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1.
Nutrients ; 11(10)2019 Oct 01.
Article in English | MEDLINE | ID: mdl-31581549

ABSTRACT

Diseases involving inflammation and oxidative stress can be exacerbated by high blood glucose levels. Due to tight metabolic regulation, safely reducing blood glucose can prove difficult. The ketogenic diet (KD) reduces absolute glucose and insulin, while increasing fatty acid oxidation, ketogenesis, and circulating levels of ß-hydroxybutyrate (ßHB), acetoacetate (AcAc), and acetone. Compliance to KD can be difficult, so alternative therapies that help reduce glucose levels are needed. Exogenous ketones provide an alternative method to elevate blood ketone levels without strict dietary requirements. In this study, we tested the changes in blood glucose and ketone (ßHB) levels in response to acute, sub-chronic, and chronic administration of various ketogenic compounds in either a post-exercise or rested state. WAG/Rij (WR) rats, a rodent model of human absence epilepsy, GLUT1 deficiency syndrome mice (GLUT1D), and wild type Sprague Dawley rats (SPD) were assessed. Non-pathological animals were also assessed across different age ranges. Experimental groups included KD, standard diet (SD) supplemented with water (Control, C) or with exogenous ketones: 1, 3-butanediol (BD), ßHB mineral salt (KS), KS with medium chain triglyceride/MCT (KSMCT), BD acetoacetate diester (KE), KE with MCT (KEMCT), and KE with KS (KEKS). In rested WR rats, the KE, KS, KSMCT groups had lower blood glucose level after 1 h of treatment, and in KE and KSMCT groups after 24 h. After exercise, the KE, KSMCT, KEKS, and KEMCT groups had lowered glucose levels after 1 h, and in the KEKS and KEMCT groups after 7 days, compared to control. In GLUT1D mice without exercise, only KE resulted in significantly lower glucose levels at week 2 and week 6 during a 10 weeks long chronic feeding study. In 4-month and 1-year-old SPD rats in the post-exercise trials, blood glucose was significantly lower in KD and KE, and in KEMCT groups, respectively. After seven days, the KSMCT group had the most significantly reduced blood glucose levels, compared to control. These results indicate that exogenous ketones were efficacious in reducing blood glucose levels within and outside the context of exercise in various rodent models of different ages, with and without pathology.


Subject(s)
3-Hydroxybutyric Acid/pharmacology , Acetoacetates/pharmacology , Blood Glucose/drug effects , Butylene Glycols/pharmacology , Carbohydrate Metabolism, Inborn Errors/therapy , Diet, Ketogenic , Dietary Supplements , Epilepsy, Absence/therapy , Monosaccharide Transport Proteins/deficiency , Animals , Biomarkers , Blood Glucose/metabolism , Carbohydrate Metabolism, Inborn Errors/blood , Carbohydrate Metabolism, Inborn Errors/genetics , Carbohydrate Metabolism, Inborn Errors/physiopathology , Disease Models, Animal , Down-Regulation , Epilepsy, Absence/blood , Epilepsy, Absence/genetics , Epilepsy, Absence/physiopathology , Glucose Transporter Type 1/deficiency , Glucose Transporter Type 1/genetics , Male , Mice, Knockout , Monosaccharide Transport Proteins/blood , Monosaccharide Transport Proteins/genetics , Physical Exertion , Rats, Sprague-Dawley , Rest , Time Factors
2.
Epilepsy Res ; 132: 84-90, 2017 05.
Article in English | MEDLINE | ID: mdl-28324682

ABSTRACT

OBJECTIVE: Childhood and Juvenile Absence Epilepsy account for 30% of all genetic generalized epilepsies with a strong genetic contribution. At the current state the genetic background remains to be resolved. The aim of this study was to identify disease associated transcripts pinpointing potential underlying disease mechanisms in patients with CAE and JAE. METHODS: We performed gene expression analysis from peripheral blood mononuclear cells (PBMCs) in 30 patients with newly-diagnosed absence epilepsy prior to initiating treatment and 30 healthy age - and gender-matched pediatric controls. In a first group (group 1), 10 patients and controls we performed genome-wide transcriptome analysis using the Affymetrix HG U133 2.0+ microarray. 75 differentially expressed genes were followed up by qRT-PCR in two independent groups of 10 patients and controls (group 2 and 3). Furthermore, we analyzed 18 candidate genes by qRT-PCR in groups 2 and 3, which had previously been considered strong candidates for genetic epilepsies. RESULTS: Genome-wide gene expression analysis in group 1 revealed 601 differentially regulated genes. Independent validation of 75 group 1-derived genes by qRT-PCR in groups 2 and 3 confirmed candidate genes with a consistent, but non-significant pattern of up- or down-regulation across all groups (ATP1B3, CAND1, PRPF6, TRIM8). Previously known genes including GABRA1, GABRB3, GABRG2, and RCN2 showed evidence for up- or down-regulation in individual experiments, but were not reliable across groups either. DISCUSSION: Gene expression analysis in absence epilepsy from PMBCs displayed a high degree of heterogeneity between different patient groups. Our study provides several potentially interesting candidate genes, while demonstrating the limits of using gene expression analysis from blood in the identification of novel pathogenic mechanisms. In particular, we found that gene expression levels vary in response to altered experimental conditions, representing a substantial challenge for the identification of disease-related gene expression signatures for neurological diseases from whole blood.


