Neurosurgical Steps and Lessons Learned in Final Separation of 3-Year-Old Craniopagus Twins.

The only published paper1 describing the separation of the conjoined twins did not describe the novel steps and techniques of the microsurgery part, which lasted 26 hours. That paper did not include the neurosurgical video, either. The massive intracerebral hemorrhage that occurred on postoperative day 33 was not reported, and its potential causes have not been scrutinized. The strategy of final separation was developed during day-by-day microsurgical practice on cadavers and did lead us to novel surgical solutions as the introduction of the application of hinge and distractors. One of the twins advanced to GOS 5 status during first 5 postoperative months. The other twin slowly advanced to GOS 3 status and remained at that functional level. The latter suffered the massive brain hemorrhage on postoperative day 33, which led to delayed rehabilitation and interfered with a potentially better outcome. The thorough analysis of the potential causative factors revealed the possible pathophysiologic mechanism behind that complication.2 Two major factors have been identified, one of which is the traction-related traumatic brain injury that evolved during supine position. Another probable theory is the lack of sufficient reconstruction of the posterior part of the skull, which caused a recurring tactile microtrauma of the brain due to the supine position. The hemorrhage may have been facilitated by the fact that their coagulation tests were on the lower edge of normal parameters. It was a mistake that this part of the surgery was not performed by the neurosurgeons who designed it and practiced extensively on fresh cadavers using 3-dimensional models. Sufficient cranioplasty was performed 3 months later. It is impossible to say with certainty the cause of the hemorrhage, since there may have been other unknown causes (e.g., blood pressure spike). As a contributing factor, congestion of the veins is also possible.3 We concluded that closer monitoring, a stricter management of the interdisciplinary team work, and realizing the seriousness of the lack of sufficient structural support earlier could have prevented this unfortunate complication. In a similar case we advise future professionals to use a halo ring postoperatively for posterior protection until a sufficient cranioplasty can safely be done.

The effect of deep brain stimulation of the subthalamic nucleus on executive functions: impaired verbal fluency and intact updating, planning and conflict resolution in Parkinson's disease.

Although the improvement of motor symptoms in Parkinson's disease (PD) after deep brain stimulation (DBS) of the subthalamic nucleus (STN) is well documented, there are open questions regarding its impact on cognitive functions. The aim of this study was to assess the effect of bilateral DBS of the STN on executive functions in PD patients using a DBS wait-listed PD control group. Ten PD patients with DBS implantation (DBS group) and ten PD wait-listed patients (Clinical control group) participated in the study. Neuropsychological tasks were used to assess general mental ability and various executive functions. Each task was administered twice to each participant: before and after surgery (with the stimulators on) in the DBS group and with a matched delay between the two task administration points in the control group. There was no significant difference between the DBS and the control groups' performance in tasks measuring the updating of verbal, spatial or visual information (Digit span, Corsi and N-back tasks), planning and shifting (Trail Making B), and conflict resolution (Stroop task). However, the DBS group showed a significant decline on the semantic verbal fluency task after surgery compared to the control group, which is in line with findings of previous studies. Our results provide support for the relative cognitive safety of the STN DBS using a wait-listed PD control group. Differential effects of the STN DBS on frontostriatal networks are discussed.

Positioning Accuracy in Otosurgery Measured with Optical Tracking.

OBJECTIVES: To assess positioning accuracy in otosurgery and to test the impact of the two-handed instrument holding technique and the instrument support technique on surgical precision. To test an otologic training model with optical tracking. STUDY DESIGN: In total, 14 ENT surgeons in the same department with different levels of surgical experience performed static and dynamic tasks with otologic microinstruments under simulated otosurgical conditions. METHODS: Tip motion of the microinstrument was registered in three dimensions by optical tracking during 10 different tasks simulating surgical steps such as prosthesis crimping and dissection of the middle ear using formalin-fixed temporal bone. Instrument marker trajectories were compared within groups of experienced and less experienced surgeons performing uncompensated or compensated exercises. RESULTS: Experienced surgeons have significantly better positioning accuracy than novice ear surgeons in terms of mean displacement values of marker trajectories. The instrument support and the two-handed instrument holding techniques significantly reduce surgeons' tremor. The laboratory set-up presented in this study provides precise feedback for otosurgeons about their surgical skills and proved to be a useful device for otosurgical training. CONCLUSIONS: Simple tremor compensation techniques may offer trainees the potential to improve their positioning accuracy to the level of more experienced surgeons. Training in an experimental otologic environment with optical tracking may aid acquisition of technical skills in middle ear surgery and potentially shorten the learning curve. Thus, simulated exercises of surgical steps should be integrated into the training of otosurgeons.

