Transcranial direct current stimulation: a computer-based human model study.

Publication Type:

Journal Article

Authors:

Wagner, Tim; Fregni, Felipe; Shirley Fecteau; Grodzinsky, Alan; Zahn, Markus; Pascual-Leone, Alvaro

Source:

Neuroimage, Volume 35, Issue 3, p.1113-24 (2007)

Keywords:

Brain, Computer Simulation, Electromagnetic Fields, Finite Element Analysis, Head, Humans, Models, Neurological, Radiation Dosage, Radiometry, Scattering, Radiation, Transcranial Magnetic Stimulation

Abstract:

OBJECTIVES: Interest in transcranial direct current stimulation (tDCS) in clinical practice has been growing, however, the knowledge about its efficacy and mechanisms of action remains limited. This paper presents a realistic magnetic resonance imaging (MRI)-derived finite element model of currents applied to the human brain during tDCS.EXPERIMENTAL DESIGN: Current density distributions were analyzed in a healthy human head model with varied electrode montages. For each configuration, we calculated the cortical current density distributions. Analogous studies were completed for three pathological models of cortical infarcts.PRINCIPAL OBSERVATIONS: The current density magnitude maxima injected in the cortex by 1 mA tDCS ranged from 0.77 to 2.00 mA/cm(2). The pathological models revealed that cortical strokes, relative to the non-pathological solutions, can elevate current density maxima and alter their location.CONCLUSIONS: These results may guide optimized tDCS for application in normal subjects and patients with focal brain lesions.