Neural effects of transcranial direct current stimulation in schizophrenia: A case study using functional near-infrared spectroscopy

• Main Authors: S Trevor Taylor, Harleen Chhabra, Vanteemar S Sreeraj, Venkataram Shivakumar, Sunil V Kalmady, Ganesan Venkatasubramanian
• Format: Article
• Language: English
• Published: SAGE Publishing 2017-01-01
• Series: Indian Journal of Psychological Medicine
• Subjects: Auditory signal detection; functional near-infrared spectroscopy; schizophrenia; transcranial direct current stimulation
• Online Access: http://www.ijpm.info/article.asp?issn=0253-7176;year=2017;volume=39;issue=5;spage=691;epage=694;aulast=Taylor

Schizophrenia is a severe neuropsychiatric disorder characterized by delusions, hallucinations, behavioral symptoms, and cognitive deficits. Roughly, 70%–80% of schizophrenia patients experience auditory verbal hallucinations (AVHs), with 25%–30% demonstrating resistance to conventional antipsychotic medications. Studies suggest a promising role for add-on transcranial direct current stimulation (tDCS) in the treatment of medication-refractory AVHs. The mechanisms through which tDCS could be therapeutic in such cases are unclear, but possibly involve neuroplastic effects. In recent years, functional near-infrared spectroscopy (fNIRS) has been used successfully to study tDCS-induced neuroplastic changes. In a double-blind, sham-controlled design, we applied fNIRS to measure task-dependent cerebral blood flow (CBF) changes as a surrogate outcome of single session tDCS-induced effects on neuroplasticity in a schizophrenia patient with persistent auditory hallucinations. The observations are discussed in this case report.