RESUMO
OBJECTIVE: To test the hypothesis that long-term postnatal development may be modified by metabolic experiences in utero. RESEARCH DESIGN AND METHODS: We enrolled offspring of women with pregestational diabetes (this included insulin-dependent diabetes mellitus [IDDM] and non-insulin-dependent diabetes mellitus [NIDDM]) and gestational diabetes in a prospective study from 1977 through 1983. Fetal beta-cell function was assessed by measurement of amniotic fluid insulin (AFI) at 32-38 weeks gestation. Postnatally, plasma glucose and insulin were measured yearly from 1.5 years of age after fasting and 2 h after 1.75 g/kg oral glucose. Control subjects had a single oral glucose challenge at 10-16 years. RESULTS: In offspring of diabetic mothers, the prevalence of impaired glucose tolerance (IGT) (2-h glucose concentration > 7.8 mmol/l) was: 1.2% at < 5 years, 5.4% at 5-9 years, and 19.3% at 10-16 years. The 88 offspring of diabetic mothers (12.3 +/- 1.7 years), when compared with 80 control subjects of the same age and pubertal stage, had higher 2-h glucose (6.8 +/- 1.4 vs. 5.7 +/- 0.9 mmol/l, P < 0.001) and insulin (660 +/- 720 vs. 455 +/- 285 pmol/l, P < 0.03) concentrations. The 17 subjects with IGT at > 10 years of age (9 boys and 8 girls) include one girl with NIDDM. IGT was not associated with the etiology of the mother's diabetes (gestational versus pregestational) or macrosomia at birth. IGT was found in only 3.7% (1 of 27) of adolescents whose AFI was normal ( < or = 100 pmol/l) and 33.3% (12 of 36) of those with elevated AFI (P < 0.001). Although most of the children with IGT are obese, AFI and obesity are independently associated with IGT by multiple logistic analysis. CONCLUSIONS: In confirmation of our original hypothesis, IGT in the offspring is a long-term complication of maternal diabetes. Excessive insulin secretion in utero, as assessed by AFI concentration, is a strong predictor of IGT in childhood.
Assuntos
Diabetes Gestacional/genética , Intolerância à Glucose/epidemiologia , Gravidez em Diabéticas/genética , Adolescente , Fatores Etários , Envelhecimento , Líquido Amniótico/química , Glicemia/análise , Criança , Pré-Escolar , Estudos Transversais , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 2/genética , Feminino , Intolerância à Glucose/genética , Hemoglobinas Glicadas/análise , Humanos , Insulina/análise , Masculino , Mães , Núcleo Familiar , Gravidez , Prevalência , Valores de Referência , Caracteres Sexuais , Testículo/anatomia & histologiaRESUMO
We present a case of generalized chorea, with complete recovery, due to MRI-documented bilateral lacunar infarcts of the caudate nucleus, putamen, and deep frontal white matter. MRI is probably more sensitive than CT in disclosing small deep cerebral infarcts.
Assuntos
Infarto Cerebral/complicações , Coreia/etiologia , Idoso , Infarto Cerebral/diagnóstico , Coreia/diagnóstico , Feminino , Humanos , Tomografia Computadorizada por Raios XRESUMO
The cerebrospinal fluid (CSF) content of homovanillic acid (HVA) was assayed in 10 patients with Huntington disease. On doses of less than 40 mg of bromocriptine daily, there was clinical improvement and the CSF HVA concentration increased. On higher doses of bromocriptine, chorea worsened and the CSF HVA concentration decreased. Bromocriptine at low dosage seems to act as a partial dopamine antagonist, with phenothiazine-like effects, and at higher doses it acts as a direct dopamine-receptor stimulating agent.
Assuntos
Bromocriptina/uso terapêutico , Doença de Huntington/fisiopatologia , Receptores Dopaminérgicos/fisiologia , Adulto , Idoso , Feminino , Ácido Homovanílico/líquido cefalorraquidiano , Humanos , Doença de Huntington/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Receptores Dopaminérgicos/efeitos dos fármacosRESUMO
We studied Sprague-Dawley rats with spike activity and myoclonus after intraperitoneal injections of penicillin. Twenty minutes after penicillin injection, one group received a random crossover treatment by intraperitoneal GABA (gamma-aminobutyric acid) or liposome-entrapped GABA (LEG) or phosphatidylserine alone. The other group received GABA, LEG, or phosphatidylserine followed 15 minutes later by the injection of penicillin. LEG decreased or prevented the epileptic activity, whereas no significant changes were seen with either GABA or phosphatidylserine given alone. LEG may enhance penetration of GABA across the blood-brain barrier because of the carrier action of the liposomes.
