Subgroup comparison according to clinical phenotype and serostatus in autoimmune encephalitis: a multicenter retrospective study.

BACKGROUND AND PURPOSE: Autoimmune encephalitides (AE) include a spectrum of neurological disorders whose diagnosis revolves around the detection of neuronal antibodies (Abs). Consensus-based diagnostic criteria (AE-DC) allow clinic-serological subgrouping of AE, with unclear prognostic implications. The impact of AE-DC on patients' management was studied, focusing on the subgroup of Ab-negative-AE. METHODS: This was a retrospective multicenter study on patients fulfilling AE-DC. All patients underwent Ab testing with commercial cell-based assays (CBAs) and, when available, in-house assays (immunohistochemistry, live/fixed CBAs, neuronal cultures) that contributed to defining final categories. Patients were classified as Ab-positive-AE [N-methyl-d-aspartate-receptor encephalitis (NMDAR-E), Ab-positive limbic encephalitis (LE), definite-AE] or Ab-negative-AE (Ab-negative-LE, probable-AE, possible-AE). RESULTS: Commercial CBAs detected neuronal Abs in 70/118 (59.3%) patients. Testing 37/48 Ab-negative cases, in-house assays identified Abs in 11 patients (29.7%). A hundred and eighteen patients fulfilled the AE-DC, 81 (68.6%) with Ab-positive-AE (Ab-positive-LE, 40; NMDAR-E, 32; definite-AE, nine) and 37 (31.4%) with Ab-negative-AE (Ab-negative-LE, 17; probable/possible-AE, 20). Clinical phenotypes were similar in Ab-positive-LE versus Ab-negative-LE. Twenty-four/118 (20.3%) patients had tumors, and 19/118 (16.1%) relapsed, regardless of being Ab-positive or Ab-negative. Ab-positive-AE patients were treated earlier than Ab-negative-AE patients (P = 0.045), responded more frequently to treatments (92.3% vs. 65.6%, P < 0.001) and received second-line therapies more often (33.3% vs. 10.8%, P = 0.01). Delays in first-line therapy initiation were associated with poor response (P = 0.022; odds ratio 1.02; confidence interval 1.00-1.04). CONCLUSIONS: In-house diagnostics improved Ab detection allowing better patient management but was available in a patient subgroup only, implying possible Ab-positive-AE underestimation. Notwithstanding this limitation, our findings suggest that Ab-negative-AE and Ab-positive-AE patients share similar oncological profiles, warranting appropriate tumor screening. Ab-negative-AE patients risk worse responses due to delayed and less aggressive treatments.

Improvement of quality of life in adolescents with epilepsy after an empowerment and sailing experience.

PURPOSE: Epilepsy in adolescents affects their psychological health, independence, and emotional adjustment. Psychological and self-management interventions might give benefits to adolescent with epilepsy in terms of quality of life, emotional well-being, and reduced fatigue. "Fondazione Tender To Nave Italia" promotes a project using sailing activities as an empowerment opportunity. The main aim of our study was to examine the empowerment effects on quality of life of adolescents with epilepsy attending sailing activities, and to compare the results perceived by adolescents and their parents. METHODS: Fifty-eight patients with a diagnosis of epilepsy were included in an empowerment project titled "Waves rather than spikes" from June 2013 to July 2018. Intellectual level was based on the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) criteria. Patients were administered Pediatric Quality of Life Inventory (PedsQL), adolescent and parent version. Behavioral data were collected by parent-report Child Behavior Checklist (CBCL). RESULTS: Thirty female and 28 male patients with a mean age of 15 years, referred to "Bambino Gesù Children's Hospital" in Italy, were included. Thirty-three (56.9%) patients had a history of refractory epilepsy; 34 (56.2%) received polytherapy, 19 (32.7%) monotherapy, and 5 (8.6%) were not taking antiepileptic drugs. Intellectual functioning was normal in 43 (74.1%), borderline in 9 (15.5%), and mildly impaired in 6 (10.3%). Results from PedsQL adolescent report revealed significant postintervention improvement for total score (p = 0.023) and in two domains: physical health (p = 0.0066) and emotional functioning (p = 0.015). Results from PedsQL parent report showed significant postintervention improvement for the domain of school functioning (p = 0.023). In the multivariate model, a low CBCL value was predicting a higher score in the health subscore difference between pre- and postempowerment activity (p = 000.8). CONCLUSION: Empowerments activities are crucial in order to reduce the burden of epilepsy in adolescents, and to improve quality of life. These are critical factors for a well-managed transition phase to adulthood.

