due to theophylline or isoniazid toxicity. Control of blood pressure is important in patients with renal failure and seizures. Non-convulsive status epilepticus should be considered in any patient with confusion or coma of unclear cause, and electroencephalography should be done at the earliest opportunity. Most ill patients with secondary seizures do not have epilepsy, and this should be explained to patients and their families. Only those patients with recurrent seizures and uncorrectable predisposing factors need long-term treatment with anticonvulsant medication.     

Outcome and life prospects after surgical management of medically intractable epilepsy in patients under 18 years of age

A retrospective analysis of seizure outcome and quality of life assessment was done in 64 patients under 18 years of age with medically refractory epilepsy who underwent 64 primary and 16 repeat operative procedures in an attempt to control their epilepsy. At least 2 years' follow-up data were available for each patient. Operative procedures were 44 temporal lobe resections; 16 extratemporal resections; and 4 hemispherectomies. Effective control of previously intractable seizures was obtained in most patients: 55%, 11%, and 17% achieved Engel class I, II, and III status, respectively. Successful seizure control was thus obtained in 83%, while 17% (Engel class IV) failed to improve significantly after operation. Quality-of-life measures parallelled the improvements in seizures control, being highest in Engel I, outcome group and lowest in Engel IV outcome group. In appropriately selected pediatric and adolescent patients with medical refractory epilepsy, surgical management can offer a safe and effective adjunct to medication.     

The postictal state. A clinically oriented observation of patients with epilepsy

Epileptic seizures are followed by dynamic alterations in neurologic function in the postictal period which have received little attention by clinicians over a long period of time. We therefore retrospectively studied videotapes of 160 patients with focal epilepsy who underwent presurgical evaluation, for the occurrence of postictal symptoms to determine whether these phenomena have any localizing or lateralizing value in defining the seizure onset zone. Results: (1) We found postictal paresis in 22 of 160 patients (18.8%) in each case contralateral to the hemisphere of seizure onset. (2) 'Perservative' automatisms which start during the ictus and continue in the postictal period occurred in 25.2% of 135 patients with temporal lobe epilepsy but not in patients with frontal lobe epilepsy. (3) Sexual automatisms defined as manipulations of the genitals were found exclusively in patients with temporal lobe epilepsy (in 5.9% of 135 patients). (4) Postictal 'Nose-wiping' was evident in 51.3% of 76 temporal lobe epilepsy patients but only in 12.0% of 25 extratemporal lobe epilepsy patients and was performed with the hand ipsilateral to the hemisphere of seizure onset in 86.5% of all temporal lobe seizures. (5) Postictal language disturbances were observed only in patients with temporal lobe epilepsy (34% of 97 patients) and pointed to a seizure onset in the dominant hemisphere in 80.8%. We conclude that postictal phenomena can provide reliable information for the localization of the seizure onset zone in patients with complex partial seizures. Thus, more attention should be given to the postictal state during presurgical epilepsy monitoring.     

Seizure disorders in the dog. 1. Clinical features and differential diagnosis

For differential diagnosis, therapy, and prognosis of seizures in dogs it is recommended to distinguish between two groups of diseases: 1. Epilepsy is diagnosed if seizures occur repeatedly without an active, underlying disorder. Idiopathic epilepsy occurs most commonly. A hereditary component has been demonstrated in several breeds. Symptomatic epilepsy results from previous resolved forebrain disorders, which cause epileptic seizures through scar formation. 2. Seizures are caused by active structural forebrain disease or metabolic-toxic imbalances. Upon initial presentation of the dog, a preliminary classification may be achieved with the seizure history, clinical and neurological examination, and routine laboratory evaluation. The diagnosis of idiopathic epilepsy is based on typical seizure history and exclusion of structural forebrain disease and metabolic-toxic imbalances with special laboratory testing, CSF examination, and brain scanning procedures.     

