%0 Journal Article %T Anatomy of the Human Subthalamic Nucleus: A Combined Morphometric Study %A Ioannis Mavridis %A Efstathios Boviatsis %A Sophia Anagnostopoulou %J Anatomy Research International %D 2013 %I Hindawi Publishing Corporation %R 10.1155/2013/319710 %X Purpose. Our purpose was to provide a combined clinically oriented study focused on the detailed anatomy of the human STN, with great respect to its targeting. Methods. For our imaging study, we used cerebral magnetic resonance images (MRIs) from 26 neurosurgical patients and for our anatomic study 32 cerebral hemispheres from 18 normal brains from cadaver donors. We measured and analyzed the STN dimensions (based on its stereotactic coordinates). Results. At stereotactic level , the STN length was 7.7£¿mm on MRIs and 8.1£¿mm in anatomic specimens. Its width was 6£¿mm on MRIs and 6.3£¿mm in anatomic specimens. The STN was averagely visible in 3.2 transverse MRI slices and its maximum dimension was 8.5£¿mm. The intercommissural distance was 26.3£¿mm on MRIs and 27.3£¿mm in anatomic specimens. We found statistically significant difference of the STN width and length between individuals <60 and ¡İ60 years old. Conclusion. The identification of the STN limits was easier in anatomic specimens than on MRIs and easier on T2 compared to T1-weighted MRIs sections. STN dimensions appear slightly smaller on MRIs. Younger people have wider and longer STN. 1. Introduction The human subthalamic nucleus (STN) is a massive biconvex lens-shaped nucleus located under the thalamus. Among the basal ganglia nuclei, the STN has a major function in the motor cortico-basal ganglia-thalamocortical circuit and is a target site for neurosurgical treatment such as parkinsonian patients with long-term motor fluctuations and dyskinesia [1]. The motor functions of the STN were established in humans from clinical observations of contralateral hemiballism induced by STN ischemia. Its motor role was confirmed by metabolic, electrophysiological, and behavioral studies performed in healthy animals and animals¡¯ models of Parkinson¡¯s disease (PD) [1]. Experimental studies in animals and clinical observations of parkinsonian patients showed that the STN had also associative and limbic functions. After STN stimulation, some patients became apathetic or depressed or had impaired recognition of facial emotion [1]. Although the role of the STN in the motor cortico-basal ganglia-thalamocortical loop is well known, its implication on limbic functions remains to be described by a new scheme of the limbic loop including the STN. After chronic STN stimulation in patients with PD, many studies showed executive impairments, apathy, depression, hypomania, and impairment of recognition of negative facial emotions. The medial tip of the STN represents its limbic part. This part receives inputs from the anterior %U http://www.hindawi.com/journals/ari/2013/319710/