Midazolam vs diazepam in prolonged seizures in children: A pharmacoeconomic approach.

OBJECTIVE: A previous European cost-utility study reported that use of buccal midazolam in the community setting for the treatment of prolonged seizures (ie, seizures lasting ≥5 minutes) in children was associated with an overall €12 507 399 reduction in annual costs charged to the Italian national health service compared with rectal diazepam. We re-evaluated these findings by applying a more conservative approach. METHODS: The Italian Delphi panel reconvened to apply a more conservative assessment of available reports. A decision-tree model was used, allowing for different treatment pathways depending on whether or not a caregiver administers treatment, an ambulance is required for transport of the child to hospital, and an inpatient stay is required. Direct medical costs were derived from Italian healthcare system data. Estimates of the annual number of prolonged tonic-clonic seizures expected in the country were based on studies which assessed seizure duration using video-EEG recordings and medical records. RESULTS: Although drug acquisition costs were greater for buccal midazolam than for rectal diazepam, the acquisition cost difference was outweighed by larger cost savings resulting mostly from a reduction in hospital admissions. Assuming that 1.2% of tonic and/or clonic seizures occurring in children and adolescents over a 12-month period are prolonged, the annual nationwide reduction in costs from preferring buccal midazolam to rectal diazepam was estimated at €3 577 587.9. CONCLUSIONS: In this more conservative revised analysis, the high cost of buccal midazolam is still counteracted by greater cost savings compared with rectal diazepam, but cost reduction was less than previously estimated.

Somatosensory system hyperexcitability in alternating hemiplegia of childhood.

BACKGROUND AND PURPOSE: Alternating hemiplegia of childhood (AHC) is a rare neurological disease characterized by recurrent paroxysmal attacks of hemiplegia. The aim of the study was to assess the recovery cycle of the somatosensory evoked potentials (SEPs) in a group of AHC patients. METHODS: Seven AHC patients and 10 control age-matched subjects (CS) were recruited. Right and left median nerve SEPs were recorded. The somatosensory system excitability was assessed by calculating the SEP changes after paired electrical stimuli. All patients were studied during the interictal phase, whilst four patients were studied also during the ictal phase. RESULTS: In AHC patients during the interictal phase, the amplitudes of the cervical N13 and of the cortical N20, P24 and N30 responses showed a faster recovery than in CS. In AHC patients during the ictal phase, the cortical N20 recovery cycle was prolonged compared with the interictal phase. CONCLUSIONS: A shortened SEP recovery cycle in AHC during the interictal phase suggests multilevel somatosensory system hyperexcitability in AHC. A partial recovery of this phenomenon during the ictal phase possibly reflects a functional reset of the somatosensory system. Overall, there is a disinhibition of the somatosensory system in AHC, a functional change of brain function associated with a possible involvement of the Na(+) /K(+) channels. This abnormality and its partial recovery during the attacks might be linked to the pathophysiological and genetic mechanisms of the disease.

Somatic mosaicism of PCDH19 mutation in a family with low-penetrance EFMR.

The occurrence of epilepsy with mental retardation limited to females (EFMR; MIM 300088) has been recently associated to mutations in the PCDH19 gene, located on chromosome X and encoding for protocadherin 19. EFMR shows a rare X-linked inheritance wherein affected females may be segregating a mutation through unaffected transmitting males (Fabisiak and Erickson Clin Genet 38(5):353-358, 1990; Juberg and Hellman J Pediatr 79:726-732, 1971; Ryan et al. Nat Genet 17(1):92-95, 1997). The description of a pedigree segregating PCDH19 mutations from unaffected mothers to patients (Depienne et al. Hum Mutat 32:E1959-1975, 2011; Dibbens et al. Neurology 76:1514-1519, 2011) complicates disease inheritance and genetic counseling. In the present study, we describe a PCDH19 mutation segregating from an asymptomatic mother to an EFMR patient. In order to correlate the healthy phenotype with the genotype of the transmitting mother, we quantified in a few tissues the level of the mutant allele by real-time PCR, disclosing a somatic mosaicism. This finding has a great impact on genetic counseling.