Effects of intracerebroventricular injection of histamine on memory deficits induced by hippocampal lesions in rats

This review was conducted to evaluate the long-term prognosis of children responding to vigabatrin by examining the incidence of increased seizure frequency, loss of efficacy, and appearance of new seizures in a cohort of 196 children (mean age, 68.2 months; range, 2 months to 19 years) with drug-resistant epilepsy, who had received vigabatrin as add-on treatment in clinical trials. The results indicate that an increase in seizure frequency was uncommon, occurring in only 10% of children with highly drug-resistant epilepsy and that it usually appears shortly after the initiation of treatment. It was clearly not dose-dependent and most often occurred in patients with nonprogressive myoclonic epilepsy. No specific seizure type was specially involved and usually the problem reversed on discontinuing vigabatrin. Loss of efficacy was also uncommon (12% of patients), and again no specific seizure type was found to be associated. Epilepsy syndrome does seem to be a better predictor of loss of efficacy because it occurred most often in symptomatic generalized epilepsies and cryptogenic infantile spasms. A total of 21 patients (11%) developed genuinely new types of seizures. Fifteen of these patients developed new partial seizures that had little impact on the patients' overall clinical improvement. The new partial seizures were better tolerated than the initial seizure type which in most cases had disappeared. Approximately 3% of patients experienced new generalized seizures that aggravated their initial condition. These occurred most often in patients with nonprogressive myoclonic epilepsy; therefore vigabatrin should be used with particular caution in such patients.     

EEG findings in frontal lobe epilepsies

As a group, epilepsies of frontal lobe origin are thought to be poorly localized using surface EEG recordings. This finding may depend on the specific areas of frontal lobe from which the seizures originate or the pathologic substrate. We reviewed the presurgical surface EEGs of patients with frontal lobe epilepsy who underwent epilepsy surgery. The specific area of the frontal lobe where seizures originated was determined by 1) intracranial ictal EEG recordings, or 2) the presence of a structural lesion, identified by imaging studies in patients who achieved complete seizure control following surgery. We differentiated patients whose seizures began in the dorsolateral frontal convexity from those whose seizures began in the medial frontal region, and we correlated EEG findings in the interictal, postictal, and ictal states with seizure semiology, pathologic substrate, and surgical outcome. Four of nine patients had seizures originating in the dorsolateral frontal convexity and five had medial frontal onset seizures. Patients whose seizures originated from the dorsolateral convexity had focal interictal epileptiform abnormalities that localized to the region of seizure onset. Patients whose seizures began in the medial frontal region had either no interictal epileptiform abnormality or had multifocal epileptiform discharges. Patients whose seizures began in the dorsolateral convexity showed focal electrographic seizure activity that was localizing. This rhythmic fast activity did not appear to be substrate-specific. Patients whose seizure onset localized to the medial frontal region did not show focal electrographic seizure at clinical onset. We conclude that the scalp EEG recordings of frontal lobe epilepsies contain features that enable differentiation of seizures originating from two different regions of the frontal lobe.     

Platelet glycoprotein Ia* is the processed form of multimerin--isolation and determination of N-terminal sequences of stored and released forms

The authors report on a patient who exhibited intractable epilepsy due to an inaccessible hypothalamic hamartoma and subsequently underwent stereotactic radiosurgery. This 25-year-old man had a 24-year history of intractable gelastic and tonic-clonic seizures. Magnetic resonance (MR) imaging performed at examination as well as that performed 30 months earlier demonstrated a nonenhancing and nonprogressive spherical mass, approximately 10 mm in diameter, located on the patient's right side at the floor of the third ventricle. Focal radiation treatment performed with a gamma knife unit administered 36 Gy to the center and 18 Gy to the periphery of the lesion. This treatment resulted in an improvement in seizure control. Before the patient underwent radiosurgery, he suffered from three to six generalized seizures per month in spite of attentive compliance with an anticonvulsant medication regimen. After irradiation of the harmatoma, the frequency of the seizures transiently increased and then subsided 3 months posttreatment. The patient has been free of seizures for the last 21 months, with no neurological or endocrinological complications. Magnetic resonance imaging performed 12 months posttreatment demonstrated complete disappearance of the lesion.     

