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PubMed1980

[Reflex epilepsy evoked by decision making: report of a case (author's transl)].

A 17-year-old girl with a story of Gran Mal attacks occurring during lessons of mathematics or solving mathematical problems, was investigated with prolonged EEG recordings. During the sessions, relax periods were alternated with arithmetical or mathematical testing, with card or checkers games and solution of puzzles and crossword problems, and with different neuropsychological tests. EGG recordings were characterized by the appearance, on a normal background, of bilaterally synchronous and symmetrical spike-and-wave and polispike-and-wave discharges, associated with loss of consciousness. During relax their mean frequency was one/54 min., it doubled during execution of tests involved with nonsequential decision making, and was eight times as high (one/7 min.) during tests involving sequential decision making. Some tension, challenge and complexity of the performance were also important as precipitating factors. Their lack deprived sequential tests of their efficacy, while on the contrary their presence sometimes gave nonsequential tests full efficacy.

Adolescent↗
PubMed1991

The non-N-methyl-D-aspartate receptor antagonists, GYKI 52466 and NBQX are anticonvulsant in two animal models of reflex epilepsy.

The effect of i.p. or i.v. administration of the non-N-methyl-D-aspartate antagonists, GYKI 52466 (1-(4-aminophenyl)-4-methyl-7,8-methylendioxy-5H-2,3-benzodiazepin e.HCl, molecular weight 330) and NBQX (2,3-dihydroxy-6-nitro-7-sulfamoyl-benzo(F)-quinoxaline, molecular weight 342) on sound-induced seizures in rats and photically induced myoclonus in baboons was studied. In both species an anticonvulsant effect occurred 15-60 min after administration of GYKI 52466 or NBQX. The ED50 value for clonic seizure suppression for GYKI 52466 at 30 min was 39 (rats, i.p.) and at 15 min was 13 (Papio papio, i.v.) mumol kg-1 and for NBQX at 30 min was 40 (rats, i.p.) and at 15 min approximately 10 (Papio papio, i.v.) mumol kg-1. Side effects were not observed in rats; apparent side effects in baboons probably arose from drug formulation. The anticonvulsant actions of GYKI 52466 and NBQX suggest a possible role for non-NMDA antagonists in the therapy of epilepsy.

Acoustic Stimulation↗
PubMedDate not supplied

[Reflex myoclonic epilepsy in infancy: a new reflex epilepsy syndrome or a variant of benign myoclonic epilepsy in infancy].

CASE REPORTS: We report a clinical and EEG study of 8 children with reflex myoclonic epilepsy of infancy to further confirm the existence of this syndrome first described by Ricci et al in 1995. RESULTS: Between February 1990 to July 2002, we identified 64 epileptic patients with myoclonic seizures with an onset in the first six years of life. Eight (12.5%) of these patients had myoclonic seizure stimuli sensible. The seizures were characterized by generalized, myoclonic jerks triggered by tactile stimuli in six patients and acoustic stimuli in two, in one of them myoclonic jerks were triggered by both types of stimuli. The seizures appeared between 5 and 20 months of age. Two of the 8 patients had spontaneous myoclonic attacks during sleep. Interictal EEG was normal during wakefulness and occasional discharges were evident during sleep. In contrast, the ictal EEG during both wakefulness and sleep showed generalized spike wave and polyspike slow wave paroxysms. Neurologic examination, neuroimaging and neurometabolic studies were normal. Myoclonic jerks disappeared in 6 patients after valproic acid administration and in two after clobazan administration. Antiepileptic treatment was discontinued in 6 patients and no seizure recurrence was observed during a median follow up of 6 years. CONCLUSION: Our patients presented electro clinical criteria compatible with the syndrome of reflex myoclonic epilepsy of infancy. This syndrome could be considered to be a new reflex epileptic syndrome or a variant of benign myoclonic epilepsy in infancy.

Anticonvulsants↗
PubMed1976

Inhibition of reflex epilepsy by (+/-)-N-n-propylnorapomorphine.

