Data from: BCI training to move a virtual hand reduces phantom limb pain: a randomized crossover trial

Objective: To determine whether training with a brain–computer interface
(BCI) to control an image of a phantom hand, which moves based on cortical
currents estimated from magnetoencephalographic signals, reduces phantom
limb pain. Methods: Twelve patients with chronic phantom limb pain of the
upper limb due to amputation or brachial plexus root avulsion participated
in a randomized single-blinded crossover trial. Patients were trained to
move the virtual hand image controlled by the BCI with a real decoder,
which was constructed to classify intact hand movements from motor
cortical currents, by moving their phantom hands for 3 days (“real
training”). Pain was evaluated using a visual analogue scale (VAS) before
and after training, and at follow-up for an additional 16 days. As a
control, patients engaged in the training with the same hand image
controlled by randomly changing values (“random training”). The two
trainings were randomly assigned to the patients. This trial is registered
at UMIN-CTR (UMIN000013608). Results: VAS at day 4 was significantly
reduced from the baseline after real training (45.3 [24.2] to 30.9 [20.6],
1/100mm, mean [SDs]; P=0.009<0.025), but not after random training
(P=0.047>0.025). Compared to VAS at day 1, VAS at days 4 and 8 was
significantly reduced by 32% and 36%, respectively, after real training
and was significantly lower than VAS after random training
(P<0.01). Conclusion: Three-day training to move the hand images
controlled by BCI significantly reduced pain for one week. Classification
of evidence: This study provides Class Ⅲ evidence that BCI
reduces phantom limb pain.