Subject(s)
Epilepsy, Absence/blood , Epilepsy, Absence/genetics , Gene Expression , Down-Regulation , Female , Gene Expression Profiling , Genome-Wide Association Study , Humans , Male
3.
Acta Neurol Scand ; 129(5): e20-3, 2014 May.
Article in English | MEDLINE | ID: mdl-24372179

ABSTRACT

OBJECTIVE: Most patients with idiopathic generalized epilepsies (IGEs) have good seizure control when on antiepileptic drugs. To analyze prospectively the response to low-dose sodium valproate (VPA) treatment (<1000 mg/day) together with plasma VPA levels in a cohort of patients with IGE. METHODS: Patients with IGE were selected and followed for almost 2 years. In patients on VPA with no seizures in the last year, VPA dose was lowered to <1000 mg/day. Newly diagnosed patients with IGE started treatment on VPA directly on this low dose. RESULTS: Fifty-four patients were included, with juvenile myoclonic epilepsy (JME) in 23 (42.6%), juvenile absence epilepsy (JAE) in 17 (31.5%), and generalized tonic-clonic seizures only (GTCS only) in 14 (25.9%). VPA at low dose was administered to 38 (70%) patients. Mean plasma VPA level was 44.21 mg/l (18-78; SD 15.18). Seizure relapse during the 2-year follow-up was observed in 8 (21%). A reduction in adverse events was observed (P < 0.048). The only factor related to efficacy of VPA at low dose was syndromic diagnosis. Low-dose VPA controlled 92.9% (13) of patients with GTCS only, 78.3% (18) of those with JME, and 29.5% (5) of those with JAE. CONCLUSIONS: Low-dose VPA was a highly effective treatment for the majority of those with JME and GTCS only. The seizures in JAE tended to be more resistant to treatment, usually requiring higher doses of VPA or polytherapy.


Subject(s)
Anticonvulsants/administration & dosage , Epilepsy, Generalized/drug therapy , Valproic Acid/administration & dosage , Adult , Anticonvulsants/adverse effects , Anticonvulsants/blood , Epilepsy, Absence/blood , Epilepsy, Absence/drug therapy , Epilepsy, Generalized/blood , Female , Follow-Up Studies , Humans , Male , Myoclonic Epilepsy, Juvenile/blood , Myoclonic Epilepsy, Juvenile/drug therapy , Prospective Studies , Seizures/blood , Seizures/drug therapy , Treatment Outcome , Valproic Acid/adverse effects , Valproic Acid/blood
4.
Int J Neurosci ; 124(7): 486-90, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24147594

ABSTRACT

Autoimmunity has aroused interest in the last years as a contributory mechanism of epilepsy, especially in epilepsies with unknown cause or therapy resistance. Since the relationship of absence epilepsy (AE) with calcium channels is well established, we aimed to investigate related antibodies in patients diagnosed with AE. Consecutive patients with typical absence seizures having either childhood absence epilepsy (CAE) or juvenile absence epilepsy (JAE) with generalized spike and wave discharges on electroencephalography (EEG) were included after their consent. The patients were diagnosed according to the International League Against Epilepsy (ILAE) 2010 criteria. Antibodies against P-Q type voltage gated calcium channels (VGCC) and T-type VGCC subunit Cav3.2 (encoded by the CACNA1H gene) were investigated by RIA and ELISA, respectively. We searched for these antibodies in 32 patients with AE and 53 patients with focal epilepsy of unknown cause (FEOUC) as the disease control group; furthermore, 30 healthy persons served as the healthy controls. Eleven patients (34.3%) with AE had CAE and the remaining patients had JAE. Only a 47-year-old female FEOUC patient, who also had systemic lupus erythematosus with normal MRI scans showed antibodies against P-Q type VGCC, whereas no antibody positivity could be found in other FEOUC and AE patients and healthy controls. Our results might suggest that calcium channel antibodies do not play an important role in the pathophysiology of AE. Further studies with larger groups of other epileptic syndromes are needed to confirm our results.


