Presence of Lactobacillus reuteri in saliva coincide with higher salivary IgA in young adults after intake of probiotic lozenges.

The aim of this study was to compare the concentration of salivary immunoglobulin A (IgA) and the selected interleukins (IL)-1ß, IL-6, IL-8 and IL-10 in young individuals with presence and non-presence of Lactobacillus reuteri in saliva after a three-week intervention with probiotic lozenges. The study group consisted of 47 healthy individuals aged 18-32 years with no clinical signs of oral inflammation. In a randomised, double-blind, placebo-controlled, cross-over trial participants ingested two lozenges per day containing two strains of the probiotic bacterium L. reuteri or placebo lozenges. The intervention and wash-out periods were three weeks. Stimulated and unstimulated whole saliva was collected at baseline and immediately after termination of the intervention periods. The samples were analysed for total protein, salivary IgA and selected cytokines. In this extended analysis, data were collected by analysing baseline and follow-up saliva samples related to ingestion of the probiotic lozenges for the presence of L. reuteri through DNA-extraction, PCR-amplification and gel-electrophoresis. At baseline, 27% of the individuals displayed presence of L. reuteri and 42% were positive immediately after the three-week probiotic intervention. Individuals with presence of L. reuteri in saliva had significantly higher (P<0.05) concentrations of salivary IgA and %IgA/protein at the termination of the probiotic intake compared with non-presence. No differences in the cytokine levels were observed. In conclusion, detectable levels of L. reuteri in saliva coincided with higher concentrations of salivary IgA and %IgA/protein in stimulated whole saliva after the three-week daily intake of probiotic lozenges. Our findings suggest that monitoring the presence of probiotic candidates in the oral environment is important to interpret and understand their possible immune-modulating role in maintaining oral health.

Perceived oral discomfort and pain in children and adolescents with intellectual or physical disabilities as reported by their legal guardians.

AIM: This was, firstly, to study the occurrence of oral pain and discomfort, using the Dental Discomfort Questionnaire (DDQ), in children and adolescents with intellectual or physical disabilities, compared with controls. Secondly, was to analyse the relationship between pain and discomfort, as measured by the DDQ, and dental health, as well as oral hygiene habits and dietary habits. METHODS: The study included 135 children and adolescents (12-18 years), registered at the Child and Adolescent Habilitation Unit in Göteborg and Södra Bohuslän, Sweden, and 135 gender- and age-matched controls. The children's legal guardians completed a questionnaire comprising the DDQ and questions on oral hygiene and dietary habits. Data on dental health were retrieved from dental records. RESULTS: The DDQ total mean score was higher for the study group, compared with the control group, 3.2 (SD 2.9) vs. 1.6 (SD 2.0), respectively (p = 0.001). Furthermore, children and adolescents with a severe intellectual disability had higher total mean DDQ scores than children with a mild intellectual disability, 4.8 (SD 4.2) vs. 2.4 (SD 2.9), respectively (p = 0.034), and also higher than children with a physical disability, 2.2 (SD 2.1) (p = 0.012). There were no differences in DMFT between children with disabilities and age-matched controls. There was no relationship between the DDQ scores and oral hygiene/dietary habits in children with disabilities. CONCLUSIONS: Children and adolescents with intellectual or physical disabilities experienced oral discomfort and pain more often than matched controls. Dental health expressed as DMFT could not be related to the DDQ responses.

Variants in the genes DCTN2, DNAH10, LRIG3, and MYO1A are associated with intermediate Charcot-Marie-Tooth disease in a Norwegian family.

INTRODUCTION: Charcot-Marie-Tooth disease (CMT) is a heterogeneous inherited neuropathy. The number of known CMT genes is rapidly increasing mainly due to next-generation sequencing technology, at present more than 70 CMT-associated genes are known. We investigated whether variants in the DCTN2 could cause CMT. MATERIAL AND METHODS: Fifty-nine Norwegian CMT families from the general population with unknown genotype were tested by targeted next-generation sequencing (NGS) for variants in DCTN2 along with 32 CMT genes and 19 other genes causing other inherited neuropathies or neuronopathies, due to phenotypic overlap. In the family with the DCTN2 variant, exome sequencing was then carried out on all available eight family members to rule out the presence of more potential variants. RESULTS: Targeted NGS identified in one family a variant of DCTN2, c.337C>T, segregating with the phenotype in five affected members, while it was not present in the three unaffected members. The DCTN2 variant c.337C>T; p.(His113Tyr) was neither found in in-house controls nor in SNP databases. Exome sequencing revealed a singular heterozygous shared haplotype containing four genes, DCTN2, DNAH10, LRIG3, and MYO1A, with novel sequence variants. The haplotype was shared by all the affected members, while the unaffected members did not have it. CONCLUSIONS: This is the first time a haplotype on chromosome 12 containing sequence variants in the genes DCTN2, DNAH10, LRIG3, and MYO1A has been linked to an inherited neuropathy in humans.

