The human nucleus accumbens: where is it? A stereotactic, anatomical and magnetic resonance imaging study.

Objectives.   Identification, delimitation, and stereotactic localization of the human nucleus accumbens (Acc) in order to allow its accurate definition and three-dimensional targeting on magnetic resonance imaging (MRI) enabling its use for deep brain stimulation. Methods.   Magnetic resonance imaging and anatomical coronal serial cuts were performed on 24 Acc from human cadaver brains perpendicular to the anterior commissure-posterior commissure line; identification, localization, and determination of its dimensions and three-dimensional stereotactic coordinates. Results.   Twenty Acc were studied anatomically, 14 by MRI and 12 by both methods. The contours of the Acc were traced and the dimensions measured; mean values: length 10.5 mm, width 14.5 mm and height 7.0 mm. The stereotactic coordinates were obtained every millimeter along its length. Conclusion.   It was possible to identify well the human Acc, define its limits and establish its three-dimensional coordinates as potential MRI-guided stereotactic target.