Subject(s)
Autoantibodies/blood , Calcium Channels/immunology , Epilepsy, Absence/immunology , Adolescent , Adult , Child , Epilepsy, Absence/blood , Female , Humans , Male , Middle Aged , Young Adult
5.
Horm Behav ; 61(5): 706-10, 2012 May.
Article in English | MEDLINE | ID: mdl-22465594

ABSTRACT

Although stress can alter the susceptibility of patients and animal models to convulsive epilepsy, little is known about the role of stress and glucocorticoid hormones in absence epilepsy. We measured the basal and acute stress-induced (foot-shocks: FS) concentrations of corticosterone in WAG/Rij rats, non-epileptic inbred ACI rats and outbred Wistar rats. The WAG/Rij strain is a genetic model for absence epilepsy and comorbidity for depression, which originates from the population of Wistar rats and, therefore, shares their genetic background. In a separate experiment, WAG/Rij rats were exposed to FS on three consecutive days. Electroencephalograms (EEGs) were recorded before and after FS, and the number of absence seizures (spike-wave-discharges, SWDs) was quantified. Both WAG/Rij rats and ACI rats exhibited elevated basal levels of corticosterone and a rapid corticosterone increase in response to acute stress. The WAG/Rij rats also displayed the most rapid normalization of corticosterone during the recovery phase compared to that of ACI and Wistar rats. FS had a biphasic effect on SWDs; an initial suppression was followed by an aggravation of the SWDs. By the third day, this aggravation of seizures was present in the hour preceding FS. This increase in SWDs may arise from anticipatory stress about the upcoming FS. Together, these results suggest that the distinct secretion profile of corticosterone found in WAG/Rij rats may contribute to the severity of the epileptic phenotype. Although the acute stressor results in an initial suppression of SWDs followed by an increase in SWDs, stress prior to a predictable negative event aggravates absences.


Subject(s)
Epilepsy, Absence/genetics , Epilepsy/genetics , Glucocorticoids/blood , Stress, Psychological/genetics , Animals , Circadian Rhythm/physiology , Corticosterone/blood , Disease Models, Animal , Electric Stimulation/methods , Electroencephalography , Epilepsy/blood , Epilepsy/complications , Epilepsy, Absence/blood , Epilepsy, Absence/etiology , Epilepsy, Absence/pathology , Glucocorticoids/analysis , Male , Rats , Rats, Transgenic , Rats, Wistar , Stress, Psychological/blood , Stress, Psychological/etiology , Stress, Psychological/pathology
6.
Pediatr Infect Dis J ; 30(11): 1001-3, 2011 Nov.
Article in English | MEDLINE | ID: mdl-21633320

ABSTRACT

Efavirenz, used in treating pediatric human immunodeficiency virus infection, has central nervous system side effects. We report on a 5-year-old girl with perinatally acquired human immunodeficiency virus infection, presenting with new onset absence seizures after starting treatment with efavirenz. Plasma efavirenz values were above therapeutic range. The child was homozygous for the CYP2B6-516T/T genotype, which is associated with poor efavirenz clearance. Seizures abated after efavirenz discontinuation.


Subject(s)
Anti-HIV Agents/adverse effects , Aryl Hydrocarbon Hydroxylases/genetics , Benzoxazines/adverse effects , Epilepsy, Absence/genetics , HIV Infections/genetics , HIV/physiology , Oxidoreductases, N-Demethylating/genetics , Alkynes , Anti-HIV Agents/blood , Aryl Hydrocarbon Hydroxylases/deficiency , Benzoxazines/blood , Child, Preschool , Cyclopropanes , Cytochrome P-450 CYP2B6 , Epilepsy, Absence/blood , Epilepsy, Absence/chemically induced , Epilepsy, Absence/physiopathology , Epilepsy, Absence/virology , Female , Genetic Predisposition to Disease , Genotype , HIV/drug effects , HIV Infections/blood , HIV Infections/drug therapy , HIV Infections/physiopathology , HIV Infections/virology , Homozygote , Humans , Oxidoreductases, N-Demethylating/deficiency , Polymorphism, Genetic , South Africa , Viral Load/drug effects
7.
Seizure ; 20(1): 72-9, 2011 Jan.
Article in English | MEDLINE | ID: mdl-21093310

ABSTRACT

PURPOSE: Controlled-release formulations of Valproate (VPA) reduce side effects by minimizing peak plasma VPA concentrations in patients with epilepsy. However, the impact of this on anti-seizure efficacy has not been thoroughly explored. Here the pharmacokinetics and pharmacodynamics of chronic intermittent (consequently, peak VPA concentrations) and continuous VPA administration were directly compared in two rat models of epilepsy. METHODS: Genetic Absence Epilepsy Rats from Strasbourg (GAERS) received a single acute bolus of VPA (100 mg/kg intravenously) combined with electroencephalography (EEG) and/or blood sampling for 180 min post-injection. GAERS and epileptic rats post-kainic acid-induced status epilepticus were chronically infused intravenously (3-5 days, respectively) with (i) saline followed by in random order (ii) intermittent and (iii) continuous VPA (42 mg/kg/h), separated by two days of wash-out. Seizures were quantified using video-EEG monitoring and VPA levels measured in brain, cerebrospinal fluid and plasma. RESULTS: Following acute VPA administration seizure suppression in GAERS persisted after plasma VPA levels became very low. Chronic intermittent and continuous VPA significantly suppressed seizures in both models (p<0.01) with no difference between administration regimens. In GAERS, the pattern of seizure suppression during intermittent treatment was constant, in contrast to the fluctuating VPA plasma and brain levels. There was discordance between the temporal pattern of plasma, brain VPA levels and seizure suppression efficacy in GAERS. CONCLUSION: Administration regimes that result in fluctuating VPA blood levels achieve equivalent sustained seizure suppression as those that maintain steady mid-range concentrations.


