TY - JOUR
T1 - Transcranial direct current stimulation in the treatment of visual hallucinations in Charles Bonnet syndrome
T2 - A randomized placebo-controlled crossover trial.
AU - da Silva Morgan, Katrina
AU - Schumacher, Julia
AU - Collerton, Daniel
AU - Colloby, Sean J.
AU - Elder, Greg
AU - Olsen, Kirsty
AU - Ffytche, Dominic H.
AU - Taylor, John-Paul
N1 - Funding information: This work was supported by a grant from the Macular Society (BH152932). Additional support came from the NIHR Newcastle Biomedical Research Centre (BRC) based at Newcastle upon Tyne Hospitals NHS Foundation Trust and Newcastle University and the South London and Maudsley NHS Foundation Trust Mental Health BRC.
D.H.ff., D.C., K.O., and J.-P.T.: Supported by NIHR Programme Grants for Applied Research (RP-PG-0610-10100 - SHAPED). The views expressed are those of the authors and not necessarily those of the NIHR or the Department of Health and Social Care. The funding organization had no role in the design or conduct of the study.
HUMAN SUBJECTS: Human subjects are included in this study. All participants provided written informed consent, and ethical approval was granted by the local Research Ethics and NHS Research and Development Committees (ref: 17/NE/0131). This study was conducted in concordance with the tenets of the Declaration of Helsinki and is registered at www.isrctn.com under the identifier ISRCTN16758036.
PY - 2022/12/1
Y1 - 2022/12/1
N2 - Objective: To investigate the potential therapeutic benefits and tolerability of inhibitory transcranial direct current stimulation (tDCS) on the remediation of visual hallucinations in Charles Bonnet syndrome (CBS). Design: Randomized, double-masked, placebo-controlled crossover trial. Participants: Sixteen individuals diagnosed with CBS secondary to visual impairment caused by eye disease experiencing recurrent visual hallucinations. Intervention: All participants received 4 consecutive days of active and placebo cathodal stimulation (current density: 0.29 mA/cm
2) to the visual cortex (Oz) over 2 defined treatment weeks, separated by a 4-week washout period. Main Outcome Measures: Ratings of visual hallucination frequency and duration following active and placebo stimulation, accounting for treatment order, using a 2 × 2 repeated-measures model. Secondary outcomes included impact ratings of visual hallucinations and electrophysiological measures. Results: When compared with placebo treatment, active inhibitory stimulation of visual cortex resulted in a significant reduction in the frequency of visual hallucinations measured by the North East Visual Hallucinations Interview, with a moderate-to-large effect size. Impact measures of visual hallucinations improved in both placebo and active conditions, suggesting support and education for CBS may have therapeutic benefits. Participants who demonstrated greater occipital excitability on electroencephalography assessment at the start of treatment were more likely to report a positive treatment response. Stimulation was found to be tolerable in all participants, with no significant adverse effects reported, including no deterioration in preexisting visual impairment. Conclusions: Findings indicate that inhibitory tDCS of visual cortex may reduce the frequency of visual hallucinations in people with CBS, particularly individuals who demonstrate greater occipital excitability prior to stimulation. tDCS may offer a feasible intervention option for CBS with no significant side effects, warranting larger-scale clinical trials to further characterize its efficacy.
AB - Objective: To investigate the potential therapeutic benefits and tolerability of inhibitory transcranial direct current stimulation (tDCS) on the remediation of visual hallucinations in Charles Bonnet syndrome (CBS). Design: Randomized, double-masked, placebo-controlled crossover trial. Participants: Sixteen individuals diagnosed with CBS secondary to visual impairment caused by eye disease experiencing recurrent visual hallucinations. Intervention: All participants received 4 consecutive days of active and placebo cathodal stimulation (current density: 0.29 mA/cm
2) to the visual cortex (Oz) over 2 defined treatment weeks, separated by a 4-week washout period. Main Outcome Measures: Ratings of visual hallucination frequency and duration following active and placebo stimulation, accounting for treatment order, using a 2 × 2 repeated-measures model. Secondary outcomes included impact ratings of visual hallucinations and electrophysiological measures. Results: When compared with placebo treatment, active inhibitory stimulation of visual cortex resulted in a significant reduction in the frequency of visual hallucinations measured by the North East Visual Hallucinations Interview, with a moderate-to-large effect size. Impact measures of visual hallucinations improved in both placebo and active conditions, suggesting support and education for CBS may have therapeutic benefits. Participants who demonstrated greater occipital excitability on electroencephalography assessment at the start of treatment were more likely to report a positive treatment response. Stimulation was found to be tolerable in all participants, with no significant adverse effects reported, including no deterioration in preexisting visual impairment. Conclusions: Findings indicate that inhibitory tDCS of visual cortex may reduce the frequency of visual hallucinations in people with CBS, particularly individuals who demonstrate greater occipital excitability prior to stimulation. tDCS may offer a feasible intervention option for CBS with no significant side effects, warranting larger-scale clinical trials to further characterize its efficacy.
KW - Charles Bonnet syndrome
KW - Macular degeneration
KW - Noninvasive stimulation
KW - Visual hallucinations
UR - http://www.scopus.com/inward/record.url?scp=85138786623&partnerID=8YFLogxK
U2 - 10.1016/j.ophtha.2022.06.041
DO - 10.1016/j.ophtha.2022.06.041
M3 - Article
SN - 0161-6420
VL - 129
SP - 1368
EP - 1379
JO - Ophthalmology
JF - Ophthalmology
IS - 12
ER -