Presence Of EEG Abnormalities Research Articles

Long-term effectiveness and seizure recurrence risk factors of ketogenic diet for pediatric refractory epilepsy: Experience from a tertiary care center in China.

This study aimed to assess the long-term effectiveness and seizure recurrence risk in children with drug-resistant epilepsy who achieved seizure freedom on a ketogenic diet (KD). Predictors associated with seizure recurrence were also evaluated. Patients with drug-resistant epilepsy who received KD therapy for at least 3 months between May 2011 and April 2020 were included. The clinical efficacy of the KD was evaluated. Patients who achieved seizure freedom for at least 3 months on the KD were focused. Multivariate Cox regression models were used to explore the risk factors of seizure relapse in patients who achieved seizure freedom. This study included 288 patients (163 males, 125 females). The seizure-free rates of the KD at 3, 6, 12, and 24 months were 9.7%, 16.7%, 14.2%, and 9.0%, respectively. Additionally, the seizure reduction rates between 50% and 99% were 46.5%, 39.9%, 30.2%, and 20.5%, respectively. Patients with Angelman syndrome (AS) showed the highest efficacy rate, followed by those with Dravet syndrome (DS). 51 patients achieved at least 3 months of seizure freedom on the KD. Seizures recurred in 24 (47.1%) patients. None of the patients with AS relapsed, while those with DS had the highest recurrence rate. The etiology of epilepsy, KD maintenance treatment period, and electroencephalography (EEG) abnormalities during follow-up differed significantly between patients with and without recurrence. However, multivariate Cox regression analysis indicated that a KD maintenance treatment period of less than 12 months and the presence of EEG abnormalities during follow-up were significantly correlated with a higher risk of relapse. Epilepsy control was restored in 3 of the 24 (12.5%) patients who experienced relapse. KD appears to be effective in children with various types of drug-resistant epilepsy. A short KD maintenance treatment period and EEG abnormalities during follow-up were associated with an increased risk of seizure recurrence.

P300 event-related potentials in people with epilepsy: clinico-neurophysiologic study

BackgroundThere is increasing evidence that prolonged or recurrent seizures can cause or exacerbate cognitive impairment (CI) in memory, attention, orientation, and visuospatial and abstraction disabilities, all of which can jeopardize educational progress and achievement throughout life. The objectives of our study are to assess the cognitive functions in people with epilepsy (PwE) using P300 event-related potentials (ERPs), and correlate each P300 components with six explanatory variables (epilepsy type, seizure type, NHS3 score- seizure severity, disease duration, age at first seizure, and the number of anticonvulsant medications).MethodsOne hundred and two PwE [52 with focal epilepsy and 50 with generalized epilepsy, as classified by the International League Against Epilepsy in 2017]. They underwent electroencephalography (EEG) and P300. The Montreal Cognitive Assessment (MoCA) scale was used to assess baseline cognitive functions.ResultsEpileptic patients showed significant latency prolongation and amplitude reduction of P300 as compared to non-epileptic population. Longer P300 latency and lower amplitude were seen in patients with abnormal EEG records. P300 latency was longer in patients using poly-therapy. P300 components correlated well with age at presentation and disease duration but not with NHS3. According to epilepsy type, 50.98% of PwE had focal epilepsy and 49.02% had generalized epilepsy, 85.29% of them had abnormal EEG recording. Considering seizure type, 47.06% had a generalized tonic–clonic seizure, 38.24% had a focal to bilateral tonic–clonic seizure, 20.59% had a myoclonic seizure, 12.75% had a focal with impaired awareness seizure, 3.92% had a focal aware seizure, and 2.94% had an absence seizure. Seventy-seven PwE had one type of seizure, while 25 had more than one type of seizure. The NHS3 score was higher in those with a single seizure type than in those with multiple seizure types.ConclusionAll seizure types had an abnormal P300 component, indicating cognitive function deficits. P300 may be a promising objective method for assessing cognitive function in PwE. The number of antiepileptic drugs used, the presence of EEG abnormalities, the age at presentation, and the duration of the disease are the factors that best correlate with cognitive impairment (CI).

Electroencephalography Findings in Older Adults Undergoing Geriatric Treatment: A Surrogate for the Outcome?