Subject(s)
Epilepsy, Absence/blood , Epilepsy, Absence/drug therapy , Valproic Acid/administration & dosage , Valproic Acid/blood , Animals , Epilepsy/blood , Epilepsy/drug therapy , Epilepsy/genetics , Epilepsy, Absence/genetics , Female , Infusion Pumps , Male , Rats , Rats, Mutant Strains
8.
Zh Nevrol Psikhiatr Im S S Korsakova ; 111(10 Pt 2): 20-2, 2011.
Article in Russian | MEDLINE | ID: mdl-22500328

ABSTRACT

Psychoemotional status and blood serotonin level were investigated in 69 patients with different forms of idiopathic epilepsy during the seizures and interictal period. Twenty-two patients with juvenile myoclonic epilepsy, 22 patients with absence forms and 22 patients with generalized convulsive seizures, aged 10-47 years, were included in the study. We found the significant decrease in blood serotonin levels during the interictal period, with the lower levels seen after generalized convulsive and myoclonic seizures. After the treatment with antidepressant fluvoxamine as add-on treatment, 16 patients revealed improved psychoemotional well-being and quality of life as well as a decreased number of generalized convulsive seizures along with the increasing of blood serotonin level.


Subject(s)
Antidepressive Agents, Second-Generation/therapeutic use , Emotions/drug effects , Epilepsy, Generalized/blood , Epilepsy, Generalized/drug therapy , Fluvoxamine/therapeutic use , Serotonin/blood , Synaptic Transmission , Adolescent , Adult , Anticonvulsants/therapeutic use , Child , Drug Therapy, Combination , Epilepsies, Myoclonic/blood , Epilepsies, Myoclonic/drug therapy , Epilepsies, Myoclonic/psychology , Epilepsy, Absence/blood , Epilepsy, Absence/drug therapy , Epilepsy, Absence/psychology , Epilepsy, Generalized/psychology , Epilepsy, Tonic-Clonic/blood , Epilepsy, Tonic-Clonic/drug therapy , Epilepsy, Tonic-Clonic/psychology , Female , Humans , Male , Middle Aged , Young Adult
9.
Epileptic Disord ; 13(4): 452-5, 2011 Dec.
Article in English | MEDLINE | ID: mdl-22258053

ABSTRACT

We report the case of a six-year-old female with childhood absence epilepsy who developed combined aPTT prolongation, not corrected by normal plasma, and atypical skin eruption six months after initiating lamotrigine treatment with dose increment. Two weeks after lamotrigine withdrawal, the skin eruption disappeared and aPTT normalised. To our knowledge, this is the first report of aPTT prolongation possibly due to factor inhibitors associated with lamotrigine monotherapy.


Subject(s)
Anticonvulsants/adverse effects , Drug Eruptions/pathology , Epilepsy, Absence/complications , Partial Thromboplastin Time , Triazines/adverse effects , Anticonvulsants/therapeutic use , Blood Chemical Analysis , Blood Coagulation Factors/metabolism , Child , Electroencephalography , Epilepsy, Absence/blood , Epilepsy, Absence/drug therapy , Female , Humans , Lamotrigine , Skin/pathology , Triazines/therapeutic use
10.
Epilepsia ; 52(1): 115-20, 2011 Jan.
Article in English | MEDLINE | ID: mdl-21175610

ABSTRACT

PURPOSE: Absence epilepsies are common, with a major genetic contribution to etiology. Certain environmental factors can influence absence occurrence but a complete understanding of absence precipitation is lacking. Herein we investigate if lowering blood glucose increases spike-wave activity in mouse models with varying seizure susceptibility. METHODS: Three mouse models were used: an absence seizure model based on the knockin of a human GABA(A) γ2(R43Q) mutation (DBA(R43Q)), the spike-wave discharge (SWD)-prone DBA/2J strain, and the seizure resistant C57Bl/6 strain. Electrocorticography (ECoG) studies were recorded to determine SWDs during hypoglycemia induced by insulin or overnight fasting. KEY FINDINGS: An insulin-mediated reduction in blood glucose levels to 4 mm (c.a. 40% reduction) was sufficient to double SWD occurrence in the DBA(R43Q) model and in the SWD-prone DBA/2J mouse strain. Larger reductions in blood glucose further increased SWDs in both these models. However, even with large reductions in blood glucose, no discharges were observed in the seizure-resistant C57Bl/6 mouse strain. Injection of glucose reversed the impact of insulin on SWDs in the DBA(R43Q) model, supporting a reduction in blood glucose as the modulating influence. Overnight fasting reduced blood glucose levels to 4.5 mm (c.a. 35% reduction) and, like insulin, caused a doubling in occurrence of SWDs. SIGNIFICANCE: Low blood glucose can precipitate SWDs in genetically predisposed animal models and should be considered as a potential environmental risk factor in patients with absence epilepsy.


