Related Experiment Video
Updated: Jan 2, 2026
Randomized, Triple-Blind, and Parallel-Controlled Trial of Transcranial Direct Current Stimulation for Cognitive Rehabilitation after Stroke
Published on: June 6, 2025
Randomized Controlled Trials in Functional Neurosurgery-Association of Device Approval Status and Trial Quality
Tej D Azad1,2, Austin Y Feng1, Swapnil Mehta1
1Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA.
Introduction:
Randomized controlled trials (RCTs) have been critical in evaluating the safety and efficacy of functional neurosurgery interventions. Given this, we sought to systematically assess the quality of functional neurosurgery RCTs.
Methods:
We used a database of neurosurgical RCTs (trials published from 1961 to 2016) to identify studies of functional neurosurgical procedures (N = 48). We extracted data on the design and quality of these RCTs and quantified the quality of trials using Jadad scores. We categorized RCTs based on the device approval status at the time of the trial and tested the association of device approval status with trial design and quality parameters.
Results:
Of the 48 analyzed functional neurosurgery RCTs, the median trial size was 34.5 patients with a median age of 51. The most common indications were Parkinson's disease (N = 20), epilepsy (N = 10), obsessive-compulsive disorder (N = 4), and pain (N = 4). Most trials reported inclusion and exclusion criteria (95.8%), sample size per arm (97.9%), and baseline characteristics of the patients being studied (97.9%). However, reporting of allocation concealment (29.2%), randomization mode (66.7%), and power calculations (54.2%) were markedly less common. We observed that trial quality has improved over time (Spearman r, 0.49). We observed that trials studying devices with humanitarian device exemption (HDE) and experimental indications (EI) tended to be of higher quality than trials of FDA-approved devices (p = 0.011). A key distinguishing quality characteristic was the proportion of HDE and EI trials that were double-blinded, compared to trials of FDA-approved devices (HDE, 83.3%; EI, 69.2%; FDA-approved, 35.3%). Although more than one-third of functional neurosurgery RCTs reported funding from industry, no significant association was identified between funding source and trial quality or outcome.
Conclusion:
The quality of RCTs in functional neurosurgery has improved over time but reporting of specific metrics such as power calculations and allocation concealment requires further improvement. Device approval status but not funding source was associated with trial quality.
