Article
Morphological findings after surgical treatment for medulloblastoma in children: tumor recurrence or neurogenic degeneration?
Morphologische Veränderungen nach Medulloblastomoperation bei Kindern: Tumorrezidiv oder neurogene Degeneration?
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Published: | May 4, 2005 |
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Outline
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Objective
Changes in the dento-rubo-olivary pathway detected via magnetic resonance imaging (MRI) have been described in adult patients after intracerebral haemorrhage, infarction, trauma and tumor. Only rare data exist about MRI findings in this pathway in children.
Methods
MR images of 12 children (mean age: 9,1 years; range: 4-16 years) before and after surgical treatment for medulloblastoma were reviewed retrospectively. MR imaging consisted of axial and coronar T1-, axial proton density- and T2-weighted turbospin-echo sequences, using a 1,5 T magnetic resonance scanner. MR imaging was performed preoperatively and 1 week, 3 months, 6, 12, 18, 24, 30, 36 and 48 months after craniotomy.
Results
Preoperative MR imaging showed normal configuration of the inferior olivary nuclei (ION), dentate nuclei (DN) and red nuclei. After surgical treatment, all 12 children showed MR changes in the dento-rubo-olivary pathway. Hyperintense areas in ION became detectable 3 months after operation and mostly disappeared until 24 months after ictus. Hypertrophic ION were observed at least 6 months after operation and were not found to vanish within 48 months. Hyperintensity of DN was found 6 months after ictus and disappeared 24 month after operation. In 5 out of 8 children with postoperative lesion affecting both DN, bilateral ION were hyperintense on T2-, proton density- and partly on T1-weighted images without enlargement. 3 out of these 8 patients showed hypertrophic degeneration with enlargement of the bilateral ION in addition to bilateral hyperintensity. In 2 out of the remaining 3 children with affection of the left DN and left superior cerebellar peduncle (SCP), hypertrophic degeneration of the right ION was seen. In one out of these 3 children bilateral degeneration of ION and hyperintensity of the right DN occurred. In one child with affection of the right DN and right SCP, the left ION was found hypertrophic.
Conclusions
MRI findings in children with Medulloblastoma suggest surgical treatment to be a frequent cause for degeneration in the dento-rubo-olivary pathway, manifesting as hypertrophic olivary degeneration and signal alteration in the DN. Occurring either uni- or bilaterally, they show high variability in their radiological appearance and therefore tend to be mistaken for neoplastic, ischaemic or other pathological conditions.