Motor and electrocorticographic epileptic activity induced by 3-mercaptopropionic acid in immature rats.

The convulsant action of 3-mercaptopropionic acid (3-MPA), a known inhibitor of glutamate decarboxylase activity, was studied in 7-, 12-, 18- and 25-day-old rats and in adult animals. 3-MPA elicited predominantly clonic, minimal seizures as well as generalized tonic-clonic (major) seizures at all developmental stages studied. The CD50 for major seizures did not change during development; CD50 for minimal seizures was significantly lower in 18-day-old rats than in older animals. Latency to the onset of seizures was shortest in 18-day-old rats and extremely long in 12- and, especially, in 7-day-old rats. This long latency might signify either changing molecular properties of glutamate decarboxylase during development or slow turnover of GABA at early postnatal stages. Electrocorticographic recordings demonstrated sharp EEG components in the frontal region as a first sign of 3-MPA action, and seizure patterns exhibited similar developmental changes as found with other seizure models (a decrease in duration of individual graphoelements and an increase in synchronization among various cortical regions). This indicates the primary importance of brain maturation in the expression of epileptic EEG phenomena. The correlation between EEG and motor phenomena was poor in the youngest animals and it ameliorated with age, but it never became perfectly coincidental.

[Differential diagnosis in early muscular hypotonia: spinal atrophy]. / Diferenciální diagnostika casných svalových hypotonií: spinální atrofie.

Changes in type, size and structure of muscle fibres were analyzed in 68 biopsies with clinical and morphological signs of spinal atrophy. Reliability of clinical prebioptic diagnosis was evaluated in comparison with bioptic finding and final diagnosis. Muscle biopsy is often to be performed in spite of apparently unambiguous clinical and electromyographical finding. Contribution of biopsy to the diagnosis of spinal atrophy with characteristical grouping of atrophic fibres is undisputable in most cases. However, unproper sampling in excessively atrophic areas and structural "myogenic" changes can made the bioptic diagnosis difficult or impossible. Size analysis of muscle fibres proved participation of both the basic fibre types in atrophy with increase in number of immature type 2c fibres, and prevalence of type 1 fibres in hypertrophic areas (compensatory hypertrophy or re-innervation respectively) where also hybrid fibres can often be found during transformation of their type. Angular atrophic fibres occurring in hypertrophic fibre groups gave evidence of continuous or secondary denervation in benign forms of spinal atrophy. The author found regressive structural changes in benign form and in malignant Werdnig-Hoffman atrophy either--though less extensive.

[Computer tomography in the diagnosis of neuromuscular diseases in children]. / Prínos výpocetní tomografie pro diagnostiku nervosvalových onemocnení u detí.

Recently in the literature occasional reports were published on the use of computed tomography (CT) in the diagnosis of neuromuscular diseases. The authors compared in a group of 23 children aged 3 to 15 years the results of clinical, laboratory, electromyographic, bioptic and CT findings on muscles. Only in four children the result of CT did not correlate with the clinical finding because of the incipient stage of the disease with structural changes which were yet only slightly expressed. Consistent with data in the literature it was possible from the CT to differentiate primary myopathies from neurogenic ones. The objective of the work was to prove the assets of the new method in the diagnosis of neuromuscular diseases, in particular in young children who do not cooperate during routine EMG examinations. There CT is an important guide for selective EMG and in particular for aimed bioptic studies which still hold priority in the specification of the disease. In already diagnosed and treated patients it is possible to investigate by means of CT the course of the disease by a non-invasive approach.

Benign posttraumatic encephalopathy.

Twenty-eight post-injury states were assessed in 27 children (in one child two attacks occurred) aged 1-9 years. The states could be classed as so called benign posttraumatic encephalopathy. The mild head injury was followed after a latent period (proved in 22 attacks) of 5 min. to 14 hours by transient brain disorder (in 17 cases quantitative, qualitative and combined alteration in consciousness, in 7 children cortical blindness, in 2 epileptic seizure and in two brain stem disturbance). The duration of symptoms lasted 5 minutes to 48 hours. After recovery the children had no difficulties; the mean of follow-up was 3.3 years. The EEG showed predominantly a normal picture or only abnormal background activity of bioccipital slow waves. In the history and clinical picture we found after the attack most often perinatal abnormality and minimal brain dysfunction (15x, 57%) and various forms of migraine (4x, 16%). It indicates that in the pathogenesis of benign posttraumatic encephalopathy apparently an important part is played by pretraumatic cerebral affection.

[Transcranial Doppler measurement of hemodynamics in the major cerebral arteries]. / Transkraniální dopplerovské merení hemodynamiky hlavních tepen mozku.

