Diagnostic efficiency of monitoring methods of brain bioelectric activity in temporal lobe pharmacoresistant epilepsy

Background. The basis of pre-surgical neurophysiological examinations of patients with pharmaco-resistant structural epilepsy is the method of monitoring bioelectrical activity of the brain, video-electroencephalographic monitoring and, if indicated, long-term invasive monitoring.Objective. The goal of the study is to estimate the diagnostic efficacy of the methods used for monitoring of the brain bioelectric activity on the basis of longterm results of surgical treatment of patients with temporal structural pharmaco-resistant epilepsy.Design and methods. The study included 61 patients with temporal lobe pharmaco-resistant epilepsy, who were divided into two groups: performance of video-EEG monitoring only (33 patients) and the additional use of invasive monitoring for the localization of the epileptogenic zone (28 patients). Each group was divided into subgroups depending on the outcome of surgical treatment: patients, in whom seizures ceased (Engel 1) and patients in whom seizures persisted to some degree (Engel 2-3-4). Invasive monitoring with ictal event recording was chosen as the reference method to calculate diagnostic efficacy.Results. Invasive monitoring was performed as part of the pre-surgical evaluation of patients with temporal lobe pharmaco-resistant epilepsy with a higher sensitivity (72.7 %) and accuracy (82.4 %) than video-EEG monitoring (sensitivity 50 %, accuracy 45.9 %).Conclusion. In simple monofocal variants of structural epilepsy, video-EEG monitoring has a sufficient level of diagnostic efficiency. The phenomenon of neurophysiological phenotypes convergence is responsible for the reduced diagnostic efficacy of noninvasive and invasive monitoring.

Neuroimaging predictors of structural epilepsy in the COVID-19 catamnesis

Respiratory system pathology is the most common clinical disorder associated with COVID-19. However, there are also lesions of the immune, cardiovascular, genitourinary, endocrine systems, and digestive tract. In addition, there are numerous reports on infection-related neurological manifestations, which can be divided into 3 groups: central nervous system manifestations (headache and dizziness, stroke, encephalopathy, encephalitis, acute myelitis), lesions of the peripheral nervous system (anosmia, Guillain–Barre syndrome), secondary lesions in the skeletal muscles. Brain damage that occurs during novel coronavirus infection and determines some of the above-mentioned manifestations often account for the development of structural epilepsies. Only a few scarce review articles on neuroimaging features in patients with COVID-19 have been found in Russian research publications.The objective of the review was to collect, analyze and summarize the results of brain magnetic resonance imaging (MRI), currently accumulated worldwide in patients with COVID-19. We present the most common diagnoses based on brain MRI in patients with COVID-19 established by foreign researchers from March 2020 to March 2021, as well as initial attempts to interpret the pathophysiological mechanisms of the changes observed in the brain substance.

Epilepsy in children with perinatal arterial ischemic stroke

Purpose: Perinatal ischemic stroke (PIS) is a frequent cause for perinatal brain structure defects resulting in epilepsy, cerebral palsy and disability. Since the severity of symptoms is variable, the aim of this study was to evaluate the outcome of children with PIS and seizures/epilepsy to aid parental counseling and therapy decisions. Material: We studied retrospectively patients with arterial PIS and structural epilepsy or seizures in the newborn treated at a single center in 2000-2019. Specifically, signs and symptoms of cerebral palsy (CP), developmental and motor delay, epilepsy and thrombophilia were assessed. Results: From the identified 69 individuals with arterial PIS, we only included the 50 patients (64% male) who had structural epilepsy at the time of investigation or previously in their medical history.The mean age of the included patients was 7.1 years (range 0.08-22) at last consultation. Infarct localisation was predominantly unilateral (86%), left sided (58%) and affecting the middle cerebral artery (94%). Genetic thrombophilia was identified in 52% of the patients examined with genetic testing. More than half of the individuals had CP (52%), and 38.5% had a cognitive outcome below average. First seizures occurred in the neonatal period in 58% of patients and developed into drug-refractory epilepsy in 24.1%. Children with late-onset of epilepsy were twice as likely to develop drug-refractory epilepsy (52.4%). Discussion: Our study shows that patients with PIS and seizures as common sequela often also develop CP. Children with later onset of epilepsy have a worse outcome. Patients with seizure onset in the neonatal period and reccuring seizures have a good response to treatment. Therefore, early diagnosis, follow-up examination and adequate therapy are important. Most children need intensive physiotherapy and speech therapy; however, participation in life is usually age-appropriate.