Subject(s)
Blood Glucose/genetics , Blood Glucose/metabolism , Disease Models, Animal , Epilepsy, Absence/blood , Epilepsy, Absence/genetics , Genetic Predisposition to Disease/genetics , Action Potentials/genetics , Animals , Electroencephalography/methods , Epilepsy, Absence/physiopathology , Female , Humans , Hypoglycemia/blood , Hypoglycemia/genetics , Hypoglycemia/physiopathology , Male , Mice , Mice, Inbred C57BL , Mice, Inbred DBA
11.
Epilepsia ; 51(8): 1560-9, 2010 Aug.
Article in English | MEDLINE | ID: mdl-19919665

ABSTRACT

PURPOSE: Epilepsy is a heterogeneous syndrome characterized by recurrent, spontaneous seizures; continuous medication is, therefore, necessary, even after the seizures have long been suppressed with antiepileptic drug (AED) treatments. The most disturbing issue is the inability of AEDs to provide a persistent cure, because these compounds generally suppress the occurrence of epileptic seizures without necessarily having antiepileptogenic properties. The aim of our experiments was to determine, in the WAG/Rij model of absence epilepsy, if early long-term treatment with some established antiabsence drugs might prevent the development of seizures, and whether such an effect could be sustained. METHODS: WAG/Rij rats were treated for ∼3.5 months (starting at 1.5 months of age, before seizure onset) with either ethosuximide (ETH; drug of choice for absence epilepsy) or levetiracetam (LEV; a broad-spectrum AED with antiabsence and antiepileptogenic properties). RESULTS: We have demonstrated that both drugs are able to reduce the development of absence seizures, exhibiting antiepileptogenic effects in this specific animal model. DISCUSSION: These findings suggest that absence epilepsy in this strain of rats very likely follows an epileptogenic process during life and that early therapeutic intervention is possible, thereby opening a new area of research for absence epilepsy and AED treatment strategies.


Subject(s)
Anticonvulsants/therapeutic use , Epilepsy, Absence/drug therapy , Ethosuximide/therapeutic use , Piracetam/analogs & derivatives , Age Factors , Analysis of Variance , Animals , Anticonvulsants/blood , Chromatography, High Pressure Liquid/methods , Disease Models, Animal , Epilepsy, Absence/blood , Epilepsy, Absence/genetics , Epilepsy, Absence/physiopathology , Ethosuximide/blood , Levetiracetam , Male , Piracetam/blood , Piracetam/therapeutic use , Rats , Rats, Mutant Strains , Time Factors
12.
Epilepsia ; 50(3): 480-5, 2009 Mar.
Article in English | MEDLINE | ID: mdl-19178558

ABSTRACT

PURPOSE: To study the impact of pregnancy on the serum concentration/dose ratio (C/D-ratio) of topiramate (TPM). METHODS: Twelve women with epilepsy using TPM during pregnancy, and 15 pregnancies were studied. The main target variable was the C/D-ratio at baseline and during pregnancy. Additional variables were changes in TPM dose, concomitant use of other antiepileptic drugs, seizure frequency, and pregnancy outcome. Clinical and pharmacological data were obtained from the women's medical records. RESULTS: The average C/D-ratios in the second and third trimester were 30% (p = 0.002, n = 11) and 34% (p = 0.001, n = 8) lower than the baseline values, respectively. The interindividual variability was pronounced. Increased seizure frequency was common in pregnant women using TPM, but a correlation to the decline in TPM C/D-ratio could not be established from our data. DISCUSSION: Dose-corrected serum concentrations of TPM appear to decline gradually throughout pregnancy. The underlying mechanisms are not known. Increased glomerular filtration may play a major role. During pregnancy, therapeutic drug monitoring of TPM may be useful.


Subject(s)
Anticonvulsants/pharmacokinetics , Epilepsy/blood , Fructose/analogs & derivatives , Pregnancy Complications/blood , Abnormalities, Drug-Induced/etiology , Anticonvulsants/adverse effects , Anticonvulsants/therapeutic use , Dose-Response Relationship, Drug , Drug Therapy, Combination , Epilepsies, Myoclonic/blood , Epilepsies, Myoclonic/drug therapy , Epilepsies, Partial/blood , Epilepsies, Partial/drug therapy , Epilepsy/drug therapy , Epilepsy, Absence/blood , Epilepsy, Absence/drug therapy , Epilepsy, Tonic-Clonic/blood , Epilepsy, Tonic-Clonic/drug therapy , Female , Fructose/adverse effects , Fructose/pharmacokinetics , Fructose/therapeutic use , Humans , Infant, Newborn , Metabolic Clearance Rate/physiology , Pregnancy , Pregnancy Complications/drug therapy , Pregnancy Outcome , Pregnancy Trimester, First , Pregnancy Trimester, Second , Pregnancy Trimester, Third , Topiramate , Treatment Outcome
13.
Neurochem Res ; 29(10): 1873-7, 2004 Oct.
Article in English | MEDLINE | ID: mdl-15532543

