Biomedical subjects
Publications and source records attributed to C Dravet.
Genetic linkage analysis shows that Baltic and Mediterranean myoclonus, two forms of progressive myoclonus epilepsy, are closely linked to marker D21S113 on the long arm of chromosome 21. Baltic and Mediterranean myoclonus are most probably due to mutations of the same gene.
We report a girl 3 years and 6 months old with onset of aphasia at age 3 years and 3 months. There was no evidence of brain damage and there were no seizures. The neuropsychological evaluation showed that the girl tended to be right-handed, that aphasia was global and that other higher cortical functions seemed to be preserved. Isolated spikes and spikes-and-wave were recorded during wake over the right temporal region with rare independent contralateral abnormalities. During polysomnography (PSG), the physiological patterns of sleep were preserved and right temporal epileptiform discharges were significantly increased in all sleep stages. Maximal activation was obtained at sleep onset and during rapid eye movement (REM) sleep periods, when focal abnormalities became continuous and spread contralaterally. Repeat PSGs showed that the activation profile retained this particular trait, although subclinical discharges tended to increase during slow wave sleep (SWS). This pattern of subclinical temporal status epilepticus during REM sleep differs from the characteristic activation profile found in the syndrome of continuous spikes-and-waves during SWS. However, this profile was transient and all epileptiform changes disappeared during clinical recovery at 18 months of follow-up.
We retrospectively collected plasma level assessments performed in 96 adult patients with epilepsy on stable monotherapy, including 9 patients on clobazam (CLB), 34 on carbamazepine (CBZ), 24 on phenobarbital (PB), 9 on phenytoin (PHT), and 20 on valproate (VPA); these results were compared to those obtained in 54 adult patients on stable bitherapy with the association of CLB with either CBZ (n = 17), PB (n = 17), PHT (n = 5), or VPA (n = 15). Our results show that CLB has no significant effect on the level to dose ratio (LDR) of CBZ, PB, PHT, or VPA. Conversely, CBZ, PB, and PHT significantly decrease the LDR of CLB. CBZ and PHT significantly increase the LDR of N-desmethylclobazam (NCLB), the major metabolite of CLB. A significant increase in the NCLB/CLB ratio was found in CBZ + CLB, PB + CLB, and PHT + CLB bitherapies. These findings are of clinical significance: clobazam is useful as adjunctive treatment in human epilepsy and is often chosen as the benzodiazepine adjunctive drug in chronic resistant epilepsy. Sedative side effects may occur, especially in patients treated by a CBZ + CLB or PHT + CLB bitherapy, and both CLB and NCLB plasma levels should be monitored in such patients.
The authors studied 10 patients aged between six and 23 years (mean age 14 years 5 months) with magnetic resonance imaging, which detected bilateral 'macrogyric-like' maldevelopment of the insulo-opercular regions. The data confirm that biopercular gyral anomaly, associated with mental retardation, pseudobulbar palsy (cortical or central) and epilepsy, represents an anatomo-clinical syndrome. Nevertheless, a wide clinical spectrum was found varying from pictures correlating with the topography and extent of the MRI-detected anomaly to conditions indicating wider cerebral involvement. Epilepsy, varying greatly in age at onset and severity, consistently influenced the prognosis for five patients with diffuse EEG abnormalities and intractable seizures with falls. Anterior callosotomy relieved such seizures in one case.
The authors studied 10 patients (mean age 15 years 6 months) with localized developmental gyral disorder detected by MRI. There were two groups of major malformations. Seven patients (group 1) had unilateral 'macrogyric-like' insulo-opercular changes, one of whom died early in life and had extensive microgyria. The six others had mental retardation and epilepsy, three of whom had focal neurological signs. Age at onset of epilepsy varied greatly. Clinical and EEG data suggested a wider cerebral involvement than recognized on MRI. The remaining three patients (group 2) had abnormal gyri of variable topography and extension, with bulging grey matter and ventricular deformity. One had mental retardation, another had neurological signs. All had intractable complex partial seizures and focal EEG anomalies correlating with the MRI lesion site, pointing to a well-defined epileptogenic zone. No clinical or EEG evidence of significant malformation in the remaining brain tissue was observed. Ablative surgery was beneficial for one patient; focal cortical dysplasia was the pathological substrate.
