A clinical case report on transcranial low-intensity focused ultrasound neuromodulation for central post-stroke pain
Sijin He, Kaixuan Luo, Xiang Li, Jiajia Duan, Lei Ding, Moxian Chen, Xuan Xu, Xianghua Sun, Lijuan Ao, Xiangjun Feng
Frontiers in Neuroscience 2025 · 10.3389/fnins.2025.1686623
Abstract
Central post-stroke pain (CPSP) manifests as persistent or intermittent pain following cerebral infarction or hemorrhage and is described as "one of the most agonizing, disabling, and refractory pain syndromes." Its treatment represents a significant clinical challenge. In this case, we used transcranial low-intensity focused ultrasound (tLIFU), an emerging non-invasive neuromodulation approach distinct from pharmacological and traditional neuromodulation methods, to treat CPSP patients, achieving satisfactory outcomes. This approach may inspire new perspectives on innovative pain management. A 66-year-old male veteran suffered long-term CPSP, with unsatisfactory pain relief from previous paregoric interventions, including transcranial magnetic stimulation (TMS). Blood oxygenation level-dependent functional magnetic resonance imaging (BOLD-fMRI) revealed abnormal activity in a region of interest (ROI) that responded to analgesic medication adjustments. This ROI was anatomically consistent with the cingulum bundle. Given this finding, we used tLIFU to demonstrate deep stimulation of the ROI. Remarkable pain reduction was observed after 1 week of tLIFU neuromodulation, allowing for a slight tapering of the gabapentin dose. The analgesic effects of tLIFU were sustained throughout a 5-month follow-up period, with no adverse events reported. Since day 120, the patient has remained off analgesic medications, and at the 150-day follow-up, BOLD-fMRI revealed a normalized activity pattern in the region of interest (ROI). Additionally, significant clinical improvement was noted in the patient's emotional state. This case report highlights the potential of tLIFU technology to expand therapeutic options in clinical pain management. Exploratory research into the clinical efficacy and the underlying mechanisms of tLIFU in pain treatment may contribute to a deeper understanding of pain pathogenesis and support the development of novel therapeutic strategies.
Abstract via europepmc.
Exposures
Exposure 1: tLIFU to cingulum bundle ROI1 (left, healthy side)
Target: cingulum bundle — “cingulum bundle”
Device: other named manufacturer · GreenValley BrainTech Medical Technology Corporation · single-element focused ultrasonic transducer F0050A03 ✓
| Waveform | pulsed | |
|---|---|---|
| Fundamental frequency (kHz) | 500 | ✓✓✓ |
| Pulse duration (ms) | not reportedimplied by duty cycle ÷ PRF: 0.05 ms (not stated by the paper) | |
| Pulse repetition frequency (Hz) | 200 | ✓✓✓ |
| Duty cycle (%) | 1 | ✓✓✓ |
| Sonication duration (s) | 1,200 | ✓✓✓⚑ |
| 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 | |
| Pressure, domain unspecified (kPa) | 830 | ✓✓✓⚑ |
| Isppa, domain unspecified (W/cm²) | 0.00537 | ✓✓✓⚑ |
| Ispta, domain unspecified (W/cm²) | 0.0537 | ✓✓✓ |
The therapeutic session lasted 20 min and was administered once daily for 7 consecutive days; focus aligned to the target by optical navigation and monitored in real time.
Consistency checks: intensity pressure inconsistent unspecified domain.
Flags from extraction
exposures[0].unspecified_domain.isppa_w_cm2— Text gives ISPPA as 5.37 mW/cm2 and ISPTA as 53.73 mW/cm2; with a 1% duty cycle these look mutually inconsistent (the same paper cites 28.37 W/cm2 for a previous study). Recorded as stated, converted from mW/cm2; possible unit typo.exposures[0].unspecified_domain.pressure_kpa— Stated as peak-to-peak acoustic pressure 0.83 MPa; domain not stated; recorded as 830 kPa without conversion to peak negative.exposures[0].timing.sonication_duration_s— Only the 20 min session length is stated; whether it was one continuous train is not stated, and no pulse duration is given.n_subjects— Single-patient case report.exposures[0].target.terms— Target is an fMRI-defined ROI the authors say is consistent with the cingulum bundle, close to the left ACC.