# Longitudinal Blood‐Biomarker‐Based Assessment of Brain Injury in Patients Undergoing Deep Brain Stimulation and Magnetic Resonance–Guided Focused Ultrasound

## TL;DR

This study uses blood biomarkers to assess brain injury in patients undergoing DBS or MRgFUS, finding that DBS causes more lasting damage.

## Contribution

The study introduces longitudinal blood-biomarker analysis to compare neuroaxonal and astroglial injury between DBS and MRgFUS.

## Key findings

- sNfL peaked at day 7 and sGFAP at 24 hours post-intervention in both DBS and MRgFUS groups.
- sNfL normalized at 6 months in DBS and 3 months in MRgFUS, while sGFAP normalized within 7 days in both.
- Biomarker elevations were higher in DBS patients, indicating greater neuroaxonal injury and astroglial activation.

## Abstract

Deep brain stimulation (DBS) and magnetic resonance–guided focused ultrasound (MRgFUS) are associated with neuroaxonal damage and astroglial activation; yet their extent and timing remain unclear despite clinical relevance for monitoring and outcome assessment.

This study assessed neuroaxonal damage and astroglial activation after DBS (n = 21) and MRgFUS (n = 19) reflected by serum neurofilament light chain (sNfL) and serum glial fibrillary acidic protein (sGFAP).

Samples were collected at baseline, 24 h, 7 days, and 3/6/9 months posttreatment. Biomarker levels were measured using a single‐molecule array (Simoa).

sNfL peaked at day 7 and sGFAP at 24 h post‐intervention in both groups. sNfL normalized at 6 months in DBS and 3 months in MRgFUS. sGFAP normalized within 7 days in both groups. Biomarker elevations were higher in DBS patients.

DBS and MRgFUS cause transient neuroaxonal injury and astroglial activation, with greater extent in DBS. Biomarker monitoring suggests final clinical evaluation should be performed 6 months after treatment at the earliest. © 2025 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.