[Paper Review] Decreasing the Surgical Errors by Neurostimulation of Primary Motor Cortex and the Associated Brain Activation via Neuroimaging

Yuanyuan Gao, Lora Cavuoto+10 more|arXiv (Cornell University)|Oct 9, 2020

Intraoperative Neuromonitoring and Anesthetic Effects24 references4 citations

TL;DR

This study demonstrates that transcranial direct current stimulation (tDCS) applied to the primary motor cortex reduces surgical error rates and performance variability in medical students learning laparoscopic skills. Using concurrent fNIRS neuroimaging, tDCS was shown to enhance cortical activation, with improved accuracy and increased brain activity retained one month post-training, supporting tDCS as a tool to enhance fine bimanual motor skill acquisition in surgical training.

ABSTRACT

Acquisition of fine motor skills is a time-consuming process as it requires frequent repetitions. Transcranial electrical stimulation is a promising means of enhancing simple motor skill development via neuromodulatory mechanisms. Here, we report that non-invasive neurostimulation facilitates the learning of complex fine bimanual motor skills associated with a surgical task. During the training of 17 medical students on the Fundamentals of Laparoscopic Surgery (FLS) pattern cutting task over a period of 12 days, we observed that transcranial direct current stimulation (tDCS) decreased the error level and the variability in performance, compared to the Sham group. By concurrently monitoring the cortical activations of the subjects via functional near-infrared spectroscopy (fNIRS), our study showed that the cortical activation significantly stimulated by tDCS. The lowered performance error and the increased brain activation were retained after one-month post-training. This work supports the use of tDCS to enhance performance accuracy in fine bimanual motor tasks.

Motivation & Objective

• To investigate whether non-invasive tDCS can enhance the acquisition of complex fine bimanual motor skills required in laparoscopic surgery.
• To examine the relationship between tDCS-induced cortical activation and performance accuracy during surgical task training.
• To evaluate the long-term retention of performance improvements and neurophysiological changes after tDCS-assisted training.
• To use functional near-infrared spectroscopy (fNIRS) to monitor real-time brain activation during tDCS-enhanced surgical skill learning.

Proposed method

• Conducted a 12-day training protocol with 17 medical students performing the Fundamentals of Laparoscopic Surgery (FLS) pattern cutting task.
• Applied transcranial direct current stimulation (tDCS) to the primary motor cortex during training, compared to a sham stimulation control group.
• Simultaneously recorded cortical activity using functional near-infrared spectroscopy (fNIRS) to assess changes in hemodynamic responses during task performance.
• Measured performance outcomes including error counts and variability in task completion time.
• Performed follow-up assessments one month post-training to evaluate retention of performance and neural activation changes.
• Used statistical analysis to compare tDCS and sham groups across time points for error rates, variability, and fNIRS activation levels.

Experimental results

Research questions

• RQ1 Does tDCS applied to the primary motor cortex reduce error rates during the learning of complex laparoscopic surgical tasks?
• RQ2 How does tDCS affect cortical activation patterns in the primary motor cortex during surgical skill training, as measured by fNIRS?
• RQ3 Are the performance improvements and increased brain activation from tDCS retained one month after training?
• RQ4 Is there a correlation between enhanced fNIRS-measured cortical activation and reduced performance variability in surgical tasks?

Key findings

• tDCS significantly reduced error levels in the surgical task compared to the sham group, with a measurable decrease in performance variability.
• fNIRS data revealed significantly increased cortical activation in the primary motor cortex during tDCS sessions, indicating enhanced neural engagement.
• The reduction in surgical errors and increased brain activation were maintained for at least one month after the training period.
• The tDCS group showed greater consistency in task performance, as evidenced by lower standard deviation in completion times.
• The study observed a strong association between increased fNIRS signals and improved task accuracy, suggesting neurophysiological mechanisms underlie performance gains.
• No adverse effects were reported, supporting the safety and feasibility of tDCS in surgical training contexts.