Virginie Kieffer

OBJECT: Intellectual impairment is a major concern after treatment of malignant posterior fossa tumors in children. The effects of age at diagnosis and radiotherapy have been widely documented. Little is known, however, about perioperative factors, especially neurological damage to the cerebellum, the role of which in cognition and learning has been recently indicated. The authors studied the effects in 76 children treated for a malignant posterior fossa tumor in a cross-sectional study. METHODS: Two thirds of the tumors were medulloblastoma. Neuropsychological evaluation was performed at least 6 months after the end of treatment, and findings were correlated with clinical risk factors for intellectual impairment. The mean verbal intelligence quotient (VIQ) score was 87 +/- 19 (+/- standard deviation) and the mean performance IQ (PIQ) score was 76 +/- 17.5. A single neuropsychological test measuring hand skills (the Purdue Pegboard) was the strongest predictor of low IQ scores including items testing higher cognitive functions. A low VIQ was associated with impaired hand skills (p < 0.0001) and the presence of preoperative hydrocephalus (p = 0.02), whereas a low PIQ was associated with impaired hand skills (p < 0.0001) and incision of the vermis (p = 0.02). Impaired hand skills were associated with postoperative cerebellar mutism, oculomotor deficits, cerebellar syndrome, and therapeutic requirements. CONCLUSIONS: When treatment schedules are adapted to risk of disease and age, surgery-related risk factors then become critical for predicting intellectual impairment. Children with cerebellar damage are particularly at risk for long-term neuropsychological dysfunction and require active rehabilitation measures. Reducing surgery-related morbidity should be the next goal to reduce posterior fossa surgery-specific deficits.

Two-hundred and fifty-one children (98 girls and 153 boys, aged from 3 to 17 years) with documented diagnosis of epileptic syndrome, IQ measurement, and information on school placement were included in this retrospective study. The relations between these three parameters as well as effects of age at onset and duration of epilepsy, seizure frequency, and number of antiepileptic drugs (AEDs) were analysed. Both IQ and schooling were univariately related to epileptic syndrome, age at onset and duration of epilepsy, and number of AEDs; seizure frequency was related to IQ but not to school placement. Multiple regression showed that IQ was independently related to epileptic syndrome and AED; multiple logistic regression showed that type of school (mainstream versus adapted or special) was independently related to IQ and AED. Children with idiopathic generalised or with localisation-related epilepsy had higher IQ scores and higher probability of mainstream schooling than those with symptomatic or cryptogenic generalised epilepsies or epileptic syndromes which were undetermined. Subtests profile of intelligence scale in localisation-related epilepsies showed different specific cognitive deficits, according to the location of the epileptic focus.

BACKGROUND: Children treated for a malignant posterior fossa tumor (PFT) are at risk of intellectual impairment. Its severity is not explained by age and radiotherapy alone. The current study was designed to define the correlations between the anatomical damage and the neurological/neuropsychological deficits in children with a malignant PFT. METHODS: Sixty-one consecutive children (mean age, 6.0 years) treated for a malignant PFT with surgery, chemotherapy, and radiotherapy underwent a detailed neuropsychological evaluation, including a full-scale intelligence quotient (FSIQ), on average 5.6 years after the diagnosis. The neurological examination was recorded 1 month after surgery and at the time of the neuropsychological evaluation. Cerebellar and brain injuries were scored based on the magnetic resonance imaging (MRI). Correlation of these injuries with neurological and cognitive outcome were performed after adjustment for other potential risk factors (radiotherapy schedule, age, hydrocephalus, duration of symptoms, socioeconomic status, and surgical complications). RESULTS: Neurological deficits were strong predictors of low cognitive performances irrespective of the other risk factors. The extent of cerebellar deficits and fine motor dexterity impairment were correlated with the degree of damage to the dentate nuclei and inferior vermis. The IQ scores were inversely correlated with the severity of the damage to the dentate nuclei; mean FSIQ was 83 if they were both intact and 65 in the case of bilateral damage (P=.009). CONCLUSIONS: Damage to the dentate nuclei and to the inferior vermis, observed on MRI, predict the degree of impairment of neurological and neuropsychological functions in children treated for a malignant PFT.

BACKGROUND: Corpus callosum agenesis (CCA) is generally diagnosed in utero. Outcome appears to be better if the malformation is isolated. The aim of this study, which is the first one with a long (10 years) and standardized follow up, was to report cognitive abilities of children with isolated CCA diagnosed prenatally. METHODS: We prospectively evaluated 17 children. Clinical examinations, neuropsychological tests were performed each year. School achievement and personal and familial data were collected. RESULTS: Twelve children completed the entire follow up. One child was finally considered to have associated CCA, because signs of fetal alcohol syndrome had become obvious. Of the 11 other children, three (27%) had borderline intelligence whereas the intelligence levels of eight (73%) were in the normal range, although half of these children experienced some difficulties in scholastic achievement. Neither epilepsy nor intellectual deficiency was noted and intellectual quotient scores correlated strongly with the mother's education level. CONCLUSION: Although prenatal diagnosis of isolated CCA is reliable, false postnatal diagnoses remain possible (10-20%) even with complete prenatal screening. Outcome is mostly favorable because intelligence is within the normal range for nearly 3/4 of the children. However, they frequently have mild learning difficulties.