Evaluating the therapeutic effect of LIPUS in the early stage of traumatic brain injury using FA and T2* in rats

Dan Du, Tao Zheng, Zhanqiu Wang, Yansheng Chen, Shuo Wu, Linsha Yang, Jiabin Lu, Lanxiang Liu

Aging 2024 · 10.18632/aging.206060

rodenttraumatic brain injuryother mrihistology molecular

Abstract

To evaluate the protective effect of LIPUS at the early stage of brain trauma in rats, 45 rats were randomly divided into 3 groups: sham ( n = 15), TBI ( n = 15) and LIPUS treatment groups ( n = 15). Ipsilateral and contralateral cortical and thalamic parameters obtained by diffusion tensor imaging (DTI) and fast low-angle shot magnetic resonance imaging (FLASH-MRI) were measured at different times after trauma. For fractional anisotropy (FA) and T2 * values, two-way repeated measures ANOVA with Tukey's post hoc was used for intergroup comparisons. With observation time prolonged, the FA values of the ipsilateral cortex in the TBI group gradually increased and were significantly higher than those in the LIPUS treatment group on Day 7 (adjusted P = 0.0067). FA values in the contralateral cortex decreased at this time and were significantly lower than those in the LIPUS treatment group (adjusted P = 0.0192). Meanwhile, compared with LIPUS group, FA values were significantly higher in the injured thalamus (adjusted P = 0.0025). Combined with correlation analysis, FA values were positively correlated with neuronal damage ( P = 0.0148, r 2 = 0.895). At 7 days after trauma, T2 * values in the ipsilateral cortex of the TBI group were significantly lower. After analysis of ferritin content and correlation, we found that T2 * values were negatively correlated with ferritin ( P = 0.0259, r 2 = -0.849). By measuring post-traumatic changes in FA and T2 * values, it is possible to demonstrate a neuronal protective effect of LIPUS in the early phase of TBI rats and promote brain rehabilitation.

Abstract via europepmc.

Speciesrat (Sprague Dawley)

Subjects15 animals

Sessions per subject7

Randomisedyes

Blindingnot reported

Sham / controlno treatment control

Auditory controlnot reported

Readout timingoffline

Anaesthesiaanaesthetised

Readoutsother mri, histology molecular — DTI fractional anisotropy; T2* (FLASH); HE, Nissl and ferritin staining

Direction of effectmixed or unclearLIPUS-treated rats showed lower FA rise in ipsilateral cortex at day 7, less Nissl-body loss and fewer ferritin-positive cells than untreated TBI; neuronal excitation or inhibition not assessed.

Adverse eventsnot reported

Exposures

Exposure 1: LIPUS to the injured area, 10 min daily for 7 days

Target: cerebral cortex — “the part of the rat's head that needed to be stimulated”
Device: Olympus / Panametrics · Olympus, Japan · V301-SU ✓

Pulse timing
Waveform	pulsed
Fundamental frequency (kHz)	500	✓✓✓
Pulse duration (ms)	0.5	✓✓✓
Pulse repetition frequency (Hz)	1,000	✓✓✓
Duty cycle (%)	not reportedpulse duration × PRF gives 50%
Sonication duration (s)	0.4	✓✓✓⚑

Pressure and intensity, by domain
Free-field pressure (kPa)	not reported
Free-field Isppa (W/cm²)	not reported
Free-field Ispta (W/cm²)	not reported
In-situ estimate	not reported
In-situ pressure (kPa)	not reported
In-situ Isppa (W/cm²)	not reported
In-situ Ispta (W/cm²)	not reported

Protocol, in the paper’s words

Stimulation duration 400 ms per trial, each trial 3 s, 200 trials, total stimulation 10 min; given 30 min after CCI then daily for a week.

Flags from extraction

exposures[0].target.terms — Target not named; the figure shows a gray circle near the CCI site. Cortex chosen as the injured region.
exposures[0].timing.sonication_duration_s — SD = 400 ms is the per-trial stimulation duration; trials are 3 s apart.
sham_type — The sham group (surgery without CCI) received no ultrasound; TBI group had CCI only. No sham ultrasound.
n_subjects — 15 per group; LIPUS group n=15.