Jahrestagung der Sektion Stereotaxie und Radiochirurgie der DGNC

15. – 16.01.2010 Magdeburg

Jahrestagung der Sektion Stereotaxie und Radiochirurgie der DGNC, 15. – 16.01.2010 Programm Tagungsort: InterCityHotel Magdeburg, Bahnhofstraße 69, 39104 Magdeburg

Freitag, 15.01.2010 14:00 - 14:10 Begrüßung

Voges J

Epilepsie 14:10 - 14:30 Tiermodelle Epilepsie

Vorsitz: Winkler P Holtkamp M

14:30 - 14:50 Neurologische Diagnostik

Schmitt FC

14:50 - 15:05 Invasive Diagnostik

Trippel M et al.

15:05 - 15:20 Erste Erfahrungen mit der Implementierung von Fibertracking in die navigationsgesteuerte Fokusresektion bei pharmakoresistenten Epilepsien

Winkler P et al.

15:20 - 15:35 Der Einsatz der Neuronavigation zur Amygdalohippokampektomie

Glaser MB

15:35 - 15:50 Vagusnervstimulation

Büntjen L, Voges J

15:50 - 16:05 Thermoablation - Therapieoption für einen kleinen, umschriebenen Anfallsfokus?

Voges J, Schmitt FC

16:05 - 16:30 PAUSE Funktionelle Stereotaxie Vorsitz: Krauss J 16:30 - 16:50 Tiefe Hirnstimulation zur Behandlung von Kamptokormie bei Galazky I et al. M. Parkinson 16:50 - 17:05 Deep Brain Stimulation for camptocormia in dystonia and Parkinson's disease

Capelle HH et al.

17:05 - 17:20 Pallidal Deep Brain stimulation (DBS) in Chorea Huntington

Meinhard D et al.

17:20 - 17:35 Chronic deep brain stimulation in patients with tardive dystonia without a history of major psychosis

Capelle HH et al.

17:35 - 17:50 Pallidal deep brain stimulation may induce freezing of gate in patients with focal and segmental dystonia

Schrader C et al.

17:50 - 18:05 C-fos expression after deep brain stimulation of the pedunculopontine tegmental nucleus in the rat 6-hydroxydopamine Parkinson mode

Saryyeva A et al.

18:05 - 18:20 Chronic Motor Cortex Stimulation and predictive value of rTMS

Vesper J, Wille C

18:30 ABFAHT ABENDESSEN

Samstag, 16.01.2010 Funktionelle Stereotaxie 08:30 - 08:55 10 Jahre Tiefe Hirnstimulation zur Behandlung bei neuropsychiatrischen Erkrankungen

Vorsitz: Nikkhah G Lenartz D et al.

08:55 - 09:15 THS im N. acc. zur Behandlung der schweren Alkoholabhängigkeit

Voges J et al.

09:15 - 09:30 Tiefe Hirnstimulation bei therapie-resistenter Zwangserkrankung: Fallbericht und Diskussion der aktuellen Literatur

Pinsker MO et al.

09:30 - 09:45 The medial forebrain bundle (MFB) in humans – an Coenen VA et al. understudied structure investigated with diffusion tensor imaging 09:45 - 10:00 Digitale OP Unterstützung für funktionell stereotaktische Hertel F et al. Operationen (FDSS Projekt) 10:00 - 10:15 The accurate depiction of the pyramidal tract (PT) with Coenen VA et al. Diffusion tensor imaging fibre tracking (DTI FT) is verified by in vivo electrophysiology 10:15 - 10:35 PAUSE Radiochirurgie und Freie Themen Vorsitz: Wowra B 10:35 - 10:55 Möglichkeiten der Radiochirurgie bei der neurochirurgischen Wowra B Therapie von Tumoren bei Neurofibromatose 10:55 - 11:10 Interdisziplinäres Rezidiv-Management bei aggressiv wachsenden Meningiomen

Hamm K et al.

11:10 - 11:25 Intrakranielles Plasmazellgranulom der Dura – InterdisziHamm K et al. plinäre Therapiestrategie mit stereotaktischer Radiotherapie 11 :25 - 11:40 Bild- und Roboter-geführte Radiochirurgie benigner spinaler Tumore

Kufeld M et al.

11:40 - 11:55 A Comparison of Stereotactic 125Iodine Brachytherapy with Stereotactic Radiosurgery (LINAC) for the Treatment of Singular Cerebral Metastases

Ruge MI et al.

11:55 - 12:10 Stereotactic 125Iodine Brachytherapy for the Treatment of Singular Cerebral Metastases. Closing the Gap?

Ruge MI et al.

12:10 - 12:25 Brachytherapie als Teil eines Therapiekonzeptes zur Behandlung rezidivierender niedergradiger Gliome

Voges J et al.

12:25 - 12:40 Wert der stereotaktischen Serienbiopsie in der Diagnostik und Therapie von Hirnstammgliomen im Erwachsenenalter

ReithmeierT et al.

12:40 - 12:55 Prädiktiver Wert und Korrelation zwischen intraoperativer Blutung und postoperativem CCT Befund

Eibach S et al.

