Mlg. Joy et al., Imaging of current density and current pathways in rabbit brain during transcranial electrostimulation, IEEE BIOMED, 46(9), 1999, pp. 1139-1149
A magnetic resonance imaging (MRI) method was used for a noninvasive study
of current density (CD) and current pathways (CP's) inside the skull during
transcranial electrostimulation in rabbits. The transcranial impulse curre
nt directions studied were those previously used in transcranial electric t
reatment either sagittally or bilaterally. MRI data were collected from sli
ces perpendicular to the direction of current application. In these slices,
only the perpendicular component of the CD was measured. Computer methods
for accurate topographic mapping of the main areas with high CD and for rec
onstruction of CP's are described.
It was revealed that current applied on the head sagittally passed mostly t
hrough the cerebrospinal fluid in the basal brain cisternas connected in se
ries, and through the anterior horns of the lateral ventricles, foramina of
Monro, ventrocaudal part of the third ventricle, aqueductus, and fourth ve
ntricle. Possible connections between these CP's are suggested. Bilaterally
applied current passed through the brain and skull core more diffusely wit
hout concentrations in cisternas and ventricles. The results of the present
study suggest an explanation for the observation that sagittally applied c
urrent more effectively stimulates brain structures with antinociceptive fu
nction and elicits more pronounced analgesic effect.