Using a pulsed Doppler velocity meter, the authors assessed by a transcranial approach, in order to obtain an idea on the normal haemodynamics of the basal cerebral arteries, the maximal systolic blood flow (Vmax., m.s-1) in these arteries in a group of 25 healthy young men and in 20 healthy children. In different arteries of the two groups the following mean values of Vmax. were recorded: middle cerebral artery 0.73 +/- 0.11 parallel 0.80 +/- 0.17 m.s-1; anterior cerebral artery 0.55 +/- 0.06 parallel 0.51 +/- 0.09 m.s-1 and posterior cerebral artery 0.44 +/- 0.04 parallel 0.40 +/- 0.02 m.s-1. The assessed values of Vmax. are in agreement with data of other authors. Using the transcranial Doppler method (TD), the authors recorded in 10 children examined in the acute and subsequent stage of cerebrovascular disease recanalization of original occlusions in the anterior, middle and posterior cerebral arteries in the carotid siphon and in the basal artery and improved cerebral haemodynamics in A-V malformation in the basal ganglia. The TD method thus makes it possible to diagnose and follow up the course of these diseases. To illustrate the assessment of the function of the circle of Willis we made in three of our followed up patients with stenosis of extracranial internal carotid arteries static compression tests of both common carotid arteries. The TD method makes it possible to follow up the course of haemodynamic changes in diseases of the cerebral arteries and along with the angiographic examination it extends and supplements the evaluation of the pathological condition of the cerebral arteries and its extent.

[Supratentorial and infratentorial localization of brain tumors in various periods in childhood]. / Supratentoriální a infratentoriální lokalizace mozkových nádor v jednotlivých udobích detského veku.

The authors evaluated a group of 220 children (119 boys and 101 girls) aged 11 months to 15 years with histologically confirmed brain tumours hospitalized at the Clinic of Child Neurology, Childrens Hospital, Brno in 1953-1986. Tumours were diagnosed in infants 15 times, in 41 toddlers, in 72 preschool children, in 56 young school children and in 36 older school children. The ratio of supra- and infratentorial localization in infants was practically identical, in toddlers and preschool children there was a marked predominance of infratentorial tumours, in younger school age this localization was slightly predominating, in older school age supratentorial tumours predominated. The most frequent incidence of tumours throughout childhood was in the posterior cranial fossa from the cerebellar vermis, medulloblastomas being the most frequent type. In the supratentorial localization tumours in the temporal lobe predominated, astrocytomas being the most frequent type.

[The clinical picture and treatment of migraine in children]. / Klinický obraz a lécba migrény u detí.

Child neurologists present their experience with diagnosis and treatment assembled in a group of 111 children hospitalized on account of migraine. The figure indicates the age distribution of the children; the first attack developed in 80% of the children during puberty, up to the age of 10 the sex ratio was proportional, later girls predominate 3:1.

Motor and electrocorticographic epileptic activity induced by bicuculline in developing rats.

Motor seizures were induced by intraperitoneally (i.p.) injected bicuculline in 270 rats aged 7, 12, 18, 25, or 90 days. Bicuculline was able to elicit both minimal (clonic) and major (tonic-clonic) seizures in all age groups, but in 7-day-old rats minimal seizures were only noted exceptionally. CD50s (for major seizures) ranged from 2.48 to 2.85 mg/kg in the three younger groups and increased to approximately 7 mg/kg in 25- and 90-day-old rats. An intravenous (i.v.) administration of bicuculline in 67 rats, 18 and 25 days old, caused identical CD50s in these groups, indicating that the difference that occurs with an i.p. administration is due to pharmacokinetic reasons. Electrocorticographic (ECoG) studies in acute experiments as well as in young rats with implanted electrodes demonstrated general principles of the development of EEG: an increase in frequency of individual elements, in generalization of the epileptic activity, in synchronization of activity among various cortical regions, and in the correlation between ECoG and motor phenomena. An exception occurred as an age-related phenomenon: rhythmic activity of the spike-and-wave type. This activity appeared in 18-day-old and older rats and was invariably accompanied by "freezing" of the animals.

Relationship of focal epileptogenesis to hemispheric motor prevalence in human ontogenesis.

The authors describe the clinical and electroencephalographic findings in 220 children with focal and secondary generalized epilepsies without gross structural aetiology, with the aim of evaluating the significance of hemispheric motor prevalence for the formation, activity and possibility of compensation of the focus. Focal epileptogenesis was observed significantly more often: a) in partial seizures with elementary symptomatology in the motor non-dominant hemisphere, b) in the motor non-dominant hemisphere in boys, c) in the whole series, irrespective of the form of epilepsy and sex, in the motor nondominant hemisphere in children under the age of six and in the motor dominant hemisphere in children over the age of six. The findings in partial seizures with an elementary motor symptomatology probably arise from the very close relationship to motor areas of the cerebral cortex, in boys from evidently greater hemispheric functional asymmetry than in girls and the age correlation from unequal maturation of functionally identical parts of the brain hemispheres during ontogenesis.