Genetic epidemiology of Charcot-Marie-Tooth disease.

BACKGROUND: Charcot-Marie-Tooth disease (CMT) is the most common inherited disorder of the peripheral nervous system. The frequency of different CMT genotypes has been estimated in clinic populations, but prevalence data from the general population is lacking. Point mutations in the mitofusin 2 (MFN2) gene has been identified exclusively in Charcot-Marie-Tooth disease type 2 (CMT2), and in a single family with intermediate CMT. MFN2 point mutations are probably the most common cause of CMT2. The CMT phenotype caused by mutation in the myelin protein zero (MPZ) gene varies considerably, from early onset and severe forms to late onset and milder forms. The mechanism is not well understood. The myelin protein zero (P(0) ) mediates adhesion in the spiral wraps of the Schwann cell's myelin sheath. X-linked Charcot-Marie Tooth disease (CMTX) is caused by mutations in the connexin32 (cx32) gene that encodes a polypeptide which is arranged in hexameric array and form gap junctions. AIMS: Estimate prevalence of CMT. Estimate frequency of Peripheral Myelin Protein 22 (PMP22) duplication and point mutations, insertions and deletions in Cx32, Early growth response 2 (EGR2), MFN2, MPZ, PMP22 and Small integral membrane protein of lysosome/late endosome (SIMPLE) genes. Description of novel mutations in Cx32, MFN2 and MPZ. Description of de novo mutations in MFN2. MATERIAL AND METHODS: Our population based genetic epidemiological survey included persons with CMT residing in eastern Akershus County, Norway. The participants were interviewed and examined by one geneticist/neurologist, and classified clinically, neurophysiologically and genetically. Two-hundred and thirty-two consecutive unselected and unrelated CMT families with available DNA from all regions in Norway were included in the MFN2 study. We screened for point mutations in the MFN2 gene. We describe four novel mutations, two in the connexin32 gene and two in the MPZ gene. RESULTS: A total of 245 affected from 116 CMT families from the general population of eastern Akershus county were included in the genetic epidemiological survey. In the general population 1 per 1214 persons (95% CI 1062-1366) has CMT. Charcot-Marie-Tooth disease type 1 (CMT1), CMT2 and intermediate CMT were found in 48.2%, 49.4% and 2.4% of the families, respectively. A mutation in the investigated genes was found in 27.2% of the CMT families and in 28.6% of the affected. The prevalence of the PMP22 duplication and mutations in the Cx32, MPZ and MFN2 genes was found in 13.6%, 6.2%, 1.2%, 6.2% of the families, and in 19.6%, 4.8%, 1.1%, 3.2% of the affected, respectively. None of the families had point mutations, insertions or deletions in the EGR2, PMP22 or SIMPLE genes. Four known and three novel mitofusin 2 (MFN2) point mutations in 8 unrelated Norwegian CMT families were identified. The novel point mutations were not found in 100 healthy controls. This corresponds to 3.4% (8/232) of CMT families having point mutations in MFN2. The phenotypes were compatible with CMT1 in two families, CMT2 in four families, intermediate CMT in one family and distal hereditary motor neuronopathy (dHMN) in one family. A point mutation in the MFN2 gene was found in 2.3% of CMT1, 5.5% of CMT2, 12.5% of intermediate CMT and 6.7% of dHMN families. Two novel missense mutations in the MPZ gene were identified. Family 1 had a c.368G>A (Gly123Asp) transition while family 2 and 3 had a c.103G>A (Asp35Asn) transition. The affected in family 1 had early onset and severe symptoms compatible with Dejerine-Sottas syndrome (DSS), while affected in family 2 and 3 had late onset, milder symptoms and axonal neuropathy compatible with CMT2. Two novel connexin32 mutations that cause early onset X-linked CMT were identified. Family 1 had a deletion c.225delG (R75fsX83) which causes a frameshift and premature stop codon at position 247 while family 2 had a c.536G>A (Cys179Tyr) transition which causes a change of the highly conserved cysteine residue, i.e. disruption of at least one of three disulfide bridges. The mean age at onset was in the first decade and the nerve conduction velocities were in the intermediate range. DISCUSSION: Charcot-Marie-Tooth disease is the most common inherited neuropathy. At present 47 hereditary neuropathy genes are known, and an examination of all known genes would probably only identify mutations in approximately 50% of those with CMT. Thus, it is likely that at least 30-50 CMT genes are yet to be identified. The identified known and novel point mutations in the MFN2 gene expand the clinical spectrum from CMT2 and intermediate CMT to also include possibly CMT1 and the dHMN phenotypes. Thus, genetic analyses of the MFN2 gene should not be restricted to persons with CMT2. The phenotypic variation caused by different missense mutations in the MPZ gene is likely caused by different conformational changes of the MPZ protein which affects the functional tetramers. Severe changes of the MPZ protein cause dysfunctional tetramers and predominantly uncompacted myelin, i.e. the severe phenotypes congenital hypomyelinating neuropathy and DSS, while milder changes cause the phenotypes CMT1 and CMT2. The two novel mutations in the connexin32 gene are more severe than the majority of previously described mutations possibly due to the severe structural change of the gap junction they encode. CONCLUSION: Charcot-Marie-Tooth disease is the most common inherited disorder of the peripheral nervous system with an estimated prevalence of 1 in 1214. CMT1 and CMT2 are equally frequent in the general population. The prevalence of PMP22 duplication and of mutations in Cx32, MPZ and MFN2 is 19.6%, 4.8%, 1.1% and 3.2%, respectively. The ratio of probable de novo mutations in CMT families was estimated to be 22.7%. Genotype- phenotype correlations for seven novel mutations in the genes Cx32 (2), MFN2 (3) and MPZ (2) are described. Two novel phenotypes were ascribed to the MFN2 gene, however further studies are needed to confirm that MFN2 mutations can cause CMT1 and dHMN.

