Injuries to Inferior Vermis and Dentate Nuclei Predict Poor Neurological and Neuropsychological Outcome in Children With Malignant Posterior Fossa Tumors

Department of Neurosurgery, Necker-Enfants Malades Hospital, Paris, France.
Cancer (Impact Factor: 4.89). 03/2009; 115(6):1338-47. DOI: 10.1002/cncr.24150
Source: PubMed

ABSTRACT

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.
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).
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).
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.

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Available from: Christine Bulteau, Oct 13, 2014
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    • "Timing impairment performance as a function of the localization of lesions in the cerebellum As the children with cerebellar lesions showed impaired timing in the production of motor rhythm in the synchronization task, we examined the differences in the synchronization behaviors in the medulloblastoma group as a function of anatomical structures that had been damaged by the tumor or/and its surgery. Following the classification by Puget et al. (2009), four anatomical scores of cerebellar damage were defined based on magnetic resonance imaging (MRI): (1) vermis, (2) dental nuclei, (3) hemisphere, and (4) a total score for the extent of the cerebellar damage (see Table 1 from Droit-Volet et al., 2013). Table 2 shows the correlation between these different scores and the timing measures for which a significant group effect was found. "
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    ABSTRACT: The aim of this study was to investigate the temporal abilities of children treated by surgery for a malignant tumor in the cerebellum, both in the perception and the production of rhythm. Children with a diagnosed medulloblastoma and age-matched control children were tested in a rhythm discrimination task and a sensorimotor synchronization task. Their motor and cognitive capabilities were also assessed through a battery of age-adapted neuropsychological tests. The results did not show any significant difference in performance between groups for the discrimination task. On the contrary, children with cerebellar lesions produced longer and more variable inter-tap intervals (ITI) in their spontaneous motor tempo (SMT) than did the control children. However, the length and, to a lesser extent, the variability of their SMT decreased after a synchronization phase, when they had been instructed to tap in synchrony with a beep. During the synchronization task, the children with medulloblastoma succeeded to modify the length of their ITI in response to an auditory rhythm, although with better success when the inter-stimuli intervals (ISI) were shorter than when they were longer than the ITIs of their own SMT. Correlational analyses revealed that children's poorer synchronization performance was related to lower scores in neuropsychological tests assessing motor dexterity and processing speed.
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    • "Timing impairment performance as a function of the localization of lesions in the cerebellum As the children with cerebellar lesions showed impaired timing in the production of motor rhythm in the synchronization task, we examined the differences in the synchronization behaviors in the medulloblastoma group as a function of anatomical structures that had been damaged by the tumor or/and its surgery. Following the classification by Puget et al. (2009), four anatomical scores of cerebellar damage were defined based on magnetic resonance imaging (MRI): (1) vermis, (2) dental nuclei, (3) hemisphere, and (4) a total score for the extent of the cerebellar damage (see Table 1 from Droit-Volet et al., 2013). Table 2 shows the correlation between these different scores and the timing measures for which a significant group effect was found. "
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