Background: Comprehensive geriatric care (CGC) is a multidisciplinary approach developed to meet the needs of older patients. Electroencephalography (EEG) provides valuable information for monitoring the cerebral function. As a surrogate, EEG findings may help to estimate the course of diseases as well as the treatment outcomes. Objectives: Therefore, the aim of the present study is to investigate EEG findings in older patients receiving CGC. Methods: Patients with an initial EEG in a geriatric unit between May 2019 and April 2020 and treated using the CGC approach were analyzed. EEG abnormalities were defined as generalized (diffuse) background slowing and/or intermittent/persistent focal slowing and/or epileptiform discharges. Assessment results for the Barthel index (BI), Tinetti Balance and Gait test (TBGT), and Timed Up and Go test (TUG) were analyzed in relation to the presence of EEG abnormalities. Results: The study included 398 patients (mean age: 83.0 ± 6.57 years, 69.3% were female). Abnormal EEG patterns were found in 94 (23.6%) patients. Patients with EEG abnormalities had a mean age of 83.4 years versus a mean of 82.8 years in those without (p = 0.451). Based on all calculated scores, the majority of the patients improved after CGC, with a tendency to higher-grade improvements in those without EEG abnormalities (BI: 86.2% vs. 75.5%, p = 0.024; TUG: 53.3% vs. 31.9%, p < 0.001); for TBGT, only a gradual difference was detected (TBGT: 79.9% vs. 71.3%, p = 0.088). The presence of EEG abnormalities was associated with the parameters dementia (36.2% vs. 22.4%, p = 0.010), known epilepsy/seizure (19.1% vs. 5.9%, p < 0.001), structural brain lesion (47.9% vs. 19.7%, p < 0.001), and delirium (9.6% vs. 3.6%, p = 0.030) during hospitalization. Conclusions: We found EEG abnormalities in almost a quarter of the patients treated in the geriatric unit. In older patients, the presence of EEG abnormalities is associated with lower improvements after CGC.

EEG and MRI Abnormalities in Patients With Psychogenic Nonepileptic Seizures.

To compare the rate of EEG and MRI abnormalities in psychogenic nonepileptic seizures (PNES) patients with and without suspected epilepsy. Patients were also compared in terms of their demographic and clinical profiles. A retrospective analysis of 271 newly diagnosed PNES patients admitted to the epilepsy monitoring unit between May 2000 and April 2008, with follow-up clinical data collected until September 2015. One hundred ninety-four patients were determined to have PNES alone, 16 PNES plus possible epilepsy, 14 PNES plus probable epilepsy, and 47 PNES plus confirmed epilepsy. Fifty-seven of the 77 patients (74.0%) with possible, probable, or definite epilepsy exhibited epileptiform activity on EEG, versus only 16 of the 194 patients (8.2%) in whom epilepsy was excluded. Twenty-four of these 194 patients (12.4%) had MRI abnormalities. Three of 38 patients (7.9%) with both EEG and MRI abnormalities were confirmed not to have epilepsy. In PNES patients with EEG or MRI abnormalities compared with those without, patients with abnormalities were more likely to have epilepsy risk factors, such as central nervous system structural abnormalities, and less likely to report minor head trauma. The presence of EEG abnormalities in PNES-only patients did not influence antiseizure medication reduction, whereas those with MRI abnormalities were less likely to have their antiseizure medications reduced. Psychogenic nonepileptic seizure patients without MRI or EEG abnormalities are less likely to have associated epilepsy, risk factors for epilepsy, and had different demographic profiles. There is a higher-than-expected level of EEG and MRI abnormalities in PNES patients without epilepsy.

Electroencephalogram abnormalities in children have rotated error on block design performance: An university hospital child and adolescent psychiatry clinic sample.