[Administration of high doses of B6 in age-related epileptic encephalopathies]. / Aplikace vysokych dávek B6 u vekove vázaných epileptických encefalopatií.

The authors present an account on 14 patients with markedly pharmaco-resistant age-conditioned epileptic encephalopathies (4 x West's syndrome, 5 x Lennox-Gastaut's syndrome and 5 x an intermediate stage of the two), treated with large doses of vitamin B6 (Pyridoxin Spofa). The mean age at the onset of therapy was 2.5 years (0.5-6 years). In addition to hitherto unsuccessful medication, the patients were given at first five-day treatment of vitamin B6 50-100 mg/day by the i.m. route, and then 200-300 mg/day orally. A marked clinical effect was recorded in five children, in another five it was less marked and usually only transient. Only in four patients the seizures were not affected, incl. three times in Lennox-Gastaut's syndrome. The EEG changes correlated with the clinical course. The authors recommend to attempt early administration of large doses of vitamin B6 in refractory age-conditioned epilepsies in the first three years of life.

[Therapeutic effect of dopaminergic substances in drug-resistant Lennox-Gastaut syndrome]. / Terapeutický efekt dopaminergních substancí u farmakorezistentního Lennox-Gastautova syndromu.

The authors administered to 18 children with an expressed pharmaco-resistant Lennox-Gastaut syndrome as adjuvant treatment medium doses of amantadine (Viregyt-K, Egyt), 8 mg/kg/day divided into 1-2 portions or L-DOPA (Nakom, Lek) 22 mg/kg/day in 3-4 portions. The mean age at the time of administration of the agonist or dopamine precursor was 5 years (1-12.5 years). A very favourable clinical effect was recorded in eight children, in another five the positive effect was less obvious and was transient. Only in five instances the paroxysmal manifestations were not affected. Reduction of the EEG pathology corresponded to the clinical improvement. In 11 children the psychic make-up was favourably influenced and only once polymorphous hyperkinesias developed after Nakom administration. The authors assume that dopaminergic substances may play a part in the pathogenesis of some epileptic syndromes, in particular in the period of early ontogenesis of the brain.

Ontogenetic development of ketamine-induced sleeping time and electrocorticographic changes in rats.

Latency to the loss of righting reflex and sleeping time after ketamine were measured in 261 rats aged 7, 12, 18, 25 and 90 days. The sensitivity to ketamine was highest in 7-day-old animals and decreased with age. In the youngest group rats slept after the 20-mg/kg dose whereas not all adult animals lost their righting ability after a dose of 160 mg/kg. Electrocorticographic (ECoG) study demonstrated an age dependence of changes induced by ketamine. The youngest group exhibited only suppression of the originally discontinuous ECoG whereas signs of slow-wave sleep or depression appeared in older rats.

Transient global amnesia after mild head injury in childhood.

In seven entirely healthy children in the age group of 6.5 to 14.5 years, mild head injury produced transient global amnesia (TGA) of median duration of 4.5 hours. None of the patients had convincing signs of brain concussion or clinical focal symptomatology. In four cases CT examination of the brain showed normal findings. Four children had a transient abnormal EEG (intermittent delta rhythms, slowed background activity inconstant local finding (of slow waves). During the period monitored (2-34 months) there was no recurrent attack and the children have had no difficulties. Pathologically, the authors assume ischemia of temporobasal structures induced by mild trauma with a relationship to migraine diathesis and rank the child group among so called benign posttraumatic encephalopathy with a noncomplicated course and good outcome.

EEG changes induced by convulsants interfering with GABAergic inhibition in rats. I. Cortical recordings.

Electrocorticographic changes induced by 3 convulsant drugs interfering with the GABA system were studied in 73 adult rats. Aminooxyacetic acid first elicited changes (periods of theta waves) nearly constantly in occipital regions. Bicuculline induced not only occipital theta waves but also groups of spikes with the same frequency in frontal regions; there was no predominance of one of these regions. 3-Mercaptopropionic acid invariably elicited groups of spikes in the frontal region as the first sign of its action. As it progressed, this rhythmic activity became generalized so that differences among the 3 drugs disappeared. Paroxysmal activity induced by the 3 drugs studied was identical. It always started with rhythmic spikes which were gradually transformed into spike-and-wave rhythm. Differences among the 3 convulsants studied were found in the very first electrocorticographic changes. Long latency to the onset of action of 3-mercaptopropionic acid and especially of aminoocyacetic acid qualifies these drugs for studies of preparoxysmal changes.