ABSTRACT

Childhood absence epilepsy (CAE) is a well-defined generalized epilepsy syndrome clinically characterized by frequent absence seizures. The aim of this study was to assess the activity of GABA transaminase (GABA-T) and the kinetic parameters of GABA uptake in platelets from patients with CAE. We studied 13 patients with CAE and eight sex- and age-matched controls. The mean activity of GABA-T was lower in patients with CAE than in controls (1.22+/-0.05 vs. 1.75+/-0.10 micromol/min/kg protein). The capacity of GABA uptake into the platelets was higher in patients using valproate (0.66+/-0.09 micromol/min/kg protein), but not in those using ethosuximide (0.34+/-0.05 micromol/min/kg protein), when compared to controls (0.26+/-0.06 micromol/min/kg protein). The affinity of the transporters was not altered. The observed peripheral alterations may indicate impaired function of brain GABAergic systems in children with absence epilepsy.


Subject(s)
4-Aminobutyrate Transaminase/blood , Blood Platelets/metabolism , Epilepsy, Absence/blood , gamma-Aminobutyric Acid/blood , Adolescent , Blood Platelets/drug effects , Child , Child, Preschool , Dose-Response Relationship, Drug , Enzyme Activation/drug effects , Enzyme Activation/physiology , Ethosuximide/pharmacology , Female , Humans , Male
14.
Epilepsia ; 45(10): 1240-7, 2004 Oct.
Article in English | MEDLINE | ID: mdl-15461678

ABSTRACT

PURPOSE: A nonhuman primate model of generalized absence status epilepticus was developed for use in functional magnetic resonance imaging (fMRI) experiments to elucidate the brain mechanisms underlying this disorder. METHODS: Adult male marmoset monkeys (Callithrix jacchus) were treated with gamma-butyrolactone (GBL) to induce prolonged absence seizures, and the resulting spike-wave discharges (SWDs) were analyzed to determine the similarity to the 3-Hz SWDs that characterize the disorder. In addition, blood-oxygenation-level-dependent (BOLD) fMRI was measured at 4.7 Tesla after absence seizure induction with GBL. RESULTS: Electroencephalographic recordings during imaging showed 3-Hz SWDs typical of human absence seizures. This synchronized EEG pattern started within 15 to 20 min of drug administration and persisted for >60 min. In addition, pretreatment with the antiepileptic drug, ethosuximide (ESM), blocked the behavioral and EEG changes caused by GBL. Changes in BOLD signal intensity in the thalamus and sensorimotor cortex correlated with the onset of 3-Hz SWDs. The change in BOLD signal intensity was bilateral but heterogeneous, affecting some brain areas more than others. No significant negative BOLD changes were seen. CONCLUSIONS: The BOLD fMRI data obtained in this marmoset monkey model of absence status epilepticus shows activation within the thalamus and cortex.


Subject(s)
Brain/physiopathology , Cerebral Cortex/physiopathology , Disease Models, Animal , Epilepsy, Absence/chemically induced , Epilepsy, Absence/physiopathology , Magnetic Resonance Imaging/statistics & numerical data , Status Epilepticus/chemically induced , Status Epilepticus/physiopathology , Thalamus/physiopathology , 4-Butyrolactone/pharmacology , Animals , Brain/drug effects , Callithrix , Cerebral Cortex/drug effects , Consciousness/physiology , Epilepsy, Absence/blood , Male , Neural Pathways/drug effects , Neural Pathways/physiopathology , Oxygen/blood , Status Epilepticus/blood , Thalamus/drug effects
15.
Physiol Behav ; 81(4): 623-7, 2004 Jun.
Article in English | MEDLINE | ID: mdl-15178155

ABSTRACT

Spontaneously occurring spike-wave discharges (SWDs) and serum concentrations of ovarian steroid hormones were investigated before, during and after pregnancy in WAG/Rij rats, a rat strain with genetically determined absence seizures. Eight groups of rats were included in the assays of progesterone and estradiol: rats at diestrus, at various days of pregnancy and at lactating days. The number of SWDs in cortical EEG of WAG/Rij rats was decreased from the 3rd up to the 18th day of pregnancy and subsequently increased to control level. Thereafter, a new decrease was found 2-3 days after parturition. Serum concentration of progesterone was threefold increased at the 3rd day of pregnancy, remained elevated until the 18th day of pregnancy and returned to control values before delivery. Over measured days, estradiol was significantly elevated only at the 18th day of pregnancy. Results demonstrate that physiological conditions induced by the state of pregnancy lead to suppression of occurrence of SWDs. Changes in plasma progesterone concentration correspond to the changes in number of SWDs: an increased level of progesterone during pregnancy is accompanied by a decreased number of SWDs, while a decrease in circulating progesterone before parturition is paralleled by an increase of SWDs. Of interest, the relationship between SWDs and concentration of progesterone found during pregnancy is diametrically opposite to results obtained in acute administration studies of progesterone in nonpregnant animals.


