Removal Notice to 'Neurosurgical Steps and Lessons Learned in Final Separation of Three-Years-Old Craniopagus Twins' [World Neurosurgery (2022) 18924].

This article has been removed: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/locate/withdrawalpolicy). This article has been removed at the request of the Editor-in-Chief because the authors did not have authorised consent from the legal representatives of the patients to publish the details of their case.

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.

Impaired sequential and partially compensated probabilistic skill learning in Parkinson's disease.

The striatal dopaminergic dysfunction in Parkinson's disease (PD) has been associated with deficits in skill learning in numerous studies, but some of the findings remain controversial. Our aim was to explore the generality of the learning deficit using two widely reported skill learning tasks in the same group of Parkinson's patients. Thirty-four patients with PD (mean age: 62.83 years, SD: 7.67) were compared to age-matched healthy adults. Two tasks were employed: the Serial Reaction Time Task (SRT), testing the learning of motor sequences, and the Weather Prediction (WP) task, testing non-sequential probabilistic category learning. On the SRT task, patients with PD showed no significant evidence for sequence learning. These results support and also extend previous findings, suggesting that motor skill learning is vulnerable in PD. On the WP task, the PD group showed the same amount of learning as controls, but they exploited qualitatively different strategies in predicting the target categories. While controls typically combined probabilities from multiple predicting cues, patients with PD instead focused on individual cues. We also found moderate to high correlations between the different measures of skill learning. These findings support our hypothesis that skill learning is generally impaired in PD, and can in some cases be compensated by relying on alternative learning strategies.

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.

Effect of subthalamic stimulation on distal and proximal upper limb movements in Parkinson's disease.

INTRODUCTION: A different innervation pattern of proximal and distal muscles from the contra- and ipsilateral motor circuits raises the question as to whether bilateral, contra- and ipsilateral subthalamic stimulation may have different effects on the distal and proximal movements of the upper limb. To answer this question, we performed kinematic analyzes in patients with Parkinson's disease. METHODS: Twenty-eight Parkinsonian patients treated by bilateral subthalamic stimulation were examined with an age-matched control group of 28 healthy subjects. They performed 14s of finger tapping, hand grasping and pronation-supination. The patient group performed these sessions in four conditions (BOTH ON, BOTH OFF, CONTRA ON, IPSI ON) after withdrawal of dopaminergic medication for 12h and a fifth condition after taking medication (BOTH ON-MED ON). A motion sensor with a three-dimensional gyroscope was worn on the index finger. Speed, amplitude, rhythm and decrement of movements were calculated and compared across these conditions. RESULTS: Speed and amplitude of the more distal movements were improved similarly by contra- and bilateral stimulation. Bilateral stimulation was more effective than contralateral stimulation for the more proximal movements. Contra- and bilateral stimulation ameliorated the rhythm similarly in each movement task. Decrement of distal and proximal movements was not affected by the stimulation conditions. CONCLUSION: This is the first study to show that the outcome of bi- and unilateral subthalamic stimulation on proximal and distal upper limb movements should be evaluated separately postulating the different somatotopic organization of subloops in the cortico-basal ganglia motor circuits.

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.

The importance of very early decompressive craniectomy as a prevention to avoid the sudden increase of intracranial pressure in children with severe traumatic brain swelling (retrospective case series).

PURPOSE: The purpose of the retrospective case series of eight consecutive patients is to call our attention to the optimal timing of decompressive craniectomy (DC) in children. METHOD: We report the outcomes of eight children under the age of 12 with severe head injuries. DC was performed at different intracranial pressure (ICP; 20 and 25 mmHg) levels. RESULTS: Our results suggest that above 20 mmHg, very fast progression of ICP (within 15 min) can occur, which may limit the time available to plan and perform DC with a successful patient outcome. CONCLUSION: Considering the anamnestic data, it could be useful to perform DC at 20-22 mmHg ICP in young patients in order to prevent the potential of very fast brain swelling if there is no possibility to perform durotomy within 20 min after the onset of raising the ICP. It is especially considerable in poor countries where the emergency route could be less organized because of locations of building and extreme load of the staff. Further controlled trials are necessary to evaluate the indication and standardization of early decompressive craniectomy as a standard preventive therapy in pediatric severe traumatic brain swelling.

