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Biomedical subjects

T Deonna

Publications and source records attributed to T Deonna.

At least 19 recordsLinked to original sources

Speech delay due to a prelinguistic regression of epileptic origin.

A 2-year-old boy presented with an early form of benign partial epilepsy with centro-temporal spikes (BCERS) and a severe speech delay. Family video analysis revealed an early regression of babbling and stagnation since the age of 12 months. Complete recovery occurred with anti-epileptic treatment. The deficit corresponded to a transient speech apraxia attributed to an epileptic disconnection of networks coordinating speech articulation. This observation is, to the best of our knowledge, the first demonstration that delayed emergence of language can be due to an epileptic dysfunction interfering with prelinguistic skills and therefore mimicking a developmental delay.

Child, Preschool↗

Treatment with Sulthiame (Ospolot) in benign partial epilepsy of childhood and related syndromes: an open clinical and EEG study.

The effect of Sulthiame on the EEG and on clinical seizures was evaluated in an open uncontrolled study in 25 children with focal sharp waves on the EEG (FSW). 16 children had typical benign partial epilepsy with rolandic spikes (BPERS), 5 children with atypical forms and 4 children with no clinical seizures but cognitive disturbances possibly related to the FSW. The effect of Sulthiame in suppressing the EEG discharges was evaluated on the waking and sleep EEG before introduction of the drug, and at 3 - 6 months, 6 to 12 months and beyond while under therapy. The children were followed clinically for one to several years. The EEG discharges disappeared or decreased under Sulthiame in 13/21 cases at 3 to 6 months but reappeared in 3/13 cases beyond this period. No case had a worsening of the EEG or of clinical seizures under Sulthiame, and no cognitive stagnation was noted. Our data confirm the good tolerance and positive effects on the EEG and justify systematic trials of this drug in the partial "functional" epilepsies, especially when negative cognitive consequences of the epileptic discharges are suspected.

Adolescent↗

Rhombencephalosynapsis: clinical findings and neuroimaging in 9 children.

Rhombencephalosynapsis is a rare congenital abnormality characterised by dorsal fusion of the cerebellar hemispheres, agenesis or hypogenesis of the vermis, fusion of dentate nuclei and superior cerebellar peduncles. We describe 9 children, aged 1.5 to 6 years, with rhombencephalosynapsis. Isolated rhombencephalosynapsis was found in 2 patients, hydrocephalus in 3 children and another 3 children had ventriculomegaly. Additional supratentorial abnormalities were documented in 5 patients. Clinical findings ranged from mild truncal ataxia and normal cognitive abilities to severe cerebral palsy and mental retardation. No correlation between clinical findings and magnetic resonance imaging could be established so far.

Cerebellum↗

Vision after early-onset lesions of the occipital cortex: I. Neuropsychological and psychophysical studies.

We analyzed the visual functions of two patients (MS, FJ) with bilateral lesion of the primary visual cortex, which occurred at gestational age 33 wk in MS and at postnatal month 7 in FJ. In both patients basic visual functions--visual acuity, contrast sensitivity, color, form, motion perception-are similarly preserved or modestly impaired. Functions requiring higher visual processing, particularly figure-ground segregation based on textural cues, are severely impaired. In MS, studied longitudinally, the deficits attenuated between the ages of 4.5 and 8 y, suggesting that the developing visual system can display a considerable degree of adaptive plasticity several years after the occurrence of a lesion. In FJ (age 18:9 to 20:6 y), who is more impaired, the recovery, if any, was less.

Adolescent↗

Vision after early-onset lesions of the occipital cortex: II. Physiological studies.

In one of two patients (MS and FJ) with bilateral, early-onset lesion of the primary visual cortex, Kiper et al. (2002) observed a considerable degree of functional recovery. To clarify the physiological mechanisms involved in the recovery, we used fMRI and quantitative EEG to study both patients. The fMRI investigations indicated that in both patients, isolated islands of the primary visual cortex are functioning, in the right hemisphere in MS and in the left in FJ. The functional recovery observed in MS roughly correlated with the functional maturation of interhemispheric connections and might reflect the role of corticocortical connectivity in visual perception. The functionality of interhemispheric connections was assessed by analyzing the changes in occipital inter-hemispheric coherence of EEG signals (ICoh) evoked by moving gratings. In the patient MS, this ICoh response was present at 7:11 y and was more mature at 9:2 y. In the more visually impaired patient, FJ, a consistent increase in ICoh to visual stimuli could not be obtained, possibly because of the later occurrence of the lesion.

Adolescent↗

Functional activation of microgyric visual cortex in a human.

We report on the case of a 20-year-old man with bilateral parasagittal parieto-occipital polymicrogyria and epilepsy. Functional magnetic resonance imaging responses to reversing checkerboard and interhemispheric electroencephalogram coherence changes to moving gratings were investigated. Results of both studies indicate that the polymicrogyric cortex was activated by visual stimuli, suggesting preserved function in the dysplastic area.

