András Csókay

Vascular tunnel creation to improve the efficacy of decompressive craniotomy in post-traumatic cerebral edema and ischemic stroke.

BACKGROUND Decompressive craniectomy with durotomy has been well described but remains a controversial treatment for traumatic or ischemic brain swelling. Although the technique can reduce intracranial pressure it frequently results in infarction of the brain tissue which extends through the durotomy because of compression and subsequent complications associated with decompressive craniectomy. METHODS All patients treated with surgical decompression were comatose with Grade 3 or 4 Glasgow Coma Scores. Since 1998 we have changed our technique for decompressive craniectomy by creating vascular channels around the major vessels crossing the durotomy margin. Outcomes in 21 patients treated with this technique are compared to 20 patients treated with a conventional decompression and durotomy between 1997 through 1999. RESULTS Clinical outcome was substantially better in the group treated with a vascular tunnel. CONCLUSIONS Our results suggest that placing vascular tunnels at the margins of a durotomy when performing a decompression may reduce vascular congestion and the subsequent ischemia in brain tissue which herniates through the durotomy, leading to better clinical outcomes.

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.

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.

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 Parkinsons 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.

Pallidal Deep Brain Stimulation and L-Dopa Effect on PET Motor Activation in Advanced Parkinson's Disease

The antiakinetic effect of internal Globus pallidus deep brain stimulation (Gpi‐DBS) in Parkinsons disease is not clear and not either how this effect is modulated by L‐dopa.

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

Abstract 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.

CORRESPONDENCE: LETTERS: Fingertip support technique and instrument support for reducing unintentional instrument movements in otology

Sir, Physiological tremor is a main risk factor in microsurgery and the range of tremor magnitude varies widely. Our team developed two simple but very effective low-cost techniques for the reduction of physiological tremor. ‘Fingertip support’ technique (FS) is basically a mechanical support called ‘bridge’ for the first three (instrument holding) fingers of the surgeon. This bridge can be placed both above and near the operating site (Fig. 2). This technique eliminates interference from all of the joints trans-

Fingertip support technique and instrument support for reducing unintentional instrument movements in otology.

Sir, Physiological tremor is a main risk factor in microsurgery and the range of tremor magnitude varies widely. Our team developed two simple but very effective low-cost techniques for the reduction of physiological tremor. ‘Fingertip support’ technique (FS) is basically a mechanical support called ‘bridge’ for the first three (instrument holding) fingers of the surgeon. This bridge can be placed both above and near the operating site (Fig. 2). This technique eliminates interference from all of the joints trans-

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.

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

BackgroundThe 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.MethodsA 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.ResultsThe 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.ConclusionThis 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.