#KeyLIMEPodcast 192: How to ‘jump start’ learning: Transcranial direct-current brain stimulation

Reference:

Ciechanski et, al. Effects of Transcranial Direct-Current Stimulation on Neurosurgical Skill Acquisition: A Randomized Controlled Trial. World Neurosurg. 2017 Dec;108:876-884.e4. Epub 2017 Aug 31.

Reviewer: Jonathan Sherbino (@sherbino)

Background

Ok.  Let’s just start with the obvious.  This is cool.  Electrical brain stimulation to improve technical skills.  I’m always looking for a life hack (e.g. modafinil for attention, ketosis for energy, sleep cycles for… well sleep).

By my estimation, we have never critiqued an educational intervention outside of the traditional domain of learning sciences, here on KeyLIME.  So, this episode is going to be a first.

If you want to know how to ‘jump start’ (sorry.. I couldn’t resist) your learning… read on.

Purpose

“We hypothesized that anodal [transcranial direct-current stimulation] over the dominant primary motor cortex would enhance the acquisition of simulation-based neurosurgical tumor resection skills by medical trainees.”

Key Points on Method

• Double blind, randomized, sham controlled single centre study
• Recruitment of 1^st year medical students without neurological or neuropsychiatric disorders
• Training (and measurement) via NeuroTouch Neurosurgical Simulator (proprietary) to use ultrasonic aspirator to resect a virtual brain tumor (BT)
• Trial design =
  • Baseline measure
  • Eight consecutive practice sessions (each 3 min long)
  • Feedback provided at end of each session via computer-based scores about % of BT resected and amount of excessive force applied. No corrective feedback provided
  • Post training measure
  • 6 week retention measure
• Intervention (tDCS)
  • Sponge anode positioned over dominant primary motor cortex with cathode over contralateral supraorbital area
    • Primary motor cortex localized by EEG
  • 1mA for 20 min
• Primary outcome = difference in remaining BT between baseline and training

Key Outcomes

n= 22

For the primary outcome:

• Participants receiving tDCS increased the amount of tumour resected
• Participants receiving sham did not increase the amount of tumour resected
• No difference between control and intervention groups when comparing the delta between baseline and posttraining measures
• No decay in % BT resection at retention testing

For the secondary outcomes:

• Multiple comparisons were conducted some showing an effect, while others did not.
• Individuals with low skills (compared to neurosurgery residents who provided baseline scores for comparison) performed better if exposed to tDCS.

There were no serious adverse events visual analogue scales for all symptoms of use were very low (itchy, tingling, pain).

Key Conclusions

The authors conclude… 

“The addition of tDCS to neurosurgical training may enhance skill acquisition in a simulation based environment. Trials of additional skills in high-skill residents, and translation to nonsimulated performance are needed to determine the potential utility of tDCS insurgical training.”

Spare Keys – other take home points for clinician educators

1. This is a great example of a research collaboration between clinicians, clinician educators and HPE scientists. Integrating a clinical problem (safe surgical skills) within a learning context makes for a study of broad interest and applicability.
2. This is truly a pilot study. Using a best case scenario (novice operators without basic surgical skill techniques, single intervention without the opportunity for sustained practice) in a simulated environment the value of this intervention is modest at best. Be cautious about shiny, new things.
3. Be cautious about multiple comparisons involving a secondary outcome. It often is a signal that the intervention is ineffective.

Access KeyLIME podcast archives here

Check us out on iTunes