Presence Of Epileptiform Activity Research Articles

MiR-134 And MiR-106b Are Circulating Biomarkers For Temporal Lobe Epilepsy: Pilot Study Results

Temporal lobe epilepsy (TLE) is among the most common forms of focal epilepsy in adults. Currently, scientists search for microRNAs as noninvasive epilepsy biomarkers. MicroRNAs constitute a class of short (or small) non-coding RNAs that control the level of gene expression affecting the stability of mRNA. They are key regulators and therapeutic targets in epilepsy. Considering the role of miRNA-134 and miRNA-106b in the processes of epileptogenesis, the goal of our study was the clinical evaluation of their circulation as novel noninvasive molecular diagnostic markers of TLE. Material and Methods — Our pilot study involved 59 participants. The main group included 33 patients with mesial temporal lobe epilepsy, the control group encompassed 26 healthy volunteers. The ranking of patients was carried out depending on the disease duration, presence of epileptiform activity on the electroencephalogram (EEG) and hippocampal sclerosis on MRI, the number of taken antiepileptic drugs (AEDs), and patient response to the pharmacotherapy of epilepsy. The isolation of circulating microRNAs from blood plasma was accomplished via the sorption method, and the analysis of microRNA expression was performed by real-time PCR. Results — The expression levels of miR-134 and miR-106b in blood plasma in patients with TLE were reduced. Therefore, these microRNAs can be diagnostic biomarkers of patients with TLE, compared with the control group. The results of receiver operating characteristic (ROC) analysis yielded high sensitivity and specificity values of this biomarker for the diagnosis of TLE. Conclusion — Circulating miR-134 and miR-106b concentrations were significantly reduced in patients with mesial TLE (MTLE), compared with healthy controls. At the same time, the level of microRNA expression did not depend on the presence of hippocampal sclerosis and the response to antiepileptic therapy.

Outcomes In Patients with Traumatic Acute Subdural Hematoma with Non-Convulsive Status Epilepticus (N3.002)

<h3>Objective:</h3> To evaluate the factors contributing to poor outcomes in patients with acute traumatic subdural hematoma (aSDH) who developed nonconvulsive status epilepticus (NCSE). <h3>Background:</h3> NCSE in patients with aSDH is an underdiagnosed yet fatal complication that requires prompt diagnosis and treatment. A high degree of clinical suspicion and evaluation with continuous EEG is required for prompt diagnosis and treatment. <h3>Design/Methods:</h3> This is a single-institution retrospective study approved by the local IRB. Patients with traumatic brain injury (TBI) with aSDH diagnosed with status epilepticus between the years 2016–2020 were included. Demographic, clinical, imaging, treatment, and EEG details were reviewed and collected in a HIPPA-compliant format. Logistic regression analysis was used to evaluate factors contributing to poor outcomes. <h3>Results:</h3> Out of a total of 540 patients, who had presented with traumatic acute intra-cerebral hemorrhage between the years 2016–2022, 28 patients with traumatic aSDH who had presented with status epileptics during the same hospitalization were included in the present study. NCSE was the most common form of status epilepticus (27/28). The mean age was 67 (range 20–92) years and 17(60%) were male. 12(48%) of the patients had an initial presenting GCS of 7 or less. The mean length of stay in the hospital was 16 (5–44) days. Overall mortality was 19(64%). Logistic regression analysis identified the presence of central spikes on EEG (p:0.43, OR:12.72; 95% CI 1.083–149.35) and thickness of aSDH&gt; 1cm (p: 0.025; OR: 16.545; 95%CI: 1.426–191.95) as predictors of mortality in both univariate and multivariate analysis. Good functional outcomes with mRS&lt;2 were seen in rarely 10(35%) of these patients. <h3>Conclusions:</h3> Nonconvulsive status epilepticus (NCSE) is a common form of presentation of status epilepticus in patients with acute traumatic SDH. The presence of epileptiform activity in the central leads in EEG often leads to resistant seizures. NCSE carries a poor prognosis with high mortality. <b>Disclosure:</b> Dr. Mohammed has nothing to disclose. Miss Stebbins has nothing to disclose. The institution of Dr. Shah has received research support from Eisai pharma .