Neuropsychiatric assessment is essential part of child and adolescent psychiatry clinic practice, also provides important information about central nervous system dysfunctions. In studies conducted to date, it has been known that both the high frequency of psychiatric comorbidity in epileptic patients and that epilepsy comorbidity is quite common in neurodevelopmental disorders. In fact, considering the high comorbidity of epileptic abnormalities and psychiatric disorders, it has been very important to determine predictors for epileptic abnormalities in a clinical sample of child and adolescent psychiatry. In this retrospective study, we aim to determine possible predictive factors for epileptic abnormalities in a clinical sample of child and adolescent psychiatry according to Weschler Intelligence Scale for Children (WISC-R) results. We identified patients who had two or more rotation errors in the block design subtest of WISC-R by retrospectively scanning the system records of 2609 cases who were applied WISC-R with different prediagnoses at Gazi University Child and Adolescent Psychiatry Outpatient Clinic between January 2013 and December 2020 (n=71). After the first step identification, we selected the ones who had a previous electroencephalography (EEG) recording available for our own re-review (n=60). We found 15% EEG abnormalities and ADHD is the most common diagnosis in both normal and abnormal EEG groups. Due to correlation analysis, there was a positive-mild correlation between presence of EEG abnormality and WISC-R performance (r=0.56) in intellectual disability (ID) group and a positive-strong correlation between presence of EEG abnormality and WISC-R performance-verbal scores (r=0.74) in ID group. This study has shown that many different abnormal EEG patterns can be found in patients who have rotation errors in the block design test of WISC-R, suggesting diagnoses of ID, and having notable performance-verbal subtests scores difference and rotation errors in the block design subtest of WISC-R should be predicitive factors for epileptic abnormalities.

Migraine in mitochondrial disorders: Prevalence and characteristics.

Background Migraine is a well-known feature of mitochondrial disorders (MDs). However, no systematic epidemiological data are available in large populations of patients. Aims The aim of this cross-sectional cohort study was to describe the prevalence and migraine characteristics in a large cohort of patients with mitochondrial encephalomyopathies. Methods We studied 93 consecutive patients with characterised MDs referred to our Neuromuscular Unit during a 12-month period. All patients (age range = 16-78 years; 31 men; 58 progressive external ophthalmoplegia [PEO], 12 myoclonic epilepsy with ragged red fibres [MERRF], eight mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes [MELAS], two mitochondrial neurogastrointestinal encephalomyopathy [MNGIE] and 13 other MDs) underwent a structured diagnostic headache interview using an operational diagnostic tool following the IHS criteria. If they met the criteria for migraine, they were included in the 'Migraine Group'. The other patients were counted in the 'No Migraine Group'. Patient demographic and migraine characteristics were examined. Clinical, neuroradiological and neurophysiological data were compared between groups. Results Migraine was reported in 35.5% of patients. Migraine without aura was the most common headache (81.8%). The migraine group showed younger age ( P < 0.01), increased prevalence of epilepsy ( P = 0.01), myoclonus ( P = 0.03), stroke-like episodes ( P = 0.03) and decreased prevalence of muscle weakness ( P < 0.01). Multivariate analysis showed that migraine was positively associated with absence of muscle weakness ( P = 0.04) and presence of EEG abnormalities ( P = 0.02). Conclusion Migraine has a higher prevalence in MDs compared with general population-based data, independently from genotype or phenotype. Migraine is not merely a phenotypic aspect of specific MDs but is rather the expression of vulnerability of the central nervous system, probably directly related with defects of the respiratory chain.

Risk of recurrence after a first unprovoked seizure in children

ObjectivesThis study aimed to evaluate the first episode of unprovoked epileptic seizure in children and assess recurrence risk factors. MethodsThis was a retrospective observational study, based on the analysis of medical records of patients admitted between 2003 and 2014, with first epileptic seizure, at the pediatric service of a secondary hospital. The data were analyzed using the SPSS 20.0 program. ResultsOf the 103 patients, 52.4% were boys. The median age at the first seizure was 59 (1‐211) months. About 93% of children were submitted to an electroencephalogram (EEG) at the first episode and 47% underwent neuroimaging assessment. Treatment with an antiepileptic drug was started in 46% of patients. The recurrence rate was 38% and of these, 80% had the second seizure within six months after the first event. Of the assessed risk factors, there was a statistically significant association between seizure during sleep and recurrence (p=0.004), and between remote symptomatic etiology seizure and occurrence of new seizure (p=0.02). The presence of EEG abnormalities was also associated with the occurrence of new seizures (p=0.021). No association was found between age, duration of the seizure, and family history of epilepsy with increased risk of recurrence. ConclusionsMost children with a first unprovoked epileptic seizure had no recurrences. The risk of recurrence was higher in patients with seizure occurring during sleep or remote symptomatic ones and those with abnormal EEG results.