12:55

Wahl des nächsten Tagungsortes, Verabschiedung

Voges J

Gegen 13:15

Buffet und Ende der Veranstaltung

Stereotactic implantation of depth electrodes in epileptology Trippel M. 1, Hefft S.2, Cordeiro J.1, Reithmeier T.1, Pinsker M.1, Schulze-Bonhage A.2, Nikkhah G.1 Stereotaktische Neurochirurgie1 und Abteilung Epileptologie2, Universitätsklinikum Freiburg, Breisacher Straße 64, 79106 Freiburg

Neurozentrum,

Since 2000, we implanted 480 depth electrodes in 152 patients suffering from pharmacologically intractable seizures for diagnostic purposes. Most of these patients were implanted in the mesiotemporal lobes by a temporo-lateral (45 patients) or posterior-occipital (79) approach, or by a combination of both (12) in order to determine the side and precise location of the primary epileptogenic focus. 36 patients received extratemporal electrodes (mean of 1 to 2 electrodes per patient), while 20 of these patients in combination with the temporal implantations. In another group of patients (14) we used up to fifteen (mean 9 -10) cortically implanted electrodes in a wide variety of locations in order to register a stereo-EEG. This technique allows to record from infolded cortical structures such as the insula and the cingular gyrus. Furthermore we implanted twelve patients with a variable number of additional microwire bundles in combination with standard macroelectrodes. These microwire bundles, consisting of 8 individually isolated 40 µm thick wires and one reference wire, were used to record unit activity of single nerve cells as well as local field potential oscillations. Special tools were designed in cooperation with industrial partners in order to optimize this stereotactic procedure. The purpose of this technique is both clinical as well as cognitive state of the art research. Apart from these diagnostic procedures, four patients with progressive myoclonic epilepsy received a total of 14 deep brain stimulation electrodes in the substantia nigra pars reticulata (SNR), subthalamic nucleus (STN) and ventral intermediate nucleus (VIM) of the thalamus in order to control debilitating myoclonus. For all implantations, diagnostic and therapeutic, we recognized only two minor adverse events without any impact on the clinical condition of these two patients: one intracerebral bleeding along one of the macroelectrode tracts in the first, and one small sized subdural hematoma in a second patient. In conclusion, stereotactic implantation of depth electrodes for the purpose of invasive epilepsy diagnostics is a very safe neurosurgical procedure, providing substantial benefit for both patients and clinical research if it is based on optimized technical tools and careful preoperative planning.

Der Einsatz der Neuronavigation zur Amygdalahippocampektomie Glaser MB. Neurochirurgische Klinik, Stereotaktische und Funktionelle Neurochirurgie, JohannesGutenberg-Universität, Langenbeckstr. 1, 55131 Mainz Es wird eine Serie von 28 konsekutiven Patienten (m12/w16, mittleres Alter 38 Jahre), die aufgrund einer Pharmako-resistenten Temporallappenepilepsie über eine anteriore temporale Craniotomie operiert wurden, zusammengestellt. Die Eingriffe wurden zur Miniaturisierung des Eingriffes unter Zuhilfenahme der Neuronavigation durchgeführt. Es erfolgte jeweils eine anteriore Temporallappenresektion mit anschließender Amygdalahippocampektomie. Histologisch gesichert lag bei 20 Patienten eine Hippocampussklerose vor. Bei den übrigen acht Patienten konnte zum Teil keine relevante Veränderung gefunden werden; z. T. wurde eine Dysplasie, aktivierte Astrozyten oder das Vorliegen von corpora amylacea beschrieben. Outcome bei einem follow up ab dem 12. postop. Monat: Engel class I: 12, II 5, IV 1 (erneute pharmakoresistente TLE nach 3 ½ Jahren Anfallsfreiheit). Folgende dauerhaften Komplikationen traten auf: eine Beeinträchtigung der Feinmotorik nach einem kleinen thalamischen Infarkt, drei Quadrantenanopsien nach contralateral apikal. Es kam zu einer aseptischen Wundheilungsstörung. Das Resektionsausmass wurde in der postoperativen Bildgebung in Relation zum Hirnstamm beurteilt: Bis zur Mitte des pedunculus cerebri waren 3 Hippocampi reseziert, 22 bis zur dorsalen Grenze des pedunculus cerebri und 3 bis auf Höhe des aquaeducts. Zusammenfassend postulieren wir, dass die Temporallappenteilresektion inkl. Amygdalahippocampektomie über einen kleinen anterioren temporalen Zugang sicher und effektiv ist.

