Deep br
ain stimul
ation (DBS) of the
anterior cingul
ate cortex (ACC) is
a new tre
atment for
allevi
ating intr
act
able neurop
athic p
ain. However, it f
ails to help some p
atients. The l
arge size of the ACC
and the intersubject v
ari
ability m
ake it difficult to determine the optim
al site to position DBS electrodes. The
aim of this work w
as therefore to comp
are the ACC connectivity of p
atients with successful versus unsuccessful DBS outcomes to help guide future electrode pl
acement.
absSec_2">Methods
abspara0015">Diffusion magnetic resonance imaging (dMRI) and probabilistic tractography were performed preoperatively in 8 chronic pain patients (age 53.4 ± 6.1 years, 2 females) with ACC DBS, of whom 6 had successful (SO) and 2 unsuccessful outcomes (UOs) during a period of trialing.
absSec_3">Results
abspara0020">The number of patients was too small to demonstrate any statistically significant differences. Nevertheless, we observed differences between patients with successful and unsuccessful outcomes in the fiber tract projections emanating from the volume of activated tissue around the electrodes. A strong connectivity to the precuneus area seems to predict unsuccessful outcomes in our patients (UO: 160n/SO: 27n), with (n), the number of streamlines per nonzero voxel. On the other hand, connectivity to the thalamus and brainstem through the medial forebrain bundle (MFB) was only observed in SO patients.
absSec_4">Conclusions
abspara0025">These findings could help improve presurgical planning by optimizing electrode placement, to selectively target the tracts that help to relieve patients' pain and to avoid those leading to unwanted effects.