Genetic epidemiology of Charcot-Marie-Tooth in the general population.

BACKGROUND AND PURPOSE: the frequency of different Charcot-Marie-Tooth (CMT) genotypes has been estimated in clinic populations, but prevalence data from the general population are lacking. METHODS: our population-based genetic epidemiological survey included persons with CMT residing in eastern Akershus County, Norway. The participants were interviewed and examined by one geneticist/neurologist and classified clinically, neurophysiologically and genetically. RESULTS: two hundred and forty-five persons from 116 families had CMT. This corresponds to 1 per 1214 persons (95% CI 1062-1366) have CMT in the general population. CMT1 (motor conduction velocity (MCV) <38 m/s), CMT2 (MCV >38 m/s) and CMT intermediate (MCV 25-45 m/s) were found in 48.2%, 49.4% and 2.4% of the families. A total of 27.2% of the families and 28.6% of the affected had a mutation in the investigated CMT genes. The prevalence of the peripheral myelin protein 22 (PMP22) duplication and point mutation in the connexin32 (Cx32), myelin protein zero (MPZ) and mitofusin2 (MFN2) genes was found in 13.6%, 6.2%, 1.2%, 6.2% of the families, and in 19.6%, 4.8%, 1.1%, 3.2% of the affected, respectively. None of the families had point mutations in the early growth response 2 (EGR2), PMP22 or small integral membrane protein of lysosome/late endosome (SIMPLE) genes. CONCLUSIONS: CMT is the most common inherited neuropathy. At present, 43 CMT genes are known, and an examination of all known genes would probably only identify mutations in approximately 50% of those with CMT. Thus, it is probable that at least 30-50 CMT genes are yet to be identified.

Noonan and cardio-facio-cutaneous syndromes: two clinically and genetically overlapping disorders.