Deep brain stimulation Parkinson´s disease

for

camptocormia

in

dystonia

and

Hans-Holger Capelle, Christoph Schrader, Christian Blahak, Wolfgang Fogel, Hansjörg Baezner, Thomas M. Kinfe, Joachim K Krauss Department of Neurosurgery and Neurology, Medical School Hannover; Department of Neurology, Universityhospital Mannheim; Department of Neurology, Deutsche Klinik für Diagnostik, Wiesbaden Objective: Camptocormia or the “bent spine syndrome” may occur in various movement disorders such as primary dystonia or idiopathic Parkinson´s disease (PD). Although deep brain stimulation (DBS) is an established treatment in refractory primary dystonia and advanced PD there are only few data available on the effect of DBS on camptocormia comparing these two conditions. Material and Methods: Seven patients (4 with dystonia, 3 with PD; mean age 60.3 years at surgery, range 39-73 years) with camptocormia were included in the study. Five patients underwent bilateral GPi DBS and two patients underwent bilateral STN DBS guided by CTstereotactic surgery and microelectrode recording. Pre- and postoperative motor assessment included the BFM in the dystonia patients and the UPDRS in the PD patients. Severity of camptocormia was assessed by the BFM subscore for the trunk at a mean last available follow up at 17.3 months (range 9-36 months). Results: There were no surgical complications. In the four patients with dystonia there was a mean improvement of 63 % in the BFM motor score (range 50-72%) and of 69% (range 5075%) in the BFM subscore for the trunk at the last available follow-up (mean 14 months, range 9-18 months). In the three patients with camptocormia in PD who underwent bilateral STN DBS (2 patients) or pallidal DBS (1 patient) the PD symptoms improved markedly (mean improvement in the UPDRS motor subscore stimulation on/medication off 53%, range 4661%) but there was no or only mild improvement of camptocormia, however, in the two patients who underwent STN DBS and only moderate improvement in the patient with GPi DBS at the last available follow-up (mean 22 months, range 12-36 moths). Conclusion: GPi DBS is an effective treatment for camptocormia in dystonia. The response of camptocormia to chronic STN or GPi DBS in PD is more heterogenous. The latter may be due to a variety of causes and needs further clarification.

Pallidal Deep Brain stimulation (DBS) in Chorea Huntington Meinhard Da, Vesper Ja, Wojtecki Lb, Wille Ca, Groiss Stb, Schnitzler Ab a

Abteilung funkt. Neurochirurgie, Neurochirurgische Klinik, Uniklinik Düsseldorf Institut für Klinische Neurowissenschaften und Medizinische Psychologie, Uniklinik Düsseldorf

b

Introduction: At present, there is no effective treatment or cure for Huntington’s disease (HD) patients. Therefore, neural stem cell transplantation seemed to offer a potential treatment for HD patients that may slowdown this devastating illness. However there remain major concerns in transplantation. Therefore our group looked for alternatives, utilizing Deep Brain stimulation (DBS), based on the long-lasting successful treatment of other neurodegenerative movement disorders like Parkinson’s disease (PD). Questions remained concerning the optimal target. Methods: This phase I clinical trial is based on the hypothesis that deep brain stimulation of the internal pallidum can reduce choreatic symptoms in HD patients. In addition, this trial should demonstrate which target point within the pallidum can be used effectively for specific features of HD in order to further refine this promising strategy for a phase II multicenter trial approach. Four consecutive cases with DBS of the Pallidum (GPi/GPe region) are reported1,2,3,4. Electrodes were stereotactically implanted under general anesthesia, followed by the implantation of a neurostimulation system. Results: No complications occurred. The coordinates for the active contacts in the GPi/GPe range were adapted to individual anatomical changes. Under DBS of the pallidum choreatic movements could be reduced by 50 to 80% (UHDRS). The quality of life, which was measured by ADL, was significantly improved in the three patients. Since the effects are delayed, the adjustment and testing of the remaining contacts took place in the course of 6 months postoperatively. The most effective active contacts were in projection of the border of GPi and GPe. Conclusion: Systematic positive influence of DBS in Huntington’s disease patients is reported for the first time. In the context of the following study it will have to be clarified whether the internal or the external part or other targets are suitable for DBS and which long-term results can be obtained. Literature: 1

GPi-DBS in Huntington's disease: results on motor function and cognition in a 72-year-old case. Fasano A, Mazzone P, Piano C, Quaranta D, Soleti F, Bentivoglio AR. Mov Disord. 2008 Jul 15;23(9):1289-92.

2

Bilateral stimulation of the globus pallidus internus to treat choreathetosis in Huntington's disease: technical case report. Hebb MO, Garcia R, Gaudet P, Mendez IM. Neurosurgery. 2006 Feb;58(2):E383; discussion E383.

3

Pallidal deep brain stimulation influences both reflexive and voluntary saccades in Huntington's disease. Fawcett AP, Moro E, Lang AE, Lozano AM, Hutchison WD. Mov Disord. 2005 Mar;20(3):371-7.

4

Bilateral globus pallidus stimulation for Huntington's disease. Moro E, Lang AE, Strafella AP, Poon YY, Arango PM, Dagher A, Hutchison WD, Lozano AM. Ann Neurol. 2004 Aug;56(2):290-4.

