István Valálik

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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(More)
BACKGROUND The visualization of any morphological volume (i.e. CT, MRI) together with an additional second morphological volume (i.e. CT, MRI) or functional data set, which may come from SPECT or PET, is a new method for treatment planning, verification and follow-up of interstitial irradiation. METHOD The authors present their experience on interstitial(More)
OBJECTIVE To evaluate the effect of unilateral thalamotomy in patients with Parkinson's disease. METHODS The junction of the ventralis oralis posterior and ventralis intermedius nuclei targeted under CT-guidance, and confirmed by impedance recording and macrostimulation. RESULTS At the 6-month assessment the tremor has been completely abolished in 37(More)
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)(More)
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(More)
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(More)
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(More)
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(More)
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.(More)