Dysfunction of the visual cortex is implicated in psychosis and recently, the extrastriate visual cortex (V5/MT) has been causally linked to visual hallucinations through lesion network mapping. Transcranial electric stimulation (tES) has been shown to improve psychotic symptoms and cognition in psychosis spectrum disorders. However, few investigations have used novel approaches, such as high definition tES (HD-tES) to target specific brain circuits. Previously, we showed that stimulation delivered to V5/MT using HD-tDCS (direct current) reduced Positive and Negative Syndrome Scale (PANSS) general symptoms in the short-term (5 days), while HD-tACS (alternating current) improved general symptoms and functioning in the long-term (30 days). Here, we aim to determine if HD-tES to V5/MT has altering effects on cognition and self-reported symptoms of psychosis, and to investigate the differences between self-reported and clinician-reported symptoms. A pilot open label study with a within-subjects, single blind, crossover design was conducted in order to characterize the efficacy of cathodal HD-tDCS and 2Hz delta HD-tACS for psychosis treatment. Enrolled patients received 20 mins of HD-tES twice daily for 5 consecutive days applied bilaterally to V5/MT with a washout between conditions. Assessments were performed at baseline, day 5, and day 30. HD-tACS treatment was found to improve cognition on Digit Sequencing, Tower of London, Semantic Fluency, and “S” Letter Fluency tasks as measured by brief assessment of cognition in schizophrenia (BACS) as well as symptoms of paranoid ideation and anger/hostility as measured by the symptom checklist 90 (SC-90) 1 month after treatment. HD-tDCS treatment yielded significant improvement on “F” Letter Fluency as measured by BACS and did not yield any significant improvement on SC-90 symptoms. Lastly, correlations between SC-90 and PANSS described a distinct relationship between the two scales and their measures of psychiatric morbidity. Ultimately, delta wave tACS may be able to improve cognition and certain symptoms of psychosis by altering cortico-cortico communication between relevant brain structures. Future large-scale investigations are needed to further solidify these results. / 2026-03-04T00:00:00Z
| Identifer | oai:union.ndltd.org:bu.edu/oai:open.bu.edu:2144/48340 |
| Date | 05 March 2024 |
| Creators | Molho, Willa |
| Contributors | McKnight, C. James, Lizano, Paulo |
| Source Sets | Boston University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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