EEG abnormalities and long term seizure outcome in high functioning autism.

Electroencephalographic abnormalities may occur in autistic spectrum disorders (ASD) even in the absence of clinical seizures. These abnormalities may vary from nonspecific changes to epileptiform abnormalities and are more common compared to the overall population. The level of intelligence is a significant risk factor for epilepsy in ASD. However, the relation between the functionality of the individuals with autism and the electroencephalographic (EEG) abnormalities, and the clinical significance of these abnormalities still remain relatively unclear. In this study we investigated the presence of EEG abnormalities in sixteen children diagnosed with high-functioning ASD. EEG recording was performed for at least 2h and included at least 90min of sleep activity. While none of the patients had clinical seizures, 5 patients (31.3%) were detected to have EEG abnormalities. Four of these were epileptiform (25%), and one patient developed seizure during follow-up. Our results support the fact that EEG abnormalities are observed at a higher rate also in ASD with a better functionality. The potential impact of EEG abnormalities on cognition and behavior, and the risk of epilepsy should be considered during long-term follow-up of these patients.

Electroencephalographic Findings in Children with Attention Deficit Hyperactivity Disorder

Objective: The relationship between cognitive functions, EEG findings and epilepsy in patiens with ADHD is controversial. The aim of this study is to determine the frequency of EEG abnormality and its relationship with clinical findings of children with ADHD. Methods: A total of 434 children’s sleep and/or awake EEG who received the diagnosis of ADHD were taken regardless of seizure history. Results: A total of 21.9% epileptic and 15.2% nonepileptic discharges were detected in EEG. Epileptic discharges were found to bemore common in the attention deficit type of ADHD, in right hemisphere regions and were significantly higher in patients who had sleep EEG compared to those who had awake EEG (p<0.0001). Conclusion: The presence of EEG abnormalities in patients with ADHD is associated with clinical findings. Interictal epileptic discharges could affect cognitive functions. EEG recordings including sleep should be taken even in the absence of seizure history.

Cerebrospinal fluid findings after epileptic seizures.

We aimed to evaluate ictally-induced CSF parameter changes after seizures in adult patients without acute inflammatory diseases or infectious diseases associated with the central nervous system. In total, 151 patients were included in the study. All patients were admitted to our department of neurology following acute seizures and received an extensive work-up including EEG, cerebral imaging, and CSF examinations. CSF protein elevation was found in most patients (92; 60.9%) and was significantly associated with older age, male sex, and generalized seizures. Abnormal CSF-to-serum glucose ratio was found in only nine patients (5.9%) and did not show any significant associations. CSF lactate was elevated in 34 patients (22.5%) and showed a significant association with focal seizures with impaired consciousness, status epilepticus, the presence of EEG abnormalities in general and epileptiform potentials in particular, as well as epileptogenic lesions on cerebral imaging. Our results indicate that non-inflammatory CSF elevation of protein and lactate after epileptic seizures is relatively common, in contrast to changes in CSF-to-serum glucose ratio, and further suggest that these changes are caused by ictal activity and are related to seizure type and intensity. We found no indication that these changes may have further-reaching pathological implications besides their postictal character.

Transcraneal Magnetic Stimulation Improves Sleep Parameters in Patients Affected with Imsomnia Associated to Electroencephalographic Abnormalities

Insomnia is one of the most frequently observed sleep disorders, affecting nearly 10% of the general population. It has multiple etiological factors. Recently, it has been reported that EEG abnormalities are associated with insomnia in patients previously diagnosed as idiopathic insomniacs. In addition, transcranial magnetic stimulation (TMS) has shown to be effective in the treatment of disorders characterized by neural hyper-excitability. Method: In the present study, patients with insomnia and EEG abnormalities were submitted to slow repetitive trans-cranial magnetic stimulation, for 15 minutes daily during 10 days. Polysomnographic recordings were performed before and after TMS. Results: The results indicate that the presence of EEG abnormalities significantly decreased after TMS. In addition, most of the sleep parameters showed significant improvement. Conclusions: These data support the notion that TMS is a reliable therapeutic tool for patients affected with abnormalities linked to neuronal hyper-excitability.

