A computational pipeline to find lobule-specific electric field distribution during non-invasive cerebellar stimulation

Objective: Cerebellar Transcranial direct current stimulation (ctDCS) of cerebellar lobules is challenging due to the complexity of the cerebellar structure. Therefore, we present a freely available computational pipeline to determine the subject-specific lobule-specific electric field distribution during ctDCS. Methods: The computational pipeline isolates subject-specific cerebellar lobules based on a spatially unbiased atlas template (SUIT) for the cerebellum, and then calculates the lobule-specific electric field distribution during ctDCS. The computational pipeline was tested using Colin27 Average Brain. The 5 cm × 5 cm anode was placed 3 cm lateral to inion, and the same sized cathode was placed on the contralateral supra-orbital area (called Manto montage) and buccinators muscle (called Celnik montage). A published 4x1 HD-ctDCS electrode montage was also implemented for a comparison using analysis of variance. Results: The electric field strength of both the Celnik and the Manto montages affected the lobules Crus II, VIIb, VIII, and IX of the targeted cerebellar hemispheres while Manto montage had a more bilateral effect. The HD-ctDCS montage primarily affected the lobules Crus I, Crus II, VIIb of the targeted cerebellar hemisphere. Discussion: Our freely available subject-specific computational modeling pipeline can be used to analyze lobulespecific electric field distribution to select an optimal ctDCS electrode montage.