Adult↗

Primary neonatal thalamic haemorrhage and epilepsy with continuous spike-wave during sleep: a longitudinal follow-up of a possible significant relation.

Epilepsy with continuous spike-waves during sleep was diagnosed in a child who suffered primary neonatal thalamic haemorrhage, and who was followed from birth to 17 years of age. Early cognitive development was normal. Acquired behavioural problems and cognitive stagnation could be directly related to the epilepsy and not to the initial lesion and posthaemorrhagic hydrocephalus. This case and long-term follow-up data on a few children who suffered primary neonatal thalamic haemorrhage suggest that epilepsy with continuous spike-waves during sleep can be a sequel. Disturbances of thalamocortical interactions could play a role in the still poorly understood syndrome of epilepsy with continuous spike-waves during sleep.

Adolescent↗

Benign partial epilepsy of childhood: a longitudinal neuropsychological and EEG study of cognitive function.

The study combined prospective neuropsychological and EEG results of 22 children presenting with typical benign partial epilepsy with rolandic spikes (n=19) and occipital spikes (n=3). The aims were to assess the types of cognitive problems which may be encountered in this population, to evaluate the course of cognitive and learning capacities during the active phase of epilepsy, and to see if there was a correlation with paroxysmal activity on the EEG. Average age at entry in the study was 8.4 years and each child was seen two to four times over a period of 1 to 3 years. EEGs showed persistent spike foci in most cases that worsened in three cases, but there were no continuous spike-waves during sleep. No child had persistent stagnation, marked fluctuations, or a regression in cognitive abilities. Of 22 children, 21 had average IQ (>80). Eight children had school difficulties requiring special adjustment. No single cognitive profile was identified. Four children had delayed language development and eight children had transient weak scores in one isolated domain (verbal, visuospatial, memory) which improved or normalized during the course of the study with concomitant EEG improvement or normalization. In two of the three children with aggravation of the paroxysmal EEG activity, clinical changes were documented. A proportion of children with typical benign partial epilepsy with rolandic spikes showed mild, varied, and transient cognitive difficulties during the course of their epilepsy, and in most cases this probably had a direct relation with the paroxysmal EEG activity.

Child↗

Hypothalamic hamartoma, precocious puberty and gelastic seizures: a special model of "epileptic" developmental disorder.

Based on a review of the literature and a detailed longitudinal single case study of a child with early onset gelastic seizures and hypothalamic hamartoma, the authors review the arguments suggesting that the acquired cognitive and behavioral symptoms seen in the majority of cases of this special epileptic syndrome result from a direct effect of the seizures. The early neurobehavioral profile of the case presented in this paper and that of a previous study is particular and combines features of a pervasive developmental and an attention deficit disorder which are probably closely related to the particular location of the epilepsy and its spread from the hypothalamus.

Behavior↗

Acquired hippocampal damage after temporal lobe seizures in 2 infants.

Two infants developed unilateral hippocampal swelling on magnetic resonance imaging after prolonged seizures of temporal origin. Subsequent images suggested hippocampal sclerosis. The first child had febrile status epilepticus with exanthem subitum and developed refractory complex partial seizures. Histological findings after temporal lobectomy confirmed hippocampal sclerosis but also revealed sequelae of a focal encephalitis and microdysgenesis of the hippocampus. The second child had signs of brain dysgenesis, but acquired hippocampal damage affecting each side successively was documented by serial magnetic resonance imaging. These cases illustrate that different clinical conditions combining preexisting and acquired pathological characteristics can lead to hippocampal sclerosis.

Epilepsy, Temporal Lobe↗

Rolandic epilepsy: neuropsychology of the active epilepsy phase.

This paper reviews the main studies which have evaluated precisely cognitive functions in rolandic epilepsy. There are very few longitudinal data on the cognitive evolution of these children, particularly in relationship to the paroxysmal electroencephalographic activity. The difficulty to demonstrate direct effects of the epileptic EEG discharges on some cognitive functions and on learning, as occurs in some cases, is discussed.

Age Factors↗

High prevalence of CACNA1A truncations and broader clinical spectrum in episodic ataxia type 2.