Isolation and characterization of cDNA encoding chicken egg yolk aminopeptidase Ey

Twenty-five to 40 percent of patients with epilepsy continue to have seizures despite optimal treatment with traditional antiepileptic drugs. Treatment with standard anticonvulsants such as phenytoin, carbamazepine, valproic acid and phenobarbital is often complicated by side effects and by failure to adequately control seizures. Up to 61 percent of patients with seizures report having side effects with antiepileptic drugs. After a 15-year hiatus since the last new antiepileptic drug was marketed, five new drugs have been approved by the U.S. Food and Drug Administration for the control of seizures. Three of these, gabapentin, lamotrigine and topiramate, are approved for use in adults with partial seizures with or without generalization. Felbamate is approved for the above indication and also for use in children with Lennox-Gastaut syndrome, a rare childhood seizure disorder. Felbamate and lamotrigine have the potential of significant side effects and should be prescribed by physicians experienced in managing patients with complicated epilepsy. Fosphenytoin is a parenteral prodrug of phenytoin that is more tolerable than parenteral phenytoin.     

Latest tests for prostatic neoplasia

Neurofibromatosis 1 is a common, genetically transmitted neurodevelopmental disorder with a high potential to cause subcortical focal brain lesions. Although seizures occasionally complicate neurofibromatosis 1, they have not been characterized adequately in the disease. Other phacomatoses with attendant subcortical focal brain lesions have been associated with an evolution from generalized to focal-onset epilepsy. This evolution may be related to the cortical dysplasias that also appear in such disorders. Cortical dysplasias, although occasionally found in neurofibromatosis 1 epileptic patients, are not as frequent as in other phacomatoses. The authors retrospectively screened 499 neurofibromatosis 1 patients for the prevalence and etiology of seizures, their response to therapy, and the evolution of seizure type over time. The prevalence of epileptic seizures (4.2%) was about twice the prevalence in the general population. There were no significant cortical dysplasias identified radiographically nor was there a relationship among the presence of subcortical focal brain lesions and seizure type, response to treatment, or evolution of epilepsy in the neurofibromatosis 1 population. The authors' data do not suggest an ontogeny of epilepsy in neurofibromatosis 1 that is different from the general epileptic population.     

Serum levels of cytokeratin 19 fragments in cervical cancer

The objective of this study was to compare the efficacy and tolerability of two new antiepileptic drugs, lamotrigine (LTG) and vigabatrin (GVG) in everyday clinical practice. A comprehensive retrospective survey of a computerized data base and hospital case notes was carried out at the Mersey Regional Epilepsy Clinic (MREC), Liverpool, which services a population of 3 million in the North West of England. The study comprised 333 out-patients with refractory epilepsy exposed to LTG and GVG forming a subset in a total population of 2250 patients with epilepsy held on a comprehensive database. The main outcome measures were duration of treatment with each drug described by a Kaplan-Meier survival curve, seizure control determined by a 50% decrease in seizure frequency and freedom from seizures, and incidence of adverse drug effects leading to discontinuation. The Kaplan-Meier curve indicated a 57% probability of patients continuing to take LTG and 43% GVG after 40 months. A 50% improvement in seizure control followed the addition of LTG in 45% of patients, with 10% seizure free, compared with 32% and 6%, respectively after the addition of GVG. LTG was discontinued because of adverse events (most frequently skin rash) in 15% of patients compared to GVG in 25% (particularly because of personality disturbance and psychiatric disorder). Both LTG and GVG are effective new AEDs in patients with refractory epilepsy, treated in a tertiary referral out-patient setting. LTG has a broader spectrum of antiepileptic efficacy for patients with both partial and idiopathic generalized seizures, whereas GVG should be reserved for patients with partial seizures at low risk of psychiatric disorder.     

