Publications by authors named "Zelma Kiss"

The subgenual anterior cingulate cortex (sgACC) has been identified as a key brain area involved in various cognitive and emotional processes. While the sgACC has been implicated in both emotional valuation and emotional conflict monitoring, it is still unclear how this area integrates multiple functions. We characterized both single neuron and local field oscillatory activity in 14 patients undergoing sgACC deep brain stimulation for treatment-resistant depression.

View Article and Find Full Text PDF

Magnetic resonance-guided focused ultrasound (MRgFUS) is one of the newest surgical treatments for essential tremor (ET). During this procedure, a lesion is created within the thalamus to mitigate tremor. Targeting is done using a combination of stereotaxy, MR tractography, and sublesional heating, with tremor assessed during the procedure to gauge therapeutic effectiveness.

View Article and Find Full Text PDF

The increasing ability of neuroscience to analyse and modulate human brain functions calls for a new regulatory approach to identify and deal with potential harmful applications in the early stages of development. [Image: see text]

View Article and Find Full Text PDF

Objectives: This study compared machine learning models using unimodal imaging measures and combined multi-modal imaging measures for deep brain stimulation (DBS) outcome prediction in treatment resistant depression (TRD).

Methods: Regional brain glucose metabolism (CMRGlu), cerebral blood flow (CBF), and grey matter volume (GMV) were measured at baseline using 18F-fluorodeoxy glucose (18F-FDG) positron emission tomography (PET), arterial spin labelling (ASL) magnetic resonance imaging (MRI), and T1-weighted MRI, respectively, in 19 patients with TRD receiving subcallosal cingulate (SCC)-DBS. Responders ( = 9) were defined by a 50% reduction in HAMD-17 at 6 months from the baseline.

View Article and Find Full Text PDF

Deep brain stimulation (DBS) has shown therapeutic benefits for treatment resistant depression (TRD). Stimulation of the subcallosal cingulate gyrus (SCG) aims to alter dysregulation between subcortical and cortex. However, the 50% response rates for SCG-DBS indicates that selection of appropriate patients is challenging.

View Article and Find Full Text PDF

. Focused ultrasound (FUS) neuromodulation non-invasively alters brain activity, likely via acoustic radiation force with dynamics of the pulse repetition frequency (PRF). PRF impacts neuromodulation as well as indirect auditory activation, a confound linked to skull vibrations.

View Article and Find Full Text PDF

Introduction: Rhythmic beta activity in the subthalamic nucleus (STN) local field potential (LFP) is associated with Parkinson disease (PD) severity, though not all studies have found this relationship. We investigated whether aperiodic 'noise' elements of LFP, specifically slope of the 1/f broadband, predict PD motor symptoms and outcomes of STN-DBS.

Methods: We studied micro-LFP from 19 PD patients undergoing STN-DBS, relating the aperiodic 1/f slope and the periodic beta oscillation components to motor severity using the UPDRS-III and improvement with DBS at 1 year.

View Article and Find Full Text PDF
Article Synopsis
  • The study explores the history and current state of women in Canadian neurosurgery, highlighting their late entry into the field and the continued underrepresentation of women compared to their increasing numbers in medical school.
  • It reviews the experiences and achievements of female neurosurgeons, noting both challenges and supportive factors they have faced throughout their careers.
  • This overview aims to shed light on gender inequities within neurosurgery, offer insights from current and retired female surgeons, and inspire future generations of women in the specialty.
View Article and Find Full Text PDF

WHAT IS KNOWN ON THE SUBJECT?: Major depressive disorder is the most prevalent of all mental illnesses. 10%-20% of patients with depression and 1% of the population overall have treatment-resistant depression (TRD). DBS is an emerging investigational treatment for TRD with documented clinical efficacy and safety.

View Article and Find Full Text PDF

Background: Magnetic resonance-guided focused-ultrasound (MRgFUS) thalamotomy is an effective treatment for essential and other tremors. It targets the ventrointermedius (Vim) nucleus, which is the thalamic relay in a proprioceptive pathway, and contains kinesthetic cells. Although MRgFUS thalamotomy reduces some risks associated with more invasive surgeries, it still has side effects, such as balance and gait disturbances; these may be caused by the lesion impacting proprioception.

View Article and Find Full Text PDF

Deep brain stimulation (DBS) is a revolutionary treatment for movement disorders. Measuring DBS-induced hemodynamic responses may be useful for surgical guidance of DBS electrode implantation as well as to study the mechanism and assess therapeutic effects of DBS. In this study, we evaluated the performance of a single fiber spectroscopic (SFS) system for measuring hemodynamic response in different cortical layers in a DBS animal model.

