Kaviraja Udupa

Kaviraja Udupa
National Institute of Mental Health and Neuro Sciences | NIMHANS · Department of Neurophysiology

MBBS, MD, PhD
Neuroscience researcher working in the field of Clinical Neurophysiology to understand the brain and behaviour

About

114
Publications
26,273
Reads
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Introduction
Neuroscience researcher working in the field of Clinical Neurophysiology to understand the intracortical and basal ganglia-motor cortical circuits using non-invasive transcranial magnetic stimulation and deep brain stimulation in patients with movement or mood disorders to treat their conditions effectively
Additional affiliations
January 2017 - May 2017
University Health Network
Position
  • Scientific Associate
December 2014 - December 2016
University Health Network
Position
  • Analyst
Description
  • I work in patients with various movement disorders trying to understand the pathophysiology and design novel treatment options using both invasive deep brain stimulation and non-invasive transcranial magnetic stimulation techniques
December 2014 - September 2016
University Health Network
Position
  • Analyst
Education
September 2007 - December 2014
Toronto Western Research Institution, University Health Network, U of Toronto
Field of study
  • Clinical Neurophysiology
April 2005 - August 2007
May 2000 - August 2004

Publications

Publications (114)
Article
Full-text available
Background: In transcranial direct current stimulation (tDCS), the injected current becomes distributed across the brain areas. The objective is to stimulate the target region of interest (ROI) while minimizing the current in non-target ROIs (the ‘focality’ of tDCS). For this purpose, determining the appropriate current dose for an individual is di...
Article
Objective While previous studies showed that the single nucleotide polymorphism (Val66Met) of brain-derived neurotrophic factor (BDNF) can impact neuroplasticity, the influence of BDNF genotype on cortical circuitry and relationship to neuroplasticity remain relatively unexplored in human. Methods Using individualised transcranial magnetic stimula...
Article
HRV is inversely proportional to severity of depression. Effect of 12-weeks adjunct yoga therapy on HRV in patients with MDD was assessed through a randomized controlled trial. Sixty-eight subjects (40 females) with mean age 31.58 ± 8.79 years, scoring ≥18 on HDRS were randomized to either (YG; n=35) or (WG; n=33). Linear mixed model analysis showe...
Article
The brain has the innate ability to undergo neuronal plasticity, which refers to changes in its structure and functions in response to continued changes in the environment. Although these concepts are well established in animal slice preparation models, their application to a large number of human subjects could only be achieved using noninvasive b...
Article
Objective Motor cortical (M1) inhibition and facilitation can be studied with short-interval intracortical inhibition (SICI) and short-interval intracortical facilitation (SICF). These circuits are altered in Parkinson’s disease (PD). The sensorimotor measure short latency afferent inhibition (SAI) is possibly altered in PD. The aim was to determin...
Article
Full-text available
This review is part of the series on the clinical neurophysiology of movement disorders. It focuses on Parkinson’s disease and parkinsonism. The topics covered include the pathophysiology of tremor, rigidity and bradykinesia, balance and gait disturbance and myoclonus in Parkinson’s disease. The use of electroencephalography, electromyography, long...
Presentation
Full-text available
Dr Ananda's invited presentation at the National Conclave on Yoga Research and Applications organised as part of the Yogamahotsav by Sant Hirdaram Medical College & Hospital, Bhopal, Madhya Pradesh on 21st March, 2022.
Article
Background: Chanting “OM” is a form of meditation that has numerous health benefits. However, the neurophysiological mechanisms underpinning its effect are surprisingly scarce. The present study aimed to investigate the effect of OM chanting on autonomic modulation, using heart rate variability (HRV), on experienced yoga practitioners and yoga naïv...
Chapter
This chapter is divided into four subsections: the first section of the chapter provides an update on current evidence for yoga therapy in common mental health disorders, the second section provides brief overview on neurophysiological abnormalities in psychiatric disorders and their relationship with psychological stress, the third section deals w...
Article
The world was shocked with the sudden outbreak of a virus in the early 2020 destroying lives and livelihoods of millions across the globe. The COVID-19 pandemic with its epicentre in Wuhan, China spread across the globe like a fire. To restrict the further spread of the virus, nations around the world went into complete lockdown restraining people...