Modelling pathology from autolog fresh cadaver organs as a novel concept in neurosurgical training.

BACKGROUND: The aim of neurosurgical cadaver training for residents and fellows is not only to obtain a high level of skills, but also to keep the number of complications during the learning curve as low as possible. To move this process forward, we have worked out a novel method in further training. METHODS: Tumours can be modelled from the autolog organs. We can then implant the modelled tumour from the opposite direction and a colleague can remove the pathology from the correct approach. RESULTS: We have experienced improving skills in difficult microsurgical operations. CONCLUSION: We have performed more than 800 fresh cadaver operations over the last 6 years. The last 70 cases have been performed with modelling pathology. In our department, we introduce a regular weekly program in our cadaver operating theatre. The consideration could be useful not only for the young neurosurgeons but also for experienced colleagues.

Straight needle with fingertip support technique reduces exclusion time during bypass (in vitro, in vivo animal study): a technical note.

BACKGROUND: The duration of exclusion time of recipient artery is an important factor in bypass surgery of cerebral revascularization. The longest period of exclusion is the suturing time. The fingertip support technique (first published in 2006) reduced the physiological tremor to speed up this extra-precise microsurgical procedure. The use of a straight needle proved to further decrease suturing time during the bypass procedure. METHODS: A straight micro needle was added to the fingertip support method for further reduction of exclusion time. A comparative study, measuring the duration of suturing time in vitro and in vivo for animal cases, was performed. This was a golden opportunity to examine how to simplify vascular transposition, using the fingertip support technique and straight needle. RESULTS: The average time of the bypass procedure by the novel considerations (fingertip support and straight needle) was significantly less than the average time by traditional microsurgical support. CONCLUSION: This in vitro/in vivo animal study provides evidence of the reduction of the suturing time, and thus the exclusion time, by using the fingertip support technique with a straight needle in the bypass procedure.

Target identification for stereotactic thalamotomy using diffusion tractography.

BACKGROUND: Stereotactic targets for thalamotomy are usually derived from population-based coordinates. Individual anatomy is used only to scale the coordinates based on the location of some internal guide points. While on conventional MR imaging the thalamic nuclei are indistinguishable, recently it has become possible to identify individual thalamic nuclei using different connectivity profiles, as defined by MR diffusion tractography. METHODOLOGY AND PRINCIPAL FINDINGS: Here we investigated the inter-individual variation of the location of target nuclei for thalamotomy: the putative ventralis oralis posterior (Vop) and the ventral intermedius (Vim) nucleus as defined by probabilistic tractography. We showed that the mean inter-individual distance of the peak Vop location is 7.33 mm and 7.42 mm for Vim. The mean overlap between individual Vop nuclei was 40.2% and it was 31.8% for Vim nuclei. As a proof of concept, we also present a patient who underwent Vop thalamotomy for untreatable tremor caused by traumatic brain injury and another patient who underwent Vim thalamotomy for essential tremor. The probabilistic tractography indicated that the successful tremor control was achieved with lesions in the Vop and Vim respectively. CONCLUSIONS: Our data call attention to the need for a better appreciation of the individual anatomy when planning stereotactic functional neurosurgery.

In vitro and in vivo surgical and MRI evidence to clarify the effectiveness of the vascular tunnel technique in the course of decompressive craniectomy.

OBJECTIVE: To demonstrate the efficacy of a vascular protection technique during decompressive craniectomy (DC) which can reduce the risk of secondary venous infarction due to the blocking pressure for venous outflow through bridging veins. METHOD: The observation was carried out In vitro (cadaver) and in vivo (surgery and magnetic resonance imaging) in order to verify the durability of the vascular tunnel. RESULTS: in vivo observation proved the durability of vascular tunnel even 2 months later. The cadaveric experimental model showed that after the 12×13 cm size DC had been obtained, the observed vein was occluded at 18-21 mmHg without vascular protection; however, the control preparation remained open even at 50 mmHg. CONCLUSION: The in vivo case study and the cadaver experiment suggest that vascular protection helps prevent secondary venous infarction after DC. This is therefore an aid in preventing further injury and cerebral oedema. The vascular tunnel guarantees the efficacy of DC even at a high level of intracranial pressure.

Effectiveness of unilateral pallidotomy for meige syndrome confirmed by motion analysis.