Chronic deep brain stimulation in patients with tardive dystonia without a history of major psychosis Hans-Holger Capelle, Christian Blahak, Christoph Schrader, Hansjörg Baezner, Thomas M. Kinfe, Jan Herzog, Reinhard Dengler, Joachim K Krauss Department of Neurosurgery and Neurology, Medical School Hannover; Department of Neurology, Universityhospital Mannheim; Department of Neurology, Universityhospital Schleswig-Holstein, Campus Kiel Objective: Tardive dystonia usually occurs after neuroleptic exposure in patients with major psychosis with a delay. A subgroup of patients, however, is given such medication for “mild depression” or “neurasthenia”. Tardive dystonia, in general, may respond favorably to pallidal deep brain stimulation (DBS). Nevertheless, it remains unclear thus far whether or not similar beneficial outcome is achieved with pallidal DBS in different subgroups of patients with tardive dystonia. Material and Methods: Four women (mean age 59 years at surgery) underwent stereotactic pallidal DBS in the frame of an observational study. Tardive dystonia occurred secondary to medication with fluspirilene and haloperidol, and injection of long-acting depot neuroleptics prescribed for mild depression or “nervousness”. Assessment included the Burke-FahnMarsden (BFM) scale preoperatively and at 12 months follow-up. Extended follow-up was available at a mean of 27.3 months postoperatively (range 16-36 months). Results: There were no surgically related complications. All four patients experienced sustained statistically significant benefit from pallidal DBS. Mean improvement at 12 months was 77% for the BFM motor score (range, 45-91%; p=0.043), and 84% at the last available follow-up (range, 70-91%; p=0.03). This was paralleled by improvement of the BFM disability score. Conclusion: Chronic pallidal DBS in patients with tardive dystonia without a history of major psychosis provides sustained improvement which is similar to that in other subgroups of patients with tardive dystonia. This effect is stable on extended follow-up for up to 3 years.

Pallidal Deep Brain Stimulation may induce freezing of gait in patients with focal and segmental dystonia Christoph Schrader, Hans-Holger Capelle, Götz Lütjens, Thomas Kinfe, Joachim K. Krauss Department of Neurosurgery and Neurology, Medical School Hannover

Background: Deep brain stimulation (DBS) of the globus pallidus internus (GPi) has been shown to be an effective, well-tolerated, and safe treatment for patients with medically refractory segmental and generalized dystonia. Recently, stimulationinduced bradykinesia or parkinsonism have been reported as rare side effects of chronic DBS of the GPi; yet there is few data on its frequency. The aim of this work was to determine the frequency of spontaneously reported (and therefore clinically relevant) gait disorders and to describe their nature. Methods: We retrospectively screened our data base of dystonia patients who underwent DBS of the posteroventral GPi in the period between 2006 and 2009. Those who spontaneously reported a newly emerged gait disorder after DBS were included into this study. Results: Of a collective of 52 dystonia patients we identified 5 patients (2 male, 3 female, mean age 58 years (48 - 69 yrs), one with cranio-cervical dystonia, one with DYT-1 positive segmental dystonia of the arms, two with tardive dystonia and one with dystonic camptocormia) who met the inclusion criterion. All of them had significant benefit from DBS with regard to the suppression of dystonia. The two tardive dystonia patients exhibited a gait disorder prior to DBS, which was characterized by a somewhat unsteady gait. After DBS, all of them described a gait disorder closely resembling freezing of gait (FOG): difficulties with initiation of gait, tripping steps, difficulties with turning, having their feet glued to the ground. At higher amplitudes, dystonia improved, but FOG occurred, mostly immediately, sometimes worsening over a period of a few hours and vanished within minutes after turning off DBS. In one patient, by reducing the frequency from 130 to 60 Hz dystonia was well controlled without the recurrence of FOG; in the other 4 patients, after extensive testing of settings (monopolar, bipolar, pulse witdth 60-210 µs, frequency 60-180 Hz) no optimal configuration was found, so a compromise between improvement of dystonia and stimulation-induced adverse effects was made. Conclusion: In about 10% of our patients with dystonia a stimulation-induced FOGlike gait disorder following GPi DBS was noted with high output chronic stimulation. In all cases, a compromise between treatment of dystonia and FOG was achieved.

C-fos expression after deep brain stimulation of the pedunculopontine tegmental nucleus in the rat 6-hydroxydopamine Parkinson model Saryyeva A, Schwabe K, Nakamura M, Krauss JK Department of Neurosurgery, Medical University, MHH, Carl-Neuberg-Str.1, D-30625 Hannover, Germany Objective: We here evaluated the expression of c-fos after 25 Hz and 130 Hz deep brain stimulation (DBS) of the pedunculopontine tegmental nucleus (PPTg) in the rat 6hydroxydopamine (6-OHDA) Parkinson model. Background: DBS is increasingly used to alleviate motor dysfunction in Parkinson´s disease (PD). The PPTg may be a potential target for DBS in PD patients with severe postural instability with 25 Hz stimulation being considered more effective than 130 Hz stimulation. Methods: Anaesthetized male Sprague Dawley rats with unilateral 6-OHDA induced nigrostrial lesions were stimulated with 25 Hz or 130 Hz for four hours by electrodes stereotaxically implanted into the ipsilateral PPTg. In sham-stimulated rats the electrode was placed in the PPTg for four hours without stimulation. Thereafter the distribution and number of neurons expressing the immediate early gene c-fos, a marker for acute neuronal activity, was assessed. Results: DBS of the PPTg induced strong ipsilateral c-fos expression at the stimulation site, with 25 Hz having a more marked impact than 130 Hz. Additionally, c-fos was strongly expressed in the central gray. In the dorsal part expression was stronger after 25 Hz stimulation, while in the medial and ventral part there was no difference between 25 Hz and 130 Hz stimulation. Expression in the basal ganglia was negligible, but in the piriform cortex and motorcortex c-fos expression was reduced after 130 Hz or 25 Hz stimulation compared to sham-stimulation. Conclusions: While in the rat 6-OHDA Parkinson model there was little change in c-fos expression in the basal ganglia after stimulation of the PPTg, c-fos was markedly altered in other functional circuitries. We conclude that PPTg stimulation might interfere also with other neuronal systems. Careful analysis of possible interferences with these systems in men would be warranted.