Article
Full-text available
Background: Functions of the autonomic nervous system have cardinal importance in day-to-day life. Heart rate variability (HRV) has been shown to estimate the functioning of the autonomic nervous system. Imbalance in the functioning of the autonomic nervous system is seen to be associated with chronic conditions such as chronic kidney disease, card...
Chapter
This chapter reviews the alterations in motor learning and motor cortical plasticity in Parkinson's disease (PD), the most common movement disorder. Impairments in motor learning, which is a hallmark of basal ganglia disorders, influence the performance of motor learning-related behavioral tasks and have clinical implications for the management of...
Article
Full-text available
We review the findings for motor cortical excitability, plasticity and evoked potentials in dystonia. Plasticity can be induced and assessed in cortical areas by non-invasive brain stimulation techniques such as transcranial magnetic stimulation (TMS) and the invasive technique of deep brain stimulation (DBS), which allows access to deep brain stru...
Article
There has been increased awareness about choosing the field and career progress in Physiology and its related branches. In spite of the many available resources, there exists a need for proper mentoring and guidance that is required to build up a good career as a physiologist. There is a high demand for physiologists in various fields with the adva...
Article
Full-text available
Objectives: Transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) have been used as neuromodulators in neuropsychiatric conditions. This study is aimed to find the effects of a single session of priming cathodal tDCS with intermittent theta-burst stimulation (iTBS) over left dorsolateral prefrontal cortex on hea...
Preprint
Full-text available
Background: In Transcranial Direct Current Stimulation (tDCS) the injected current gets distributed across the brain areas. The motive is to stimulate the target region-of-interest (ROI), while minimizing the current in non-target ROIs. For this purpose, determining the appropriate current-dose for an individual is difficult. Aim: To introduce Dose...
Article
Full-text available
This article is based on the “Open House Discussion on Yoga Research: Strength, weakness, opportunities, and threat (SWOT) analysis” that was organized during the international seminar cum workshop conducted by the Centre for Yoga Therapy, Education and Research (CYTER), an innovative center of Sri Balaji Vidyapeeth (SBV), on “Wholistic Approach of...
Article
Transcranial magnetic stimulation (TMS) is a non-invasive, painless technique to stimulate the human brain. Although it has been used in clinical research both as an investigative tool and treatment modality for the past three decades, its use has been restricted to tertiary health centres or higher-end academic research institutions. The aim of th...
Article
Full-text available
Continuous oxidation of carbohydrates, lipids, and amino acids generate extremely reactive carbonyl species (RCS). Human body comprises some important RCS namely hexanal, acrolein, 4-hydroxy-2-nonenal, methylglyoxal, malondialdehyde, isolevuglandins, and 4-oxo-2-nonenal etc. These RCS damage important cellular components including proteins, nucleic...
Article
Full-text available
Background & Objectives:Morvan’s syndrome is characterized by central, autonomic, and peripheral hyperexcitability due to CASPR-2-antibody. Our objective was to study the clinical spectrum, electrophysiological, autonomic, polysomnographic and neuropsychological profile in patients of CASPR-2 related Morvan’s syndrome. Materials & Methods Serum an...
Poster
Full-text available
NUMBER: 1081 The study aimed to assess cardiac autonomic dysfunction in patients with multiple system atrophy (MSA).
Presentation
Full-text available
This study is a prospective randomized controlled trial aimed at assessing the effect of 12 weeks of adjunct Yoga therapy on cortical inhibition (CI) using Trans-cranial Magnetic Stimulation (TMS) in MDD patients.
Chapter
Full-text available
This chapter is divided into four subsections: the first section of the chapter provides an update on current evidence for yoga therapy in common mental health disorders, the second section provides brief overview on neurophysiological abnormalities in psychiatric disorders and their relationship with psychological stress, the third section deals w...
Article
Introduction: Deep brain stimulation improves motor symptoms in Parkinson's disease and changes primary motor cortex excitability, but how subthalamic nucleus stimulation affects premotor-motor cortical connectivity remains unclear. Methods: We investigated 10 Parkinson patients in whom single subthalamic nucleus stimulation was time-locked to t...
Chapter
We review the motor cortical and basal ganglia involvement in two important movement disorders: Parkinson's disease (PD) and dystonia. Single and paired pulse transcranial magnetic stimulation studies showed altered excitability and cortical circuits in PD with decreased silent period, short interval intracortical inhibition, intracortical facilita...
