Anatomy of the human subthalamic nucleus: a combined morphometric study

Area of Science:

• Neuroanatomy
• Neurosurgery
• Medical Imaging

Background:

• Accurate anatomical knowledge of the subthalamic nucleus (STN) is crucial for stereotactic neurosurgery.
• Variations in STN dimensions and visibility on imaging can impact surgical precision.

Purpose of the Study:

• To provide a detailed, clinically oriented anatomical study of the human STN.
• To enhance understanding of STN anatomy for improved surgical targeting.

Main Methods:

• Combined analysis of cerebral MRI scans from 26 neurosurgical patients and anatomical study of 32 hemispheres from 18 cadaver donors.
• Measurement and stereotactic coordinate-based analysis of STN dimensions (length, width).
• Comparison of STN visibility and dimensions between MRI (T1 and T2-weighted) and anatomical specimens, and across age groups.

Main Results:

• STN length measured 7.7 mm on MRI vs. 8.1 mm in specimens; width was 6 mm on MRI vs. 6.3 mm in specimens.
• STN was visible in an average of 3.2 MRI slices, with a maximum dimension of 8.5 mm.
• Statistically significant differences in STN width and length were observed between individuals younger than 60 and those 60 years or older, with younger individuals exhibiting larger dimensions.

Conclusions:

• STN identification is easier in anatomical specimens than on MRI, and clearer on T2-weighted than T1-weighted MRI sequences.
• STN dimensions appear slightly smaller on MRI compared to anatomical specimens.
• Age influences STN dimensions, with younger individuals possessing wider and longer STN structures.