Subject(s)
Epilepsy, Absence/blood , Estradiol/blood , Estrous Cycle/blood , Parturition/blood , Pregnancy Complications/blood , Progesterone/blood , Animals , Disease Models, Animal , Epilepsy, Absence/physiopathology , Female , Pregnancy , Pregnancy Complications/physiopathology , Rats , Rats, Inbred Strains
16.
Neurosci Lett ; 354(2): 119-22, 2004 Jan 09.
Article in English | MEDLINE | ID: mdl-14698453

ABSTRACT

Near-infrared spectroscopy (NIRS) is a noninvasive method that allows the assessment of activation-induced cortical oxygenation changes in humans. It has been demonstrated that an increase in oxygenated and a decrease in deoxygenated haemoglobin can be expected over an area activated by functional stimulation. Likewise, an inverse oxygenation pattern has been shown to be associated with cortical deactivation. The aim of the current study was to determine the oxygenation changes that occur during absence seizures. We performed ictal NIRS simultaneously with video-EEG telemetry in three adult patients with typical absence seizures. NIRS probes were placed over the frontal cortex below the F1/F2 leads. During all absence seizures studied, pronounced changes in cerebral Hb-oxygenation were noted and there were no changes in the interval. We observed a reproducible decrease in [oxy-Hb] and an increase in [deoxy-Hb] during absence seizures indicating a reduction of cortical activity. Oxygenation changes started several seconds after the EEG-defined absence onset and outlasted the clinically defined event by 20-30 s.


Subject(s)
Brain/physiopathology , Cerebrovascular Circulation , Epilepsy, Absence/physiopathology , Hemoglobins/metabolism , Hypoxia, Brain/physiopathology , Adult , Brain/metabolism , Down-Regulation/physiology , Electroencephalography , Epilepsy, Absence/blood , Epilepsy, Absence/complications , Female , Humans , Hypoxia, Brain/etiology , Male , Middle Aged , Oxygen Consumption/physiology , Spectroscopy, Near-Infrared , Telemetry
17.
Epilepsy Res ; 54(2-3): 97-107, 2003 May.
Article in English | MEDLINE | ID: mdl-12837561

ABSTRACT

Absence epilepsy is characterised by recurrent periods of physical and mental inactivity coupled to bilateral, synchronous spike and wave discharges (SWDs) on the electroencephalogram. The mechanism of action of ethosuximide (ETX), a drug specific for absence seizures, is believed to involve a reduction in the low threshold T-type Ca(2+) current in thalamocortical and nucleus reticularis thalami (NRT) neurones, although other electrophysiological data have questioned this. Here, we employed a genetic rat model of absence seizures to investigate the effects of directly administering ETX to the thalamus.SWDs were immediately and substantially reduced (approximately 90%) by systemic administration of ETX (177-709 micromol/kg), or by bilateral microinfusion into the thalamus of the GABA(B) antagonist, CGP 36742 (5-27 nmol per side). However, infusion of ETX (1-200 nmol per side) into the ventrobasal complex or the NRT resulted in a reduction of SWDs that was delayed (30-60 min) and less marked (approximately 50%). Administration of ETX (0.2 mM to 1M) to a greater volume of thalamus by reverse microdialysis also produced significant but delayed reduction of SWDs at concentrations >1mM. Only at 5mM were seizures significantly reduced (approximately 70%) within 30 min of administration. These results suggest that targeting of the thalamus alone may be insufficient for an immediate and full anti-absence action for ETX. Concomitant or exclusive actions in the cortex remain a possibility.


Subject(s)
Disease Models, Animal , Drug Delivery Systems/methods , Epilepsy, Absence/drug therapy , Ethosuximide/administration & dosage , Thalamic Nuclei/drug effects , Animals , Anticonvulsants/administration & dosage , Anticonvulsants/blood , Epilepsy, Absence/blood , Epilepsy, Absence/physiopathology , Ethosuximide/blood , Rats , Rats, Wistar , Thalamic Nuclei/physiology
18.
Ross Fiziol Zh Im I M Sechenova ; 88(6): 741-50, 2002 Jun.
Article in Russian | MEDLINE | ID: mdl-12154571

ABSTRACT

Progesterone and oestradiol serum level was investigated in WAG/Rij rats with genetically determined absences. Blood samples were drawn before and after the pregnancy following the parturition. The serum concentration of progesterone increased after the 3rd day of pregnancy. There is no increasing of oestradiol during pregnancy as large as this. The progesterone is kept high to the 18th day of pregnancy and drastically decreased before the parturition. Common duration of absences--spontaneous spikewave discharges (SWD), frequency and the duration of every SWD decreased from 3rd to 19th days of pregnancy before the parturition. On the basis of these data and modern investigations, regulation of GABAA receptor expression during pregnancy by progesterone (Brusaartd A. B. et al., 1999) it can be assumed that the changes in the parameters of SWD are possibly correlated with the progesterone changes in serum during pregnancy in WAG/Rij rats.