EEG for Predicting Early Neurodevelopment in Preterm Infants: An Observational Cohort Study

To clarify the prognostic value of conventional EEG for the identification of preterm infants at risk for subsequent adverse neurodevelopment in the current perinatal care and medicine setting. We studied 780 EEG records of 333 preterm infants born <34 weeks' gestation between 2002 and 2008. Serial EEG recordings were conducted during 3 time periods; at least once each within days 6 (first period), during days 7 to 19 (second period), and days 20 to 36 (third period). The presence and the grade of EEG background abnormalities were assessed according to an established classification system. Neurodevelopmental outcomes were assessed at a corrected age of 12 to 18 months. Of the 333 infants, 33 (10%) had developmental delay and 34 (10%) had cerebral palsy. The presence of EEG abnormalities was significantly predictive of developmental delay and cerebral palsy at all 3 time periods: the first period (n = 265; odds ratio [OR], 4.5; 95% confidence interval [CI], 2.2-9.4), the second period (n = 278; OR, 7.6; 95% CI, 3.6-16), and the third period (n = 237; OR, 5.9; 95% CI, 2.8-13). The grade of EEG abnormalities correlated with the incidence of developmental delay or cerebral palsy in all periods (P < .001). After controlling for other clinical variables, including severe brain injury, EEG abnormality in the second period was an independent predictor of developmental delay (OR, 3.2; 95% CI, 1.1-9.7) and cerebral palsy (OR, 6.8; 95% CI 2.0-23). EEG abnormalities within the first month of life significantly predict adverse neurodevelopment at a corrected age of 12 to 18 months in the current preterm survivor.

Anomalies électroencéphalographiques paroxystiques et troubles spécifiques du langage de l’enfant : vers un modèle neurodéveloppemental ?

Specific language impairment (SLI) is a primary developmental disorder in which language is significantly more impaired than other developmental domains. Abnormal electroencephalographic recordings without clinical seizures are often observed. The aim of this retrospective study was to characterize the frequency of these abnormalities, to describe them and to analyze their association with anamnestic, clinical, paraclinical and evolution characteristics. The cases of 35 children with a diagnosis of SLI, who also underwent electroencephalography and MRI, were systematically reviewed retrospectively. In this population, aged between 4 and 7 years, 49% (n=17) of patients exhibited a specific expressive language disorder and 51% (n=18) a specific receptive disorder. Forty-nine percent of the children featured abnormal electroencephalography results. Abnormalities were essentially localized on the left side of the brain and in two specific regions: the temporo-occipital (60%) and the frontorolandic (30%) regions. The groups with and without abnormalities were compared statistically with each other in terms of clinical, paraclinical and evolution characteristics. Evolution data were available for 24 patients through a telephone interview and for nine patients through a new complete language evaluation.The comparison of the two groups showed significant differences in terms of severity of the phonological disorder, a higher number of delayed acquisition of walking and cleanliness and a higher range of non specific psychomotor difficulties. A large proportion of children suffering from SLI present abnormal electroencephalography recordings with no clinical seizures. This rate is much higher than in the general population and the abnormalities are essentially localized on the left side of the brain in regions known for their specific role in language development. These abnormalities are more frequent in children with a severe phonological disorder, suggesting that they may share common pathophysiological features with SLI. The presence of EEG abnormalities in a large group of patients suffering from SLI associated with minor neurological abnormalities suggests a possible theoretical neurodevelopmental model. Minor neurodevelopmental abnormalities, genetically transmitted or acquired during the pre- or perinatal period, may create vulnerability towards SLI. This vulnerability, in conjunction with environmental influences such as family environment, linguistic stimuli, exposure to multiple languages, or transitory hearing loss, might take the form of SLI. This hypothesis underlines the importance of prevention and early detection of SLI when identifying vulnerable subjects. Monitoring the family early through parental guidance and early school support would facilitate the acquisition of language.