Focal non-motor seizures and subsequent focal motor seizures as the main clinical expression of GLUT-1 deficiency.

The seizure type most frequently described in GLUT1 deficiency is generalized (mainly absence). We report the case of a young boy who, as the main clinical manifestation presented with focal non-motor, and then focal motor seizures. At the age of 3 months episodes of face pallor/cyanosis and hypotonus lasting about 1 min, occurred. They were initially misdiagnosed as gastroesophageal reflux. These episodes disappeared spontaneously at 6 months of age. At 12 months, episodes similar to the previous ones reappeared. A few months later, a cluster of several episodes manifest as impaired responsiveness and vomiting occurred. The patient initially performed long-term video-EEG monitoring (LTVEM) however, no seizures were captured. During a second hospitalization for LTVEM, a focal to bilateral clonic seizure was recorded. Brain MRI was normal. Next Generation Sequencing (NGS) panel for genes associated with epilepsy showed a de novo mutation of SCL2A1 gene. The CSF showed glucose of 41 mg/dL, and the CSF/serum glucose ratio was equal to 0.46. The ketogenic diet was started with optimal efficacy in seizure control. Meal-sensitivity in childhood onset focal seizures may be associated with GLUT-1 deficiency syndrome that can be confirmed by biochemical analysis on blood and CSF following diagnostic genetic study.

Childhood refractory focal epilepsy following acute febrile encephalopathy.

BACKGROUND: We describe a group of previously normal children who developed severe focal epilepsy after an acute/sub-acute illness resembling encephalitis. METHODS: This is a retrospective study. An acute phase (encephalitis/encephalopathy period) and a chronic phase (chronic focal resistant epilepsy) were defined. RESULTS: Eight patients were enrolled. The median age at onset was 6.6 years (range 8 months-17.6 years). In the acute phase, fever was the first symptom in all cases and was associated with seizures and status epilepticus. All patients had focal seizures arising in both hemispheres. Seizure onset occurred in the frontal and temporal regions. EEGs showed slowing background activity associated with focal or diffuse slow waves with rare epileptiform abnormalities. Cerebrospinal fluid oligoclonal bands were observed in four out of six patients tested. MRI images showed bilateral peri-insular hyperintensity in four cases. Five patients received corticosteroids, and in four cases, they were given along with intravenous immunoglobulins. The median duration of the acute phase was 19 days (range 15-30 days). During the chronic phase, which followed the acute phase without interval, patients presented with drug-resistant focal seizures and neuropsychological deficits, which ranged from hyperactivity and attention deficits to short-term verbal memory deficit, pervasive developmental disorders, and language delay. CONCLUSION: Considering the clinical presentations, EEG findings, and the associated occurrence of non-specific immunological activations, a possible immune-mediated pathogenesis can be hypothesized, although firm conclusions cannot be drawn out.

Diagnosis of pediatric anti-NMDAR encephalitis at the onset: A clinical challenge.