View Article and Find Full Text PDF

Over the past 15 years, deep brain stimulation (DBS) has been actively investigated as a groundbreaking therapy for patients with treatment-resistant depression (TRD); nevertheless, outcomes have varied from patient to patient, with an average response rate of ∼50%. The engagement of specific fiber tracts at the stimulation site has been hypothesized to be an important factor in determining outcomes, however, the resulting individual network effects at the whole-brain scale remain largely unknown. Here we provide a computational framework that can explore each individual's brain response characteristics elicited by selective stimulation of fiber tracts.

View Article and Find Full Text PDF

Essential tremor (ET) is a tremor syndrome characterized by bilateral, upper limb action tremor. Essential tremor-plus (ET-plus) describes ET patients with additional neurologic signs. It is unknown whether there is a difference in response to treatment with ventralis intermedius nucleus deep brain stimulation (VIM DBS) in patients with ET and ET-plus.

View Article and Find Full Text PDF

Background: Deep brain stimulation (DBS) is a promising investigational approach for treatment-resistant depression. However, reports suggesting changes in personality with DBS for movement disorders have raised clinical and ethical concerns. We prospectively examined changes in personality dimensions and antidepressant response to subcallosal cingulate (SCC)-DBS for treatment-resistant depression.

View Article and Find Full Text PDF

Motor cortical representation can be probed non-invasively using a transcranial magnetic stimulation (TMS) technique known as motor mapping. The mapping technique can influence features of the maps because of several controllable elements. Here we review the literature on six key motor mapping parameters, as well as their influence on outcome measures and discuss factors impacting their selection.

View Article and Find Full Text PDF
Article Synopsis
  • This chapter talks about the ethical problems related to brain surgery and technology in Canada, looking through the work of a special group called PCNEC.
  • It discusses important issues like new technology, risks, vulnerable people, and legal matters that come with these kinds of medical practices.
  • The goal is to ensure that any new brain technology is developed in a way that is fair, respectful, and focused on helping people.
View Article and Find Full Text PDF

Purpose: Cerebellar connectivity is thought to be abnormal in cervical dystonia (CD) and other dystonia subtypes, based on evidence from imaging studies and animal work. The authors investigated whether transcranial magnetic stimulation-induced cerebellar brain inhibition (CBI), a measure of cerebellar efficiency at inhibiting motor outflow, is abnormal in patients with CD and/or is associated with clinical features of CD. Because of methodological heterogeneity in CBI reporting, the authors deployed additional controls to reduce potential sources of variability in this study.

View Article and Find Full Text PDF

Deep brain stimulation (DBS) of the subcallosal cingulate gyrus (SCG) is a promising therapy for treatment-resistant depression. Pre-clinical models have been widely used to investigate the neural mechanisms underlying its antidepressant benefit. The ventral division of the medial prefrontal cortex (vmPFC), particularly the infralimbic cortex (IL), is the homologous region in rat and DBS applied to vmPFC shows antidepressant-like effects in the forced swim test.

View Article and Find Full Text PDF

Introduction: Deep brain stimulation (DBS) is currently an investigational treatment for treatment-resistant depression (TRD). There is a need for more DBS trials to strengthen existing evidence of its efficacy for both regulatory and clinical reasons. Recruitment for DBS trials remains challenging due to unproven efficacy in sham-controlled DBS trials, invasive nature of the intervention and stringent eligibility criteria in patient selection.

View Article and Find Full Text PDF

A deeper understanding of the cross-cultural applicability of cognitive tests across countries and cultures is needed to better equip neuropsychologists for the assessment of patients from diverse backgrounds. Our study compared cognitive test scores in patients with advanced Parkinson's disease (PD) at the Prince of Wales Hospital ( = 63; Hong Kong) and the Foothills Medical Center ( = 20; Calgary, Canada). The groups did not differ in age or sex ( > .

View Article and Find Full Text PDF

Objectives: Occipital nerve regional stimulation (ONS) is reported to improve pain in several studies. We examined long-term pain and functional outcomes of ONS in an open-label prospective study.

Methods: Patients with medically refractory and disabling craniofacial pain were prospectively selected for ONS.

View Article and Find Full Text PDF

Subcallosal cingulate (SCC) deep brain stimulation (DBS) is a promising therapy for treatment-resistant depression (TRD), but response rates in open-label studies were not replicated in a large multicenter trial. Identifying biomarkers of response could improve patient selection and outcomes. We examined SCC metabolic activity as both a predictor and marker of SCC DBS treatment response.

View Article and Find Full Text PDF