In baboons, Papio papio, spontaneously showing photosensitive epilepsy, myoclonic responses to intermittent photic stimulation were reduced or abolished for up to four hours by (+/-)-N-n-propylnorapomorphine (NPA) 0.05-0.2 mg/kg body weight, given i.v. In animals pretreated with allyglycine, 200 mg/kg, a transient abolition of myoclonic responses followed NPA, 0.2 mg/kg. In DBA/2 mice, seizures following auditory stimulation were attenuated or abolished by NPA 0.025-0.1 mg/kg given intraperitoneally (ED50 for abolition of clonic phase = 0.032 mg/kg). The ED50 for pentylenetetrazol seizures in MF 1 mice was not altered by NPA 0.25 mg/kg.

Animals↗
PubMed1983

Comparative assessment of dopamine agonist aporphines as anticonvulsants in two models of reflex epilepsy.

The anticonvulsant action of various aporphine derivatives that act on dopamine receptors has been investigated in two genetically determined animal models--DBA/2 mice with sound-induced seizures and baboons Papio papio with photically-induced seizures. Protection against the clonic and tonic phases of the seizures response in DBA/2 mice was seen for 15-60 min after (-)2,10,11-trihydroxy-N-n-propylnoraporphine (1.25 mg/kg) and (-)10,11-methyl-enedioxy-N-n-propylnoraporphine (0.625-1.25 mg/kg) and for 30-60 min after (-)2,10,11-trihydroxyaporphine (31.25 mg/kg). Short-lasting protection (up to 30 min) was seen following (-)2,10,11-trihydroxy-N-ethyl-noraporphine (1.25-6.25 mg/kg). Changes in audiogenic seizure susceptibility were accompanied by piloerection, ptosis and loss of spontaneous locomotor and exploratory behaviour. No protection was seen after (-)norapomorphine (0.05-18.75 mg/kg). All the compounds (including norapomorphine) significantly lowered rectal temperature, although the time course of this effect was often longer than that of protection against audiogenic seizures. In baboons, marked reductions in photomyoclonic responses were seen following (-)10,11-methylenedioxy-N-n-propylnoraporphine (0.25 mg/kg, lasting up to 2h); (-)2,10,11-trihydroxy-N-n-propylnoraporphine (0.5-2.5 mg/kg, lasting up to 7 h); (-)2,10,11-trihydroxyaporphine (5 mg/kg, duration of action 1-4 h) and (-)2,10,11-trihydroxy-N-ethylnoraporphine (6.25 mg/kg, lasting 2 h). Little change in responsiveness followed administration of (-)norapomorphine 1.25 or 6.25 mg/kg. Changes in photosensitivity were accompanied by yawning and pupil dilatation. (-)10,11-Methylenedioxy-N-n-propylnoraporphine (0.5-6.25 mg/kg) was also administered orally in baboons.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Chronic administration of the 5-HT3 receptor antagonist BRL 43694; effects on reflex epilepsy and social behaviour of the Mongolian gerbil.

The 5-HT3 receptor antagonist BRL 43694 was administered in drinking fluid to Mongolian gerbils, previously selected for their propensity to exhibit seizures on mild stimulation, for 11 days at doses of 1.5 micrograms/kg, 150 micrograms/kg and 1 mg/kg daily, while controls received tap water. Effects upon behaviour during encounters under white light with an untreated resident gerbil were assessed using ethological procedures. Effects upon seizure susceptibility and severity were also examined. All doses of BRL 43694 significantly increased the time spent by gerbils in the social activity "attend", and acts of social investigation involving physical contact between animals were significantly increased only by the highest dose of 1 mg/kg, as was occurrence of the specific element, "groom". The duration of flight was increased in gerbils receiving the drugs at 1.5 micrograms/kg. The treatment had no effect upon seizure susceptibility or severity. It is suggested that BRL 43694 increases the sensitivity of gerbils to their social environment. At the lower dose this was seen as an increase in flight, at all doses it was associated with increase of the social activity "attend" and at the high dose it was manifested as an increase in active social interaction. Further investigations are required to assess the relevance of these findings to the purported anxiolytic activity of 5-HT3 receptor antagonists.

Aggression↗
PubMed1977

Focal reflex epilepsy with myoclonus; electrophysiological investigation and therapeutic implications.