Assuntos
Comportamento Animal/efeitos dos fármacos , Lipossomos/administração & dosagem , Convulsões/fisiopatologia , Ácido gama-Aminobutírico/farmacologia , Animais , Potenciais Evocados/efeitos dos fármacos , Penicilinas , Ratos , Ratos Endogâmicos , Convulsões/induzido quimicamente , SuspensõesRESUMO
We immunocytochemically analyzed pieces of olfactory mucosa removed by biopsy in 8 patients with probable Alzheimer's disease (AD) and 6 age-matched controls, with tau and ubiquitin antisera. There were tau-reactive and, partially, ubiquitin-reactive dystrophic neurites in the lamina propria of olfactory mucosa in all AD cases. The tau-reactive neurites contained abnormal straight filaments, 15 to 18 nm in diameter, morphologically identical to those found in AD cerebral brain tissue obtained at autopsy. Tau and ubiquitin immunoreactivity were absent in controls. If these neuritic alterations are confirmed in a larger number of cases, analysis of olfactory mucosa may increase the current reliability of clinical diagnosis of AD.
Assuntos
Doença de Alzheimer/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Mucosa Nasal/metabolismo , Doença de Alzheimer/patologia , Biópsia , Feminino , Humanos , Imuno-Histoquímica , Masculino , Microscopia Eletrônica , Pessoa de Meia-Idade , Mucosa Nasal/patologia , Proteínas do Tecido Nervoso/metabolismo , Proteínas tauRESUMO
This review presents an account of the areas and circuits of the brain that are thought to be involved in such cognitive functions as memory, affect and consciousness. Considerable progress has been made in the past two decades in the identification of the cerebral areas and in our understanding of the brain mechanisms involved in these functions, thanks in large parts to a number of imaging observations (PET and fMRI), together with many clinical neurological and experimental studies. Thus, there is now convincing evidence that these high level functions are represented in a complex organization of interconnected cortical and subcortical areas that operate as spatially distributed systems, specialized for the different cognitive activities. Despite the progress that has been made, it is still not known how genetic and environmental factors interact during early development and throughout life to create the necessary conditions out of which these cognitive capacities emerge, nor is it evident to what extent they are shaped by adaptive changes in synaptic organization and other forms of neuronal plasticity.
Assuntos
Estado de Consciência/fisiologia , Emoções/fisiologia , Memória/fisiologia , Mapeamento Encefálico , Humanos , Imageamento por Ressonância Magnética , Memória de Curto Prazo/fisiologia , Vias Neurais/fisiologia , Psicofisiologia , Telencéfalo/anatomia & histologia , Telencéfalo/fisiologia , Tomografia Computadorizada de EmissãoRESUMO
Vascular dementia (VAD) is currently considered to be the second most common cause of dementia in Europe and the USA, second to dementia of the Alzheimer's type (DAT). However, in Asia and many developing countries the incidence of VAD exceeds that of DAT. The positive clinical diagnostic workup for VAD requires six steps: (1) clear-cut quantitative assessment of cognitive deficits utilizing standard neuropsychological tests to establish and quantify the dementia syndrome and rule out pseudo-dementia OF depression; (2) ascertaining the presence of risk factors for stroke; (3) identifying cerebral vascular lesions by neuroimaging (MRI, Iodine or Xenon contrasted CT, PET and SPECT); (4) exclusion of other causes of dementia; (5) differential diagnosis of possible, probable or definite VAD versus DAT and ascertaining when there are mixtures of the two; and (6) temporal identification of causality between onset and progression of the dementia with identified cerebral vascular lesions. There are eight subtypes of VAD: (1) multi-infarct dementias. These are due to large cerebral emboli, and are usually readily identifiable; (2) strategically placed infarctions causing dementia; (3) multiple subcortical lacunar lesions. Patients with these develop VAD at least five to twenty-five times more frequently than those in age-matched general population samples; (4) Binswanger's disease (arteriosclerotic subcortical leuko-encephalopathy). This form is rare. Neuroimaging confirms the diagnosis during life but the diagnosis can not be made by neuroimaging alone; (5) mixtures of two or more of above VAD subtypes; (6) hemorrhagic lesions causing dementia; (7) subcortical dementias due to cerebral autosomally dominant arteriolopathy with subcortical infarcts and leuko-encephalopathy (CADASIL), or to familial amyloid angiopathies and coagulopathies all of which present with multiple subcortical lacunar lesions similar to Binswanger's disease; (8) mixtures of DAT and VAD. The clinical significance of leukoaraiosis and its suspected relationships to VAD remains to be better established. The presence of ischemic infarctions, single or multiple large or multiple small (lacunar) by neuroimaging are necessary for the diagnosis of VAD, but identifying their presence, by neuroimaging alone, does not permit the diagnosis of dementia which can only be established by neuropsychological assessments. VAD is a clinical entity, identifiable in at least 30-70% of patients after strokes but mechanisms responsible for the cognitive impairments are complex. Some of these mechanisms are incompletely understood but provide subjects for important future research.
