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Francis Brunelle

Publications and source records attributed to Francis Brunelle.

40 records · Page 3Linked to original sources
PubMed2002

Late plasticity for language in a child's non-dominant hemisphere: a pre- and post-surgery fMRI study.

The ability of the right hemisphere to sustain the acquisition or the recovery of language after extensive damage to the left hemisphere has been essentially related to the age at the time of injury. Better language abilities are acquired when the insult occurs in early childhood (perinatal insults) compared with later occurrence. However, while previous studies have described the neuropsychological pattern of language development in typical cases, the neural bases of such plasticity remain unexplored. Non-invasive functional MRI (fMRI) is a unique tool to assess the neural correlates of brain plasticity through repeated studies, but the technique has not been widely used in children because of methodological limitations. Plasticity of language was studied in a boy who developed intractable epilepsy related to Rasmussen's syndrome of the left hemisphere at age 5 years 6 months, after normal language acquisition. The first fMRI study at age 6 years 10 months showed left lateralization of language networks during a word fluency task. After left hemispherotomy at age 9 years, the child experienced profound aphasia and alexia, with rapid recovery of receptive language but slower and incomplete recovery of expressive language and reading. Postoperative fMRI at age 10 years 6 months showed a shift of language-related networks to the right during expressive and receptive tasks. Right activation was seen mainly in regions that could not be detected preoperatively, but mirrored those previously found in the left hemisphere (inferior frontal, temporal and parietal cortex), suggesting reorganization in a pre-existing bilateral network. In addition, neuropsychological data of this case support the hypothesis of innately more bilateral distribution of receptive than expressive language. This first serial fMRI study illustrates the great plasticity of the child's brain and the ability of the right hemisphere to take over some expressive language functions, even at a relatively late age. It also suggests a limit for removal of the dominant hemisphere beyond the age of 6 years, a classical limit for the critical period of language acquisition.

Brain↗
PubMed2002

Thoracic CT in pediatric patients with difficult-to-treat asthma.

OBJECTIVE: . The aim of this study was to establish objective, simple criteria for bronchial wall thickening in children with difficult-to-treat asthma. SUBJECTS AND METHODS: . Bronchial sections were counted at five levels in both lungs and at three levels in the right lung on high-resolution CT and plotted against lung function. Findings from 27 children with persistent symptoms of asthma (mean age, 11.4 years; SD, +/-3.1 years) that were severe (group A, n = 15) or moderate (group B, n = 12) were compared with findings from 21 control subjects (mean age, 10.8 years; SD, +/-3.0 years) using the Student's t test, analysis of variance, and Dunn-Bonferroni test. RESULTS: . A bronchial wall thickening score based on the number of visible bronchi at three levels (three-level score) proved to be as valuable as and simpler to obtain than a score based on the number of bronchi at five levels (five-level score). The three-level scores for groups A and B were similar (mean +/- SD, 16.8 +/- 4.2 vs 18.4 +/- 3.4, respectively; p = not significant), but these scores were significantly higher than those for the control subjects (mean +/- SD, 8.2 +/- 3.4, respectively; p < 0.001). There was no correlation between the three-level score and forced expiratory volume in 1 sec or forced expiratory flow between 25% and 75% of forced vital capacity. In contrast with adults with severe asthma, our pediatric patients with difficult-to-treat asthma did not have CT evidence of mucoid impaction, emphysema, areas of hyperlucency, bronchiectasis, or sequellar line shadows. CONCLUSION: . Bronchial wall thickening visible on high-resolution CT may constitute an additional criterion of asthma severity in children. CT evidence of bronchial wall thickening might help to identify patients with a higher risk of airway remodeling.

Adolescent↗
PubMed1999

Failure of third ventriculostomy in the treatment of aqueductal stenosis in children.

Object. The goal of this study was to analyze the types of failure and long-term efficacy of third ventriculostomy in children. Methods. The authors retrospectively analyzed clinical data obtained in 213 children affected by obstructive triventricular hydrocephalus who were treated by third ventriculostomy between 1973 and 1997. There were 120 boys and 93 girls. The causes of the hydrocephalus included: aqueductal stenosis in 126 cases; toxoplasmosis in 23 cases, pineal, mesencephalic, or tectal tumor in 42 cases; and other causes in 22 cases. In 94 cases, the procedure was performed using ventriculographic guidance (Group I) and in 119 cases by using endoscopic guidance (Group II). In 19 cases (12 in Group I and seven in Group II) failure was related to the surgical technique. Three deaths related to the technique were observed in Group I. For the remaining patients, Kaplan-Meier survival analysis showed a functioning third ventriculostomy rate of 72% at 6 years with a mean follow-up period of 45.5 months (range 4 days-17 years). No significant differences were found during long-term follow up between the two groups. In Group I, a significantly higher failure rate was seen in children younger than 6 months of age, but this difference was not observed in Group II. Thirty-eight patients required reoperation (21 in Group I and 17 in Group II) because of persistent or recurrent intracranial hypertension. In 29 patients shunt placement was necessary. In nine patients in whom there was radiologically confirmed obstruction of the stoma, the third ventriculostomy was repeated; this was successful in seven cases. Cine phase-contrast (PC) magnetic resonance (MR) imaging studies were performed in 15 patients in Group I at least 10 years after they had undergone third ventriculostomy (range 10-17 years, median 14.3 years); this confirmed long-term patency of the stoma in all cases. Conclusions. Third ventriculostomy effectively controls obstructive triventricular hydrocephalus in more than 70% of children and should be preferred to placement of extracranial cerebrospinal shunts in this group of patients. When performed using ventriculographic guidance, the technique has a higher mortality rate and a higher failure rate in children younger than 6 months of age and is, therefore, no longer preferred. When third ventriculostomy is performed using endoscopic guidance, the same long-term results are achieved in children younger than 6 months of age as in older children and, thus, patient age should no longer be considered as a contraindication to using the technique. Delayed failures are usually secondary to obstruction of the stoma and often can be managed by repeating the procedure. Midline sagittal T2-weighted MR imaging sequences combined with cine PC MR imaging flow measurements provide a reliable tool for diagnosis of aqueductal stenosis and for ascertaining the patency of the stoma during follow-up evaluation.

Journal Article↗