Giriraj S. Shekhawat

Prof. Giriraj S. Shekhawat


Research Focus & Metrics

Academic Career Length

20Years (2007-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 September 2013 in Journal of the American Academy of Audiology
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Journal Article
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GSGiriraj S. Shekhawat
Giriraj S. Shekhawat
GSGrant Searchfield
Grant Searchfield
CSCathy M. Stinear
Cathy M. Stinear
Background:Tinnitus can have a devastating impact on the quality of life of the sufferer. Although the mechanisms underpinning tinnitus remain uncertain, hearing loss is often associated with its onset, and hearing aids are among the most commonly used tools for its management.Purpose:To conduct a scoping review to explore the role of hearing aids in tinnitus management.Research Design:Scoping review based on the six-stage framework of Arksey and O'Malley (2005).Study Sample:Relevant studies were identified using various databases (Scopus, Google Scholar, SpringerLink, and PubMed) and hand searching of journals and a reference list of articles. Out of 277 shortlisted articles, 29 studies (18 research studies and 11 reviews) were chosen for charting of data based on their abstracts.Data Collection and Analysis:Tinnitus assessment measures used in studies were recorded along with changes in their scores. Measures used in studies included the Tinnitus Handicap Inventory (THI), Tinnitus Handicap Questionnaire (THQ), Tinnitus Severity Index (TSI), Tinnitus Reaction Questionnaire (TRQ), German version of Tinnitus Questionnaire (TQ), Beck Depression Inventory (BDI), and visual analogue scale (VAS) of tinnitus intensity. Where possible Cohen's d effect size statistic was calculated.Results:Although the quality of evidence for hearing aids' effect on tinnitus is not strong, the weight of evidence (17 research studies for, 1 against) suggests merit in using hearing aids for tinnitus management.Conclusions:The majority of studies reviewed support the use of hearing aids for tinnitus management. Clinicians should feel reassured that some evidence shows support for the use of hearing aids for treating tinnitus, but there is still a need for stronger methodology and randomized control trials.

15 July 2015 in Neurorehabilitation and Neural Repair
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Journal Article
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GSGiriraj S. Shekhawat
Giriraj S. Shekhawat
FSFrederick Sundram
Frederick Sundram
MBMarom Bikson
Marom Bikson
DTDennis Truong
Dennis Truong
DRDirk De Ridder
Dirk De Ridder
GSGrant Searchfield
Grant Searchfield
Background and Objective. Tinnitus is the perception of a phantom sound. The aim of this study was to compare current intensity (center anode 1 mA and 2 mA), duration (10 minutes and 20 minutes), and location (left temporoparietal area [LTA] and dorsolateral prefrontal cortex [DLPFC]) using 4 × 1 high-definition transcranial direct current stimulation (HD-tDCS) for tinnitus reduction. Methods. Twenty-seven participants with chronic tinnitus (>2 years) and mean age of 53.5 years underwent 2 sessions of HD-tDCS of the LTA and DLPFC in a randomized order with a 1 week gap between site of stimulation. During each session, a combination of 4 different settings were used in increasing dose (1 mA, 10 minutes; 1 mA, 20 minutes; 2 mA, 10 minutes; and 2 mA, 20 minutes). The impact of different settings on tinnitus loudness and annoyance was documented. Results. Twenty-one participants (77.78%) reported a minimum of 1 point reduction on tinnitus loudness or annoyance scales. There were significant changes in loudness and annoyance for duration of stimulation, F(1, 26) = 10.08, P < .005, and current intensity, F(1, 26) = 14.24, P = .001. There was no interaction between the location, intensity, and duration of stimulation. Higher intensity (2 mA) and longer duration (20 minutes) of stimulation were more effective. Conclusions. A current intensity of 2 mA for 20-minute duration was the most effective setting used for tinnitus relief. The stimulation of the LTA and DLPFC were equally effective for suppressing tinnitus loudness and annoyance.

9 October 2017 in BioMed Research International
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Journal Article
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KFKathryn Fackrell
Kathryn Fackrell
IPIskra Potgieter
Iskra Potgieter
GSGiriraj S. Shekhawat
Giriraj S. Shekhawat
DBDavid M. Baguley
David M. Baguley
MSMagdalena Sereda
Magdalena Sereda
DHDerek James Hoare
Derek James Hoare
Background.There is no universally accepted definition for hyperacusis, but in general it is characterised by decreased sound tolerance to ordinary environmental sounds. Despite hyperacusis being prevalent and having significant clinical implications, much remains unknown about current management strategies.Purpose.To establish the current position of research on hyperacusis and identify research gaps to direct future research.Design and Sample.Using an established methodological framework, electronic and manual searches of databases and journals identified 43 records that met our inclusion criteria. Incorporating content and thematic analysis approaches, the definitions of hyperacusis, management strategies, and outcome measures were catalogued.Results. Only 67% of the studies provided a definition of hyperacusis, such as “reduced tolerance” or “oversensitivity to sound.” Assessments and outcome measures included Loudness Discomfort Levels, the Hyperacusis Questionnaire, and Tinnitus Retraining Therapy (TRT) interview. Management strategies reported were Cognitive Behavioural Therapy, TRT, devices, pharmacological therapy, and surgery.Conclusions. Management strategies were typically evaluated in patients reporting hyperacusis as a secondary complaint or as part of a symptom set. As such the outcomes reported only provided an indication of their effectiveness for hyperacusis. Randomised Controlled Trials are needed to evaluate the effectiveness of management strategies for patients experiencing hyperacusis.

