Acute infantile encephalopathy predominantly affecting the frontal lobe (AIEF): a European case.

Acute infantile encephalopathy predominantly affecting the frontal lobes (AIEF) has been described as a new entity, based on MRI findings (acute abnormal diffusion-weighted imaging signals in the frontal lobes followed by atrophy) and exclusion of other acute encephalopathies. Patients present with acute onset of fever, status epilepticus, and coma. Different causal mechanisms have been suggested such as localized viral infection, toxic insult due to cytokines, or postictal damage. Only children of Japanese descent have been described. We report the case of a Caucasian girl whose history and MRI findings were similar to the Japanese cases. She had a massive regression with verbal apraxia, while cognitive development was less affected; she initially presented with a cluster of complex partial seizures (and not convulsive status epilepticus), making epileptic or post anoxic-ischemic sequelae highly unlikely. The place of this proposed entity among other recently described acute encephalopathies with abnormal diffusion on MRI is discussed.

The role of epilepsy in early language development in a child with a congenital lesion in the right hemisphere.

Early epilepsy is known to worsen the developmental prognosis of young children with a congenital focal brain lesion, but its direct role is often very difficult to delineate from the other variables. This requires prolonged periods of follow-up with simultaneous serial electrophysiological and developmental assessments which are rarely obtained. We studied a male infant with a right prenatal infarct in the territory of the right middle cerebral artery resulting in a left spastic hemiparesis, and an epileptic disorder (infantile spasms with transient right hemihypsarrhythmia and focal seizures) from the age of 7 months until the age of 4 years. Pregnancy and delivery were normal. A dissociated delay of early language acquisition affecting mainly comprehension without any autistic features was documented. This delay was much more severe than usually expected in children with early focal lesions, and its evolution, with catch-up to normal, was correlated with the active phase of the epilepsy. We postulate that the epilepsy specifically amplified a pattern of delayed language emergence, mainly affecting lexical comprehension, reported in children with early right hemisphere damage.

Deficit in memory consolidation (abnormal forgetting rate) in childhood temporal lobe epilepsy. Pre and postoperative long-term observation.

Deficits in memory consolidation have been reported in adult patients with epilepsy but, not to our knowledge, in children. We report the long-term follow-up (9 y. o. to 18 y. o.) of a boy who suffered from temporal lobe epilepsy and underwent a left temporal lobectomy with amygdalo-hippocampal resection at the age of 10. He showed an abnormal forgetting rate when trying to encode new information and a significant deficit for retrieving remote episodic memories (when compared with his twin brother), both consistent with a consolidation disorder. His memory condition slightly improved after cessation of the epilepsy, nevertheless did not normalize. No standard memory assessment could pinpoint his memory problem, hence an adapted methodology was needed. We discuss the nature of the memory deficit, its possible causes and its clinical implications.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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).

On nature and limits of cortical developmental plasticity after an early lesion, in a child.

MS is a little girl who suffered severe, bilateral destruction of her primary visual areas at six weeks, after premature birth at 30 weeks. Between the ages of 4.5 and 5.5 years she partially recovered different aspects of visual function, and, in particular, the ability to segregate figures from background, based on texture cues. The recovery might have been due to the compensatory role of the remaining visual areas that could have acquired response properties similar to those of the primary visual areas. This is not supported by the available FMRI (functional magnetic resonance imaging) responses to visual stimuli. Instead, abnormalities in the pattern of stimulus-induced changes of interhemi-spheric EEG-coherence in this patient suggest that her visual callosal connections, and possibly other cortico-cortical connections have re-organized abnormally. Since cortico-cortical connections, including the callosal ones appear to be involved in perceptual binding and figure-background segregation, their reorganization could be an important element in the functional recovery after early lesion, and/or in the residual perceptual impairment.