Assuntos
Demência Vascular/diagnóstico , Demência Vascular/epidemiologia , Demência Vascular/classificação , HumanosRESUMO
We studied immunocytochemically with 2 amyloid beta protein (ABP) antisera brains from 5 non-demented elderly subjects with evidence of diffuse periventricular white matter hypodensity on computed tomography. In periventricular white matter of all brains we found ABP reactive deposits arranged around small vessels walls. Furthermore ABP reactive deposits, identical to those currently called diffuse plaques, were detected in neocortex in amount proportional to that of white matter deposits. We suggest that ABP microangiopathy and parenchymal deposition is responsible of white matter rarefaction in a subset of cases with a diffuse hypodensity on CT scan which has been called leukoaraiosis.
Assuntos
Peptídeos beta-Amiloides/análise , Encéfalo/patologia , Demência/patologia , Idoso , Encéfalo/diagnóstico por imagem , Demência/diagnóstico por imagem , Humanos , Imuno-Histoquímica , Especificidade de Órgãos , Tomografia Computadorizada por Raios XRESUMO
We report open-label clinical observations of additional lamotrigine (LTG) in 16 adult patients with refractory epilepsy, aimed to assess the long-term efficacy and safety of LTG in clinical use. LTG was added to the current antiepileptic drug (AED) regimen at a daily dosage of 200-400 mg depending on the concomitant treatment. Ten patients completed one year's treatment and were followed up to an overall exposure ranging 15-38 months. Six patients (38% of the initial group) had a reduction of seizure frequency greater than 50% of pre-treatment baseline after one year; the further follow-up indicated some efficacy decline, since the percentage of improved patients dropped to 19% after 2 years and 13% after 3 years. The dropouts during the first year were due to seizure breakthrough (two patients), Steven-Johnson-like syndrome (one patient) and reasons unrelated to treatment (three patients); in one patient LTG treatment was stopped due to macrocytic anemia after 23 months. Other reported adverse events were dizziness, mild ataxia, diplopia and localized purpura. No other hematological or biochemical changes were noted. LTG was not associated with any significant changes in plasma concentrations of concomitant AEDs. These findings confirm the moderate efficacy and low toxicity of long-term LTG in severe epilepsy.
Assuntos
Anticonvulsivantes/uso terapêutico , Epilepsia/tratamento farmacológico , Triazinas/uso terapêutico , Adolescente , Adulto , Quimioterapia Combinada , Epilepsia/classificação , Epilepsia/fisiopatologia , Feminino , Seguimentos , Humanos , Lamotrigina , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Triazinas/efeitos adversosRESUMO
The effects of intraperitoneal injection of 2-amino-5-phosphono-valeric acid (APV) on EEG-monitored penicillin-induced epileptic activity in rats were evaluated. A significant decrease in the frequency of spikes occurred with low APV dosages (10 and 20 mg/kg), while an almost complete disappearance of spike activity was observed at higher APV doses (40 and 160 mg/kg). Our data suggest that excitatory amino acids play a relevant role in penicillin-induced epileptic activity in rats.