BACKGROUND: Noonan syndrome (NS) and cardio-facio-cutaneous syndrome (CFC) are related disorders associated with disrupted RAS/RAF/MEK/ERK signalling. NS, characterised by facial dysmorphism, congenital heart defects and short stature, is caused by mutations in the genes PTPN11, SOS1, KRAS and RAF1. CFC is distinguished from NS by the presence of ectodermal abnormalities and more severe mental retardation in addition to the NS phenotype. The genetic aetiology of CFC was recently assigned to four genes: BRAF, KRAS, MEK1 and MEK2. METHODS: A comprehensive mutation analysis of BRAF, KRAS, MEK1, MEK2 and SOS1 in 31 unrelated patients without mutations in PTPN11 is presented. RESULTS: Mutations were identified in seven patients with CFC (two in BRAF, one in KRAS, one in MEK1, two in MEK2 and one in SOS1). Two mutations were novel: MEK1 E203Q and MEK2 F57L. The SOS1 E433K mutation, identified in a patient diagnosed with CFC, has previously been reported in patients with NS. In one patient with NS, we also identified a mutation, BRAF K499E, that has previously been reported in patients with CFC. We thus suggest involvement of BRAF in the pathogenesis of NS also. CONCLUSIONS: Taken together, our results indicate that the molecular and clinical overlap between CFC and NS is more complex than previously suggested and that the syndromes might even represent allelic disorders. Furthermore, we suggest that the diagnosis should be refined to, for example, NS-PTPN11-associated or CFC-BRAF-associated syndromes after the genetic defect has been established, as this may affect the prognosis and treatment of the patients.

Symptomatic Charcot-Marie-Tooth? A pair of concordant monozygotic twins.

BACKGROUND: A pair of monozygotic twin brothers were referred due to hereditary peripheral neuropathy resembling late onset Charcot-Marie-Tooth (CMT). AIM OF THE STUDY: Diagnostic classification of the twin pair. METHOD: Clinical, neurological, genetical and neurophysiological examination, and molecular genetic testing. RESULTS: The clinic and neurophysiology was compatible with CMT disease with late onset. Molecular genetic analysis excluded mutations in PMP22, connexin32, MPZ, LITAF and MFNZ genes, as well as duplication and deletion of PMP22. CONCLUSIONS: The twins were employed in PVC production and developed symptoms after 14 years of massive exposure. We think that the heavy exposure to various neurotoxic compounds caused symptoms that mimic late-onset CMT. However, the twins had distal dysesthesia which is unusual in inherited neuropathies. This illustrates the importance of an occupational history even in the molecular genetic era.

[Diagnostic DNA testing for Huntington disease]. / Diagnostisk DNA-testing for Huntingtons sykdom.

Direct DNA testing for the autosomal dominant neurodegenerative disorder, Huntington's disease, may be performed in a diagnostic setting, as a presymptomatic procedure or prenatally. This paper is intended for physicians practising outside departments of medical genetics who are considering diagnostic testing of patients presenting with symptoms or signs compatible with Huntington's disease. It offers a brief overview of practically relevant clinical, epidemiological, molecular and legal aspects of diagnostic genetic testing for Huntington's disease in Norway. We stress the need for adequate information before sampling and after the test has been performed, and for close contact with the genetics centre which offers the test for Huntington's disease and provides genetic counselling. As with other diagnostic tests, the treating physician is responsible for informing the patient about the result of the test and for ensuring adequate follow-up. The physician will often need the assistance of an expert in clinical genetics. A positive DNA test for Huntington's disease in a patient may have a profound impact on family members, who should be offered genetic counselling and support. Since asymptomatic at-risk family members may ask for a presymptomatic test in the future, diagnostic confirmation at the DNA level is warranted in any person examined because of clinical signs of Huntington's disease, even when the clinical diagnosis is considered unquestionable.

[Genetic counseling in presymptomatic testing for Huntington disease]. / Genetisk veiledning ved presymptomatisk testing for Huntingtons sykdom.

Norwegian law and international guidelines require genetic counselling before, during and after presymptomatic testing for Huntington's disease. The genetic counselling of at-risk persons who considers taking tests, includes explanation of the possible implications of a test result for both participant and relatives. The test is performed only when explicitly requested by the participant and after informed consent. The participant decides if and when the test should be conducted. The participant also has major influence on the timing of the consecutive phases of the testing procedure, in compliance with medical and ethical recommendations. This paper reviews main issues raised during genetic counselling and the preparation period preceding the test and communication of the test result. We illustrate different individual situations and backgrounds for considering presymptomatic testing for Huntington's disease by describing three anonymized cases and associated pedigrees.