BACKGROUND: We report the case of a 64-year-old woman with bilateral manifestation of Meige syndrome (MS) successfully treated with left-side unilateral ventroposterolateral pallidotomy. METHODS: Symptoms were evaluated according to the Burke-Fahn-Marsden dystonia rating scale. Head tremor, blepharospasm and orofacial dyskinesia were measured with an infrared, video-based, computerized, real-time passive marker-based analyzer of motions (RTPAM). RESULTS: The Burke-Fahn-Marsden score showed a 90.2% reduction (from 25.5 to 2.5) at 6 months, and an 88.2% long-lasting benefit (to 3.0) at the 3-year follow-up with good bilateral control of the blepharospasm and orofacial movements. The RTPAM showed a substantial regression of acceleration for all markers, and abolishment of the 4.8-Hz head tremor. The correlation between symmetrical markers, and between markers within the right and left sides, was significantly decreased. CONCLUSIONS: Pallidotomy with staged procedure is recommended for the treatment of MS in patients on whom deep brain stimulation could not be performed. In case of good bilateral benefits from the unilateral procedure, contralateral surgery is not needed. The RTPAM is a useful tool for the mapping of facial involuntary movements.

[Application of robot hand technique in the course of microneurosurgical operations]. / Robotkéztechnika alkalmazása a mikroszkópos idegsebészeti mutéteknél.

INTRODUCTION: The aim of this study was to determine whether the new robot hand technique can help to avoid the complication in the course of high precise microneurosurgical operations. METHODS: The physical efficacy was measured by tremorometry. The comparative study of the incidence of complications measured the clinical efficacy. RESULTS: The tremors of the operating hand and the number of complications have decreased effectively. CONCLUSION: The precise level of robots could be available by novel robot hand technique. By this technique the microsurgical work has become more effective.

[125-I brachytherapy of pineal parenchymal tumours in two patients and review of the literature]. / Két pinealoblastomás beteg 125-jód-brachytherapiája során nyert tapasztalatok es irodalmi áttekintés.

INTRODUCTION: Pineal parenchymal tumours make up 0.3% of all brain tumours. Stereotactic biopsy has by now become an indispensable method to detect these tumours and it can be safely performed. PATIENTS AND METHOD: Two patients with pineoblastoma were treated with 125I brachytherapy. The MRI and CT images taken 15 and 18 months after irradiation showed significant tumour shrinkage. RESULTS: Tumour volume was 0.76 cm3 in the control CT image in Case 1, a shrinkage by 73% compared to 2.87 cm3 measured at the time of planning the interstitial irradiation. In Case 2, tumour volume measured on the control MRI examination was 0.29 cm3 as opposed to 1.27 cm3 of original tumour volume, which represents a 77% shrinkage. CONCLUSION: The insertion of isotope seeds was performed at the same time as the biopsy, because thus the knowledge of the histological diagnosis could spare the patients from a second stereotactic intervention. The CT- and image fusion guided 125I stereotactic brachytherapy is a procedure that can be dosimetrically precisely planned and surgically accurately and safely performed.

[Volumetric changes following 125I interstitial brachytherapy of gliomas]. / Térfogatváltozások agydaganatok 125-jód-izotópos brachytherapiája után.

BACKGROUND: Image fusion permits quantitative analysis of the consequences of 125 Iodine interstitial irradiation of brain tumors. The volume of tumor necrosis, reactive zone and edema can be compared to the dosimetric data. PATIENTS AND METHOD: Nineteen patients with low grade glioma were analyzed on the average 14.5 months following 125 Iodine interstitial irradiation. Dose planning and image fusion were performed with the Target 1.19 (BrainLab) software. The CT/MR images showing the so called "triple ring" (necrosis, reactive ring and edema) developing after the interstitial irradiation of brain tumors were fused with the planning images and the isodose curves. The volume of the three regions was measured. Values at the intersections of isodose curves and necrosis borders were averaged and used for calculation of tumor necrosis. The volume of normal brain tissue irradiated by given dose values, as well as homogeneity and conformality indices were also determined. RESULTS: The relative volumes of the different parts of the "triple-ring" compared to the reference dose volume were the following: necrosis 54.9%, reactive zone 59.7%, and edema 445.3%. Tumor necrosis developed at 71.9 Gy dose. At the irradiation of an average size glioma with a volume of 12.7 cm3, 5 to 7 cm3 normal brain tissue around the tumor received 60-70 Gy dose. The average homogeneity and conformality indices were 0.24 and 0.57, respectively. CONCLUSION: The analysis of changes in the volume of edema, reactive ring and necrosis caused by interstitial irradiation, and their correlation with the dosimetric data using the image fusion method provide useful information for patient follow-up, clinical management and further therapeutic decisions.

Iodine-125 brachytherapy of brain stem tumors.