Assuntos
2-Amino-5-fosfonovalerato/uso terapêutico , Epilepsia/tratamento farmacológico , Animais , Eletroencefalografia/efeitos dos fármacos , Epilepsia/induzido quimicamente , Masculino , Atividade Motora/efeitos dos fármacos , Penicilinas/antagonistas & inibidores , Ratos , Ratos EndogâmicosRESUMO
Previous experimental studies have shown that the simultaneous administration of gamma-aminobutyric acid (GABA) and phosphatidylserine (PS) can exert an anticonvulsant activity in different seizure models; moreover, a preliminary trial showed some effect of the association GABA-PS in patients with absence seizures. The aim of this study was to investigate the antiepileptic properties of GABA-PS in the model of human photosensitivity. Nine patients with epilepsy associated with an EEG pattern of photoconvulsive response at intermittent photic stimulation entered a 3-day study. The photosensitivity range (PSR) was determined at hourly intervals both in basal conditions and after the administration of a single oral dose of GABA (3000 mg) and PS (600 or 1200 mg). The administration of GABA-PS was not associated with any systematic changes of PSR, nor with any significant differences of time course profiles on each daily session. No correlation was found between PSR percent deviations from baseline and GABA serum levels. These results indicate that a single acute administration of GABA-PS has no effect in the human photosensitivity model, and suggest that the efficacy of GABA-PS in human epilepsy, as shown by a preliminary investigation, may possibly require chronic administration.
Assuntos
Epilepsia/prevenção & controle , Fosfatidilserinas/uso terapêutico , Ácido gama-Aminobutírico/uso terapêutico , Adolescente , Adulto , Eletroencefalografia/efeitos dos fármacos , Epilepsia/fisiopatologia , Feminino , Humanos , Masculino , Estimulação Luminosa , Projetos Piloto , Ácido gama-Aminobutírico/efeitos adversos , Ácido gama-Aminobutírico/sangueRESUMO
The efficacy and safety of oral vigabatrin (VGB) as add-on therapy in the long-term treatment of poorly controlled epilepsy were evaluated in 19 patients with complex partial seizures, either with or without secondary generalization. The study was run with a single-blind, placebo-controlled, crossover design, and included 2 months of placebo and 13-15 months of treatment with VGB, at doses ranging from 1 to 4 g/day. Of the 14 patients who completed the trial, 2 were seizure free, in 5 seizure frequency dropped by more than 75% and in another 5 by more than 50% with respect to baseline. The decrease in seizure frequency in the group as a whole was significant at all observation points of the trial. Three patients were not entered into the long-term phase due to lack of improvement (an increase in seizure frequency was observed in one of them), and 2 were excluded later because improvement disappeared leading to unauthorized changes in comedication. Side effects were mild and never caused discontinuation of treatment. In conclusion, VGB showed a remarkable efficacy and safety in the long-term treatment of complex partial seizures.
Assuntos
Aminocaproatos/uso terapêutico , Epilepsia do Lobo Temporal/tratamento farmacológico , Administração Oral , Adolescente , Adulto , Aminocaproatos/efeitos adversos , Aminocaproatos/farmacocinética , Relação Dose-Resposta a Droga , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , VigabatrinaRESUMO
The effect of the combined administration of gamma-aminobutyric acid (GABA) and phosphatidylserine was evaluated in a pilot study of 42 patients with drug-resistant epilepsy. The group included patients with complex partial seizures, simple partial seizures and absence seizures. Patients with complex partial seizures and simple partial seizures showed no significant improvement; on the other hand, there was a remarkable decrease in absence seizures, linearly related to the dose of GABA and phosphatidylserine. Side effects occurred in 9 patients and were usually mild.
Assuntos
Epilepsia Tipo Ausência/tratamento farmacológico , Epilepsia/tratamento farmacológico , Fosfatidilserinas/uso terapêutico , Ácido gama-Aminobutírico/uso terapêutico , Adolescente , Adulto , Idoso , Anticonvulsivantes/uso terapêutico , Epilepsia/metabolismo , Epilepsia Tipo Ausência/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fosfatidilserinas/efeitos adversos , Ácido gama-Aminobutírico/efeitos adversosRESUMO
The purpose of this paper is to propose a preliminary scheme which standardizes the terminology and the manner of classifying comatose states due to organic cerebral lesions. This attempt is based on recognition of the need to use a common language in order to facilitate the transmission of information in this field.
