|
Examining Neuroplasticity modulation as mechanistic basis of tDCS treatment effects on Auditory Verbal Hallucination in Schizophrenia (2020-Present) |
Scientific Brief: 20-30% of schizophrenia (SCZ) patients struggle with auditory verbal hallucinations (AVH) minimally responsive to
pharmaceutical treatments. Add-on fronto-temporoparietal transcranial direct current stimulation (tDCS) is suggested to address persistent AVH in SCZ patients. High heterogeneity among existing randomized control trials for AVH treatment in SCZ and the lack of empirical studies investigating the tDCS action mechanisms warrant systematic investigation into the mechanistic basis of tDCS action. This study proposes and examines the brain’s neuroplasticity potential as a biological phenomenon driving the treatment effects of tDCS. Using a randomized, double-blind, sham-controlled parallel-arm, pre-post design, changes in neuroplasticity potential with tDCS treatment for AVH in SCZ will be assessed. The four composite outcome measures will be a reduction in AVH severity (clinical), changes in resting-state functional connectivity (neuroimaging), changes in glutamine-glutamate levels (neurochemical) and changes in N100-derived event-related-potential waveforms (neurophysiological). The correlation between neurobiological measures of neuroplasticity changes induced by tDCS and clinical improvement in AVH will indicate the nature and strength of the relationship between the two. Additionally, exploring the effect of verum (active) tDCS on early course versus late course SCZ patients will uncover if illness chronicity is a potential barrier to tDCS responsivity. Predicting tDCS responsivity through measures of neuroplasticity and exploring the contribution of illness chronicity can inform tDCS recommendations.
Layman Brief: Schizophrenia is a brain disorder; these patients often hear voices inside their heads. Despite adequate
medication, these voices may continue, perpetuating dysfunction and distress. Transcranial direct current stimulation (tDCS) is a safe, non-invasive brain stimulation technique that reduces ‘hearing voices’. However, how and why add-on tDCS works is unclear. Brain can change itself in response to its environment; this is called neuroplasticity. tDCS possibly changes the brain’s environment and/or enhances brain’s ability to respond favourably to its environment. This theory will be examined here by studying changes in brain functions before and after giving tDCS to schizophrenia patients hearing voices.
Implications:
Principal Investigator: Dr. Anushree Bose
Fellowship Supervisor: Prof. Venkatasubramanian G.
Funding: DBT-Wellcome Trust India Alliance Early Career Fellowship (CPH) - Reference: IA/CPHE/19/1/504591
pharmaceutical treatments. Add-on fronto-temporoparietal transcranial direct current stimulation (tDCS) is suggested to address persistent AVH in SCZ patients. High heterogeneity among existing randomized control trials for AVH treatment in SCZ and the lack of empirical studies investigating the tDCS action mechanisms warrant systematic investigation into the mechanistic basis of tDCS action. This study proposes and examines the brain’s neuroplasticity potential as a biological phenomenon driving the treatment effects of tDCS. Using a randomized, double-blind, sham-controlled parallel-arm, pre-post design, changes in neuroplasticity potential with tDCS treatment for AVH in SCZ will be assessed. The four composite outcome measures will be a reduction in AVH severity (clinical), changes in resting-state functional connectivity (neuroimaging), changes in glutamine-glutamate levels (neurochemical) and changes in N100-derived event-related-potential waveforms (neurophysiological). The correlation between neurobiological measures of neuroplasticity changes induced by tDCS and clinical improvement in AVH will indicate the nature and strength of the relationship between the two. Additionally, exploring the effect of verum (active) tDCS on early course versus late course SCZ patients will uncover if illness chronicity is a potential barrier to tDCS responsivity. Predicting tDCS responsivity through measures of neuroplasticity and exploring the contribution of illness chronicity can inform tDCS recommendations.
Layman Brief: Schizophrenia is a brain disorder; these patients often hear voices inside their heads. Despite adequate
medication, these voices may continue, perpetuating dysfunction and distress. Transcranial direct current stimulation (tDCS) is a safe, non-invasive brain stimulation technique that reduces ‘hearing voices’. However, how and why add-on tDCS works is unclear. Brain can change itself in response to its environment; this is called neuroplasticity. tDCS possibly changes the brain’s environment and/or enhances brain’s ability to respond favourably to its environment. This theory will be examined here by studying changes in brain functions before and after giving tDCS to schizophrenia patients hearing voices.
Implications:
- Neuroplasticity, as a biomarker, could predict tDCS response
- Potential development of personalized tDCS treatment plan
- Optimization of tDCS parameters towards achieving greater efficacy.
- Deep insight into biological mechanism underlying AVH pathophysiology
Principal Investigator: Dr. Anushree Bose
Fellowship Supervisor: Prof. Venkatasubramanian G.
Funding: DBT-Wellcome Trust India Alliance Early Career Fellowship (CPH) - Reference: IA/CPHE/19/1/504591