Benign myoclonic epilepsy in infancy (BME) is characterized by the occurrence of brief myoclonic attacks in normal infants aged 4 months to 3 years. There is no prior personal history, although in some patients 1 or 2 isolated febrile convulsions may occur prior to the onset of myoclonias. A family history of epilepsy or febrile convulsions is present in 30% of cases. Myoclonic attacks are short and mild, they involve mainly the head and upper limbs. The psychomotor development continues normally after the onset of seizures. The EEG shows a normal background activity and generalized spike-wave or polyspike-wave discharges associated with the myoclonias. These abnormalities are activated by drowsiness and during the first stages of sleep. A clinical and EEG photosensitivity is present in one-third of the patients. Myoclonias can be easily controlled by valproate monotherapy. Rare grand mal seizures can occur during adolescence, after withdrawal of drug treatment. The psychomotor evolution is good if treatment is started early. When myoclonias begin during the first year of life, the diagnoses of cryptogenic infantile spasms and of non-epileptic benign infantile myoclonus must be eliminated. In cases with a later onset, the following diagnoses can usually be easily discarded: cryptogenic Lennox-Gastaut syndrome, myoclonic-astatic epilepsy and unclassified epilepsies with the association of myoclonias and other types of seizures.
We conducted a prospective study of teratogenic effects of antiepileptic drugs (AEDs) in pregnant women with epilepsy in southeast France, comparing malformation rates with those collected by a birth defects registry. We evaluated isolated microcephalies separately. Malformations were seen in 7% of infants of mothers with epilepsy (IME) and in 1.36% of the general population. No significant relationship was found between type and severity of epilepsy and occurrence of malformations or isolated microcephaly. Valproate and phenytoin were the most teratogenic (all malformations). None of the malformations observed in IME whose mothers received valproate, phenytoin, or phenobarbital was seen in IME not exposed to the respective AEDs. Phenytoin plus phenobarbital was more teratogenic than phenobarbital alone. Benzodiazepines, prescribed only in combinations, had a borderline, nonspecific effect on microcephaly.
We describe a young man with a progressive neurological disorder including myoclonus, mental retardation, muscle weakness and a mitochondrial myopathy (myoclonus epilepsy and ragged red fibres--MERRF). Multiple abnormalities of the mitochondrial respiratory chain in skeletal muscle are shown by direct measurement of the flux through the individual complexes, low-temperature redox spectroscopy and decreased immunodetectable subunits of complexes I and IV by immunoblotting. No abnormality of mitochondrial DNA was found. This is the first report of combined defects of complexes I, III and IV as a cause of this clinical syndrome. However, we propose that the occurrence of multiple respiratory chain defects may be more common than previously recognised and that this particular combination of defects, involving complexes I, III and IV, may be the predominant biochemical abnormality in MERRF.
The authors describe the electro-clinical state of four children having a type of epilepsy clinically characterized by rare partial motor seizures and frequent absences. From E.E.G. point of view they had focal (mainly frontal) and diffuse abnormalities. Such diffuse abnormalities became continuous during slow sleep, thus realizing an electrical status epilepticus. During such status partial subclinical seizures were recorded. At the onset such cases have electroclinical features resembling those observed in the form of epilepsy so-called "benign partial epilepsy of children with rolandic or mid-temporal foci". All cases, however, have behavioural problems (instability, desorientation) and decreased school performances. The epilepsy evolution, however, is favourable and such form should consequently be distinguished from the Lennox-Gastaut Syndrome.
37 children presenting with West's syndrome were studied by computerized tomography scanning. An abnormality consisting of diffuse cerebral atrophy, predominating in the fronto-temporal region, was demonstrated in 30 cases. The abnormality was sometimes associated with calcification (tuberous sclerosis) or malformation (agenesis of the corpus callosum). The aetiology of the atrophy and its relationship to clinical and electroencephalographic signs is discussed. Computerized tomography scanning is recommended for children with West's syndrome in order to distinguish between primary and secondary cases, and for greater prognostic accuracy.
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Eleven of the first 500 epileptics examined by axial tomography presented pseudo-porencephalic dilation (cavitary atrophy) of an occipital horn, associated or not with more extensive ventricular dilation. This lesion was found in 2.2% of all the epileptics and in 5% of the epileptics under the age of 20 in this group, a high incidence when compared with that of lesions of the same type located elsewhere. Clinical investigation and E.E.G. carried out on these 11 children showed that they were suffering from either hemiphegia or hemiparesis (8 out of 11 cases) and hemianopsia (7 out of 11 cases), and had serious epilepsy with partial fits (6 cases), usual temporal lobe epilepsy (5 cases), generalized secondary epilepsy (3 cases) or epilepsy defying classification (2 cases). These cases are compared with those recently published by Remillard, Ethier and Anderman. These authors consider that these cerebral lesions are the result of peri-natal thrombosis of the posterior cerebral artery. But in our group of cases, angiographic results do not appear to justify this claim.