Editors' Note: Prediction of Regaining Consciousness Despite an Early Epileptiform EEG After Cardiac Arrest

Neuroprognostication after cardiac arrest often remains reliant on neurophysiologic and serologic testing. To better prognosticate outcomes among patients with early epileptiform activity on EEG, Dr. Barbella et al. modeled various EEG predictors of favorable outcome using updated neurophysiologic criteria. Early absence of epileptiform activity, continuous background amplitude with reactivity, and later stimulus-induced rhythmic periodic or ictal discharges (SIRPIDs) strongly predicted favorable long-term outcomes in these patients after cardiac arrest (area under the curve 0.96, 95% CI 0.91–1.00). In a reader response, Dr. Sethi highlights that SIRPIDs may indicate brain reactivity, but they are not associated with cerebral hyperperfusion (as in the case of seizures). Both the investigators and Dr. Sethi agree that later SIRPIDs need not be treated aggressively in these patients. This study adds considerably to the neuroprognostication literature by showing early epileptiform activity may not always be a poor prognostic marker after cardiac arrest. Even in the presence of epileptiform activity, some features indicate a reasonable probability of functional recovery. As the investigators note in their methods—intensive care withdrawal was considered in patients with treatment-resistant myoclonus or status epilepticus, absent somatosensory-evoked potentials, incomplete return of brainstem reflexes, and elevated neuron specific enolase levels. Unsurprisingly, each of these findings strongly predicted poor outcomes. Therefore, the high sensitivity and specificity of the NEC2RAS score for predicting poor outcome does not disentangle it from the possibility of it contributing to the self-fulfilling prophecy. Neuroprognostication after cardiac arrest often remains reliant on neurophysiologic and serologic testing. To better prognosticate outcomes among patients with early epileptiform activity on EEG, Dr. Barbella et al. modeled various EEG predictors of favorable outcome using updated neurophysiologic criteria. Early absence of epileptiform activity, continuous background amplitude with reactivity, and later stimulus-induced rhythmic periodic or ictal discharges (SIRPIDs) strongly predicted favorable long-term outcomes in these patients after cardiac arrest (area under the curve 0.96, 95% CI 0.91–1.00). In a reader response, Dr. Sethi highlights that SIRPIDs may indicate brain reactivity, but they are not associated with cerebral hyperperfusion (as in the case of seizures). Both the investigators and Dr. Sethi agree that later SIRPIDs need not be treated aggressively in these patients. This study adds considerably to the neuroprognostication literature by showing early epileptiform activity may not always be a poor prognostic marker after cardiac arrest. Even in the presence of epileptiform activity, some features indicate a reasonable probability of functional recovery. As the investigators note in their methods—intensive care withdrawal was considered in patients with treatment-resistant myoclonus or status epilepticus, absent somatosensory-evoked potentials, incomplete return of brainstem reflexes, and elevated neuron specific enolase levels. Unsurprisingly, each of these findings strongly predicted poor outcomes. Therefore, the high sensitivity and specificity of the NEC2RAS score for predicting poor outcome does not disentangle it from the possibility of it contributing to the self-fulfilling prophecy.

Life-long Dietary Pesticide Cocktail Induces Astrogliosis Along with Behavioral Adaptations and Activates p450 Metabolic Pathways

Exposure to environmental contaminants is a public health concern. However, pre-clinical studies that examine the impact of pesticides at low-dose and the long-term consequences are uncommon. Here, C57BL6/j male and female mice were daily fed from weaning and up to 12 months, corresponding to early-childhood into middle-age in humans, using chow pellets containing a cocktail of pesticides at tolerable daily intake levels. We found that 12 months of dietary exposure to pesticides was associated with a moderate perenchymal or perivascular astrogliosis in specific hippocampal sub-regions. The expression of platelet-derived growth factor receptor beta was modified at the perivascular level. Examination of Iba1+ microglial cells did not reveal sizeable changes. Concomitantly to astrogliosis, spontaneous spatial memory and sociability were modified in males at 12 months of dietary exposure to pesticides. Telemetry electrocorticograhic explorations ruled out the presence of epileptiform activity or theta-gamma wave modifications in these conditions. Long-term pesticides impacted the periphery where the hepatic P450 metabolic cytochromes Cyp4a14 and Cyp4a10 were significantly upregulated in male and female mice during the 12 months of exposure. The expression of β-oxidation genes, such as Acox1, Cpt1a and Eci, was also significantly increased in male and female mice in response to pesticides. Collectively, our results indicate that a life-long exposure to a pesticide cocktail elicits sex-dependent, spatio-temporally restricted brain modifications and significant activation of P450 pathways in the periphery. These brain-peripheral adjustments are discussed as time or age-dependent vulnerability elements.