Assuntos
Encefalopatias/diagnóstico , Coma/classificação , Terminologia como Assunto , Doença Aguda , Morte Encefálica , Estado de Descerebração , Humanos , Exame NeurológicoRESUMO
Although vigabatrin is a promising new antiepileptic drug, its safety has been challenged by the report of dose-dependent central nervous system myelin vacuolation in some preclinical animal studies. Since it has been shown that vacuolation is associated with specific magnetic resonance imaging (MRI) findings in rats and dogs, MRI of the brain was performed in 11 patients with complex partial seizures who had been receiving vigabatrin for 64-78 months (mean 74.0 +/- 5.0 sd) as additional treatment for epilepsy, with a cumulative exposure ranging 4200 to 9360 g. In no case did MRI show white matter changes similar to the pathological findings of microvacuolation observed in animals. These results would appear to confirm that current doses of vigabatrin do not cause myelin vacuolation in humans, even for treatment periods of longer than 5 years.
Assuntos
Aminocaproatos/efeitos adversos , Anticonvulsivantes/efeitos adversos , Epilepsia Parcial Complexa/tratamento farmacológico , Imageamento por Ressonância Magnética , Adulto , Aminocaproatos/administração & dosagem , Anticonvulsivantes/administração & dosagem , Encéfalo/efeitos dos fármacos , Encéfalo/patologia , Relação Dose-Resposta a Droga , Quimioterapia Combinada , Epilepsia Parcial Complexa/diagnóstico , Feminino , Humanos , Assistência de Longa Duração , Masculino , Pessoa de Meia-Idade , Bainha de Mielina/efeitos dos fármacos , Bainha de Mielina/patologia , VigabatrinaRESUMO
Data on efficacy and safety of vigabatrin over very protracted treatment periods are still limited. This study reports the follow up of 23 responder epileptic patients who continued vigabatrin treatment after completion of the first year, to an overall long-term exposure ranging 21-84 months (median 60; mean 58.0 +/- 24.0 sd). The seizure frequency during the follow up was compared with that at the end of the first year on vigabatrin. The rates of patients who gained a further improvement and those who deteriorated were almost identical, ranging 33-45% and 33-46% respectively at individual time points. At the trial endpoint, nine patients (39%) were improved, five (22%) were unchanged and nine (39%) showed some deterioration. All patients still had a 14-100% decrease of seizure frequency as compared with pretreatment baseline. Two patients discontinued vigabatrin for occasional reasons. No patient experienced new adverse events during the follow up after the first year on vigabatrin. No significant effects were noted on any of the routine hematologic or metabolic screening assessments. Although reduction of concomitant treatment was rarely possible, the overall number of associated antiepileptic drugs dropped from 42 at entry to 40 at the trial endpoint. These findings indicate that vigabatrin retains its efficacy and safety in responder patients for periods up to 7 years.
Assuntos
Aminocaproatos/uso terapêutico , Anticonvulsivantes/uso terapêutico , Epilepsia/tratamento farmacológico , Adolescente , Adulto , Aminocaproatos/efeitos adversos , Anticonvulsivantes/efeitos adversos , Quimioterapia Combinada , Eletroencefalografia/efeitos dos fármacos , Epilepsias Parciais/tratamento farmacológico , Epilepsia Tipo Ausência/tratamento farmacológico , Epilepsia Parcial Complexa/tratamento farmacológico , Potenciais Evocados/efeitos dos fármacos , Feminino , Seguimentos , Humanos , Assistência de Longa Duração , Masculino , Pessoa de Meia-Idade , Método Simples-Cego , VigabatrinaRESUMO
We investigated the effects of the NMDA antagonist amino-phosphono-valeric acid (APV), alone or in combination with phosphatidylserine (PS) in the penicillin model of epilepsy. After penicillin injection, rats were treated i.p. with either APV alone (5 mg/Kg) or APV (5 mg/Kg) + PS (740 mg/Kg). EEG epileptic activity decreased significantly in the group treated with APV alone, even at the very low dose used. This effect was not further enhanced by PS, suggesting that the previously reported effects of PS on GABA activity may be related to a specific interaction between these compounds.