Chronic Motor Cortex Stimulation and predictive value of rTMS J. Vesper, C. Wille Dept. of Functional Neurosurgery, University Clinic Duesseldorf, Germany Chronic motor cortex stimulation (MCS) is used as a treatment for neuropathic pain for two decades. The aim of this study was to analyse retrospectively patient group of two centers with long term follow-up of 2 years and to compare MCS analgesic efficacy between “ON”and “OFF”- stimulation. Four patients with chronic neuropathic pain were treated with contralateral epidural stimulation electrodes over precentral gyrus. In 1 case, trigeminal neuropathic pain (TNP), in 1 cases post-stroke pain (PSP), in one case posttraumatic brachial plexus lesion and in 1 case post irradiation of an AVM were diagnosed. Preoperatively all patients underwent rTMS to estimate the MCS effect. The placement of the electrodes was performed in local anaesthesia using frame based stereotactic neuronavigation. A test trial of three days including double-blind testing was conducted and pain intensity was measured using a visual analogue scale (VAS). Placement of the electrode was achieved in all patients using postoperative stereotactic CT and refusion. In TNP and in PSP a positive effect with pain reduction 50% was observed. In posttraumatic pain the relief was 60%. Postirradiation pain resulted in a complete relief (100%) of pain. The mean follow-up period was 2.6 years (range 1–4 years). Stimulation of the motor cortex is a treatment option for patients with chronic neuropathic pain localized in the face, head, trunk or upper extremity. Non-responders can be identified with rTMS. It has some predictive value for effect. Since all patients benefited from surgery, a prospective MCT is highly warranted.

Tiefe Hirnstimulation bei therapie-resistenter Zwangserkrankung: Fallbericht und Diskussion der aktuellen Literatur Pinsker MO1, Prokop T1, Milkereit A2, Voderholzer U2, Berger M2, Nikkhah G1 1

Abteilung Stereotaktische Neurochirurgie, Universitätsklinikum Freiburg Abteilung für Psychiatrie und Psychotherapie, Universitätsklinikum Freiburg

2

Ziel: Die Zwangsstörung ist mit einer Lebenszeitprävalenz von 2% in der Erwachsenen Allgemeinbevölkerung eine wesentlich häufigere Erkrankung, als früher angenommen. Mit Spontanremissionen kann nicht gerechnet werden, bei 50% der Betroffenen besteht die Erkrankung das gesamte Leben lang. Eine Kombinationstherapie aus kognitiver Verhaltenstherapie mit Reizkonfrontation (Exposition) und Reaktionsmanagement sowie selektiver Serotonin-Wiederaufnahmehemmer führen zu Ansprechraten von 80-90%. Bei den verbleibenden 10-20% Patienten, die als therapie-resistent angesehen werden müssen, gibt es einige Hinweise, dass mittels der Tiefen Hirnstimulation eine deutliche Symptomreduktion erzielt werden kann. Im Folgenden wird der Fall eines 41jährigen Mannes mit Zwangsgedanken und -handlungen beschrieben, bei dem im Juni 2008 eine Elektrodenimplantation in die vordere Kapsel (VC/VS) durchgeführt wurde. Darüber hinaus wird die aktuelle Literatur insbesondere hinsichtlich der verwendeten Zielpunkte und Ergebnisse diskutiert. Fallbericht: Der Patient leidet seit 2003 an einem ausgeprägten Waschzwang, der sich in mehrstündigem morgendlichen Duschen äußert, sowie im Vermeiden körperlicher Tätigkeiten wie Sport, um Verschmutzungen zu verhindern. Darüber hinaus leidet er an Zwangsgedanken in der Art, dass er fürchtet, anderen Menschen Gewalt anzutun (also beispielsweise einen vorbeifahrenden Radfahrer vom Rad zu stoßen). In der Folge kommt es zu mehrstündigem Gedankenkreisen, ob er nicht doch eine der Zwangsgedanken ausgeübt habe. Aufgrund dieser Symptome ist der Patient in seinem Alltagsleben stark eingeschränkt, ist beispielsweise seit 2006 nicht mehr in der Innenstadt gewesen oder hat an sportlichen Aktivitäten teilgenommen. Die Operation erfolgte im Juni 2009. Wir implantierten bilateral eine DBS-Elektrode (Modell Medtronic 3387) in die anteriore Kapsel (VC/VS). Die funktionellen Koordinaten waren: lateral 8 mm, AP am anterioren Rand von AC, inferior 4 mm. Der intra- und postoperative Verlauf waren komplikationslos, es ließen sich intraoperativ keine Zwangsgedanken provozieren, so dass eine direkte Testung des Effektes nicht möglich war. Im postoperativen Verlauf erfolgte eine schrittweise Anhebung der Stimulationsparameter auf bis zu 7 V, monopolar auf zunächst einem Kontakt (1- und 5-). Hierunter kam es zu keiner wesentlichen Besserung der Symptomatik, der Patient beklagte darüber hinausgehend ein starkes Müdigkeitsgefühl. Erst eine Vergrößerung des elektrischen Feldes durch Stimulation eines zweiten Kontaktes (G+, 1-, 2- bzw. 5-, 6-) führte zu einer deutlichen Besserung der allgemeinen Stimmung sowie zu einer Rückbildung der Zwangsgedanken und einer Abnahme der täglichen Waschprozeduren. Schlussfolgerung: Die bilaterale tiefe Hirnstimulation der anterioren Kapsel (VC/VS) kann zu einer Verbesserung der Zwangsstörung führen. Möglicherweise ist die hier verwendete Elektrode bezüglich des elektrischen Feldes zu klein (ab 2010 wird ein neues Modell verfügbar sein). Hinsichtlich der Festlegung des idealen Zielpunktes bedarf es sicher noch größerer klinischer Erfahrung und prospektiver Studien.