MRI-EEG correlation for outcome prediction in postanoxic myoclonus: A multicenter study.

To examine the prognostic ability of the combination of EEG and MRI in identifying patients with good outcome in postanoxic myoclonus (PAM) after cardiac arrest (CA). Adults with PAM who had an MRI within 20 days after CA were identified in 4 prospective CA registries. The primary outcome measure was coma recovery to command following by hospital discharge. Clinical examination included brainstem reflexes and motor activity. EEG was assessed for best background continuity, reactivity, presence of epileptiform activity, and burst suppression with identical bursts (BSIB). MRI was examined for presence of diffusion restriction or fluid-attenuated inversion recovery changes consistent with anoxic brain injury. A prediction model was developed using optimal combination of variables. Among 78 patients, 11 (14.1%) recovered at discharge and 6 (7.7%) had good outcome (Cerebral Performance Category < 3) at 3 months. Patients who followed commands were more likely to have pupillary and corneal reflexes, flexion or better motor response, EEG continuity and reactivity, no BSIB, and no anoxic injury on MRI. The combined EEG/MRI variable of continuous background and no anoxic changes on MRI was associated with coma recovery at hospital discharge with sensitivity 91% (95% confidence interval [CI], 0.59-1.00), specificity 99% (95% CI, 0.92-1.00), positive predictive value 91% (95% CI, 0.59-1.00), and negative predictive value 99% (95% CI, 0.92-1.00). EEG and MRI are complementary and identify both good and poor outcome in patients with PAM with high accuracy. An MRI should be considered in patients with myoclonus showing continuous or reactive EEGs.

P21-F Motor cortex mapping in patients with primary glial brain tumors and structural epilepsy

Background Glial brain tumors (GBT) adjacent to motor cortical areas (MCA) are associated with tumor-related epilepsy (TRE). We analyzed aspects of intraoperative motor mapping (IOMM) in the presence of epileptiform activity in the peritumoral zone. Material and methods We studied 41 patients (m/f = 18/23, age 18–77) with GBT located in the MCA were analyzed. All patients underwent tumor resection in Polenov Russian Neurosurgical Institute in 2014–2016. IOMM was performed utilizing “IOM ISIS” hardware (Inomed, Germany). The trial group included 30 patients with TRE. Eleven patients in control group had GBT without TRE. Motor function was assessed postoperatively according to a conventional 6-grade score. Impairment degree and duration were estimated. Results The presence of TRE does not reduce the possibility of the motor response during IOMM (odds ratio – 1.0 (95% confidence interval 0.2 – 4.3)). However, current levels sufficient for IOMM in the trial group were significantly higher than in control group (22 – 25 mA vs 16 – 20 mA respectively; p Conclusions IOMM in patients with TRE is performed while motor neurons are in the state of altered reactivity. This state is associated with higher current levels for IOMM. It may also contribute to a more significant transient motor deficit in the early postoperative period.

EEG in WNV Neuroinvasive Disease.

Neuroinvasive West Nile virus (WNV) is rare, occurring in less than 1% of those infected, and may manifest as meningitis, encephalitis, and/or acute flaccid paralysis. Patients may present initially with nonspecific symptoms including fevers. Although rare, neuroinvasive WNV is associated with significant morbidity and mortality. The mainstay of treatment is supportive care. Electroencephalography (EEG) allows for identification of nonconvulsive status epilepticus and other epileptiform and nonepileptiform patterns suggestive of underlying cognitive dysfunction. Our aim was to describe specific EEG patterns observed in WNV neuroinvasive disease. A retrospective chart review was conducted. West Nile virus was confirmed with serum and/or cerebrospinal fluid markers. Patients with a history of abnormal EEG were excluded. Electroencephalography reports were classified into categories based on the presence of epileptiform activity, focal slowing, generalized periodic discharges with triphasic morphology, and frontally predominant generalized rhythmic delta activity. In our cohort of 34 patients, 60% of focal EEG abnormalities were anterior-predominant, seen as epileptiform discharges, focal slowing, or frontally predominant generalized rhythmic delta activity. Nonepileptiform EEG patterns included nonspecific slowing and generalized periodic discharges with triphasic morphology. Two patients had electrographic seizures, one arising from the frontocentral head region. EEGs are important in the evaluation of WNV infection to rule out seizures or alternative causes of encephalopathy, and because of the risk of nonconvulsive seizures or status epilepticus in encephalitis. Although an anterior predominance of EEG abnormalities was seen in our cohort, this most likely is more correlative to encephalopathy than WNV itself. Although a specific correlative EEG pattern may not accompany all cases of WNV neuroinvasive disease, WNV should be considered as a possible etiology in patients presenting with an encephalitic or meningitic syndrome in the presence of abnormal EEG findings including encephalopathic patterns, particularly those with anterior predominant EEG changes.

