Article
The role of tractography in the assessment of motor dysfunction in central glioma surgery
Die Rolle der Traktographie in Einschätzung der motorischen Dysfunktion in Chirurgie zentraler Gliomen
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Authors
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Y. Parpaley
- Neurochirurgische Klinik, Universität Bonn, Deutschland
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G. Neuloh
- Neurochirurgische Klinik, Universität Bonn, Deutschland
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M. Nelles
- Abteilung für Radiologie, Universität Bonn, Deutschland
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H. Urbach
- Abteilung für Radiologie, Universität Bonn, Deutschland
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J. Schramm
- Neurochirurgische Klinik, Universität Bonn, Deutschland
| Published: | May 30, 2008 |
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Outline
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Objective: The compromise between (sub)total resection versus prevention of functional deficit during glioma surgery is a topic of discussion over decades. One modern aspect of minimizing functional deficits is the use of motor pathway tractography in preoperative planning and intraoperative image guidance.
Methods: In our prospective study, we evaluated 15 cases with central gliomas. We reconstructed tumor volume on the preoperative MRI and resection volume on fusioned post-op MRI scans, measured distances from the corticospinal tract to the edge of the resection volume and evaluated postoperative motor deficit. MRI (T1 with gadolinium, T2, Flair) imaging including DTI (15 directions) was performed on a 3T MR scanner before operation and up to 72 hours after operation. Only patients with intact preoperative motor function were included. The protocol for defining the corticospinal tracts included separate VOI definition in the motor cortex for the upper and lower extremity, antegrade fiber tracking with retention of fibers reaching the medulla oblongata. Both tracts for upper and lower extremity were combined. In cases with distorted motor cortex, the anatomy retrograde tracking was used.
Results: In most of the cases, we achieved a plausible visualization of the central motor pathway with very low variation. Tissue edema was a serious problem for tractography in higher grade tumors. We have found a correlation between the occurrence of motor deficit, periresectional edema and the distance between resection volume and the corticospinal tract.
Conclusions: Tractography of the central motor pathways is a reliable method of structural imaging which can be standardised. It helps to understand the mechanisms of new postoperative deficit. A reliable presentation of the proximal corticospinal tract in cases with a strong distortion of the motor cortex is difficult, and depends on the skills and experience of the researcher. Preoperative planning and image guidance may help to prevent postoperative motor deficit.
