Minimizing Brain Shift during Functional Neurosurgical Procedures – A Simple Burr Hole Technique that can Decrease CSF Loss and Intracranial Air

Abstract

Background: Exact stereotactic placement of deep brain stimulation electrodes during functional stereotactic neurosurgical procedures can be impeded by intraoperative brain shift. Brain shift has been shown to correlate with the amount of intracranial (subdural) air detected on early postoperative imaging studies. We report a simple burr hole technique that reduces the loss of cerebrospinal fluid (CSF) and has the potential to significantly reduce the amount of postoperative intracranial air.

Material and Methods: A total of 16 patients were studied with half (group 2) receiving the burr hole technique designed to seal the CSF space and thereby reducing CSF loss. The other 8 patients (group 1) received the standard burr hole technique. The 2 groups were of similar age, gender, diagnosis (Parkinson's disease, n=14; cervical dystonia n=2), and surgical targets. All patients received bilateral electrodes either in the subthalamic nucleus (STN, n=14) or in the globus pallidum internus (GPi, n=2) avoiding transventricular trajectories. Early postoperative 3-dimensional computed tomography (3D CT) was used to check for possible bleeding, DBS lead location, and the amount of intracranial air. Intracranial air was assessed manually in a volumetric slice-by-slice approach in the individual postoperative CT and the groups compared by t-test.

Results: Group 2 showed significantly lower postoperative intracranial air volumes (4.86 ± 4.35cc) as compared to group 1 (27.59 ± 17.80 cc, p=0.0083*). The duration of surgery, however, was significantly longer for group 1 (435 ± 56.05 min) as compared to group 2 (316 ± 34.79 min,p=0.00015*).The time span between the conclusion of the operation and postoperative 3DCT was similar for both groups.

Conclusion: This new and simple burr hole technique was associated with a significant reduction in postoperative intracranial air. Reduction of intracranial air will ultimately reduce brain shift. That total operation time does not influence intracranial air is discussed as well as the limitations of this pilot series. In the authors’ opinion, this straightforward and cost-effective technique has the potential to reduce brain shift and to increase DBS placement accuracy during functional stereotactic neurosurgical procedures performed in the seated or half-sitting position. A larger more standardized patient series is necessary to substantiate the findings.

Key words

brain shift - burr hole - deep brain stimulation - functional Neurosurgery - pneumocephalus

References

• 1 Benabid AL, Pollak P, Koudsie A. et al .Electrical inhibition of the subthalamic nucleus for treatment of Parkinson's disease.. In: Krauss JK, Jankovic J (eds) Surgery for Parkinson's disease and movement disorders Lippincott Williams and Wilkins: USA; 2001: 176-187
• 2 Coenen VA, Krings T, Weidemann J. et al . Sequential visualization of brain and fiber tract deformation during intracranial surgery with three-dimensional ultrasound – an approach to evaluate the effect of brain shift.  Neurosurgery. 2005;  56 (1 Suppl) 133-141
• 3 Elias WJ, Fu KM, Frysinger RC. Cortical and subcortical brain shift during stereotactic procedures.  J Neurosurg. 2007;  107 983-988
• 4 Gerdes FU, Klein G, Nadjmi M. et al . X-ray studies of the brain as a basis of stereotaxy (author's transl).  J Neurol. 1975;  210 183-190
• 5 Halpern CH, Danish SF, Baltuch GH. et al . Brain shift during deep brain stimulation surgery for Parkinson's disease.  Stereotact Funct Neurosurg. 2008;  86 37-43
• 6 Hariz MI, Bergenheim AT. A comparative study in ventriculographic and computerized tomography-guided determinations of brain targets in functional stereotaxis.  J Neurosurg. 1990;  73 565-571
• 7 Hariz MI, Bergenheim AT, Fodstad H. Air-ventriculography provokes an anterior displacement of the third ventricle during functional stereotactic procedures.  Acta Neurochirurgica (Wien). 1993;  123 147-152
• 8 Kassam A, Horowitz M, Carrau R. et al . Use of Tisseel fibrin sealant in neurosurgical procedures – incidence of cerebrospinal fluid leaks and cost-benefit analysis in a retrospective study.  Neurosurgery. 2003;  52 1102-1105
• 9 Khan MF, Mewes K, Gross RE. et al . Assessment of brain shift related to deep brain stimulation surgery.  Stereotact Funct Neurosurg. 2008;  86 44-53
• 10 Martin AJ, Larson PS, Ostrem JL. et al . Placement of deep brain stimulator electrodes using real-time high-field interventional magnetic resonance imaging.  Magn Reson Medicine. 2005;  54 1107-1114
• 11 Miyagi Y, Shima F, Sasaki T. Brain shift – an error factor during implantation of deep brain stimulation electrodes.  J Neurosurg. 2007;  107 989-997
• 12 Nabavi A, Black PM, Gering DT. et al . Serial intraoperative magnetic resonance imaging of brain shift.  Neurosurgery. 2001;  48 787-797
• 13 Nimsky C, Ganslandt O, Cerny S. et al . Quantification of, visualization of, and compensation for brain shift using intraoperative magnetic resonance imaging.  Neurosurgery. 2000;  47 1070-1079
• 14 Rasmussen IA, Lindseth F, Rygh OM. et al . Functional neuronavigation with intra-operative 3D ultrasound: initial experiences during surgical resections close to eloquent brain areas and future directions in automatic brain shift compansation of preoperative data.  Acta Neurochirurgica. 2007;  149 365-378
• 15 Suess O, Kombos T, Ciklatekerlio O. et al . Impact of brain shift on intraoperative neurophysiological monitoring with cortical strip electrodes.  Acta Neurochirurgica. 2002;  144 1279-1289
• 16 Winkler D, Tittgemeyer M, Schwarz J. et al . The first evaluation of brain shift during functional neurosurgery by deformation field analysis.  J Neurol Neurosurg Psychiatr. 2005;  76 1161-1163

Correspondence