PURPOSE: To report on iodine-125 ((125)I) interstitial irradiation in the treatment of brain stem tumors. PATIENTS AND METHODS: Two patients with brain stem tumors were treated with CT- and image fusion-guided (125)I stereotactic brachytherapy. RESULTS: By March 2003, the patients had been followed up for 47 and 13 months, respectively. In case 1, the tumor volume was 1.98 cm(3) on the control CT, indicating a 65.5% shrinkage as compared to a target volume of 5.73 cm3 at the time of brachytherapy. In case 2, shrinkage was more distinct. After irradiation, the cyst volume was 0.16 cm(3) on the control MRI, indicating a 97.4% shrinkage as compared to a target volume of 6.05 cm(3) at the time of brachytherapy, i. e., the metastasis had virtually disappeared. CONCLUSION: CT- and image fusion-guided (125)I stereotactic brachytherapy can be performed during the biopsy session. The procedure can be well planned dosimetrically and is surgically precise.

[Brachytherapy of brainstem tumors]. / Agytörzsi daganatok szövetközi besugárzása.

INTRODUCTIONS: The optimal therapy of brain stem tumours of different histopathology determines the expected length of survival. Authors report 125Iodine interstitial irradiation of brain stem tumours with stereotactic brachytherapy. CASE REPORTS: Two patients having brain stem tumours were suffering from glioma or from metastases of a carcinoma. In Case 1 the tumour volume was 1.98 cm3 at the time of planning interstitial irradiation. The control MRI examination performed at 42 months post-op showed a postirradiation cyst size of 5.73 cm3 indicating 65.5% shrinkage. In Case 2 the shrinkage was more apparent as the tumour volume measured on the control MRI at 8 months post-op was only 0.16 cm3 indicating 97.4% shrinkage of the 6.05 cm3 target volume at the time of brachytherapy with the metastasis practically disappearing. Quick access to histopathological results of the stereotactic intraoperative biopsy made it possible to carry out the 125Iodine stereotactic brachytherapy immediately after the biopsy, resulting in less inconvenience for patients of a second possible intervention. The control MRI scans show significant shrinkage of tumours in both patients. CONCLUSION: The procedure can be performed as a biopsy. The CT and image fusion guided 125Iodine stereotactic brachytherapy can be well planned dosimetrically and is surgically precise.

[Image-fusion-guided radioisotope I-125 stereotactic brachytherapy of acoustic neurinoma--new surgical method]. / Akusztikus neurinoma kezelése képfúzió-vezérelt szövetközi 125-jód-izotóp-besugárzással--új mútéti eljárás.

Gamma knife and multi leaf collimator Linac have recently gained significant space in the treatment of acoustic neurinomas. As our neurosurgical department does not own gamma knife or Linac, we have successfully pursued the 125Iodine interstitial irradiation of three acoustic neurinomas. Our patients were elderly people with poor general condition, therefore we decided to undertake interstitial irradiation because of the low tolerance for surgery. The follow-up period until March 2002, lasted five, 23 and 40 months in the three cases. At the end of the follow-up period the audiometrical examination stated slight enhancement of hearing in case one and case two. In case one, the tumor volume, as measured on the control MRI was 5.32 cm3, which meant a 21% shrinkage in contrast to the 6.74 cm3 target volume at the brachytherapy. In case two, the shrinkage was even more apparent. The tumor volume measured on the control MRI examination was 6.64 cm3, which was a 42% shrinkage of the 11.45 cm3 target volume at the moment of brachytherapy. Due to financial reasons, gamma knife and Linac are not available for many countries and neurosurgical institutes. In the absence of the above mentioned radiosurgical methods, we have shown brachytherapy as a new alternative and solution in the treatment of acoustic neurinoma in three patients.

[Spinal stabilizations in our department (1989-2002)]. / Gerincstabilizációs mútétek osztályunkon 1989-2002.

With the aim to compare results to those found in the literature, authors present a retrospective overview of the spinal stabilizations carried out in the Neurosurgical Department at the St. John's Hospital, Budapest, Hungary between 1989 and 2002. This 37 bed department provides neurosurgical services to the Buda region with its one million inhabitants. Out of 156,000 injuries in total in the past 13 years, the department has dealt with 9360 neurotraumatologic cases, 560 of them suffering from spinal injuries. In parallel, non-traumatic cases were also treated for tumour, infections, degenerative diseases and for the instability of the spine. The 224 stabilised cases were classified into three groups: cervical, thoracic, lumbar. The authors enumerate the type of operation in each level and they present the number of cases belonging to each type. Septic complications occurred in 2.5% of cases. Screw breaking or slackening of the implanted devices was observed in 2% of the cases. The types of spinal operations applied provide satisfactory method for controlling the problems caused by the instability the spinal trauma, degenerative and tumourous cases. These results do not diverge from those found in the literature.