Migraine with aura with onset in childhood and adolescence: Long-term natural history and prognostic factors

The long-term course of migraine with aura (MA) has been poorly explored. The present 11-year follow-up study assessed the long-term natural history and possible prognostic factors of MA with onset in childhood or adolescence. Patients were recruited from the original case records of our department, which are specifically designed to report all headache characteristics, aura symptoms and electroencephalogram (EEG) findings. A total of 77 patients (47 females; 30 males) whose records contained detailed descriptions of both headache and aura symptoms apparently meeting the International Classification of Headache Disorders (ICHD)-II criteria for MA (i.e., 1.2.1, 1.2.2, 1.2.6) underwent structured face-to-face follow-up headache interviews, all of which were conducted by the same neurologist, who has particular expertise in this field. A multivariate model (logistic regression analysis) was used to investigate the association between possible prognostic factors and the remission of both aura and headache at follow-up. The results of our study showed that 23.4% of the MA patients were headache-free at follow-up, 44.1% still had MA and 32.5% had a transformed headache diagnosis (i.e., fulfilling the criteria for ICHD-II 1.1. or 2). Patients with basilar-type migraine (1.2.6) showed the highest headache remission rate (38.5%). Our study seems to show that migraine with typical aura (1.2.1-1.2.2) is associated with a favourable evolution of aura symptoms over time (remission of aura in 54.1% of patients). Subjects experiencing only visual aura had a lower remission rate compared with those with visual +/- sensory +/- aphasic aura symptoms (36.8% vs. 61.5%, p = 0.054). A short headache duration (<12 hrs) and the presence of EEG abnormalities at baseline were the only significant predictors of aura remission at follow-up (odds ratio [OR] = 9.12, 95% confidence interval [CI]: 1.79 +/- 46.51, and OR = 4.76, 95% CI: 1.18 +/- 19.15, respectively). No significant predictors of headache remission were found. In conclusion, our results suggest that MA shows a favourable course. Further prospective studies with detailed EEG analysis both at baseline and at follow-up are needed in order to confirm the possible prognostic role of EEG abnormalities in MA. That said, it would, in our opinion, be highly premature at present to submit children with MA to EEG examinations for prognostication purposes.

65. The correlation of migraine with EEG findings

Association between migraine and epilepsy is well known. However, few previous studies characterizedmigraine andEEGfindings. Thepurpose of this studywas to evaluate the correlation ofmigraine with EEG findings in the patients with/without epilepsy, and to discuss the pathophysiology of migraine with EEG abnormality. The subjects were 21 patients with migraine, divided into 16 patients without other neurological involvement (migraine group) and the other 5 patients complicated with epilepsy (epilepsy group). We compared clinical manifestations, EEG findings and locations of headache. Six (37.5%) of the 16 patients with migraine and all (100%) with epilepsy group showed EEG abnormalities. EEG demonstrated centrotemporal paroxysms in 4 (66.7%)withmigraine and 4 (80%) with epilepsy group. In 11 (68.8%) of the 16 patients with migraine and 4 (80%) of the 5 patientswith epilepsy group, headache was located at frontotemporal area. These results revealed clinical features inmigrainewere similar to those in epilepsy group. Furthermore, EEG demonstrated centrotemporal paroxysms in many patients of both groups. These results suggest that the presence of EEG abnormalities with migraine is not related to the underlying epileptogenic pathology. The pathophysiology of migraine with EEG abnormalities cannot be explained by the epileptic syndrome.

Lamotrigine add-on to valproate therapy for paediatric bipolar affective disorder

