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

Classification of neurovascular compression in hemifacial spasm by 3D visualization

Klassifizierung der neurovaskulären Kompression in Spasmus hemifazialis durch 3D Visualisierung

Meeting Abstract

  • corresponding author R. Naraghi - Klinik für Neurochirurgie, Universitätsklinikum Erlangen
  • L. Tanrikulu - Klinik für Neurochirurgie, Universitätsklinikum Erlangen
  • A. Doerfler - Abteilung für Neuroradiologie, Universitätsklinikum Erlangen
  • A. Bischoff - Klinik für Neurochirurgie, Universitätsklinikum Erlangen
  • M. Buchfelder - Klinik für Neurochirurgie, Universitätsklinikum Erlangen
  • P. Hastreiter - Klinik für Neurochirurgie, Universitätsklinikum Erlangen

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.08.04

The electronic version of this article is the complete one and can be found online at:

Published: May 30, 2008

© 2008 Naraghi et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.



Objective: 3D-visualization depicts the global overview of the neurovascular relationships at the brainstem in syndromes caused by neurovascular compression (NVC) such as hemifacial spasm (HFS). A standardised, reproducible assessment and classification of the findings does not exist till now. This study analyses and classifies the results of 3D visualization of the neurovascular relationships in HFS in respect to clinical and surgical relevance.

Methods: 25 patients (13 male and 12 female) with typical HFS were studied by image processing and 3D visualization based on high resolution MRI. The facial and vestibulocochlear nerves were analysed on the affected and unaffected sides referring to their root exit zone (REZ), proximal and distal segments including the corresponding blood vessels. The 3D-visualizations were interactively compared with the intraoperative situation in order to verify the results and to define characteristics for a standardized and reproducible assessment with surgical relevance. An anatomical classification is developed based on the results of 3D-visualization.

Results: The applied method of image processing displayed an anatomical separation between the facial and vestibulocochlear nerves on the affected side in 22 cases, and on the unaffected side in 23 cases. We identified three distinct types of NVC within the REZ of the N.VII at the affected sides. The AICA was the most common cause of NVC (15 cases), identified as type 1. The PICA (7 cases) as type 2 and the vertebral artery (3 cases) as type 3 are the other types of NVC. The internal auditory artery and veins also cause vascular contacts to the REZ of N.VII. We found a distinct difference in the surgical technique for each of the types of NVC. Type 3 presents the most difficult grade for surgery. We analyzed the variable courses of the vessels on the unaffected sides. There were no bilateral clinical symptoms of HFS and no bilateral vascular compression of the REZ of N.VII. We found the AICA to be the most common vessel interfering with the proximal (7 times) and distal (9 times) facial nerve portions without any vascular contact of the REZ of N.VII on the unaffected sides. 20 of 25 patients underwent MVD (80%) with complete relief of spasm in all cases.

Conclusions: 3D-visualization offers the opportunity for non-invasive exploration and anatomical categorization of the facial-vestibulocochlear-nerve complex. It is advantageous in establishing the diagnosis. The presented classification has an impact on the surgical technique for decompression, in each case with favourable results.