Assuntos
2-Amino-5-fosfonovalerato/farmacologia , Eletroencefalografia/efeitos dos fármacos , Epilepsia/fisiopatologia , Fosfatidilserinas/farmacologia , Animais , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Epilepsia/induzido quimicamente , Potenciais Evocados/efeitos dos fármacos , Masculino , Penicilina G , Ratos , Ratos Sprague-DawleyRESUMO
To assess the relationships between the efficacy and blood levels of progabide (PGB) and its active acidic metabolite (PGA) in epileptics, observations were carried out on 89 adult patients with epilepsy of different types and severity in two groups at Paris and Genoa. The Paris group received progabide in addition to other antiepileptic drugs for 6 to 12 months, whereas the Genoa group received a polytherapy for the first two months then a monotherapy with progabide alone for up to 22 months. Blood levels from monthly or bimonthly samples were significantly higher in both surveys when there was a satisfactory therapeutic response and levels were also higher in those receiving monotherapy suggesting a synergism among antiepileptic drugs. It is concluded that therapeutic drug monitoring of PGB and PGA blood concentrations may be a useful technique in optimizing progabide treatment in epileptic patients.
Assuntos
Epilepsia/tratamento farmacológico , Ácido gama-Aminobutírico/análogos & derivados , Adulto , Relação Dose-Resposta a Droga , Humanos , Estudos Longitudinais , Monitorização Fisiológica , Ácido gama-Aminobutírico/administração & dosagem , Ácido gama-Aminobutírico/sangue , Ácido gama-Aminobutírico/uso terapêuticoRESUMO
Progabide (PGB), a gamma-amino-butyric acid receptor agonist, was administered, according to an open-label long-term design, to 40 adult patients suffering from complex partial seizures, with or without secondary generalization, whose response to carbamazepine (CBZ) monotherapy was unsatisfactory. A reference-baseline period of two months with carbamazepine monotherapy was followed by a two-month "add-on" period where increasing doses of progabide were added without modifying the CBZ regimen; then CBZ was withdrawn over 15-60 days and patients were followed up to 12 months' progabide treatment. Twenty-seven patients completed the trial but 12 of them had to be returned to CBZ + PGB bitherapy due to an increase of seizures following CBZ withdrawal. A definite therapeutic effect could be observed in nine patients on PGB monotherapy and in six patients on CBZ + PGB bitherapy. Side-effects of clinical relevance occurred in three cases and were represented by remarkable anxiety in two patients and a rise in serum glutamic oxalo-acetic acid and pyruvic transaminases with clinical symptoms of liver dysfunction in one, with rapid recovery following progabide discontinuation. In conclusion, progabide was effective against complex partial seizures in about 40% of patients not responding satisfactorily to available antiepileptic drugs. Although the withdrawal of previous antiepileptic drugs was not possible in all patients, progabide monotherapy was sometimes more effective than CBZ monotherapy, and several patients in whom bitherapy had to be restored benefited from the association of progabide.
Assuntos
Epilepsia do Lobo Temporal/tratamento farmacológico , Ácido gama-Aminobutírico/análogos & derivados , Adolescente , Adulto , Ensaios Clínicos como Assunto , Esquema de Medicação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ácido gama-Aminobutírico/administração & dosagem , Ácido gama-Aminobutírico/efeitos adversos , Ácido gama-Aminobutírico/uso terapêuticoRESUMO
A parenteral penicillin model of epilepsy in the rat was investigated with the aim of evaluating its reliability. Behavioral and EEG patterns were strongly variable in a group of 100 rats injected with 1,000,000 IU/kg of penicillin i.p. Gross counts of spikes were Fourier transformed and grouped into two time windows in 24 out of the 100 rats. Analysis of variance applied to compare the two time windows showed a sufficient suitability of the phenomenon for antiepileptic drug testing purposes. Five subsequent injections of penicillin performed in 8 rats showed that a spontaneous decrease of the response takes place, preventing a crossover design in pharmacological analyses. Evans Blue studies demonstrated that there was not a breakdown of the blood-brain barrier; this model can be used for testing anticonvulsants unable to penetrate the blood-brain barrier.