Article
Deep brain stimulation (DBS) implanted in different basal ganglia nuclei regulates the dysfunctional neuronal circuits and improves symptoms in movement disorders. However, the understanding of the neurophysiological mechanism of DBS is at an early stage. Transcranial magnetic stimulation (TMS) can be used safely in movement disorder patients with...
Conference Paper
Mental illness forms a major portion of medical morbidity and also contributes immensely in the pathogenesis of many psychosomatic disorders. Previously many of these mental illnesses are thought to be idiopathic etiology with classical involvement of defective thought processing. However, with the advent of modern technology especially imaging (fu...
Article
Full-text available
Introduction Using transcranial magnetic stimulation (TMS), previous work has established that motor cortical inhibitory and facilitatory circuits are aberrant in patients with Parkinson’s disease (PD). Three such circuits are short interval intracortical inhibition (SICI), short interval intracortical facilitation (SICF) and short latency afferent...
Conference Paper
There is expanding interest in various non-invasive brain stimulation (NIBS) techniques such as repetitive transcranial magnetic stimulation (rTMS), transcranial direct current stimulation (tDCS), transcranial alternating current stimulation, transcranial static magnetic stimulation, magnetically induced seizure therapy and electroconvulsive therap...
Conference Paper
Transcranial magnetic stimulation (TMS) is a non-invasive, painless technique to stimulate the human brain. In the first part of this article, I will provide a brief overview of TMS, followed by a discussion of TMS parameters that can be studied using single and paired pulses of TMS and diagnostic & therapeutic utilities of TMS in Neuroscience. In...
Conference Paper
Autonomic nervous system has been involved in many neuropsychiatric disorders. Studies from our laboratory has shown autonomic dysregulation in several disorders including Major depression, Parkinson’s disease, epilepsy, ataxia, bipolar disorders etc. rTMS and other noninvasive brain modulation modalities have been used in the management of many ne...
Conference Paper
Regulation of autonomic nervous system is crucial for over all functions of visceral systems of the body. Through its two limbs (sympathetic and parasympathetic), autonomic nervous system regulates involuntary visceral organs and systems of the body, which is critical in maintaining the homeostasis of all the physiological functions. This homeostas...
Conference Paper
Objectives Recordings of seizures in epilepsy monitoring unit (EMU) help to characterize the epileptogenic foci, but some patients fail to have spontaneous seizures despite prolonged EMU stay and medication withdrawal. Repetitive transcranial magnetic stimulation (rTMS) can be used to increase cortical excitability and we postulated it could potent...
Article
Objective: Internal globus pallidus (GPi) deep brain stimulation (DBS) relieves symptoms in dystonia patients. However, the physiological effects produced by GPi DBS are not fully understood. In particular, how a single-pulse GPi DBS changes cortical circuits has never been investigated. We studied the modulation of motor cortical excitability and...
Chapter
Full-text available
Increased interest in exploring the physiological benefits of yoga in last few decades resulted in plethora of scientific studies involving different physiological measures in healthy volunteers and patients with various disorders. Of these measures, autonomic functions assessment remained prime role because of wider regulation of autonomic nervous...
Article
Response control in the forms of stopping and slowing responses is thought to be implemented by a frontal-subcortical network, which includes the subthalamic nucleus (STN). For manual control, stopping is linked to STN beta (13-30 Hz) and slowing responses are linked to lower frequencies (< 12 Hz). Whether similar STN oscillatory activities are ass...
Conference Paper
Major depression is the commonest psychiatric disorder affecting 3-5% of Indian population with the similar figures worldwide. Although, drugs acting on several neurotransmitter systems such as serotonin and norepinephrine are effectively used as antidepressants clinically, these drugs improve the condition only in 30-50% patients. Recurrence or re...
Conference Paper
There has been increased awareness about translational research in today’s world and young academic Physiologists are stimulated to get them involved in such research activities. These research works not only bring them forward in their careers but also collective efforts from various such research projects help to improve the health conditions of...
Article
Background: Heart rate variability is reduced in idiopathic PD, indicating cardiac autonomic dysfunction likely resulting from peripheral autonomic synucleinopathy. Little is known about heart rate variability in leucine-rich repeat kinase 2-associated PD. Objectives: This study investigated heart rate variability in LRRK2-associated PD. Method...
