Effects of sulforaphane on cognitive function in patients with frontal brain damage: study protocol for a randomised controlled trial

Introduction: Many patients with frontal brain damage show serious cognitive function deficits, which hamper their quality of life and result in poor clinical outcomes. Preclinical research has shown that sulforaphane can significantly improve spatial localisation and working memory impairment after brain injury. The primary aim of this double-blind randomised controlled clinical trial is to assess the efficacy of sulforaphane for improving cognitive function in patients with frontal brain damage.

Methods and analysis: Ninety eligible patients will be randomly allocated to an active treatment or a placebo group in a 2:1 ratio. Participants will undergo a series of cognitive and neuropsychiatric tests at baseline (week 0) and after 12 weeks to determine the effect of sulforaphane on cognition. Magnetic resonance spectrum of the brain will be studied using the 3T MRIs of the brain to detect brain metabolites markers, including N-acetyl aspartate, glutamate (Glu), glutathione (GSH) and γ-aminobutyric acid (GABA). Blood brain-derived neurotrophic factor, Glu, GSH and GABA levels and gut microbiota will also be assessed over this period. This study will also evaluate long-term outcomes of brain trauma, brain tumours and cerebrovascular disease via exploratory analyses. The primary outcome will be the difference in scores of a battery of cognitive tests after 12 weeks of sulforaphane treatment. The secondary outcomes will be changes in the Functional Activities Questionnaire (FAQ), the Patient Health Questionnaire (PHQ-9), the Self-Rating Anxiety Scale, the changes in T1-weighted MRI and resting-state functional MRI findings, and changes in brain and blood metabolic markers and gut microbiota at weeks 0 and 12. We expect that sulforaphane will yield favourable results in treating memory and learning deficits for patients with frontal brain damage. Cognitive functional treatment may also improve brain trauma, brain tumours and cerebrovascular outcomes.

Ethics and dissemination: The study protocol has been approved by the Medical Ethics committee of the Xiangya Hospital of Central South University (No. 2017121019). The results will be disseminated in peer-reviewed journals and at international conferences.

Trial registration number: This trial was registered on Clinicaltrials.gov on 31 January 2020 (NCT04252261). The protocol version is V.1.0 (20 December 2019).