# BDNF genotype associated with changes in cortical thickness, severity of symptoms, and cognitive impairments in mild traumatic brain injury

## TL;DR

This study shows that different BDNF gene variants in people with mild traumatic brain injury are linked to brain structure changes, symptom severity, and cognitive issues.

## Contribution

The study reveals how BDNF genotypes influence recovery and brain structure after mild traumatic brain injury.

## Key findings

- Val carriers showed better cognitive flexibility and symptom improvement compared to Met carriers.
- Met carriers had more significant cortical thickness changes in brain regions related to cognition and emotion.
- BDNF polymorphisms may act as biomarkers for long-term cognitive and clinical outcomes in mTBI.

## Abstract

Brain-derived neurotrophic factor (BDNF) is a critical blood protein for brain function; however, its genotypic influence on clinical outcomes and brain structure following mild traumatic brain injury (mTBI) remains unclear. This study investigated the relationship between BDNF polymorphisms and cognitive impairment, symptom severity, and cortical structural injury in mTBI patients.

Sixty-one mTBI patients underwent neuropsychological assessments and MRI scans within one week post-injury, with 46 patients followed up at one month. Fifty-two healthy controls were included for comparison. Patients with mTBI exhibited clinical symptoms, cognitive impairment, and alterations in cortical thickness during in the acute phase.

BDNF Met gene carriers (n = 41) and Val gene carriers (n = 20) demonstrated different cognitive performance in the acute phase and exhibited distinct recovery trajectories. Val carriers showed significantly better cognitive flexibility compared to Met carriers (p = 0.028) during the acute phase and greater improvement in clinical symptoms at one month (p = 0.035). Follow-up MRI scans revealed more extensive and statistically significant alterations in cortical thickness in Met carriers than in Val carriers (p < 0.01), particularly in regions associated with cognitive and emotional regulation.

These findings suggest that BDNF polymorphisms in mTBI patients are associated with brain structural changes and may serve as valuable biomarkers for identifying individuals at risk for long-term clinical symptoms and cognitive impairment.

The online version contains supplementary material available at 10.1186/s13041-025-01239-1.