The medial forebrain bundle (MFB) in humans – an understudied structure investigated with diffusion tensor imaging Volker A Coenen, M.D., Yaroslav Parpaley, M.D., Trevor Hurwitz, M.D., Horst Urbach, M.D. and Burkhard Mädler, Ph.D. Stereotaxy and MR-based operation techniques / Department of Neurosurgery (vac,yp,bm) and Department of Neuroradiology/Radiology (hu), University of Bonn, Germany; Department of Psychiatry (th), University of British Columbia, Vancouver, Canada Objective: The medial forebrain bundle (MFB) is a key structure of the reward circuitry that has been widely ignored in the human. Anatomically it has only recently been described. Evaluation of active DBS electrode contacts and inclusion of electric field sizes has shed some light on the implications of MFB activation through DBS as a possible explanation of psychiatric side effects of stimulation therapy. This study was designed to 1.) describe and evaluate MFB anatomy further in humans and 2.) create an atlas of this structure in the MNI125 space for its further use in stereotaxy. Methods: 15 patients with idiopathic Parkinson’s disease (candidates for deep brain stimulation (DBS) surgery) were included. 3T MRI data comprised 3D T2-weighted TSE, Diffusion-weighted SE EPI, and 3D T1-weighted gradient echo sequences. For a deterministic tracking procedure we utilized the StealthViz DTI™ software package (Medtronic Navigation, Louisville, USA) on a standalone Unix™ workstation. The MFB was tracked using a single region of interest in the ipsilateral VTA as identified in the T2W high resolution MRI. We defined a rectangular volume of interest (VOI) box of approximately 5x7x7mm^3 (h/l/w) that was aligned in the respective VTA. For a conceptual sketch of the VTA cf. Figure 2. As a further structure the anterior thalamic radiation (ATR) was tracked with a single VOI box located in the anterior thalamic nucleus. Individual tracking results were deformed and morphed non-rigidly to the MNI125 brain (FSL 4.1, Analysis Group, Oxford, UK). A variability map was calculated (n=12) that displays the ATR and MFB according to the most likely overlap, by this creating an atlas in stereotactic space [cf. Figure 1]. Results: MFB and ATR can be visualized as distinct and robust structures with deterministic DTI fiber tracking (DTI FT) and can be displayed in a variability map in the MNI125 space. Other than previously reported by other authors, the ATR (yellow, Figure 1) is a distinct structure that has no direct connection to the brain stem. The MFB (green, Figure 1) is a bipartite structure. It connects the ventral tegmental area (VTA) via a lower inferomedial branch to the lateral hypothalamus. An only recently recognized second branch, superolateral, connects the VTA to the accumbens nucleus (NAcc), the anterior limb of the internal capsule (ALIC) and the frontal lobe. This latter branch (slMFB) runs antidromic to the fronto-pontile tract (Arnold’s bundle) and is a newly described structure [cf. Figure 2]. The direct connection of the VTA with forebrain structures has been missing so far in classical anatomical decriptions. Conclusion: The MFB has been under-recognized and understudied in humans. This fiber system appears to be of emerging importance for the explanation of psychotropic side effects of DBS and for the structural explanation of affective disorders in the psychiatric field. Evidence from the literature suggests that this is a truly bipartite fiber system. The presented work introduces it as a robust, reproducible structure as investigated with deterministic DTI FT. Figure 1