BACKGROUNDS: To investigate the clinical and instrumental features at the onset addressing to the diagnosis of anti-NMDAR encephalitis. METHODS: Twenty children (age: 15 months-17 years; 7 males, 13 females) with initial suspected diagnosis of autoimmune encephalitis, observed between January 2008 and March 2018, were included. The final diagnosis was anti-NMDAR encephalitis in 7 children, other/probable autoimmune encephalitis in 7 children, and primary psychosis in the remaining 6 children. RESULTS: At the clinical onset, anxiety disorder was the main symptom that helped in distinguishing the group of psychotic children from children with non-infectious encephalitis (P = 0.05 OR = 0.001), while epileptic seizures strongly predicted anti-NMDAR encephalitis (P = 0.04 OR = 28.6). At the onset, anti-NMDAR encephalitis could be distinguished from other/probable autoimmune encephalitis for the presence of sleep/wake rhythm alteration (P = 0.05 OR = 15). Among the symptoms occurring during the hospitalization, movement disorders (P = 0.031 OR = 12) were predictive of non-infectious encephalitis rather than primary psychosis. More specifically, the occurrence of language impairment (P = 0.03 OR = 33), epileptic seizures (P = 0.04 OR = 28.6) and catatonia (P = 0.03, OR = 33), were predictive of anti-NMDAR encephalitis. Also at this stage, anxiety disorder (P = 0.03 OR = 0.033) was predictive of primary psychosis. CONCLUSION: Our findings suggest that at the clinical onset epileptic seizures and sleep/wake rhythm alteration represent the main features addressing to the diagnosis of anti-NMDAR encephalitis rather than primary psychosis and other/probable autoimmune encephalitis, while anxiety disorder could be a solid predictor of primary psychosis.

The abnormal recovery cycle of somatosensory evoked potential components in children with migraine can be reversed by topiramate.

The aim of this study was to compare the recovery cycle of somatosensory evoked potentials (SEPs) in children with migraine without aura before and after treatment with topiramate. Eleven migraine children were studied before and after a 3-month treatment with topiramate at the average dose of 1.3 mg/kg/day. We calculated the SEP latency and amplitude modifications after paired electrical stimuli at 5, 20 and 40 ms interstimulus intervals, comparing them with a single stimulus condition assumed as baseline. In nine patients, who had a significant reduction in headache frequency after treatment, the recovery cycles of the P24 (P = 0.03) and N30 (P < 0.005) potentials were longer after than before topiramate treatment. In two migraineurs who did not show any improvement, the recovery cycles of the cortical SEP components were even shorter after treatment. Our results suggest that topiramate efficacy in paediatric migraine prophylaxis is probably related to restored cortical excitability.

Correlation between abnormal brain excitability and emotional symptomatology in paediatric migraine.

We investigated a possible correlation between brain excitability in children with migraine and tension-type headache (TTH) and their behavioural symptomatology, assessed by using the Child Behaviour Checklist (CBCL). The mismatch negativity (MMN) and P300 response were recorded in three successive blocks to test the amplitude reduction of each response from the first to the third block (habituation). MMN and P300 habituation was significantly lower in migraineurs and TTH children than in control subjects (two-way ANOVA: P < 0.05). In migraineurs, but not in TTH patients, significant positive correlations between the P300 habituation deficit and the CBCL scores were found (P < 0.05), meaning that the migraineurs with the most reduced habituation showed also the worst behavioural symptomatology. To the best of our knowledge, this is the first study showing a correlation between neurophysiological abnormality and emotional symptomatology in migraine, suggesting a role of the latter in producing the migrainous phenotype.

De novo Absence Status Epilepticus in a pediatric cohort: Electroclinical pattern in a multicenter Italian patients cohort.

PURPOSE: Absence Status epilepticus (AS) is a form of Non Convulsive Status Epilepticus defined as a prolonged, generalized and non-convulsive seizure, with an altered content of consciousness. We aim to describe a group of healthy children, who presented recurrent and unprovoked de novo AS as the only manifestation of their epilepsy, with an excellent response to antiepileptic drugs. METHOD: We retrospectively reviewed the electroclinical and genetic features of 13 pediatric patients, referring to our epilepsy centers from 2005 to 2019, on the following criteria: (1) regular psychomotor development, (2) one or more unprovoked AS as the only epileptic manifestation, (3) normal blood testing, (4) normal neuroimaging, (5) EEG recording, (6) available follow-up (1-14 years). RESULTS: Patients are 7 females and 6 males, aged 7-22, with a mean age at AS onset of 9,3 years. All of them started an antiepileptic therapy, with an excellent response to Valproic Acid (VPA) or Ethosuximide (ETS). 5 patients did not start the therapy immediately after the first AS and they presented recurrent AS (from 2 to 4 episodes). 10 of them performed aCGH, karyotype, NGS panel or Whole Exome Sequencing. CONCLUSIONS: We suggest that de novo AS may be a well-defined age-related and self-limited epilepsy syndrome, with a good prognosis and excellent response to therapy, but it comes with a high risk of relapsing if not adequately treated with antiepileptic drugs.

