A prospective longitudinal study on visuo-cognitive development in Dravet syndrome: Is there a "dorsal stream vulnerability"?

A group of five DS patients whose first development was already reported were longitudinally followed up till the scholar age. Beside the general and epileptic clinical evolution, visual and cognitive functions were investigated in order to define their trajectory and possibly provide information about mechanisms of cognitive decline as well as to improve prognosis and tertiary prevention. Neuropsychological assessment was performed with a test battery investigating the development of visual function that progressively integrates into extrastriate components and higher cognitive skills (global form and motion coherence, stereopsis, crowding cards, ABCDEFV battery, general intelligence and specific cognitive tests). Main results showed a fall in visuo-motor items including global motion coherence and specific cognitive skills, presenting a continuity of the visual function deterioration extended from basic abilities to visuo-motor dorsal pathway skills. Moreover, a case whose previous visual and cognitive functions had been in the normal range began showing a visual deterioration with increasing age, followed by the cognitive decline; that prevents from excluding in early ages a poor development in presence of a normal visual function. A dorsal stream vulnerability seems thus shown in this sample of DS patients, like in other genetic syndromes (Williams, Prader Willi. fragile-X), providing new information about mechanisms underlying cognitive decline and suggesting a possible strategy to improve their neuropsychological outcome. Larger cohorts may confirm whether these findings are part of a specific pattern of DS neuropsychological phenotype.

Pretreatment neuropsychological deficits in children with brain tumors.

Treatment of childhood brain cancer has been associated with long-term cognitive morbidity in children. In the present study, the cognitive status of children with brain tumors was examined prior to any treatment to single out the role of tumor and tumor-related factors in cognitive deficits. Eighty-three children with newly diagnosed brain tumors (mean age, 8.6 years; range, 7 months to 16.6 years; median, 9.4 years) completed an extensive battery of age-related tests to assess cognitive function before any therapeutic intervention. Magnetic resonance imaging (MRI) was used to determine tumor site and volume and tumor-related factors. Performance under test was compared with symptom duration, neurological status, epilepsy, and MRI. Cognitive difficulties are detected at diagnosis in as many as 50% of patients for some cognitive domains; 6% of patients present with true-diagnosed mental retardation. The location of the tumor is the principal determinant of cognitive deficits, with major impairment in children with cortical tumors. Symptom duration and the presence of epilepsy are significantly associated with neuropsychological disabilities, while neuroradiological tumor-related variables do not correlate clearly with neurocognitive performance. The knowledge of the pre-existing cognitive deficits is critical to evaluate the results of treatment, providing a baseline for assessing the true impact of therapy in determining cognitive decline. In addition, the study suggests that some clinical variables require careful monitoring, because they could be specifically implicated in the neuropsychological outcome; the efforts to reduce the impact of these factors could ameliorate long-term prognosis.

Epilepsy surgery of posterior quadrant dysplasia in the first year of life: experience of a single centre with long term follow-up.

Posterior quadrant dysplasia (PQD) is a rare variant of cortical dysplasia involving the posterior regions of a single hemisphere. It is always associated with early onset, refractory epilepsy often characterized by a "catastrophic" evolution. The experience on its surgical management during the first year of life is limited to sporadic, isolated cases. Between 2002 and 2005, four children less than one-year-old and affected by drug-resistant epilepsy associated with PQD were admitted to our Institution and underwent surgical treatment. One patient remained seizure-free during all the follow-up (Engel I). The remaining three children showed a recurrence of the seizures, requiring subsequent surgical procedures in two cases. In one case (Engel II), the seizure control has been obtained thanks to pharmacological treatment. The other two patients respectively had only a partial (Engel III) and a less relevant reduction of the number of seizures (Engel IV). Both the epileptic and the neuropsychological outcome of our series were significantly influenced by persistent contralateral interictal anomalies rather than by the timing of the surgical procedure. Unpredictable results should be expected in this kind of patients if there is the detection of contralateral independent epileptiform activities on the EEG at diagnosis. Parents and relatives should be aware of the results' variability, even though a reduction of seizures may be expected, enabling an easier handling of the child's condition.

Functional hemispherectomy in children with epilepsy and CSWS due to unilateral early brain injury including thalamus: sudden recovery of CSWS.

PURPOSE: To try to prove in patients with refractory symptomatic epilepsy due to early brain injury involving thalamus and complicated by CSWS the effects of the isolation of the injured hemisphere, performed with functional hemisperectomy, on epilepsy, namely on CSWS. METHODS: Full clinical follow-up before and after surgery of two cases with CSWS onset at four years in whom functional hemispherecomy was performed with resection of inter-hemispheric connections. RESULTS: An immediate effectiveness of the surgical treatment was observed on both epileptic evolution (no more seizures) and EEG abnormalities. In particular, CSWS completely disappeared, together with a concurrent progressive improving of the cognitive and behavioural disorders. DISCUSSION: The isolation of the injured hemisphere through the section of inter-hemispheric cortico-cortical connections could prevent the contralateral diffusion of discharges coming from the injured cortex and cortico-thalamic network, favouring a normal function of thalamo-cortico-thalamic circuitries in the healthy hemisphere. That could explain the disappearance of CSWS after surgery in our patients and the consequent improvement of cognitive abilities and behaviour.

Early development of epileptic infants with pre- or perinatal brain injuries: role of the epileptic disorder.

