TMS motor mapping: Comparing the absolute reliability of digital reconstruction methods to the golden standard

Background: Changes in transcranial magnetic stimulation motor map parameters can be used to quantify plasticity in the human motor cortex. The golden standard uses a counting analysis of motor evoked potentials (MEPs) acquired with a predefined grid. Recently, digital reconstruction methods have been proposed, allowing MEPs to be acquired with a faster pseudorandom procedure. However, the reliability of these reconstruction methods has never been compared to the golden standard. Objective: To compare the absolute reliability of the reconstruction methods with the golden standard. Methods: In 21 healthy subjects, both grid and pseudorandom acquisition were performed twice on the first day and once on the second day. The standard error of measurement was calculated for the counting analysis and the digital reconstructions. Results: The standard error of measurement was at least equal using digital reconstructions. Conclusion: Pseudorandom acquisition and digital reconstruction can be used in intervention studies without sacrificing reliability