Article
Full-text available
We are interested in characterizing how brain networks interact and communicate with each other during voluntary movements. We recorded electrical activities from the globus pallidus pars interna (GPi), subthalamic nucleus (STN) and the motor cortex during voluntary wrist movements. Seven patients with dystonia and six patients with Parkinson’s dis...
Article
Full-text available
Background: Rapid action stopping leads to global motor suppression. This is shown by studies using transcranial magnetic stimulation to measure corticospinal excitability of task-unrelated effectors (e.g., from the hand during speech stopping). We hypothesize that this global suppression relates to the STN of the basal ganglia. Several STN local...
Article
Unlabelled: Noninvasive brain stimulation studies have shown abnormal motor cortical plasticity in Parkinson's disease (PD). These studies used peripheral nerve stimulation paired with transcranial magnetic stimulation (TMS) to primary motor cortex (M1) at specific intervals to induce plasticity. Induction of cortical plasticity through stimulatio...
Article
Objective: Determine the optimal dose of tetrabenazine for hemi-chorea treatment as monotherapy in NKH. Patients and methods: Four patients with hemichorea associated to NKH were included from 2013 to 2014. Other causes of hemichorea were ruled out with proper clinical evaluation and confirmed with MRI findings. Titration of TBZ was started with a...
Article
Deep brain stimulation (DBS) has been used as a treatment of movement disorders such as Parkinson's disease, dystonia, and essential tremor for over twenty years, and is a promising treatment for depression and epilepsy. However, the exact mechanisms of action of DBS are still uncertain, although different theories have emerged. This review summari...
Article
We hypothesized that subthalamic nucleus (STN) deep brain stimulation (DBS) will improve long-term potentiation (LTP)-like plasticity in motor cortex in Parkinson disease (PD). We studied 8 patients with PD treated with STN-DBS and 9 age-matched healthy controls. Patients with PD were studied in 4 sessions in medication (Med) OFF/stimulator (Stim)...
Conference Paper
Background Internal globus pallidus (GPi) deep brain stimulation (DBS) is an effective treatment for advanced generalized dystonia and cervical dystonia, but its mechanisms of action are not fully understood. We hypothesized that depotentiation is impaired in dystonia and it may be improved by GPi-DBS. Methods We studied two cervical dystonia patie...
Article
To investigate for the presence of central and peripheral physiological fatigue in electrical injury (EI) patients with experiential fatigue. Eight EI patients and eight age-matched healthy volunteers were recruited. Motor evoked potentials (MEP) following transcranial magnetic stimulation (TMS) and M-waves from ulnar nerve stimulation at the wrist...
Chapter
Central motor conduction time (CMCT) is the time taken for neural impulses to travel through the central nervous system on their way to the target muscles. When the motor cortex is stimulated with transcranial magnetic stimulation (TMS), CMCT is calculated by subtracting the peripheral conduction time from the motor evoked potential latency elicite...
Article
Introduction Variation in the brain derived neurotrophic factor (BDNF) gene affects neural plasticity. With the commonly studied single nucleotide polymorphism (SNP) BDNF Val66Met, the Met allele is associated with reduced plasticity. However, little is known about the baseline excitability measures of rarer form Met/Met compared to other forms and...
Article
Full-text available
In Parkinson's disease (PD), there are alterations of the basal ganglia (BG) thalamocortical networks, primarily due to degeneration of nigrostriatal dopaminergic neurons. These changes in subcortical networks lead to plastic changes in primary motor cortex (M1), which mediates cortical motor output and is a potential target for treatment of PD. St...
Article
Full-text available
Though neurological benefits of yoga training have been reported, lacunae still exists in understanding neurophysiological effects of such training. Hence, the present study was conducted to find the effect of yogasanas and pranayams on neurological and neuromuscular functions in healthy human volunteers and also determined differential effects of...
Article
Full-text available
Tilt table testing is taken as a safe and effective modality for subjecting a person to strong orthostatic stimulus. HRV (Heart rate variability) has the potential to provide valuable insight into physiological variations occurring in relation to postural changes. This study compares the supine basal, entire 30 minutes (Prolonged tilt), early 10 an...