OBJECTIVE: To characterize the nature of CACNA1A mutations in episodic ataxia type 2 (EA2), to search for mutations in sporadic cases, and to delineate better the clinical spectrum. BACKGROUND: EA2 is an autosomal dominant disorder characterized by recurrent acetazolamide-responsive attacks of cerebellar ataxia. The mutated gene, CACNA1A, located on chromosome 19, encodes the alpha1A subunit of a voltage-dependent calcium channel. So far, only three CACNA1A mutations have been identified-in two EA2 families and in one sporadic case. These three mutations disrupted the reading frame and led to truncated proteins. Interestingly, distinct types of CACNA1A mutations have been identified in familial hemiplegic migraine (missense mutations) and spinocerebellar ataxia type 6 (SCA-6) progressive cerebellar ataxia (expanded CAG repeats). However, except for SCA-6, these genotype-phenotype correlations relied on the analysis of very few families. METHODS: To characterize CACNA1A mutations, eight familial and seven sporadic EA2 patients were selected. All 47 exons of CACNA1A were screened by a combination of single-strand conformer polymorphism and sequencing analysis. In addition, the length of the CAG repeat has been determined in all patients. RESULTS: Seven new mutations were detected in four multiple case families and three sporadic cases. Six of them lead most likely to truncated or aberrant proteins. CAG repeat sizes were in the normal range. CONCLUSION: These data clearly establish the specificity of EA2 mutations compared with SCA-6 and familial hemiplegic migraine. Detailed clinical analysis of the mutation carriers showed the highly variable penetrance and expression of this disorder: Several of the carriers did not show any clinical symptom; others displayed atypical or permanent neurologic symptoms (such as recurrent, transient diplopia or severe, permanent, and isolated cerebellar ataxia).

Adolescent↗

Home and hospital treatment of acute seizures in children with nasal midazolam.

Rectal diazepam is widely used in the treatment of acute seizures in children but has some disadvantages. Nasal/sublingual midazolam administration has been recently investigated for this purpose but never at home or in a general paediatric hospital. The aim of this open study was to determine the efficacy, the tolerance and the applicability of nasal midazolam during acute seizures in children both in hospital and at home. We included known epileptic children for treatment at home and all children with acute seizures in the hospital. In all, 26 children were enrolled, 11 at home and 17 in the hospital (including two treated in both locations); only one had simple febrile seizure. They had a total of 125 seizures; 122 seizures (98%) stopped within 10 minutes (average 3.6 minutes). Two patients in the hospital did not respond and in three, seizures recurred within 3 hours. None had serious adverse effects. Parents had no difficulties administering the drug at home. Most of those who were using rectal diazepam found that nasal midazolam was easier to use and that postictal recovery was faster. Among 15 children who received the drug under electroencephalogram monitoring (six without clinical seizures), the paroxysmal activity disappeared in ten and decreased in three. Nasal midazolam is efficient in the treatment of acute seizures. It appears to be safe and most useful outside the hospital in severe epilepsies, particularly in older children because it is easy for parents to use. These data should be confirmed in a larger sample of children. Its usefulness in febrile convulsions also remains to be evaluated.

Acute Disease↗

Childhood epilepsy with neuropsychological regression and continuous spike waves during sleep: epilepsy surgery in a young adult.

We describe the case of a man with a history of complex partial seizures and severe language, cognitive and behavioural regression during early childhood (3.5 years), who underwent epilepsy surgery at the age of 25 years. His early epilepsy had clinical and electroencephalogram features of the syndromes of epilepsy with continuous spike waves during sleep and acquired epileptic aphasia (Landau-Kleffner syndrome), which we considered initially to be of idiopathic origin. Seizures recurred at 19 years and presurgical investigations at 25 years showed a lateral frontal epileptic focus with spread to Broca's area and the frontal orbital regions. Histopathology revealed a focal cortical dysplasia, not visible on magnetic resonance imaging. The prolonged but reversible early regression and the residual neuropsychological disorders during adulthood were probably the result of an active left frontal epilepsy, which interfered with language and behaviour during development. Our findings raise the question of the role of focal cortical dysplasia as an aetiology in the syndromes of epilepsy with continuous spike waves during sleep and acquired epileptic aphasia.

Adult↗

Post-traumatic mutism in children: clinical characteristics, pattern of recovery and clinicopathological correlations.

Among the numerous clinical syndromes observed after severe traumatic head injury, post-traumatic mutism is a disorder rarely reported in adults and not studied in any detail in children. We report seven children between the ages of 3 1/2 and 14 years who sustained severe head injury and developed post-traumatic mutism. We aim to give a precise clinical characterization of this disorder, discuss differential diagnosis and correlations with brain imaging and suggest its probable neurological substrate. After a coma lasting from 5 to 25 days, the seven patients who suffered from post-traumatic mutism went through a period of total absence of verbal production lasting from 5 to 94 days, associated with the recovery of non-verbal communication skills and emotional vocalization. During the first days after the recovery of speech, all patients were able to produce correct small sentences with a hypophonic and monotonous voice, moderate dysarthria, word finding difficulties but no signs of aphasia, and preserved oral comprehension. The neurological signs in the acute phase (III nerve paresis in three of seven patients, signs of autonomic dysfunctions in five of seven patients), the results of the brain imaging and the experimental animal data all suggest the involvement of mesencephalic structures as playing a key role in the aetiology of post-traumatic mutism.

Adolescent↗