Figure 2

Digitale OP Unterstützung für funktionell stereotaktische Operationen (FDSS Projekt) F Hertel (1,2,3, 4), P Gemmar (3,4), KP Koch (3,4) Funktionell stereotaktische Operationen sind hochkomplexe Eingriffe mit einem hohen Maß an technologischer Unterstützung für den Operateur. An verschiedenen Punkten der OP Planung, Durchführung und postoperativen Kontrolle können computerunterstützte Expertensysteme hilfreich sein und bieten die Option, die klinischen Resultate zu verbessern. Wir präsentieren die Entwicklung eines digitalen Systems, welches folgende Unterstützungen leisten kann: 1. Automatisierte (interaktiv zu kontrollierende) Zielpunktsfindung und Trajektorienplanung, 2. Intraoperative automatisierte Mikrosignalanalyse zur Unterscheidung von STN typischen versus nicht STN typischen Signalen, 3. Zielvolumenextraktion aus MRT Bilddaten und Matching derselben mit den 3 D Informationen aus der Mikroableitung, 4. Bestimmung der definitiven Elektrodenposition aus CT Daten. Hierdurch kann die gesamte OP Prozedur unetsrtützt und die gewonnenen Daten ausserdem zur postoperativen Programmierung und wissenschaftlichen Analyse benutzt werden. Dargestellt werden die Entwicklungen selbst und erste klinische Resultate.

The accurate depiction of the pyramidal tract (PT) with Diffusion tensor imaging fibre tracking (DTI FT) is verified by in- vivo electrophysiology Volker A Coenen, M.D., Burkhard Mädler, Ph.D., Uli Bürgel, M.D., Felix Schoth, M.D., PhD, Christopher R. Honey, M.D., D.phil Stereotaxy and MR-based operation techniques / Department of Neurosurgery, University of Bonn, Germany (vac,bm); Surgical Center for Movement Disorders (vac, crh), Department of Physics and Astronomy (bm), University of British Columbia, Canada, Departments of Neurosurgery (UB) and Radiology (FS) University Hospital (UK) Aachen, Germany Objective: Technique inherent limitations of DTI FT can lead to inaccurate depiction of large fibre tracts under conditions of undistorted anatomy. Attempts have been made to compensate for this under pathological conditions through creation of safety margins around the tracts. DTI FT in principle has the capability to accurately depict the PT in its full extent depending on software and procedures. The purpose of this study was to verify this accuracy of the depiction of the deep-seated PT – the internal capsule (IC) - with in-vivo electrophysiology (EP) under standardized conditions and undistorted anatomy. The ultimate goal was to justify the use of DTI FT beyond functional neuronavigation for functional stereotactic neurosurgical procedure planning. Methods: 11 patients underwent STN DBS surgery. Preoperative DTI scans and high resolution T1W and T2W MRI were conducted on a 3T scanner. The PT were depicted (Stealth DTI, Medtronic Navigation, USA) in their full extent. After surgery a) test electrode positions and current patterns that elicited IC effects (contralateral face or limb contraction) during operation and b) postoperative 3D CT derived active DBS electrode contact information and stimulation patterns that created IC side effects were used to electrophysiologically detect the medial IC border. The data from a and b, respectively, were combined in a 3D coordinate system and evaluated with the DTI FT information (Framelink 5.0, Medtronic Navigation, CO, USA). The shortest distance in space to the medial border of the IC was measured and compared to the electrophysiological distances [Figure 1]. Results: a) A total number of 40 clinical IC effects where detected intraoperatively (io) during test stimulation. The mean minimal electrophysiological distance to the medial IC border (calc. according literature) was 3.6 +/- 0.77 mm. The mean image derived distance from this position to the IC (DTI FT) was 3.0 +/- 1.27 mm, with a difference of 0.7 +/- 1.3 mm between the two [Figure 2]. b) Totally 43 IC effects where encountered during postoperative programming. 16 were further evaluated. Electrophysiological distance: 3.5 +/- 0.4 mm; image derived distance: 3.2 +/- 1.9 mm; difference: 1.2 +/- 0.8 mm. The overall accuracy was statistically determined to be better than 1.8mm (io) and 1.5mm (po). Conclusion: With an accuracy of ≤2mm, the depiction of the PT with DTI FT appears to be accurate enough for its use in functional stereotactic planning procedures. This might be extrapolated to other fibre pathways of interest. Figure 1

Figure 2

Interdisziplinäres Rezidiv- Managment bei aggressiv wachsenden Meningeomen Hamm K, Gerlach R, Kleinert G, Surber G, Rosahl S Abteilung für stereotaktische Neurochirurgie und Radiochirurgie, Neurozentrum, HELIOS Klinikum Erfurt Abstrakt Neben den seltenen malignen (WHO Grad III) und den atypischen (WHO Grad II) Meningeomen zeigen auch einige WHO Grad I- Meningeome ein aggressives, rezidivierendes Wachstumsverhalten – diese Problemfälle verlangen ein besonders individuelles, interdisziplinäres Managment. Von Mai 2000 bis April 2008 wurden insgesamt 368 Meningeome bei 302 Pat. mit Radiochirurgie (75 bei 50 Pat.) oder stereotaktischer Radiotherapie (293 bei 252 Pat.) behandelt – davon erhielten 24 Pat. mit neuen oder Rezidiv- Befunden mindestens 2 Behandlungen im Verlauf des 9,5jährigen Beobachtungszeitraumes. Bei 9 Problemfällen (6x Grad I, 3x Grad II) waren bisher 3 bis zu 8 Behandlungen erforderlich – davon werden 4 Pat. vorgestellt und diskutiert.

