Partial Status Epilepticus in Benign Childhood Epilepsy with Centrotemporal Spikes: Are Independent Right and Left Seizures a Risk Factor?

PURPOSE: To describe an association between continuous simple partial seizures and independent right and left partial seizures in children with benign childhood epilepsy with centrotemporal spikes (BCECTS). METHODS: Three children with BCECTS and episodes of continuous simple partial seizures are described. RESULTS: All three children had a history of typical rolandic seizures occurring on the right and left sides of the body on different occasions. CONCLUSIONS: The occurrence of independent right and left rolandic seizures in children with BCECTS may be a predisposing factor for the development of partial status epilepticus.     

Epileptic negative myoclonus in a newborn with hemimegalencephaly

PURPOSE: We report the case of a male newborn with Ohtahara syndrome and right hemimegalencephaly who presented epileptic negative myoclonus in the first days of life. METHODS: Prolonged polygraphic studies were performed, as well as MRI and a full clinical examination. RESULTS: EEG showed a constant and nonreactive pattern of burst suppression. There were several kinds of electro-clinical seizures (generalized myoclonia, short atonias, typical spasm and tonic spasms) at the beginning of the EEG's burst. The periods of EMG silence, lasting less than 300 ms, were associated with stereotyped EEG transients. CONCLUSIONS: Epileptic negative myoclonus can be observed also in neonatal age. The short transient impairment of motor function observed in the newborn seems linked to the slow component of spike-wave discharge, but its mechanism is still not clear.     

Motor unit hyperexcitability in amyotrophic lateral sclerosis vs amino acids acting as neurotransmitters

OBJECTIVES: Electrophysiological studies of amyotrophic lateral sclerosis (ALS) patients reveal not only lower motor neuron involvement, but also widespread signs of its hyperexcitability. They might be the consequence of changes in the level of amino acids acting as neurotransmitters. MATERIAL AND METHODS: Electrophysiological examination of 31 patients with sporadic ALS was performed. A hyperexcitability index (HI) was created to describe the amount of double discharges, fasciculation potentials or 'giant' F-waves. Glutamate, aspartate, glycine and GABA concentration in serum and cerebrospinal fluid (CSF) were estimated, using the high performance liquid chromatography technique. RESULTS: The electrophysiological studies revealed marked variability in HI in the patients group. HI did not correlate with duration of the disease and the degree of disability expressed with Norris score, as well as with the level of excitatory or inhibitory amino acids in the body fluids. CONCLUSION: Hyperexcitability of the motor unit observed in ALS is not directly related to changes in serum and CSF level of amino acids acting as neurotransmitters.     

海洛因依赖对大鼠海马自发单位放电的影响

目的:探讨海洛因依赖对大鼠海马自发单位放电的影响。方法:按剂量逐日递增原则建立海洛因依赖大鼠模型作为依赖组,对照组注射等量生理盐水。用玻璃微电极细胞外记录依赖组和对照组大鼠海马神经元自发放电。结果:海洛因依赖组大鼠海马神经元自发放电的形式以单个不匀为主(62.96%),而对照组则以单个不匀(44.30%)和混合型(36.71%)为主,组间差异显著(P<0.05);依赖组大鼠海马自发放电频率以低频(48.15%)和中频(44.44%)为主,对照组则以低频为主(58.23%),但组间差异不显著(P>0.05)。结论:海洛因依赖使大鼠海马自发单位放电发生了改变。     

Central sympatho-inhibitory effects of intracisternal and intravenous administrations of noradrenaline in high doses

Intracisternal administration of noradrenaline (10, 20, 150 μg) decreased blood pressure, heart rate and spontaneous and evoked splanchnic nerve discharges in anaesthetized intact and ‘de-buffered’ cats.I.v. administration of lower dose of noradrenaline (4 μg/kg) increased blood pressure and reduced heart rate and splanchnic discharges; de-afferentation prevented the decrease in heart rate and in splanchnic discharges. Higher doses induced a delayed phase of hypotension, bradycardia and decreased spontaneous and evoked splanchnic discharges in intact and ‘de-buffered’ cats, indicating a central sympatho-inhibitory effect.     

Prolonged deficits after focal inhibitory seizures

Introduction: Seizures are most commonly associated with positive phenomena such as tonic, clonic or myoclonic movements, automatisms, paresthesias and hallucinations. Negative phenomena, however, are not an uncommon manifestation of seizure activity. Examples of negative seizure phenomena include speech arrest, aphasia, amaurosis, amnesia, numbness, deafness, neglect and atonic seizures. Less commonly described in the literature are focal inhibitory motor seizures. Methods and Results: Two patients presenting with rapidly progressive, prolonged hemiparesis, sensory neglect and hemi-visual field obscuration are described. Computed tomography (CT) and magnetic resonance imaging (MRI) of the brain did not reveal progression of known structural lesions or new lesions. The superficial cortex of the hemisphere contralateral to the hemiparesis and sensory neglect enhanced diffusely with gadolinium on T1-weighted MRI images. Electroencephalography demonstrated periodic lateralized epileptiform discharges (PLEDs) in one patient and lateralized suppression and slowing in the other patient. Single photon emission computed tomography (SPECT) revealed hyperperfusion in the hemisphere contralateral to the hemiparesis and sensory neglect. The changes seen on MRI and SPECT resolved with resolution of the symptoms. Conclusion: Taken together with the clinical history, the results from these investigations suggest focal inhibitory seizure as the underlying etiology. A review of the literature and investigations helpful in making this difficult diagnosis are provided.     

Long-lasting antiepileptic effects of levetiracetam against epileptic seizures in the spontaneously epileptic rat (SER): differentiation of levetiracetam from conventional antiepileptic drugs

PURPOSE: Some evidence suggests that levetiracetam (LEV) possesses antiepileptogenic characteristics. The purpose of this study was to investigate the time course of seizure protection by LEV compared with that of phenytoin (PHT), phenobarbital (PB), valproate (VPA), and carbamazepine (CBZ) in the spontaneously epileptic rat (SER). The SER is a double mutant (tm/tm, zi/zi) showing both tonic convulsions and absence-like seizures. METHODS: The effect of single (40, 80, and 160 mg/kg, i.p.) and 5-day (80 mg/kg/day, i.p.) administration of LEV on tonic convulsions and absence-like seizures in SERs were studied. Tonic convulsions induced by blowing air onto the animal's head at 5-min intervals for 30 min and spontaneous absence-like seizures characterized by 5- to 7-Hz spike-wave-like complexes in the cortical and hippocampal EEG were recorded for 30 min. In the single-administration study, observations for seizure activity were performed once before and 3 times (45, 75, and 135 min) after drug administration. In the 5-day administration study, seizure observation was performed 4 times for 30 min (once before and 3 times after drug administration) during the 5-day drug-administration period, and continued once a day until 8 days after the final administration. The antiepileptic effects of 5-day administration of conventional AEDs (PHT, PB, VPA, and CBZ) were examined by using similar methods. RESULTS: Tonic convulsions and absence-like seizures were inhibited by a single administration of LEV at 80 and 160 mg/kg, i.p., but not significantly at 40 mg/kg, i.p. When LEV was repeatedly administered at 80 mg/kg/day, i.p., for 5 days to SERs, the inhibitory effects on seizures increased with administration time. The number of tonic convulsions and absence-like seizures were significantly reduced to 39.1% and 38.4% compared with previous values, respectively, after 5-day LEV administration. Furthermore, significant inhibition of tonic convulsions was detected 相似文献