The impact of sleep characteristics and epilepsy variables on memory performance in patients with focal seizures

Disturbed sleep can negatively affect overnight memory retention as well as new learning the subsequent day. In healthy participants, positive associations between memory performance and sleep characteristics (e.g., time spent in slow-wave sleep [SWS]) have been detected. In a previous study, we found that SWS was much reduced in patients with focal seizures, but when correlations between memory complaints and various sleep characteristics were considered, the only significant relationship was with the time to onset of rapid eye movement (REM) sleep (i.e., REM latency). In this study, we investigated the relationships between sleep, epilepsy, and objective memory performance variables. Twenty-five patients with focal seizures had their memory tested while undergoing a two-day ambulatory electroencephalography (EEG). The sleep variables of interest were the percentage of time spent in SWS (%SWS) and REM latency. Epilepsy variables included the presence of (1) seizures, (2) interictal epileptiform discharges, and/or (3) hippocampal lesions as well as site of seizure origin (temporal vs extratemporal). Overnight retention (of autobiographical events, a story, and a complex geometric figure) and the ability to learn a word list on day 2 were the measures of memory. A significant positive correlation was found between word-list learning and %SWS during the previous night. A significant negative correlation was observed between REM latency and overnight retention of autobiographical events. Overnight retention scores for the story and geometric figure were not related to sleep characteristics but were negatively affected by the presence of epileptiform activity. Story retention was also worse for temporal lobe epilepsy (TLE) than for patients with extratemporal epilepsy (ETE). Those with hippocampal lesions were more impaired than those without lesions on word-list learning, autobiographical events' retention, and story retention. When multiple contributing factors were entered into regression analyses, %SWS was found to be the best predictor of subsequent word-list learning, whereas the presence of a hippocampal lesion was the best predictor of overnight retention of autobiographical events and a story. These findings provide further evidence of the ways in which particular sleep characteristics are associated with memory and suggest that treatment of sleep disturbances in patients with epilepsy might be helpful for improving their performance.

Sleep deprivation and melatonin for inducing sleep in paediatric electroencephalography: a prospective multicentre service evaluation.

To compare the efficacy of the main methodologies in attaining sleep and electroencephalography (EEG) abnormalities in children with a view to producing recommendations on best practice. Fifty-one UK centres participated. Methods for sleep induction (sleep deprivation, melatonin, and combined sleep deprivation/melatonin) were compared. Data pertaining to demographics, achievement of stage II sleep, and recording characteristics (duration of study, presence of epileptiform activity in awake/sleep states) were prospectively collected for consecutive patients in November and December 2013. Five hundred and sixty-five patients were included. Age range was 1 years to 17 years (mean 7y 10mo), 27.7 per cent had an underlying neurobehavioural condition. Stage II sleep was achieved in 69 per cent of sleep deprived studies, 77 per cent of melatonin studies, and 90 per cent of combined intervention studies (p<0.001, χ2 ). In children who slept, there was no difference between the three interventions in eliciting epileptiform discharges. In children who did not sleep, epileptiform abnormalities were seen more often than after sleep deprivation alone (p=0.02, χ2 ). Seizures were rare. Combined sleep deprivation/melatonin is more effective than either method alone in achieving sleep. The occurrence of epileptiform activity during sleep is broadly similar across the three groups. We recommend the combined intervention to induce sleep for paediatric EEG. Combined sleep deprivation/melatonin is more effective in achieving sleep than either sleep deprivation or melatonin alone. Sleep latency is shorter with combined sleep deprivation/melatonin. When children do sleep, there is no difference in the occurrence of epileptiform abnormalities between different induction methods. Seizures are rare in sleep electroencephalography recordings.