Evaluation of the effect of phenobarbital administration on the biochemistry profile, with a focus on serum liver values, in epileptic cats

Objectives Phenobarbital (PB) is the most common antiseizure drug (ASD) used for the management of feline epilepsy. In dogs, PB is known to cause serum liver enzyme induction and hepatotoxicity, especially after administration long term or in high concentrations. In cats, insufficient evidence is available to draw similar conclusions. The aim of this study was to evaluate the effect of PB administration on the serum biochemistry profile of epileptic cats. As an additional objective, other adverse effects arising, related to PB treatment, were recorded. Methods Medical records of four veterinary centres were retrospectively reviewed for epileptic cats receiving PB treatment. Cats were included if they had a diagnosis of idiopathic epilepsy or structural epilepsy; a normal baseline serum biochemistry profile; at least one follow-up serum biochemistry profile; no concurrent disease or had not received medication that could possibly influence liver function or lead to serum liver enzyme induction. Alkaline phosphatase, alanine aminotransferase (ALT), aspartate transaminase and gamma-glutamyl transferase activities, and total bilirubin, bile acids, glucose, albumin, total protein, urea and creatinine concentrations before and during PB administration were recorded. PB serum concentration was also recorded, when available. Results Thirty-three cats (24 males, nine females) with a median age of 3 years (range 2 months to 12 years) met the inclusion criteria. Idiopathic or structural epilepsy was diagnosed in 25 (76%) and eight (24%) cats, respectively. The follow-up period ranged from 9 to 62 months. This study found an increase in ALT in three cats, possibly related to a PB serum concentration >30 µg/ml. No statistically significant increase in serum liver enzymes or other evaluated biochemistry parameters was found by comparing pre- and post-treatment parameters. Conclusions and relevance PB administration did not result in hepatic enzyme induction or other biochemical abnormalities in cats. This strengthens the safety profile of PB as an ASD in cats.

Certain risk factors for the development of cognitive impairment in persons with epilepsy and new therapeutic options

Epilepsy is a common chronic neurological disease. The problems of people with epilepsy go well beyond epileptic seizures. Comorbidities in epilepsy are very common and often cause more problems to the patients than the seizures themselves. Although seizures are the most prominent clinical presentation of epilepsy, people with epilepsy are exposed to risk of not only seizures, but also of many health problems. Both children and adults with epilepsy often complain of memory impairment. It is commonly believed that cognitive dysfunction in epilepsy is multifactorial. The components that deteriorate cognitive functions include active seizures and especially generalized tonic-clonic seizures, traumatic brain injuries, structural epilepsy, and drug therapy. Cognitive dysfunction is very often present as far back as during the onset of epilepsy. The cognitive dysfunction detected in patients with epilepsy depend on the localization of the epileptic focus, the frequency and type of epileptic seizures, and changes in the interictal electroencephalogram. Seizures can be controlled with antiepileptic drugs in most patients with epilepsy. Therapy of cognitive dysfunction in patients with epilepsy presents significant difficulties, as there is no evidence of the efficacy of various drugs in cognitive disorders. The article presents a new Russian antiepileptic drug based on phenosanic acid as part of combination therapy in patients with partial epileptic seizures with or without secondary generalization, which can improve cognitive functions in patients with epilepsy.

Intraoperative seizures occurrence in cortical mapping of eloquent areas

The effect of structural epilepsy on the frequency of intraoperative convulsive seizures is assessed when mapping functionally significant areas of the cerebral cortex during resection of intracerebral neoplasms. The work is based on the analysis of the results of intraoperative neurophysiological studies at the Polenov Neurosurgical Institute. For the period 20192020 87 intraoperative mappings of eloquent cortex were carried out during resections of intracerebral neoplasms: 79 mappings of the motor cortex and 16 mappings of auditory-speech areas during operations with awakening. When mapping the motor zones of the cortex, the frequency of seizures was 5.1%, while mapping the auditory-speech zones with awakening 18.75%. The division of cases of intraoperative convulsive seizures into two groups: seizures arising from motor mapping and seizures associated with the mapping of auditory zones reflects differences in factors that affect the excitability of the cerebral cortex. In motor mapping, stimulation occurs against the background of general anesthesia, unlike waking operations. The intensity of stimulation in auditory mapping is higher than in motor mapping in motor mapping. Formally, the current used in motor mapping is significantly higher than in mapping auditory zones. In general, with the development of intraoperative convulsive seizures, the current intensity of cortical stimulation does not exceed the average values required to stimulate functionally significant cortical zones. The presence of epileptic syndrome in patients with intracerebral tumors cannot be considered as a predictor of intraoperative seizure development when performing motor mapping under general anesthesia as well as during surgery with awakening for mapping of motor or auditory verbal zones.

Problems of diagnosing focal cortical dysplasia

Focal cortical dysplasia (FCD) is one of the most common causes in developing pharmacoresistant epilepsy. We present the clinical case of the patient with generalized seizures. Routine electroencephalography (EEG) data registered diffuse epileptiform activity that allowed to diagnose genetic eneralized epilepsy and pharmacoresistant course of seizures.After performing magnetic resonance imaging using the epileptological program and video-EEG-monitoring, the diagnosis was revised: structural focal epilepsy with seizures with focal onset with oroalimentary, gesture automatisms in the right hand, bilateral tonic-clonic, uncompensated by levetiracetam monotherapy (1500 mg/day). Background disease: congenital malformation of the brain: FCD in the basal parts of the left temporal lobe. Lacosamide was added to the therapy in the drug dose 300 mg/day, and the frequency of epileptic seizures decreased. Differential diagnosis between genetic generalized epilepsy and structural epilepsy with FCD usually poses no obstacles. However, in some cases, structural epilepsy occurs under the “mask” of generalized epilepsy. Hence, this clinical case demonstrates the importance of diagnostic measures in the differential diagnostics of various forms of epilepsy to determine further tactics of patient management.