Febrile infection-related epilepsy syndrome (FIRES) with super-refractory status epilepticus revealing autoimmune encephalitis due to GABAAR antibodies.

BACKGROUND: Febrile infection-related epilepsy syndrome (FIRES) has been described as an epileptic encephalopathy of unknown etiology affecting previously healthy children following febrile illness. Despite large investigations on autoimmune pathogenesis no membrane antibodies has been associated since now. CASE STUDY: We report a 13 years-old girl with negative history for neurological or autoimmune disease that developed at the sixth day of high fever a super-refractory status epilepticus. All investigations, including the most common antibodies related to immune-mediated encephalitis were negative. Seizures continued despite several therapeutic trials with anesthetics (midazolam, propofol) and antiepileptic agents as well as i.v. immunoglobulins but responded, at day 10 from the onset, to ketamine and high dose i.v. steroids. Due the high suspicion of autoimmune encephalitis we tested patient's CSF and plasma on mouse brain with positive response. We subsequently detected a high titre of GABAAR antibodies. After the resolution of the status epilepticus the patient achieved complete recovery of neurological functions. CONCLUSION: this is the first reported case of a FIRES-like condition due to autoimmune encephalitis mediated by GABAAR antibodies. Our case suggests that GABAAR antibodies should be investigated FIRES.

Role of valproate across the ages. Treatment of epilepsy in children.

In June 2005 a team of experts participated in a workshop with the objective of reaching agreement on the place of valproate use in the treatment of paediatric epilepsy patients. A general "consensus of the meeting" was that the initiation of antiepileptic drug (AED) treatment should be based on a seizure-syndromic approach in children. Participants of the meeting also agreed that valproate is currently the AED with the broadest spectrum across all types of seizures and syndromes. Its superiority has been shown over almost 40 years of clinical experience. The best results are seen in idiopathic generalized epilepsy with or without photosensitivity, idiopathic focal and symptomatic generalized tonic-clonic seizures (GTCS). Evidence supports the use of valproate, ethosuximide and lamotrigine in absence epilepsies and the use of carbamazepine, lamotrigine, oxcarbazepine, phenytoin, topiramate, valproate and phenobarbital for primary GTCS. For new AEDs trials have been undertaken to define their therapeutic role but studies comparing their role to 'old' broad-spectrum drugs in specific syndromes are missing. Experts concluded that intravenous (i.v.) valproate is a useful agent in the treatment of non-convulsive status epilepticus (SE). There is an easy transition to oral treatment following i.v. valproate use. The discussion also concluded that, despite the lack of studies, valproate is an interesting, underutilized alternative in convulsive SE but more controlled studies are needed. The side effects of valproate use are well documented. Its effect on cognition and behaviour is more favourable than many of the other AEDs which is an important consideration in children. Overall, the clinical consensus of the meeting was that valproate's well established therapeutic properties far outweigh the negative side effects. Contraindication or withdrawal should be assessed individually.

Modulation of laser-evoked potentials by experimental cutaneous tonic pain.

The present study aimed to investigate whether tonic cutaneous pain exerts any effect on the cortical processing of nociceptive input and if this effect may involve only body parts in pain. Tonic cutaneous pain was obtained in nine healthy human subjects by infusion of a hypertonic saline (5%) in the s.c. tissue over the hypothenar muscles (10 ml/h for 20 min). Nociceptive cutaneous CO2 laser-evoked potentials were recorded after stimulation of the right hand dorsum, which was adjacent to the painful area, and the right perioral region, corresponding to the adjacent cortical sensory area. Laser-evoked potentials were obtained before saline injection, at the peak pain and 20 min after pain disappeared. During saline infusion, the laser-evoked pain to right hand stimulation was reduced and the vertex laser-evoked potentials (N2a-P2, mean latency 181 ms and 319 ms for the N2a and the P2 potentials, respectively), which are generated in the anterior cingulate cortex, were significantly decreased in amplitude compared with the baseline. Moreover, the topography of these potentials was modified by cutaneous pain, shifting from the central toward the parietal region. Dipolar modeling showed that the dipolar source in the anterior cingulate cortex moved backward during saline infusion. This result suggests that cutaneous pain may modify the relative activities of the anterior and posterior anterior cingulate cortex parts, which are thought to be devoted to encode different aspects of pain sensation. No laser-evoked potential change was observed after stimulation of the right perioral region, suggesting that functional changes in the nociceptive system are selective for the painful regions and not for areas with cortical proximity.