CLINICAL SIGNIFICANCE OF EPILEPTIFORM ACTIVITY IN ELECTROENCEPHALOGRAM

The article is devoted to some issues of sensitivity and specificity of epileptiform activity in the electroencephalogram (EEG). Epileptiform activity – it is sharp waves and spikes on EEG. Normal EEG does not exclude the diagnosis of epilepsy and viсe versa: presence of epileptiform activity on EEG is not necessarily caused by epilepsy. Several EEGs may be needed to detect epileptiform activity in patients with epilepsy. EEG recording during sleep with the use of different activation methods (hyperventilation, rhythmic photic stimulation, sleep deprivation) can increase the probability of epileptiform activity detection. Clinical presentation should be taken into account while interpreting EEG results with registered epileptiform activity. The issues of epileptiform activity classification and differential interpretation of other electrical activity types are also discussed in the article. Main epileptiform patterns, their neurophysiological basis and correlation with clinical manifestations are described.

P203 – 2949: Seizures persistence's prognosis in children with arterial ischemic stroke

Objective To investigate clinical and electroencephalographic features of seizures during acute and recovery periods of arterial ischemic stroke (AIS) in children. Methods Type of study: case series. Inclusion criteria Children 0–15 y.o. with seizures during AIS's debut. We identified the type of episodes and EEG features in acute and recovery periods after one year. Results 152 children with AIS were examined. Seizures occurred during the acute period of stroke in 39 (25.7%) cases and antiepileptic therapy was prescribed for all of them. Generalized seizures type was registered in 56.4% (n=22), focal type in 23% (n=9), focal type with secondary generalization – in 20.6% (n=8) children. Epileptiform activity was registered in 31% (n=9) patients. Disorganized changes on background EEG without signs of paroxysmal activity were predominant in most children – 75.9% (n=22) as well as background activity was normal only in 13.8% (n=4) of them. In the recovery period seizures persisted in 10.5% (n=16). Generalized seizures of acute period pass to recovery period in 27.2% (n=6, RR=0.56 95%CI 0.3–1.0), and focal seizures with secondary generalization – in 75% (n=6, RR=2.75 95%CI 1.2–6.0). Seizures accompanied by epileptiform activity on EEG during acute period persisted in the recovery period in 55.6% (n=5, RR=2.7 95%CI 1.1–6.1), without activity – in 30% (n=9, RR=0.5 95%CI 0.2–1.1). At the same time generalized seizures of acute period combined with epileptiform activity on EEG persist in recovery period in 50% (n=2, RR=2.2 95%CI 0.6–8.3), without it – in 22.2% (n=4, RR=0.6 95%CI 0.2–1.7). Conclusion The presence of epileptiform activity on EEG and the development of focal with secondary generalization seizures type in children with AIS and seizures in the acute period increase the risk of seizure persistence in the recovery period in spite of antiepileptic therapy have been prescribed.

Detection of epileptiform activity in EEG signals based on time-frequency and non-linear analysis.

We present a new technique for detection of epileptiform activity in EEG signals. After preprocessing of EEG signals we extract representative features in time, frequency and time-frequency domain as well as using non-linear analysis. The features are extracted in a few frequency sub-bands of clinical interest since these sub-bands showed much better discriminatory characteristics compared with the whole frequency band. Then we optimally reduce the dimension of feature space to two using scatter matrices. A decision about the presence of epileptiform activity in EEG signals is made by quadratic classifiers designed in the reduced two-dimensional feature space. The accuracy of the technique was tested on three sets of electroencephalographic (EEG) signals recorded at the University Hospital Bonn: surface EEG signals from healthy volunteers, intracranial EEG signals from the epilepsy patients during the seizure free interval from within the seizure focus and intracranial EEG signals of epileptic seizures also from within the seizure focus. An overall detection accuracy of 98.7% was achieved.