A middle-aged man suffering from myoclonic jerks of the right arm and leg and occasional grand mal seizures was investigated electrophysiologically. The EEG showed a left central spike focus which could be activated by any stimulus which distorted the biceps, triceps or brachioradialis muscles but skin stimulation was ineffective. Electrical nerve stimulation subthreshold to the alpha motoneurone fibres evoked cortical spikes and myoclonic jerks. The evidence supports the hypothesis that the myoclonus was triggered by muscle spindle afferent fibres (Ia) which projected to an epileptogenic focus in the sensori-motor area. A marked improvement of symptoms was achieved by a combination of baclophen and dipropylacetate.

Animals↗
PubMed1985

Evaluation of different beta-carbolines in Mongolian gerbils with reflex epilepsy.

Three benzodiazepine (BZ) receptor ligands of the beta-carboline group, namely the BZ receptor agonist ZK 93 423, the partial agonist ZK 91 296, and the antagonist ZK 93 426, were studied in epilepsy-prone Mongolian gerbils with different seizure types. Diazepam and clonazepam were included in these studies for comparison. In vivo binding studies in gerbils showed that all compounds were potent in displacing [3H]lormetazepam from binding sites in cerebellum and forebrain. Except for ZK 93 426, all drugs proved capable of dose dependently protecting gerbils from minor (myoclonic) and major (tonic-clonic) seizures induced by air blast stimulation. For ZK 93 423, ZK 91 296, diazepam and clonazepam, a highly significant correlation was found between anticonvulsant ED50S and ED50S for displacement of [3H]lormetazepam binding. Calculation of receptor occupancy revealed that beta-carbolines and benzodiazepines displayed anticonvulsant effects in gerbils at low occupancy (8-15% in forebrain). Even at almost total receptor occupancy, the BZ receptor antagonist ZK 93 426 was without any effect on seizure behaviour but antagonized the anticonvulsant effect of ZK 91 296. In contrast to diazepam, ZK 91 296 was devoid of any sedative side-effects even at 90% receptor occupancy. The data suggest that anticonvulsant beta-carbolines deserve interest as a new type of anticonvulsant drug.

Animals↗
PubMed1995

The gamma-aminobutyric acid uptake inhibitor, tiagabine, is anticonvulsant in two animal models of reflex epilepsy.

The effects of i.p. administration of the gamma-aminobutyric acid (GABA) uptake inhibitors R(-)N-(4,4-di(3-methylthien-2-yl)-but-3-enyl) nipecotic acid hydrochloride (tiagabine; molecular weight 412.0), (1-(2-(((diphenylmethylene)-amino)oxy)ethyl)-1,2,5,6-tetrahydro-3- pyridinecarboxylic acid hydrochloride (NNC-711; molecular weight 386.9), and (+/-)-nipecotic acid (molecular weight 128.2) are compared with those of carbamazepine (molecular weight 236.3) on sound-induced seizures and locomotor performance in genetically epilepsy-prone (GEP) rats. The ED50 value against clonic seizures (in mumol kg-1 at the time of maximal anticonvulsant effect) for tiagabine was 23 (0.5 h), and for NNC-711 was 72 (1 h), and for carbamazepine was 98 (2 h). (+/-)-Nipecotic acid (0.4-15.6 mmol kg-1) was not anticonvulsant. High doses of NNC-711 (207-310 mumol kg-1) and of (+/-)-nipecotic acid (39-78 mmol kg-1) induced ataxia and myoclonic seizures 0.25-1 h. Tiagabine and carbamazepine did not induce myoclonic seizures and had similar therapeutic indices (locomotor deficit ED50/anticonvulsant ED50) ranging from 0.4 to 1.9. In Papio papio, we observed a reduction in photically induced myoclonic seizures with tiagabine (2.4 mumol kg-1 i.v.) accompanied with neurological impairment. Tiagabine has comparable anticonvulsant action to carbamazepine in rats and has anticonvulsant effects in non-human primates supporting the potential use of inhibitors of GABA uptake as therapy for epilepsy.

Acoustic Stimulation↗
PubMed1987

Bidirectional effects of beta-carbolines in reflex epilepsy.