From intravenous to enteral ketogenic diet in PICU: A potential treatment strategy for refractory status epilepticus.

BACKGROUND: Ketogenic diet (KD) has been used to treat refractory status epilepticus (RSE). KD is a high-fat, restricted-carbohydrate regimen that may be administered with different fat to protein and carbohydrate ratios (3:1 and 4:1 fat to protein and carbohydrate ratios). Other ketogenic regimens have a lower fat and higher protein and carbohydrate ratio to improve taste and thus compliance to treatment. We describe a case of RSE treated with intravenous KD in the Pediatric Intensive Care Unit (PICU). CASE REPORT: An 8-year-old boy was referred to the PICU because of continuous tonic-clonic and myoclonic generalized seizures despite several antiepileptic treatments. After admission he was intubated and treated with intravenous thiopental followed by ketamine. Seizures continued with frequent myoclonic jerks localized on the face and upper arms. EEG showed seizure activity with spikes on rhythmic continuous waves. Thus we decided to begin KD. The concomitant ileus contraindicated KD by the enteral route and we therefore began IV KD. The ketogenic regimen consisted of conventional intravenous fat emulsion, plus dextrose and amino-acid hyperalimentation in a 2:1 then 3:1 fat to protein and carbohydrate ratio. Exclusive IV ketogenic treatment, well tolerated, was maintained for 3 days; peristalsis then reappeared so KD was continued by the enteral route at 3:1 ratio. Finally, after 8 days and no seizure improvement, KD was deemed unsuccessful and was discontinued. CONCLUSIONS: Our experience indicates that IV KD may be considered as a temporary "bridge" towards enteral KD in patients with partial or total intestinal failure who need to start KD. It allows a prompt initiation of KD, when indicated for the treatment of severe diseases such as RSE.

Effectiveness and tolerability of perampanel in children and adolescents with refractory epilepsies-An Italian observational multicenter study.

PURPOSE: To evaluate the efficacy and tolerability of Perampanel (PER) in children and adolescents with refractory epilepsies in daily clinical practice conditions. PATIENTS AND METHODS: This Italian multicenter retrospective observational study was performed in 16 paediatric epilepsy centres. Inclusion criteria were: (i) ≤18 years of age, (ii) history of refractory epilepsy, (iii) a follow-up ≥5 months of PER add-on therapy. Exclusion criteria were: (i) a diagnosis of primary idiopathic generalized epilepsy, (ii) variation of concomitant AEDs during the previous 4 weeks. Response was defined as a ≥50% reduction in monthly seizure frequency compared with the baseline. RESULTS: 62 patients suffering from various refractory epilepsies were included in this study: 53% were males, the mean age was 14.2 years (range 6-18 years), 8 patients aged <12 years. Mean age at epilepsy onset was 3.4 years and the mean duration of epilepsy was 10.8 years (range 1-16), which ranged from 2 seizures per-month up to several seizures per-day (mean number=96.5). Symptomatic focal epilepsy was reported in 62.9% of cases. Mean number of AEDs used in the past was 7.1; mean number of concomitant AEDs was 2.48, with carbamazepine used in 43.5% of patients. Mean PER daily dose was 7.1mg (2-12mg). After an average of 6.6 months of follow-up (5-13 months), the retention rate was 77.4% (48/62). The response rate was 50%; 16% of patients achieved ≥75% seizure frequency reduction and 5% became completely seizure free. Seizure aggravation was observed in 9.7% of patients. Adverse events were reported in 19 patients (30.6%) and led to PER discontinuation in 4 patients (6.5%). The most common adverse events were behaviour disturbance (irritability and aggressiveness), dizziness, sedation and fatigue. CONCLUSION: PER was found to be a safe and effective treatment when used as adjunctive therapy in paediatric patients with uncontrolled epilepsy.