8. Angelman Syndrome revisited: An update in 2011

Aim Retrospective analysis of the clinical features, EEG and chromosomal findings in Angelman Syndrome (AS), a congenital developmental disorder due to del15 q 11–13. Methods A 20 year old man was diagnosed at age 4 years, with global developmental delay, seizure disorder with status epilepticus and R. hemiparesis, on AEDs. Results The diagnosis of AS was confirmed by chromosomal analysis: deletion of the maternal 15 q 11–13. The clinical phenotype comprises infantile spasms with hypsarrhythmia on the EEG, secondary generalized seizures intractable to AEDs, leading to status epilepticus, postictal hemiparesis; global developmental delay without speech development and autistic-type behaviour. Current medications: Depakote sprinkles©, lamotrigine and carnitine. The EEG was invariably abnormal: modified hypsarrhythmia in infancy (West syndrome), diffusely slow background activity, central spikes (at times synchronized with hand clapping) and multifocal epileptiform features, slowly progressive to low-amplitude attenuation of background, suggestive of an epileptic encephalopathy with multiple independent spike foci. Discussion The presence of epileptiform activity is likely due to mutations at subunits of the GABA-A receptor genes in the deleted segment on the long arm of maternal chromosome 15q 11–13, reducing the expression of ubiquitin ligase 3A (UBE3A) gene. Paradoxically, the same deletion of the paternal chromosome 15 produces the phenotype of the Prader–Willi Syndrome (PWS): hyperphagia, obesity and hypomentia, rare seizure activity and usually a normal EEG. The underlying basis of this genetic imprinting is not completely understood. Conclusion These “experiments of Nature” with AS and PWS reveal the complexity of the genetic bases of some of the epilepsy syndromes of childhood.

Relación entre los resultados del Electroencefalograma digital y la evaluación clínica, neuropsicológica e imagenológica en pacientes con diagnóstico clínico de Parálisis Cerebral

Objetive: To evaluate the relation between digital Electroencephalogram (EEG) results and clinic, neuropsychological and imagenologic anomaly detected in patients with Cerebral Palsy (CP) diagnosis.Subject and method: Descriptive longitudinal retrospective study was made of EEG informs emitted by a clinical neurophysiologic specialist in 64 patients with CP diagnosis. The information was recorded from January 2000 to December 2005 in a Clinical Neurophysiologist laboratory of the International Center of Neurological Restoration. It included patients between 2 and 15 years old, with CP diagnostic checked in clinical history. The variables assessed were tabulated in EEG records and were associated to clinical, neuropsychology and imagenologic variables. All recordings were performed with the MEDICID 4 Neuronic SA equipment made in Cuba with Track Walker 2 software.Results: 79 % of the electroencephalographic records were pathological. In 58% of the cases there was a predominance of epileptiform activity. 50% suffered from spastic CP. The cause of CP was perinatal in 43%. The other associated conditions were Phychomotor Retardation (PR), Mental Delay (MD) and epilepsy. There was a statistically significant association between the presence of epileptiform activity and epilepsy between the EEG records and bilateral lesion and between the epileptiform activity and the presence of MD, PR and epilepsy.Conclusions: Our results demonstrate the exististence of a statistically significant association between epileptiform anomaly and epilepsy clinical diagnosis. It was confirmed that EEG anomaly is associated with bilateral extension of motor affectation and lesions detected with Magnetic Resonance Image (MRI) studies. There was an association tendency between electroencephalographic alteration, CP type, PR and MD presence. EEG is a useful diagnostic way for the functional evaluation of CP patients.

Contribution to the genetics of symptomatic generalized tonic-clonic seizures: waking and sleep EEGs in siblings.

The presence of epileptiform activity (EA) in the EEG of patients' relatives points to the significance of genetics in the etiology of epilepsies. Waking and sleep EEGs were recorded in 83 siblings of 54 patients suffering from symptomatic generalized tonic-clonic seizures. EA was recorded in at least one sibling of 27 (50%) of the 54 patients. When the 83 siblings are taken as a basis, EA was found in 34 (41%) of them. Generalized spike-wave discharges were seen in 32 cases; 2 siblings showed benign sharp wave foci in the right parietal area. EA was seen only in sleep in 44.1%. The highest rates of EA were seen in the age range up to 15 years. EA was found in 15 of 50 male siblings (30%), but in 18 of 33 female siblings (54.5%). Therefore genetics also play an import role in the etiology of symptomatic generalized tonic-clonic seizures.