Subject(s)
Epilepsy, Absence/blood , Estradiol/blood , Pregnancy Complications/blood , Progesterone/blood , Animals , Disease Models, Animal , Electroencephalography , Epilepsy, Absence/genetics , Epilepsy, Absence/physiopathology , Estradiol/physiology , Female , Pregnancy , Pregnancy Complications/physiopathology , Progesterone/physiology , Rats , Rats, Inbred Strains
19.
J Child Adolesc Psychopharmacol ; 10(1): 27-34, 2000.
Article in English | MEDLINE | ID: mdl-10755579

ABSTRACT

The clinical course of a 9-year-old diagnosed with attention-deficit hyperactivity disorder, obsessive-compulsive disorder, and Tourette's disorder and treated with a combination of methylphenidate, clonidine, and fluoxetine is described. The patient experienced over a 10-month period, signs and symptoms suggestive of metabolic toxicity marked by bouts of gastrointestinal distress, low-grade fever, incoordination, and disorientation. Generalized seizures were observed, and the patient lapsed into status epilepticus followed by cardiac arrest and subsequently expired. At autopsy, blood, brain, and other tissue concentrations of fluoxetine and norfluoxetine were several-fold higher than expected based on literature reports for overdose situations. The medical examiner's report indicated death caused by fluoxetine toxicity. As the child's adoptive parents controlled medication access, they were investigated by social welfare agencies. Further genetic testing of autopsy tissue revealed the presence of a gene defect at the cytochrome P450 CYP2D locus, which results in poor metabolism of fluoxetine. As a result of this and other evidence, the investigation of the adoptive parents was terminated. This is the first report of a fluoxetine-related death in a child with a confirmed genetic polymorphism of the CYP2D6 gene that results in impaired drug metabolism. Issues relevant to child and adolescent psychopharmacology arising from this case are discussed.


Subject(s)
Cytochrome P-450 CYP2D6/genetics , Fluoxetine/poisoning , Polymorphism, Genetic/genetics , Selective Serotonin Reuptake Inhibitors/poisoning , Antipruritics/metabolism , Antipruritics/therapeutic use , Attention Deficit Disorder with Hyperactivity/blood , Attention Deficit Disorder with Hyperactivity/drug therapy , Child , Cytochrome P-450 CYP2D6/deficiency , Dopamine Agents/metabolism , Dopamine Agents/therapeutic use , Epilepsy, Absence/blood , Epilepsy, Absence/drug therapy , Fatal Outcome , Fluoxetine/metabolism , Humans , Male , Methylphenidate/metabolism , Methylphenidate/therapeutic use , Polypharmacy , Promethazine/metabolism , Promethazine/therapeutic use , Selective Serotonin Reuptake Inhibitors/metabolism , Tourette Syndrome/blood , Tourette Syndrome/drug therapy
20.
Epilepsia ; 40(11): 1661-3, 1999 Nov.
Article in English | MEDLINE | ID: mdl-10565597

ABSTRACT

A 5-year-old boy with generalized absence seizures was treated with valproate (VPA), 30 mg/kg/day. One month after VPA introduction, routine examination showed moderate reduction in fibrinogen and prolonged partial thromboplastin time (PTT). The search for lupus anticoagulant (LAC) was negative. After 10 months of VPA treatment, seizures persisted, and lamotrigine (LTG), 2 mg/kg/day, was progressively given with VPA. Seizures disappeared, but PTT was more prolonged than before LTG introduction. The search for LAC was positive, and enzyme-linked immunosorbent assays (ELISAs) for immunoglobulin G (IgG) anticardiolipid antibodies were positive. Serum autoantibody screen and rheumatoid factor were negative; serum complement was normal. LAC eventually disappeared with VPA discontinuation. We believe that LTG may have exacerbated an initially mild immune response induced by VPA without clinical evidence of systemic disease. We therefore suggest that careful surveillance for LAC and systemic disease should be instituted when VPA is used with LTG.


Subject(s)
Anticonvulsants/adverse effects , Epilepsy, Absence/drug therapy , Lupus Coagulation Inhibitor/blood , Triazines/adverse effects , Valproic Acid/adverse effects , Antibodies, Anticardiolipin/blood , Anticonvulsants/therapeutic use , Child, Preschool , Dose-Response Relationship, Drug , Drug Therapy, Combination , Enzyme-Linked Immunosorbent Assay , Epilepsy, Absence/blood , Humans , Lamotrigine , Lupus Erythematosus, Systemic/blood , Lupus Erythematosus, Systemic/chemically induced , Male , Triazines/therapeutic use , Valproic Acid/therapeutic use
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