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.

Voice acoustic changes during bilateral subthalamic stimulation in patients with Parkinson's disease.

OBJECTIVES: The purpose of this study was to investigate the effects of bilateral subthalamic nucleus deep brain stimulation on the phonation of patients with Parkinson's disease in three drug-free conditions: (1) stimulation off, (2) with clinically optimised stimulation parameters, and (3) subthreshold overstimulation, in order to detect differences following voice analysis. PATIENTS AND METHODS: Conversational speech and sustained vowel sounds /a/, /i/, /o/, /u/ and high /i/ were recorded from 22 PD patients. Perceptual analysis, perturbation jitter, shimmer, noise-to-harmonics ratio, and nonlinear dynamic analysis (NDA) with detrended fluctuation analysis and recurrence period density entropy were measured and compared to the above conditions. Quadratic discriminant analysis (QDA) was used to investigate stimulation conditions for given acoustic data. RESULTS: The changes of perturbation measurements for the above conditions were not significant. With differences between vowels, NDA showed more significant changes and more powerful correlation with perceptual scores than perturbation measurements. NDA was significantly more sensitive during the QDA of the conditions. CONCLUSIONS: Acoustic voice analysis of sustained vowels can help with recognizing the overstimulated condition, and, with an appropriate test battery and software package including nonlinear dynamic analysis, it can be a valuable tool for fine adjustments of stimulation parameters.

[Movement analyzing devices for assessing the actual state of patients with movement disorders]. / Mozgásérzékelô eszközök neurológiai betegségben szenvedôk aktuális állapotának elemzésére.

Movement analysis gives valuable information on the actual state of patients. Based on it, the early diagnosis and objective assessment of the progress of several diseases can be helped. Our research work has been focused on developing clinically applicable movement analyzing devices.

[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.

Pallidal deep brain stimulation and L-dopa effect on PET motor activation in advanced Parkinson's disease.

BACKGROUND AND PURPOSE The antiakinetic effect of internal Globus pallidus deep brain stimulation (Gpi-DBS) in Parkinson's disease is not clear and not either how this effect is modulated by L-dopa. METHODS Left Gpi-DBS and/or L-dopa effect was studied with auditory paced right-handed sequential movements on (15)O-butanol positron emission tomography (PET) in five patients. Rest and for conditions during movements (DBS off/L-dopa off; DBS on/L-dopa off; DBS off/L-dopa on; DBS on/L-dopa on) were compared with statistical parametric mapping. RESULTS Gpi-DBS activated the right supplementary motor area/premotor (SMA/PMC), and right insular cortex (IC), and as L-dopa decreased the left sensorimotor cortex (M1/S1) activity. L-dopa increased the left ventrolateral thalamus (VLTH), and decreased the left superior parietal cortex (PC) activity. Gpi-DBS and L-dopa interaction showed right SMA/PMC, IC, and left PC activation, decrease of left VLTH, PMC, and dorsolateral prefrontal cortex (PFC) activity. CONCLUSIONS The improvement of bradykinesia with Gpi-DBS is secondary and contributed to the regress of M1/S1-related rigidity and compensatory SMA/PMC, and IC activation. L-dopa and Gpi-DBS alone each reduces M1/S1 overactivity. Interaction ignores this effect, moreover has akinetic effect in the left VLTH, PMC, and PFC. Motor improvement possibly related to left PC and compensatory right SMA/PMC, and IC activation.

Early experiences with a novel (robot hand) technique in the course of microneurosurgery.

BACKGROUND: The physiologic tremor may cause difficulties in microsurgery, in spite of using armrest. The new (robot hand) technique consists of the I-III finger support, which holds the instruments on Bethlehem (ANDAN BT, Budapest, Hungary) bridge above the operation area, which reduces the tremor at the end of the instruments. METHODS: Exact measurement of tremor reduction was performed. Last year, 23 microsurgical cases were operated on by the robot hand technique. RESULTS: The tremors of the operating hand and the number of complications have decreased effectively. CONCLUSION: By this technique, the microsurgical work has become more precise.