Comorbidity of DCD and SLI: significance of epileptiform activity during sleep

In children affected by specific language impairment (SLI), many authors have investigated a link between language and epileptiform discharges during sleep resembling the focal sharp waves typical of benign epilepsy with centro-temporal spikes (BECTS), the so-called rolandic spikes. On the other hand, the same electroencephalographic trait occurs in more than 50% of children affected by learning or behavioural disabilities without seizures, supporting the hypothesis of a common genetic disposition. The biological background of Developmental Coordination Disorder (DCD) is currently unknown, but a genetic liability may be assumed. The aims of our study were first to estimate the prevalence of sleep-related epileptiform discharges in children affected by DCD and second to investigate the occurrence of DCD in a population of children affected by BECTS. We selected a group of eight children with severe DCD. In this group, the presence of epileptiform activity was investigated. We also searched for DCD among a group of 13 children affected by BECTS. We found rolandic spikes in more than 70% of the children with severe DCD and severe DCD in more than 30% of the children with BECTS. In children with severe DCD other disabilities are frequently associated. In these children, epileptiform activity during sleep is very frequently found and in our opinion, this represents a hallmark of 'Hereditary Impairment of Brain Maturation', a term only partially resembling 'Atypical Brain Development'.

Prevalence and duration of insensibility following electrical stunning in calves

Sixty-one calves were electrically stunned with 100-250 V currents (103-1806 mA) and the prevalence and duration of insensibility was assessed from their physical behaviour, the presence of epileptiform activity in their electrocorticograms, and the absence of visual evoked responses in their electrocorticograms. A current applied at 100 V across the head for 3 s failed to induce insensibility in all cases. Currents at 150-250 V induced insensibility in all calves and the shortest duration of insensibility was 44 s. It is recommended that a 150-200 V current would be appropriate for commercial use.

Clinical significance of focal topographic changes in the electroencephalogram (EEG) and evoked potentials (EP) of psychiatric patients.

The relationship between psychiatric symptoms that respond to anticonvulsants and epileptic activity is still debated. Evidence linking electroencephalographic changes to treatment response is scarce and controversial, partly because of the poor scalp representation of limbic electrical activity. We studied the clinical relevance of focal topographic changes in the resting EEG, the visual evoked potential and the P300 response in 90 psychiatric patients, by evaluating response to anticonvulsants and development of neurological complications. The group with focal changes was compared to a group with epileptiform activity but no focal changes and a group with normal or diffusely altered EEG. Focal EEG and EP changes predicted good response to anticonvulsants, while the presence of epileptiform activity did not. Clinical seizures developed only in patients with focal changes and no anticonvulsants medication. Structural abnormalities and selective neuropsychological deficits were seen only in the focal group. There was an association of symptom type and the site of focus. We concluded that focal EEG and EP changes in psychiatric patients have important theoretical as well as practical implications.

Electroencephalograms and electrocardiograms in young bulls following upper cervical vertebrae-to-brisket stunning

Passing an electric current (50 Hz, 400 V open circuit, current limited to 1.5 A) from two electrodes acting as a common single electrode set applied on each side of the dorsal surface of the neck (cervical vertebrae C2 to C5 region) to another placed on the brisket of young bulls causes fibrillation of the cardiac muscle, does not induce epileptiform changes in the electroencephalogram, and produces a state of body rigidity. Passing the same electric current through the same neck electrodes, now acting as two separate electrodes, without the brisket electrode, does induce epileptiform activity similar to that seen with head-only stunning, does not fibrillate the heart, and produces a state of limb rigidity lasting for some time after the stun. Given that the presence of epileptiform activity is a criterion for effective electrical stunning and is indicative of insensibility, neck-to-brisket stunning as described here does not appear to be humane.

Effect of electrical stunning on somatosensory evoked potentials in chickens

The spontaneous EEG and somatosensory evoked potentials (SEPs) were examined in chickens before and after electrical stunning using a waterbath stunner. Fifty-four per cent of the birds became epileptic and lost their SEPs, and 17% were non-epileptic and appeared to retain their SEPs. It was concluded that there was a reasonably close association between the presence of epileptiform activity in the EEG and the absence of SEPs following electrical stunning, but that the absence of SEPs could be preferred as an indicator of an effective stun on conceptual grounds.