Early discontinuation of treatment in children with uncomplicated epilepsy: a prospective study with a model for prediction of outcome.

PURPOSE: The main purpose of the present study was to identify predictor variables with significant influence on seizure outcome after discontinuation of treatment in children with uncomplicated epilepsy and to analyze whether these variables, included in a prognostic model could identify children in whom 1-year treatment would be sufficient. METHODS: Before initiation of treatment in children aged 2-16 years with uncomplicated epilepsy, the duration of treatment was randomized to 1 year (group I) or 3 years (group II). At the end of the allotted period, treatment was discontinued in 161 children who had been seizure fre during the previous 6 months. The mean follow-up period after treatment was 5.8 years. Twenty-three predictor variables were analyzed by survival methods regarding their influences on the outcome. RESULTS: At the latest follow-up check, 60 children (37%) had relapsed. The following predictor variables were selected by multiple regression analysis and constituted a model with a simple scoring system: age at seizure onset; seizure type; generalized, irregular spike-wave activity on EEG after 1 year of treatment; and persistent 3-Hz spike-wave activity after 6 months of treatment in children with absence epilepsy. In group I, the remission rate was 73% in children with high prognostic scores, 10% in children with low scores, and 40% in those with intermediate scores (log-rank test, p = 0.0001). CONCLUSIONS: After 1 year of treatment, our prognostic model identified children in whom treatment could be withdrawn at that time. Our model should be easily applicable in clinical practices and may be of clinical importance in determining the duration of treatment in children with uncomplicated epilepsy.

Motor impairments in children with epilepsy treated with carbamazepine.

Nineteen children with epilepsy were tested on two occasions, first during treatment with carbamazepine (CBZ) and then 6 months later without treatment. Plasma drug concentrations were within the therapeutic limits in all children. The children were examined with a standardized test of gross- and fine- motor functions, the Bruininks-Oseretsky test of motor proficiency. Significant improvements were found in response speed (p < 0.05), in composite fine-motor tests (p < 0.01) and in the total test battery (p < 0.05) after the treatment had been withdrawn. A tendency to improvement was found in the fine-motor subtest of upper limb coordination (p = 0.08). Another group of 12 children was tested twice during treatment with CBZ with an interval of 6 months. No difference was found in this group except for an impairment of the results in the subtest of visual-motor control on the second test occasion (p = 0.05).

A comparison between one and three years of treatment in uncomplicated childhood epilepsy: a prospective study. II. The EEG as predictor of outcome after withdrawal of treatment.

PURPOSE: We wished to evaluate the prognostic usefulness of various EEG parameters with respect to remission rates after discontinuation of antiepileptic drug (AED) therapy in children treated for epileptic seizures. METHODS: Two hundred forty-four children with uncomplicated epileptic seizures were randomized to either 1 or 3 years of treatment with AEDs. The treatment was then discontinued in patients who had been seizure-free during the last 6 months of their allotted time of treatment (n = 154). After treatment discontinuation, the children were followed for at least 2 years. EEG recordings were performed before treatment was initiated and at regular intervals during treatment. RESULTS: The overall relapse rate was 37%. In many children, the amount of epileptiform activity varied considerably between subsequent recordings made during the treatment. The remission rate was slightly higher for children whose last recordings before AED discontinuation were free of epileptiform activity as compared with children in whom such activity was present. However, children who had irregular generalized spike-wave (SW) activity in the recordings made before discontinuation of treatment had a clearly higher relapse rate (67%) both as compared with children without epileptiform activity (33%) and as compared with children with other types of epileptiform activity (33%) in their last EEG recordings before discontinuation. All children treated for only 1 year whose final EEGs displayed generalized irregular SW activity relapsed. CONCLUSIONS: We conclude that the presence of epileptiform activity does not in itself necessarily influence prognosis after discontinuation of treatment but that certain types of such activity signal a high risk of relapse.

Retrieval of total ozone abundances from the ultraviolet region of spectra recorded with an ultraviolet-visible spectrometer.