Anupam Thakur, Karuppiah Jagadheesan, Vinod Kumar Sinha, Department of Child and Adolescent Psychiatry, Central Institute of Psychiatry, Ranchi, India: Lamotrigine, a new anti-epileptic mood stabilizer, with documented therapeutic benefits for refractory bipolar disorder [1], is reported to enhance clinical improvement in bipolar affective disorder when added to valproate therapy in adults [2]. The present report reveals the clinical efficacy and safety of such combination therapy for the treatment of paediatric bipolar affective disorder. A 71/2-year-old boy, RM, presented with DSMIV bipolar affective disorder, mixed affective episode. His physical state and blood investigations were unremarkable, but electroencephalogram (EEG) showed generalized epileptiform (spike-waves) activities. He was commenced on sodium valproate 600 mg/day (20 mg/kg/day) along with olanzapine 2.5 mg/day, the latter being started for aggression. Due to lack of clinical response, at 6 weeks, lamotrigine was added to this regimen at a dose of 12.5 mg/day. The lamotrigine dose was gradually increased with 12.5 mg every 2 weeks and at 8 weeks of treatment, while on a dose of 62.5 mg/day, his symptoms remitted completely with no evidence of any adverse effects. Olanzapine was discontinued after 1 month on follow-up, and he remained symptom-free for the next 6 months. The report shows that lamotrigine add-on to sodium valproate therapy facilitated clinical remission and that this combination was well tolerated. The presence of EEG abnormalities could be considered a potential factor favouring clinical improvement with an anti-epileptic mood stabilizer therapy [3]. However, symptomatic remission in this patient, following combination therapy, suggests that the differential pharmacodynamic properties of valproate (GABA enhancer) and lamotrigine (sodium channel stabilizer) [4] could possibly have had a synergistic effect in facilitating clinical remission.

Predictive value of EEG monitoring during drug withdrawal in children with cryptogenic partial epilepsy

In order to evaluate the predictive value of the interictal EEG after discontinuation of anticonvulsant therapy in children with cryptogenic partial epilepsy, a prospective study was carried out on 84 children and adolescents who had been seizure-free for at least 2 years. Twenty-four children (28.6%) presented one or more relapses. EEG monitoring during drug withdrawal showed abnormalities in 67% of the patients (16/24) who relapsed with seizures, and in 10% of the patients (6/60) who did not relapse. Our study suggests that in children who have suffered from partial epilepsy, the detection of paroxysmal abnormalities during drug withdrawal, in a previously normal EEG is a risk factor for recurrence of seizures. It is therefore advocated that periodic EEG monitoring be carried out during the drug withdrawal period, because the presence of EEG abnormalities is associated with a high probability of seizures occurring during or after drug discontinuation.

Electroencephalographic abnormalities in addition to bilaterally synchronous 3 mper second spike and wave activity in petit mal

1. 1. In 100 consecutive patients in whom clinical petit mal attacks were associated with 3 per sec. spike and wave activity the presence of focal, lateral and diffuse EEG abnormalities was studied. 2. 2. In 51 cases the background activity of the EEG was essentially normal. In 35 cases focal or lateralizing abnormalities were present. In 14 cases the background activity was diffusely abnormal. 3. 3. Sixty-two patients were female. The average age of onset of petit mal was seven years. Nineteen had close relatives with a history of convulsions. Six patients had abnormal neurologic findings. Eleven were low in intelligence. Forty patients had atypical features to their seizures. Forty-nine had other types of seizures in addition to petit mal. Possible etiologic factors were present in the histories of only six patients. 4. 4. Correlations were noted between the presence of EEG abnormalities other than synchronous 3 per sec. spike and wave activity and ( a) mental retardation and ( b) abnormal findings on neurologic examination. 5. 5. The possible meaning of the high incidence of abnormalities, other than 3 per sec. spike and wave discharges, in terms of the genesis of petit mal activity is discussed.

Visual imagery and electroencephalographic changes

The changes in the electroencephalogram relating to active vision, visual imagery, recall, and visual-motor performance were studied in a group of 180 psychiatric patients, and in 15 blind adolescent students. The conclusions from this study are as follows: 1. 1. An accurate reproduction of a diagram was associated with a low potential (mean 22.2 μV.), relatively non-rhythmical type of electrical activity from the occipital areas during the subjects's non-stimulated state. 2. 2. An inaccurate reproduction was associated with a higher potential (mean 32 μV), rhythmical activity from the occipital areas during rest. 3. 3. The attempted recall of a previously presented picture resulted in a 31 per cent reduction in potential as opposed to the 54.5 per cent during active vision. 4. 4. The influence of “surprise” or an increased awareness appeared to produce a greater electrical change than that related to the complexity of the diagrams. 5. 5. No significant correlations were found between performance and age or sex, the presence of EEG abnormality, the percentage of reduction during active vision or recall, or the rate of reappearance of the alpha activity on eye closure. 6. 6. Some suggestive evidence was presented that visual imagery in the blind is associated with a greater potential change than other types of imagery, and that visual imagery is more prominent in individuals who have lost their sight after two years of age.