Clinical evidence of the role of the cerebellum in the suppression of overt articulatory movements during reading. A study of reading in children and adolescents treated for cerebellar pilocytic astrocytoma.

It has been suggested that the cerebellum is involved in reading acquisition and in particular in the progression from automatic grapheme-phoneme conversion to the internalization of speech required for silent reading. This idea is in line with clinical and neuroimaging data showing a cerebellar role in subvocal rehearsal for printed verbalizable material and with computational "internal models" of the cerebellum suggesting its role in inner speech (i.e. covert speech without mouthing the words). However, studies examining a possible cerebellar role in the suppression of articulatory movements during silent reading acquisition in children are lacking. Here, we report clinical evidence that the cerebellum plays a part in this transition. Reading performances were compared between a group of 17 paediatric patients treated for benign cerebellar tumours and a group of controls matched for age, gender, and parental socio-educational level. The patients scored significantly lower on all reading, but the most striking difference concerned silent reading, perfectly acquired by almost all controls, contrasting with 41 % of the patients who were unable to read any item silently. Silent reading was correlated with the Working Memory Index. The present findings converge with previous reports on an implication of the cerebellum in inner speech and in the automatization of reading. This cerebellar implication is probably not specific to reading, as it also seems to affect non-reading tasks such as counting.

Long-term functional outcome of patients with cerebellar pilocytic astrocytoma surgically treated in childhood.

UNLABELLED: Abstract Purpose: A number of studies report neurological and cognitive deficits and behavioural disorders in children after surgical treatment for a benign cerebellar tumour. The present study explores functional outcome in adolescents and adults treated for a low-grade cerebellar astrocytoma in childhood. MATERIALS AND METHODS: Participants were 18 adolescents and 46 adults treated for low-grade astrocytoma in childhood. Academic achievement, professional status and neurological, cognitive and behavioural disturbances were collected using self-completed and parental questionnaires for adolescents and phone interview for adults. For the adolescent group, a control group filled in the same questionnaires. RESULTS: Mean time lapse from surgery was 7.8 years for adolescents and 12.9 years for adults. Five adults (11%) had major sequelae related to post-operative complications, post-operative mutism and/or brain stem involvement. All the other participants presented close-to-normal academic achievement and normal autonomy, despite a high rate of reported cognitive difficulties and difficulties related to mild neurological sequelae (fine motor skills, balance). CONCLUSION: The long-term functional outcome of low-grade cerebellar astrocytoma is generally favourable, in the absence of post-operative complications and brain stem involvement. No major impact of neurological deficits, cognitive problems and emotional disorders on academic achievement and independent functioning was observed.

[A multidisciplinary consultation for children with brain tumors]. / Une consultation multidisciplinaire pour les enfants traités pour une tumeur cérébrale.

UNLABELLED: School achievement of children with brain tumors is hampered by progressive neurologic and cognitive sequelae. To help the children and their family, we have created in 1997 a multidisciplinary consultation together with Necker's hospital. MATERIAL AND METHODS: The study describes the organization of the consultation and analyses the files of 69 children seen between September 2001 and June 2002. RESULTS AND CONCLUSION: The authors conclude that this consultation is an irreplaceable mean to coordinate the complex rehabilitation process of a child treated for a brain tumor.

Late outcome of the surgical treatment of hydrocephalus.

The purpose of this report is to analyze the long-term outcome in hydrocephalic children treated by shunt placement and in particular their psycho-intellectual development. In the case of shunt placement postoperative mortality is virtually nil, and the overall mortality rate after 10 years of follow-up has been reduced to less than 5%. Morbidity, in contrast, is far from satisfactory. This study was conducted in 129 consecutive children with nontumorous hydrocephalus who underwent a first shunt insertion before the age of 2 years between 1979 and 1982 and who were followed up for at least 10 years. The final neurological examination revealed a motor deficit in 60%, visual or auditory deficits in 25%, and epilepsy in 30%. The final IQs were above 90 in 32% of the children, between 70 and 90 in 28%, between 50 and 70 in 19%, and lower than 50 in 21%. Integration into the normal school system was possible for 60% of the children, but half of them were 1-2 years behind their age group or having difficulties; 31% were attending special classes or were in institutions; and 9% were considered ineducable. The presence of behavioral disorders was a determinant factor for scholastic and social integration. Such disorders were frequent, and were characterized as severe in 30%. A relationship between final outcome and etiology, initial ventricular size, and epilepsy was observed. These results are used as the basis of a discussion on how morbidity might be improved.

Intellectual outcome in children with malignant tumors of the posterior fossa: influence of the field of irradiation and quality of surgery.

The purpose of this study was to determine the respective parts played by cerebral hemisphere irradiation, posterior fossa irradiation, and surgery in the poor late functional results often observed in children treated for medulloblastoma. To do this we compared the intellectual outcome in a series of 59 children operated on for medulloblastoma, who had received whole-brain irradiation, to that observed in a series of 37 children operated on for ependymoma of the posterior fossa, who had received radiotherapy only on the posterior fossa. Only patients who had survived for more than 2 years without recurrence were included. At the assessment 1 year after treatment, intellectual outcome was somewhat better in the ependymoma group, but the difference was not statistically significant. At the long-term follow-ups at 5 and 10 years the results remained stable in the children treated for ependymoma, around 60% having an IQ above 90, whereas the intellectual level of the children treated for medulloblastoma was seen to have deteriorated progressively: 20% had an IQ above 90 5 years after treatment and only 10% at the 10-year follow-up. This progressive degradation is most likely due to the irradiation of the cerebral hemispheres, as this prophylactic irradiation constituted the only difference between the two groups. Moreover, irradiation to the posterior fossa did not seem to affect intellectual functions, since in the group of children with ependymomas the proportion of IQs above 90 was high and remained stable over the years. Surgery was certainly responsible for some poor results. The percentage of IQs above 90 observed 1-2 years after treatment was between 70 and 80 when no postoperative complications occurred, and only between 20-40% in the presence of postoperative complications. Postoperative aggravation was in most cases related to a brain-stem lesion. These results encourage the reduction, when possible, of irradiation to the cerebral hemispheres and underline the importance of the quality of surgery.