Multilobar polymicrogyria, intractable drop attack seizures, and sleep-related electrical status epilepticus

BACKGROUND AND OBJECTIVE: Patients with cortical malformations often have intractable seizures and are candidates for epilepsy surgery. Within an unselected series of patients with various forms of cortical malformation, nine patients with multilobar polymicrogyria had electrical status epilepticus during sleep (ESES) accompanied by infrequent focal motor seizures. Eight patients also had intractable atonic drop attack seizures. Because ESES usually is accompanied by a good long-term seizure prognosis, the objective of this study was to examine ESES outcome among patients with a structural lesion that is usually highly epileptogenic and has a low seizure remission trend. METHODS: The nine patients had follow-up periods lasting 4 to 19 years. All underwent brain MRI, serial sleep EEG recordings, and cognitive testing during and after ESES. RESULTS: ESES and drop attack seizures appeared between the ages of 2 and 5 years (mean, 4 years) and ceased between the ages of 5 and 12 years (mean, 8 years). At the last visit patients were 8 to 23 years of age (mean, 14.5 years) and were either seizure free or had very infrequent focal motor seizures during sleep. Three patients were free from antiepileptic drugs. In no patient was definite cognitive deterioration apparent after ESES in comparison with earlier evaluations. CONCLUSIONS: Age-related secondary bilateral synchrony underlying ESES may be facilitated in multilobar polymicrogyria. The good seizure outcome contrasts with that usually found in the presence of cortical malformations. For children with polymicrogyria and drop attack seizures, surgical treatment of the epilepsy should be considered cautiously, and sleep EEG recordings should be performed systematically.     

Problematic standards: improving organizational performance through the assess and improve phases

Since 1987, we have diagnosed 10 patients, 4 males and 6 females, aged 2-11 years at the last evaluation, who all met the following criteria of severe myoclonic epilepsy in infancy (SMEI): generalized or unilateral long-lasting febrile clonic seizures in the first year of life; the subsequent appearance of myoclonic seizures and other types of seizure (partial seizures, atypical absences and convulsive status epilepticus); and neuropsychological deterioration for a certain period. Family histories of epilepsy and febrile seizures could be traced in 1 and 3 cases, respectively. None of them had previous personal history of brain insult. Electroencephalographic (EEGic) recordings in febrile seizure stage were normal; and continuous prophylaxis with phenobarbital failed to prevent the recurrence of febrile seizures. EEG studies in myoclonic stage showed generalized spike-and-waves, polyspike-and-waves, focal abnormalities and/or photosensitivity. The seizures were highly resistant to antiepileptic drugs. Our experiences suggested that comedication of valproic acid, clonazepam and carbamazepine may be most effective in treatment of the diverse seizures including myoclonic seizures, myoclonic-tonic-clonic seizures, atypical absences and partial seizures. Myoclonic seizures and atypical absences diminished in parallel to a clear-cut decrease in generalized abnormalities on EEG in 4 cases aged more than 7 years. However, the partial seizures, secondarily generalized seizures and status epilepticus were still present. Further investigations should aim to identify the underlying etiology and to search more effective treatment.     

Epidemiology in epilepsy. Epilepsy primarily affects small children and the elderly

Epilepsy is one of the commonest neurological/disorders, with peak incidences among the elderly and among children in the first year of life. Approximately 60,000 (0.7 per cent) of the Swedish population, 50,000 adults and 10,000 children, have active epilepsy. Stroke is the aetiology most commonly identified. The majority of those with a first-ever unproven seizure suffer no further seizures. Of those who do have further seizures (i.e., who develop epilepsy), 65-85 per cent eventually become free from seizures, and many of them are able to cease antiepileptic medication. Epilepsy is a heterogeneous disorder. The larger proportion of patients who are otherwise healthy, and who respond readily to antiepileptic treatment and manifest no side effects or only mild ones, are characterised by the best prognosis and are able to terminate treatment within 2-5 years without recurrence. At the other extreme is the smaller group of patients with onset of epilepsy very early in life, and characterised by multiple severe neurological defects, severe daily seizures, resistance (more or less) to all available treatment, and high mortality. In many cases of epilepsy, however, severity and prognosis lie somewhere between these two extremes.