Differential prefrontal-like deficit in children after cerebellar astrocytoma and medulloblastoma tumor

Abstract

BackgroundThis study was realized thanks to the collaboration of children and adolescents who had been resected from cerebellar tumors. The medulloblastoma group (CE+, n = 7) in addition to surgery received radiation and chemotherapy. The astrocytoma group (CE, n = 13) did not receive additional treatments. Each clinical group was compared in their executive functioning with a paired control group (n = 12). The performances of the clinical groups with respect to controls were compared considering the tumor's localization (vermis or hemisphere) and the affectation (or not) of the dentate nucleus. Executive variables were correlated with the age at surgery, the time between surgery-evaluation and the resected volume.MethodsThe executive functioning was assessed by means of WCST, Complex Rey Figure, Controlled Oral Word Association Test (letter and animal categories), Digits span (WISC-R verbal scale) and Stroop test. These tests are very sensitive to dorsolateral PFC and/or to medial frontal cortex functions. The scores for the non-verbal Raven IQ were also obtained. Direct scores were corrected by age and transformed in standard scores using normative data. The neuropsychological evaluation was made at 3.25 (SD = 2.74) years from surgery in CE group and at 6.47 (SD = 2.77) in CE+ group.ResultsThe Medulloblastoma group showed severe executive deficit (≤ 1.5 SD below normal mean) in all assessed tests, the most severe occurring in vermal patients. The Astrocytoma group also showed executive deficits in digits span, semantic fluency (animal category) and moderate to slight deficit in Stroop (word and colour) tests. In the astrocytoma group, the tumor's localization and dentate affectation showed different profile and level of impairment: moderate to slight for vermal and hemispheric patients respectively. The resected volume, age at surgery and the time between surgery-evaluation correlated with some neuropsychological executive variables.ConclusionResults suggest a differential prefrontal-like deficit due to cerebellar lesions and/or cerebellar-frontal diaschisis, as indicate the results in astrocytoma group (without treatments), that also can be generated and/or increased by treatments in the medulloblastoma group. The need for differential rehabilitation strategies for specific clinical groups is remarked. The results are also discussed in the context of the Cerebellar Cognitive Affective Syndrome.

Differences in Supratentorial Damage of White Matter in Pediatric Survivors of Posterior Fossa Tumors With and Without Adjuvant Treatment as Detected by Magnetic Resonance Diffusion Tensor Imaging

“…Another striking result was that these supratentorial fibers with decreased FA in PA patients were not significantly different when compared with those of MB patients. This is in line with findings on cognitive deficits comparing both patient groups that have identified similar patterns in function loss (6)(7)(8)(9).…”

“…The cerebellar parts of these circuits may be damaged by the tumor and by surgery, possibly leading to a supratentorial axonal degeneration and thereby to a decrease of FA, especially in the frontal and parietal white matter (Fig. 2, slices [6][7][8][9][10][11][12][13][14][15][16][17][18][19]. This process might possibly be similar to the pathomechanism that underlies the finding of a synapses-mediated axonal atrophy in newborn infants with cerebellar hemorrhage leading to a loss of volume and function of the contralateral supratentorial counterpart (27).…”

“…However, the significance of the various specific neurotoxic effects in posterior fossa tumor patients is poorly understood. Therefore, newer studies aimed at analyzing the different contributions to neurotoxicity, such as impact of the tumor proper, internal pressure increase by hydrocephalus, the surgical intervention, and adjuvant treatment (6)(7)(8)(9). Tools to assess and monitor the neurotoxic effects will be of great value in tailoring therapy individually and in rehabilitation to improve long-term outcome.…”

Late neurocognitive effects in children and adolescents who have undercone oncological treatment: a rehabilitation model

“…Five-year survival rate is 93% in the case of posterior fossa tumours [6] , Wilms' tumours [7] and Hodgkin's lymphoma [7] , and 65% in the case of medulloblastomas [9] , while it is only 10% in intrinsic brainstem gliomas [9] . However, although these data show that oncological treatments may fortunately cure children and adolescents, we must remember that they do not assure the complete absence of negative effects, including the so called "late effects".…”

Treatment Related Cognitive Impairment in Pediatric Oncology Patients: A Brazilian Experience

“…Among the most common types of tumours are medulloblastomas, malignant primitive neuroectodermal tumour, and low-grade gliomas, among which stand out the pilocytic astrocytomas, benign neuroepithelial-originated tumours [7,8].…”