Derivatives of ethyl-beta-carboline-3-carboxylate, ZK 91296, ZK 93423 and ZK 95962 have potent anticonvulsant activity against sound-induced seizures in audiogenic DBA/2 mice and against photically-induced seizures in the baboon, Papio papio. The convulsant beta-carbolines, DMCM and beta-CCM, have proconvulsant and convulsant activity in the same animal models. DMCM and beta-CCM are similar in potency as convulsants in DBA/2 mice (ED50 value for DMCM: 1.3 mg/kg; ED50 value for beta-CCM; 0.8 mg/kg), but differ with respect to their profiles for protection by anticonvulsant drugs. The anticonvulsant potencies of diazepam and clobazam are similar against both types of beta-carboline-induced seizures, whereas quazepam protects better against beta-CCM seizures (4 fold elevation in ED50 value at 1 mg/kg quazepam IP) than against DMCM seizures (1.7 fold elevation in ED50 value), supporting a preferential action of beta-CCM on BZ1 receptors. Valproate (400 mg/kg) and gamma-vinyl-GABA (1.5 g/kg) protect better against beta-CCM seizures (9.5 and 5.9 fold elevations in ED50 values respectively) than against DMCM seizures (1.8 and 2.7 fold elevations in ED50 values respectively). The excitatory amino acid antagonist, 2-amino-7-phosphonoheptanoic acid, has significant anticonvulsant activity against DMCM seizures. The elevated regional GABA levels in brains of DBA/2 mice observed during beta-CCM seizures are eliminated by the pretreatment with Ro 15-1788, which also blocks the seizure activity.

Animals↗
PubMedDate not supplied

Anticonvulsant activity of the NMDA antagonists, D(-)4-(3-phosphonopropyl) piperazine-2-carboxylic acid (D-CPP) and D(-)(E)-4-(3-phosphonoprop-2-enyl) piperazine-2-carboxylic acid (D-CPPene) in a rodent and a primate model of reflex epilepsy.

D-(-)4-(3-phosphonopropyl)piperazine-2-carboxylic acid (D-CPP) and its unsaturated analogue (D(-)(E)-4-(3-phosphonoprop-2-enyl) piperazine-2-carboxylic acid (D-CPPene) have been administered to DBA/2 mice (intracerebroventricularly, i.c.v., intraperitoneally, i.p., and orally, p.o.) and to photosensitive baboons, Papio papio (intravenously, i.v., and orally), and their effects on reflexly induced epileptic responses assessed. In DBA/2 mice the clonic phase of the seizure response to sound is suppressed by D-CPP with an ED50 of 5.5 micrograms/mouse, i.c.v.; 0.69 mg (2.75 mumol)/kg i.p. and 16.6 mg (65.8 mumol)/kg p.o. compared with, for D-CPPene, 2.2 micrograms/mouse i.c.v., 0.41 mg (1.54 mumol)/kg i.p. and 10.8 mg (40.2 mumol)/kg, p.o. In Papio papio myoclonic responses to stroboscopic stimulation are suppressed 24 and 48 h after D-CPP 32 mg (127 mumol)/kg p.o. Administration of D-CPPene 8-16 mg (30-60 mumol)/kg i.v. produces protection against myoclonic responses after 1-2 h, lasting for 48 h. Oral administration of D-CPPene 32-64 mg (119-239 mumol)/kg produces protection beginning after 4 h and sustained for 48 h. Measurements of plasma D-CPPene concentration show rapid clearance after i.v. injection and a low plasma concentration 1.5-5 h after oral administration. The prolonged anticonvulsant action of D-CPP and D-CPPene following oral administration suggests that these compounds merit evaluation as antiepileptic therapy in man.

Acoustic Stimulation↗
PubMed1978

Anticonvulsant action of a 1,5-benzodiazepine, clobazam, in reflex epilepsy.

Clobazam, an anxiolytic 1,5-benzodiazepine, has been evaluated as an anticonvulsant in 2 animal models. In mice showing sound induced seizures, clobazam, 1--4 mg/kg, i.p., blocked seizure responses for 1--2 hr. In Senegalese baboons Papio papio showing photically induced myoclonus or seizures, clobazam, 2--12 mg/kg, i.v., totally prevented such responses for up to 6 hr. In baboons pretreated with allylglycine, 170--185 mg/kg, a similar but briefer protection was induced by clobazam. Neurological toxicity was not prominent (transient, slight nystagmus after clobazam, 2--6 mg/kg; muscular hypotonia after clobazam, 12 mg/kg). The possibility that 1,5-benzodiazepines are superior to 1,4-benzodiazepines in the therapy of epilepsy requires clinical investigation.

Acoustic Stimulation↗