A method is described for deriving total ozone abundances from zenith-sky intensities measured by an UV-visible spectrometer, known as the System of Analysis of Observations at Zenith (SAOZ). Total ozone abundances are determined by comparison of intensity ratios measured at two wavelengths in the UV region with ratios computed with a radiative transfer model. The wavelength pair 320-307 nm was used in this study. Spectra recorded by the SAOZ spectrometer in Oslo (60 degrees N) from the beginning of May 1995 to the end of August 1995 were analyzed, and the results were compared with total ozone measured with a Brewer instrument. The relative difference in derived ozone abundances for the whole period, including days with thin and medium-thick cloud covers, is -0.18 +/- 1.46%. We study the effects of clouds and varying ground albedo on the derived total ozone. Clouds result in an overestimation of the derived total ozone. The error increases with the optical depth tau of the cloud from approximately 2% for an optically thin cloud (tau = 0.5) to approximately 10% for a thick cloud (tau = 50). The ratio between measured intensities at 550 and 350 nm, the so-called color index, can be used as a measure of the cloud optical depth for thin and medium-thick clouds. The effects of thin and medium-thick clouds on the derived ozone abundances can be compensated for by use of an empirical relationship found between the measured color index and the error in the inferred ozone abundances caused by cloud scattering. We also study the influence of changes in the ground albedo and in the ozone profiles on derived total ozone values.

Comparison between one and three years of treatment in uncomplicated childhood epilepsy: a prospective study. I. Outcome in different seizure types.

PURPOSE: The main purpose of this prospective study was to analyze whether 1 year of treatment was as effective as 3 years with respect to remission rate in children with idiopathic epilepsy. METHODS: Treatment for epileptic seizures was started in 207 children aged 2-16 years. They were randomized to treatment for 1 or 3 years. At the end of the predetermined treatment period, 161 children had been seizure-free for 6 months and the treatment could be gradually withdrawn. RESULTS: The overall remission rate in our group of patients was significantly higher (71%) in the group treated for 3 years than in the group treated for 1 year (53%). However, comparison of remission rates between patients with different seizure types showed statistically significant differences in outcome depending on duration of treatment only in children with complex partial seizures (CPS). CONCLUSIONS: Our results show that 1 year of treatment can be recommended in children with benign partial epilepsy with rolandic spikes (BECT) and in children with simple partial seizures (SPS) but is clearly insufficient in children with CPS. A proper seizure classification is one important tool, although not sufficient, in offering recommendations concerning the duration of treatment in children with idiopathic epilepsy.

Oral carriage of Candida species in children and adolescents with Down's syndrome.

Oral carriage of Candida albicans was studied in 55 children and adolescents with Down's syndrome (DS), aged between 7 months and 20 years 6 months, and compared with an age- and sex-matched control group of subjects. Twenty-two of the DS subjects were diagnosed as having congenital cardiovascular malformations. Compared to controls, the DS subjects were more prone to infections. The number of subjects colonized with C. albicans in the oral cavity was significantly higher in the DS group (69%) than in the control group (35%). Colonization with C. albicans and simultaneous erythematous or white pseudomembranous lesions of the oral mucosa were diagnosed in 22 (40%) of the DS groups and in only one of the control group. In both the DS and the healthy control subjects the frequency of colonization with C. albicans was positively correlated to age. The DS subjects were significantly more densely colonized by C. albicans than the controls. Abnormalities of the immune response in DS children may contribute to the increased oral carriage of C. albicans.

A general hospital population of childhood epilepsy.

In a general hospital population of 74,000 children under the age of 16 years in southern Stockholm, 79 children were started on antiepileptic drugs due to epilepsy during the 2 year period 1990-92. The mean annual incidence of childhood epilepsy in this area was 53 per 100,000 children younger than 16 years. Neurological impairments were identified in 35% of the children. The epilepsy diagnoses were set according to the International Classification System proposed by the International League Against Epilepsy. Partial seizures were seen in 52% of the children. The syndrome BECT was identified in 11%. The epilepsy was symptomatic in 30%, and therapy-resistant in 23%.

Valproate in the treatment of absence epilepsy in children: a study of dose-response relationships.

Seven children with absence epilepsy were treated with valproate (VPA). All but one child became free of absence seizures during VPA monotherapy. EEG was recorded for 24 h before start of VPA treatment and repeatedly during treatment. Correlation between plasma VPA concentration and reduction of the number of epileptic discharges was significant. Plasma concentration of 440-660 microM VPA was needed to achieve at least 50% reduction of seizure activity.