Intrakranielles Plasmazellgranulom der Dura – Interdisziplinäre Therapiestrategie mit stereotaktischer Radiotherapie Hamm K, Surber G, Kleinert G, Feltz R Abteilung für stereotaktische Neurochirurgie und Radiochirurgie, Neurozentrum, HELIOS Klinikum Erfurt Abstrakt Das Plasmazellgranulom (PCG) ist ein histologisch gutartiger, entzündlicher Pseudotumor unbekannter Ursache, typischerweise in den inneren Organen lokalisiert, dagegen nur selten dural oder intracerebral. PCG der Dura wachsen meist langsam, flächenhaft und erscheinen bildmorphologisch als Meningeom oder basale Meningitis. Teilweise wird auch aggressives Wachstum mit erheblicher Raumforderung beobachtet - eine konsequente Diagnostik und Therapie ist dann erforderlich. Als Behandlungs- Optionen werden Operation, Steroide und/oder Strahlentherapie beschrieben. Wir berichten über die interdisziplinäre Therapiestrategie mit erfolgreicher stereotaktischer Radiotherapie (SRT) und 8jähriger Verlaufskontrolle bei einer ausgedehnten, beidseitig am Hirnstamm gelegenen PCG der Dura.

Bild- und Roboter-geführte Radiochirurgie benigner spinaler Tumore Markus Kufeld, Berndt Wowra, Alexander Muacevic, Stefan Zausinger, Jörg Christian Tonn Europäisches Cyberknife Zentrum München-Großhadern, Klinik für Neurochirurgie der LMU München Einleitung Standardtherapie für benigne spinale Tumore ist die Operation. Die bild-kontrollierte spinale Radiochirurgie bietet eine zusätzliche Therapieoption für selektierte Fälle. Methode 15 Patienten mit spinalen Meningeomen und 22 Patienten mit spinalen Neurinomen wurden von Juli 2005 bis Juli 2009 ambulant radiochirurgisch behandelt und prospektiv nachverfolgt. Lokale Tumorkontrolle, neurologische Symptome und Nebenwirkungen wurden klinisch und mittels Bildgebung erfasst. Ergebnisse Bei den 37 Patienten mit 44 Läsionen wurden 42 Einzeitbehandlungen durchgeführt. Das Patientenalter betrug im Median 45 Jahre (18-77 Jahre), das Tumorvolumen 2,0 cm3 (0,2-43 cm3) und die Dosis 14 Gy (70% Isodose). Histologisch fanden sich in 60% Neurinome, 30 % Meningeome und 10% atypische Meningeome. Eine Neurofibromatose Typ II war bei 4 Patienten nachgewiesen. Zervikale (45%), thorakale (26%), lumbale (19%) oder sakrale (10%) Wirbelsäulenabschnitte waren betroffen. 21 Läsionen lagen intraspinal, 8 davon intradural, 23 lagen paraspinal oder intraforaminal. Alle Patienten waren voroperiert (81 % lokal), zwei Patienten waren fraktioniert vorbestrahlt. 95% der Patienten boten zum Behandlungszeitpunkt klinische Symptome. 49% der Patienten litten unter Schmerzen, 37% unter Sensibilitätsstörungen, 24% hatten manifeste Paresen und bei zwei Patienten bestand eine Myelopathie. Der mittlere Nachbeobachtungszeitraum betrug 14 Monate (3-48 Monate). Die TumorKontrollrate lag bei 98%. Das einzige Lokalrezidiv trat bei einem atypischen Meningeom WHO°II auf. Zwei Patienten entwickelten distante Rezidive (ein Patient mit WHO °I- sowie ein Patient mit WHO °II-Meningeom). Therapieinduzierte strahlentoxische Nebenwirkungen oder Zeichen einer Myelopathie in der Bildgebung wurden nicht beobachtet. Bei zwei Neurinomen und zwei atypischen Meningeomen kam es zu einer Schwellung mit vorübergehender Schmerzunahme. Eine signifikante Besserung der initialen Schmerzen wurde bei 6 Patienten erzielt. Schlussfolgerungen Die spinale Radiochirurgie ist eine sichere und effektive zusätzliche Behandlungsoption für ausgewählte Patienten mit spinalen Meningeomen und Neurinomen.

A Comparison of Stereotactic 125Iodine Brachytherapy with Stereotactic Radiosurgery (LINAC) for the Treatment of Singular Cerebral Metastases. Ruge MI1, Kocher M2, Voges J3, Hoevels M1, Treuer H1, Sturm V1. 1

Department of Stereotactic and Functional Neurosurgery and 2Department of Radiation Oncology, University of Cologne, 3 Department of Stereotactic Neurosurgery, University of Magdeburg. Objective: Radiosurgery is commonly accepted for the local treatment of small (12 months were correlated (highly) significant (p