Computerized Axial Tomography (C.A.T.) easily distinguishes between the two types of cerebral accident responsible for the two major categories of acute hemiplegia in childhood. 1) In hemiplegias which develop in association with hemiclonic status epilepticus (H. H. and H. H. E. syndromes), in the majority of cases there is an appearance of cortico-sub-cortical atrophy involving the whole hemisphere contralateral to the hemiplegia. This atrophy develops following oedema of the hemisphere which accompanies the initial status epilepticus and which is clearly shown by a very early T.A.C. 2) In congenital or acquired hemiplegias not associated with status epilepticus there is, in most cases, an appearance of cerebral infarction or, very rarely, haemorrhage. It is thus possible, from a physiopathogenic standpoint, to draw a clear distinction between these two major forms of acute infantile hemiplegia. The first (H. H. and H. H. E. syndromes) usually result from hemispheric atrophy which develops in association with a unilateral or predominantly lateral episode of status epilepticus, whilst the second group are usually the result of cerebral infarction.
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On the basis of 21 personal observations as well as those (82) from the litterature, it is concluded that the progressive myoclonic epilepsy with Lafora bodies (P.M.E.) constitutes a disease on its own. The clinical features are those described in the litterature observations and completed by some characteristics; the high frequency of visual symptoms (47 p. 100 personal cases); the relatively less bad evolution of epilepsy, perhaps in relation with use of modern drugs; the relatively moderate intensity of myoclonus which becomes complete only at the end of the evolution. From E.E.G. point of view, we can distinguish three periods: an initial one at the very onset of disease, who will show the same features as observated in primary generalized epilepsy, i.e. a well preserved background activity with superimposed generalized fast spikes and waves facilitated by the I.L.S. Then follows a period of evolutive E.E.G. (1-2 years after the onset of the disease) characterized by progressive slowing of the posterior background, enlargement of posterior slow activity and appearance of diffuse theta and delta activity. Simultaneously spikes and waves are taking less typical and bisynchronous aspect. Finally after 3 to 5 years from the onset there is a diffusely slow E.E.G. with superimposed fast multiple spikes. The E.E.G. findings in litterature usually refer only to this last period (stationary or terminal period). Occipital independent multiple spikes are frequently observed and could correlate with the visual symptoms observated in the Lafora disease. Some elements of differential diagnosis are given with respect to primary generalized epilepsy at the onset of the disease and later on with respect to dyssynergia cerebellaris myoclonica and to the progressive myoclonic epilepsy without Lafora bodies.
Three children who had been diagnosed as having infantile spasms with major psychomotor retardation were referred for the persistence of series of spasm-like seizures, which were resistant to antiepileptic drug treatment, beyond infancy. Serial seizures were elicited by a compulsive self-stimulating behavior that was documented by long-term video-polygraphy. These behaviors implicated proprioceptive inputs: tapping on the chin in one case, flexion and external rotation of the leg with dislocation of the femur in one case, a particular posturing of the body followed by rhythmic shaking of the head in the last case. This clinical picture seems to constitute a particular type of outcome for infantile spasms and is particularly resistant to therapy.
A method has been developed for gas-chromatographic determination of clonazepam ("Rivotril" or "Ro 5-4023") in plasma, using methyl-clonazepam ("Ro 4082") as an internal standard. Following extraction of the benzodiazepines and hydrolysis, the benzophenones are analyzed by gas-chromatography, using a glass column filled with 3% OV 225 on Gas Chrom Q and a 63Ni electron-capture detector. The technique has good selectivity. The limit of sensitivity is less than 1 ng/ml of plasma. Using this method the plasma kinetics of clonazepam may be studied in man and the correlations between plasma levels and therapeutic activity investigated. It is also available for toxicological analysis, as well as pharmacovigilance purpose. The same internal standard and a similar method can also be used for the determination of flunitrazpem ("Rohypnol" or "Ro 5-4200") and its major metabolite (N-desmethyl-flunitrazepam) in plasma.