Segmental inhibition of cutaneous heat sensation and of laser-evoked potentials by experimental muscle pain.

The aim of the study was to evaluate the effect of tonic muscle pain evoked by injection of 5% hypertonic saline in the right brachioradialis muscle on the somatosensory sensation of laser-evoked heat pain and laser-evoked potentials. The heat pain pathways were studied in 9 healthy human subjects by recording the scalp potentials evoked by CO(2) laser stimuli delivered on four sites: the skin above the right brachioradialis muscle (ipsilateral local pain), the wrist area where muscle pain was referred in all subjects (ipsilateral referred pain), and two areas on the left arm symmetrical to both local and referred pain (contralateral local pain and contralateral referred pain). Laser-evoked potentials were obtained from 31 scalp electrodes before saline injection, during saline infusion (bolus injection with 0.3 ml saline infused over 20 s, followed by a steady infusion rate of 30 ml/h for the next 25 min), and 20 min after muscle pain had disappeared. While the early N1/P1 component (around 130 ms and 145 ms of latency after stimulation of the skin over the brachioradialis muscle and the wrist, respectively) was not affected by muscle pain, the amplitudes of the later vertex laser-evoked potentials (N2 latency of around 175 ms and 210 ms after stimulation of the skin over the brachioradialis muscle and the wrist, respectively; P2 latency of around 305 ms and 335 ms after stimulation of the skin over the brachioradialis muscle and the wrist, respectively) evoked from ipsilateral local pain, ipsilateral referred pain, and contralateral local pain sites were significantly decreased during muscle pain compared with the baseline recording, while they recovered after pain had disappeared. At the same stimulation sites, the rating of the laser-evoked pain sensation was reduced significantly during muscle pain as compared with the baseline and it recovered after pain had disappeared. On the contrary, muscle pain did not show any effect on both laser-evoked pain and laser-evoked potential amplitude when the contralateral referred pain site was stimulated. The muscle pain inhibitory effect on both heat pain sensation and laser-evoked potential amplitude is probably mediated by an ipsilateral and contralateral segmental mechanism which acts also on the referred pain area, while more general inhibitory mechanisms, such as a distraction effect or a diffuse noxious inhibitory control, are excluded by the absence of any effect of muscle pain on laser-evoked pain and laser-evoked potentials obtained from a remote site, such as the contralateral referred pain area. Since muscle pain induced by hypertonic saline injection is very similar to clinical pain, our results can be useful in understanding the pathophysiology of the somatosensory modifications which can be observed in patients with musculoskeletal pain syndromes.

Double cortex. A neuronal migration anomaly as a possible cause of Lennox-Gastaut syndrome.

Band heterotopia, or "double cortex," is a neuronal migration disorder that consists of a symmetrical subcortical neuronal band. The overlying cortex may be normal or macrogyric. We describe two severely mentally retarded girls, aged 14 and 18 years, who had band heterotopia and Lennox-Gastaut syndrome. Band heterotopia was evident in both hemispheres as a subcortical symmetrical layer isointense with gray matter on magnetic resonance T1- and T2-weighted images. Both patients had atonic seizures, atypical absences, and tonic seizures. The electroencephalograms in both cases showed frequent generalized paroxysms and slow background activity. The association of a Lennox-Gastaut syndrome with double cortex in these two patients and in a previously reported autopsy-confirmed case suggests that this malformation may be responsible for other similar cases.

Epilepsy provoked by television and video games: safety of 100-Hz screens.

Television (TV) and video games (VG) can provoke seizures in patients with photosensitive epilepsies. Flicker frequency is the most important factor in screen activation. We tested conventional 50-Hz versus 100-Hz monitors during TV viewing and VG playing in 30 photosensitive subjects, 23 of whom had a history of TV or VG seizures or both. Fifteen subjects' discharges were activated by 50-Hz TV; 17 by 50-Hz VG; and one by a 100-Hz screen. Thus, 100-Hz screens protect against screen activation.