2 October 2012 in Neurorehabilitation and Neural Repair
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Journal Article
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GSGiriraj S. Shekhawat
Giriraj S. Shekhawat
CSCathy M. Stinear
Cathy M. Stinear
GSGrant Searchfield
Grant Searchfield
Background. Perception of sound in the absence of an external auditory source is called tinnitus, which may negatively affect quality of life. Anodal transcranial direct current stimulation (tDCS) of the left temporoparietal area (LTA) was explored for tinnitus relief. Objective. This pilot study examined tDCS dose (current intensity and duration) and response effects for tinnitus suppression. Methods. Twenty-five participants with chronic tinnitus and a mean age of 54 years took part. Anodal tDCS of LTA was carried out. Current intensity (1 mA and 2 mA) and duration (10 minutes, 15 minutes, and 20 minutes) were varied and their impact on tinnitus measured. Results. tDCS was well tolerated. Fifty-six percent of participants (14) experienced transient suppression of tinnitus, and 44% of participants (11) experienced long-term improvement of symptoms (overnight—less annoyance, more relaxed, and better sleep). There was an interaction between duration and intensity of the stimulus on the change in rated loudness of tinnitus, F(2, 48) = 4.355, P = .018, and clinical global improvement score, F(2, 48) = 3.193, P = .050, after stimulation. Conclusions. Current intensity of 2 mA for 20 minutes was the more effective stimulus parameter for anodal tDCS of LTA. tDCS can be a potential clinical tool for reduction of tinnitus, although longer term trials are needed.

29 May 2018 in Scientific Reports
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GSGiriraj S. Shekhawat
Giriraj S. Shekhawat
SVSven Vanneste
Sven Vanneste
Neuromodulation is defined as the process of augmenting neuroplasticity via invasive or non-invasive methods. Tinnitus is the perception of sound in the absence of its external source. The objective of this study was to optimize the parameters of transcranial direct current stimulation (tDCS) of dorsolateral prefrontal cortex (DLPFC) for tinnitus suppression. The following factors were optimized in the dose-response design (n = 111): current intensity (1.5 mA or 2 mA), stimulation duration (20 min or 30 min), and number of stimulation sessions (2, 4, 6, 8, or 10), with a 3–4 day washout period between each session. Participants underwent a minimum of 2 sessions in 1 week or maximum of 10 sessions in 5 weeks’ time. Tinnitus loudness was measured in pre-post design using a 10-point numeric rating scale. There was a significant reduction in tinnitus loudness after tDCS of DLPFC. There was no significant difference between the intensity and duration of stimulation. As the number of sessions increased, there was a higher reduction in the tinnitus loudness; however, this effect plateaued after 6 sessions.

10 February 2015 in Neurorehabilitation and Neural Repair
Verified
Journal Article
Closed access
GSGiriraj S. Shekhawat
Giriraj S. Shekhawat
CSCathy M. Stinear
Cathy M. Stinear
GSGrant Searchfield
Grant Searchfield
Background. Tinnitus is the phantom perception of sound and can have negative effect on the quality of life. Transcranial direct current stimulation (tDCS) is a noninvasive neuromodulation technique, which can increase or decrease the cortical excitability in the brain region to which it is applied. tDCS has been used for tinnitus research since 2006. Objective. To investigate whether tDCS affects tinnitus perception, related emotion, or both, and the potential implications for tinnitus management. Methods. A scoping review was undertaken using the methods proposed by Arksey and O’Malley. After initial consideration of title relevance and reading abstracts, 15 studies were included in this review. The data from these studies were charted to investigate the impact of tDCS on tinnitus perception and emotions. Results. tDCS results in transient suppression of tinnitus loudness and annoyance; however, it does not lead to long-term impact on tinnitus related emotion. Local stimulation of different sites of stimulation (left temporoparietal area, dorsolateral prefrontal cortex, and auditory cortex) might modulate tinnitus perception (loudness) and emotions differently; however, further research is needed to explore this hypothesis. This review has identified aspects of methodologies that require attention in upcoming tinnitus and tDCS trials to offer better insights. Conclusions. tDCS is an effective research tool for transient tinnitus neuromodulation. However, efforts should be invested in designing clinical trials using local and multiple sites of stimulation, optimized parameters, and objective outcome measures before it can be translated in to a clinical tool for tinnitus management.