Magnetic Resonance Imaging-Based Morphometry and Landmark Correlation of Basal Ganglia Nuclei

Abstract

The two principle targets for deep brain stimulation or lesioning in patients with Parkinson's disease, the subthalamic nucleus (STN) and the globus pallidus internus (GPi), reveal a high degree of individual variability which is relevant to the planning of stereotactic operations. Both nuclei can clearly be delineated in T2WI spin echo MRI which was acquired under stereotactic conditions in general anesthesia before surgery. Such images of 35 patients served for retrospective morphometric analysis of different basal ganglia nuclei (STN, GP, red nucleus, and substantia nigra) and several anatomical landmarks (anterior and posterior commissure, maximum width of third ventricle, brain length and width). The average AC-PC distance was 25.74 mm (range 21 to 29 mm) and is in agreement with previous studies. On average, the center of the STN was located 12.65 mm (+/-1.3) lateral from the midline as determined 3 mm ventral to the intercommissural plane. The average width of the third ventricle was 7.05 mm (+/-2.41). The width of the third ventricle correlated with the laterality of the STN (r(right)=.78; r(left)=.83) and GP (r(right)=.76; r(left)=.68). Although to a lesser extent, significant correlations were also observed between the laterality of the STN and brain width, improving prediction of STN laterality by multiple linear regression analysis (r(right)=.82; r(left)=.87). Similarly, the laterality of GP correlated with brain width. In addition, gender-specific differences were detected. The STN and GP was located farther lateral in males which may be due to overall brain anatomy as gender-specific differences were also observed for brain width and length and AC-PC distance. MRI-based in vivo-localization of different basal ganglia nuclei extend statistical information from common histological brain atlases which are based on a limited number of brains. The correlations observed between different basal ganglia nuclei, i.e. the STN and GPi, and anatomical landmarks may be useful for surgical planning.

Automated Optimization of Subcortical Cerebral MR Imaging−Atlas Coregistration for Improved Postoperative Electrode Localization in Deep Brain Stimulation

“…47,48 Generally, the STN and pallidum have been described as located farther laterally in men, correlating with the third ventricle width and, to a lesser extent, with the overall brain width. 16 Age-related anatomic changes, such as a craniolateral shift of the center of the STN with respect to the ACPC 49 and an increased distance from the midline to the lateral border of the STN were reported previously.…”

“…16,17 For instance, the AC can vary in diameter from 3 to 8 mm, 18 and the inter-rater ambiguity in manual selection leads to considerable variations in assessment of the target STN and GPi. 6 These inconsistencies erroneously scale distances along all 3 axes by misjudging the ACPC distance, on which this normalization is based.…”

Does probe’s eye subthalamic nucleus length on t2w MRI correspond with microelectrode recording in patients with deep brain stimulation for advanced parkinson’s disease ?

“…It is known that in the classical x,y, and z planes the radiological borders of the STN can be visualised well, except for the caudal border towards the substantia nigra pars reticulata (SNr). This can be difficult as SNr and some fibers related the STN are also seen as hypointense (14,20). To clarify grey-white matter distinction and improve image quality, we used T2W images with 2 mm slice thickness.…”

Subcortical processes of motor response inhibition during a stop signal task

“…The STN is a small subcortical structure situated ventral to the thalamus and medial to the posterior limb of the internal capsule and between the mediodorsal border of the substantia nigra and the lateral border of the red nucleus (Ashkan et al, 2007;Lee et al, 2006;Rijkers et al, 2007;Yelnik et al, 2007;Zhu et al, 2002). The location of peak activity in STN identified both in the current study and in Aron and Poldrack appeared to be somewhat medial to the MNI coordinates specified in previous studies (e.g., x=18, right STN, x=−16, left STN, Herzog et al, 2006).…”