gms | German Medical Science

59th Annual Meeting of the German Society of Neurosurgery (DGNC)
3rd Joint Meeting with the Italian Neurosurgical Society (SINch)

German Society of Neurosurgery (DGNC)

1 - 4 June 2008, Würzburg

Dynamic magnetic resonance imaging in the postoperative assessment of patients with Chiari I malformation

Dynamische MRT-Untersuchungen zur postoperativen Verlaufskontrolle nach Operation bei Chiari-I-Malformation

Meeting Abstract

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  • corresponding author U.M. Mauer - Abteilung Neurochirurgie, Bundeswehrkrankenhaus Ulm, Ulm
  • C. Müller - Abteilung Neurochirurgie, Bundeswehrkrankenhaus Ulm, Ulm
  • L. Weselak - Abteilung Neurochirurgie, Bundeswehrkrankenhaus Ulm, Ulm
  • U. Kunz - Abteilung Neurochirurgie, Bundeswehrkrankenhaus Ulm, Ulm

Deutsche Gesellschaft für Neurochirurgie. Società Italiana di Neurochirurgia. 59. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e.V. (DGNC), 3. Joint Meeting mit der Italienischen Gesellschaft für Neurochirurgie (SINch). Würzburg, 01.-04.06.2008. Düsseldorf: German Medical Science GMS Publishing House; 2008. DocMI.04.03

The electronic version of this article is the complete one and can be found online at: http://www.egms.de/en/meetings/dgnc2008/08dgnc229.shtml

Published: May 30, 2008

© 2008 Mauer et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.en). You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.


Outline

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Objective: The objective of surgery for Chiari I malformation is to restore normal cerebrospinal fluid (CSF) flow in the region of the foramen magnum. CSF flow can be visualised using dynamic phase-contrast magnetic resonance imaging (MRI).

Methods: Dynamic phase-contrast MRI was used to investigate the entire central nervous system in 22 patients with Chiari I malformation before surgery and after a mean postoperative period of 12 months (median postoperative period: 12 months; range: 3-33 months). In addition, we measured absolute flow velocities, the extension of the syrinx and tonsillar descent.

Results: In the 22 patients, the mean distance from the cerebellar tonsils to the level of C2 was 1.7 cm before surgery (median distance: 2.0 cm; range: -0.4 to 3.2 cm) and 2.4 cm after surgery (median distance: 2.4 cm; range: 0.7 to 4.0 cm). Mean postoperative tonsillar ascent was thus 0.7 cm (median ascent: 0.7 cm; range: -0.1 to 2.0 cm). This difference is highly significant (p<0.00005). The mean anterior-posterior (AP) diameter ratio decreased from 0.67 (median ratio: 0.69; range: 0.17-1) to 0.2 (median ratio: 0.17; range: 0-0.57). The mean decrease was thus 0.47 (median decrease: 0.46; range: 0-0.92) and highly significant (p<0.00005). The change in pulsation was highly significant in the region of the (enlarged) cistern (p=0.0005). In addition, the maximum and minimum velocities (= pulsation amplitude) considerably increased in the region where the syrinx was largest in diameter. It was interesting to note that the change of pulsation in these patients was significant in the subarachnoid space at all spinal segments but not in the syrinx itself and in the central canal. In 2 cases, there was no postoperative improvement in pulsation in the new cistern. Since the clinical course, too, was unsatisfactory, these patients underwent a second surgerical procedure.

Conclusions: The demonstration of CSF flow pulsations is a useful tool for assessing postoperative outcome in patients with Chiari I malformation. In addition, the results presented here question current theories on the pathogenesis of syringomyelia.