To try to understand the causative role of epilepsy PER SE in the developmental deterioration of brain injured infants, twenty-eight infants affected with early acquired, pre- and perinatal brain injuries were enrolled and divided into three groups, a) those with West syndrome, b) those with other non-West epilepsies, and c) those without epilepsy. Developmental monitoring consisted of a full clinical assessment, including examination of visual function, Griffiths developmental scales, standard EEG, long-term monitoring when necessary, and MRI, from the seizure onset or the first observation to the end of follow-up. Patients with epilepsy showed at study onset abnormal clinical features (neurological and developmental) distinct from those of non-epileptic patients, partially due to the varying severity of their brain injuries. A definite differentiation between groups was observed in the clinical evolution that showed among the epileptic patients, mostly in West syndrome, a significant deterioration. Moreover, impaired visual function at seizure onset was possibly associated with a bad developmental evolution. A developmental deterioration, mostly in West syndrome, accounts for a causative role of the epileptic disorder PER SE, but in few cases it was also observed in infants with only a brain injury, suggesting other aetiopathogenic mechanisms. The predictive value of early visual function seems to be confirmed.

Early hemispherectomy in catastrophic epilepsy: a neuro-cognitive and epileptic long-term follow-up.

The authors report their experience about a neuro-cognitive and epileptic long-term follow-up of children with catastrophic epilepsy treated with hemispherectomy in the first 5 years of life. Nineteen children with resistant epilepsy that significantly interfered with their neuro-cognitive development underwent hemispherectomy within 5 years of life (mean: 2 years, 3 months; range: 5 months to 5 years). All patients were assessed before surgery and after, at least at the end of the follow-up (mean: 6 years and 6 months; range: 2-11 years and 2 months) with a full clinical examination including motor ability and functional status evaluation as well as behaviour observation, neuroimaging and an ictal/interictal prolonged scalp video-EEG. A seizure-free outcome was obtained in 73.7% of patients. Gross motility generally improved and cognitive competence did not worsen, with an evident progress in two cases. Consistently with previous reports, evolution was worse in cortical dysplasia than in progressive or acquired vascular cerebropathies. The excellent epileptic outcome and the lack of developmental deterioration in comparison with other more aged series seem to suggest a possible better evolution in earlier surgery treatment. To confirm this suggestion, however, further experience with larger series is needed.

Antenatal post-hemorrhagic ventriculomegaly: a prospective follow-up study.

OBJECTIVE: The aim of this study was to evaluate the presence and the severity of neurological and cognitive impairment at 2 years of age in 16 infants (9 term born, 7 preterm of mean gestation 33.6 weeks) with cerebral ventriculomegaly of antenatal onset associated with intraventricular haemorrhage. METHODS: Ventricular dilatation, with or without associated lesions, was, with one exception, not identified on the antenatal routine scan at approximately 22 weeks but was obvious on the scans performed between weeks 27 and 33. In 8 of the 16 cases there were signs of parenchymal involvement or of abnormalities of the corpus callosum or cerebellum. In all patients the diagnosis of antenatal IVH was confirmed by early neonatal imaging. Outcome was measured using the Hammersmith infant neurological examination and the Griffiths developmental scales at 2 years. RESULTS AND CONCLUSIONS: At 2 years, 8 infants had normal motor outcome and 8 had cerebral palsy. The presence and severity of cerebral palsy or neurodevelopmental delay was not always related to the magnitude or symmetry of the ventricular dilatation per se. The presence of associated lesions was a negative prognostic marker. The early development of epilepsy was also associated with an abnormal outcome.

Seizure semiology of lesional frontal lobe epilepsies in children.

The aim of the study was to analyse the semiology of seizures in children with frontal lobe epilepsy (FLE) and to compare them with other paediatric cohorts described in the literature as well as with adult counterparts. We analysed 174 registered seizures of 18 cases under 12 years with lesional epilepsy whose frontal origin was defined by the concordance of neuroimaging and ictal electrographic findings, and confirmed by surgery in the six cases operated on. Seizures were generally short, with a high daily frequency and usually related to sleep. The most characteristic semiological pattern consisted of complex motor seizures, particularly hypermotor. Often seizures corresponded to a mixture of different semiological patterns (tonic, gelastic, automotor, hypermotor, versive) presenting in the same seizure, often as a unique type in the same patient. With regard to several aspects the semiology of FLE in our cohort looks like that reported in adult series, in particular as to the frequency of complex motor seizures. However, our cohort was also characterised by a more protean array of seizure semiology, stressing the occurrence of seizures typically present in adults (versive and complex motor) and of some seizure patterns more characteristic in children such as epileptic spasms; moreover, the rare occurrence of secondarily generalised tonic clonic seizures (SGTCS) was confirmed.

Cognitive assessment in epilepsy surgery of children.

INTRODUCTION: Although the neurocognitive assessment in children as in the adults is an important step before and after surgery, in the literature, the data about pre- and postoperative neurocognitive evaluations in children are very few. OBJECTIVE: The purpose of this paper is to consider some peculiar aspects of the neurocognitive assessment during development, and report literature data about neuropsychological outcome of epileptic children treated with focal resection and hemispherectomy. RESULTS AND DISCUSSION: The second section concerns our personal experience about a cohort of 45 children with refractory epilepsy operated on before 7 years. The results suggest that early surgical treatment is generally effective for seizure control and behavior improvement in children with refractory epilepsy. Concerning cognitive outcome, we found that the neurocognitive level was unchanged in the majority of the patients. CONCLUSION: We underline the importance of multicentric studies with standardized neuropsychological assessments in large series of young children.