Gómez-Acevedo H, Salgado P, Alonso-Vanegas M, Pasalle E

Language: English
References: 27
Page: 71-76
PDF size: 339.73 Kb.

ABSTRACT

Objective: the subthalamic nucleus (STN) has gained importance as a focus for histological, anatomical and imaging research due to its implications in modulation basal ganglia output and Parkinson’s disease. Little is known about the intrinsic organization of the STN. More information is needed to understand its role in the central nervous system (CNS) and allow more accurate planning in Functional Neurosurgery. We describe a method capable of delineating the boundaries of gray matter that could be used to study the internal architecture of the STN. Methods: eighty-seven patients were randomly selected from a magnetic resonance (MR) diffusion tensor imaging (DTI) data bank. From these cases, we selected forty-four in which DTI showed the STN, but not the substantia nigra (SN) in the same image. After initial scrutiny, we excluded fourteen patients with tumors in the brain stem, mass effect, hydrocephalus or obvious malformations. We developed an algorithm by selecting the region of Interest in the STN as identified by the Isotropic Image instead of the Anisotropic one. Results: after reviewing these 30 studies, we identified regions of track concurrency (RTC). In all cases reviewed, RTC showed a hierarchical position from medial to lateral according to the longitudinal axis of the STN and the origin of the fibers. This arrangement revealed a more medial position of the fibers with connection to the parietal, frontal posterior and frontal polar cortex (Brodmann´s areas 7, 4 and 11), a central position for the fibers interacting with the corpus callosum and a lateral position of the fibers interacting with the frontal-medial cortex. Conclusion: the technique described allows fiber tracking in the gray matter, undetectable by other imaging methods. It has helped detail the description of STN architecture, evidencing a constant hierarchical position regarding its interconnections. This information helps elucidate the architectural complexity of this nucleus and may prove of use during implantation and programming procedures employed in Deep Brain Stimulation (DBS).

REFERENCES

1. Passingham RE, Sthephan KE, Kotter R. The anatomical basis of functional localization in the cortex. Nat Rev Neurosci 2002;3, 606-16.

2. Barbas H, Pandya DN. Architecture and frontal cortical connections of the premotor cortex (area 6) in the rhesus monkey. J Comp. Neurol 256, 211-28.

3. Van Essen DC, Newsome WT, Maunsell JH, Bixby JL. The projections from striate cortex (V1) to areas V2 and V3 in the macaque monkey: asymmetries, areal boundaries, and patchy connections. J Comp Neurol 1986; 244, 451-80.

4. Scannell JW, Burns GA, Hilgetag CC, O’Neil MA, Young MP. The connectional organization of the corticothalamic system in the cat. Cereb Cortex 1999;9, 277-99.

5. Mufson EJ, Brady DR, Kordower JH. Tracing neuronal connections in postmortem human hippocampal complex with the carbocyanine dye Dil. Neurobiol. Aging 1990;11, 649-53.

6. Guillery RW, Sherman SM. Thalamic relay functions and their role in cortico-cortical communication: generalizations from the visual system. Neuron 2002;33, 163-75.

7. Hamani C, Saint-Cyr J, Fraser J, Kaplitt M, Lozano AM. The subthalamic nucleus in the context of movement disorders. Brain 2004;127, 4-20.

8. Joel D, Weiner I. The connections of the primate subthalamic nucleus: indirect pathways and the open-interconnected scheme of basal ganglia-thalamocortical circuitry. Brain Res Rev 1997;23:62-78.

9. Parent A, HazratiLN. Functional anatomy of the basal ganglia. II. The place of subthalamic nucleus and external pallidum in basal ganglia circuitry. Brain Res Rev 1995; 20: 128-54.

10. Basser PJ, Mattiello J, LeBihan D. MR diffusion tensor spectroscopy and imaging. Biophys J 1994;66, 259-67.

11. Basser PJ, Mattiello J, LeBihan D. Estimation of the effective self diffusion tensor from the NMR spin echo. J Magn Reson 1994; B 103, 247-54.

12. Le Bihan D, Mangin JF, Poupon C, Clark C, Pappata S, Molko N, et al. Diffusion tensor imaging: concepts and applications. JMRI 2001;13:534-46.

13. Shimony JS, McKinstry RC, Akbudak E. Quantitative diffusiontensor anisotropy brain MR imaging: Normative human data and anatomic analysis. Radiology 1999;212:770-84.

14. Parker GJ. Initial demonstration of in vivo tracing of axonal projections in the macaque brain and comparasion with the human brain using diffusion tensor imaging and fast marching tractography. Neuroimage 2002;15, 797-809.

15. Ciccarelli O. From diffusion tractography to quantitative tract matter tract measures: a reproducibility study. Neuroimage 2003;18, 348-59.

16. Mori S, Crain BJ, Chacko VP, Van Zijl PC. Three-dimensional tracking of axonal projections in the brain by magnetic resonance imaging. Ann Neurol 199;45,265-9.

17. Poupon C. Regularization of diffusion-direction based maps for the tracking of white matter fascicles. Neuroimage 2000;12,184-95.

18. Jones DK, Simmons A, Williams SC, Horsfield MA. Non-invasive assessment of axonal fiber connectivity in the human brain via diffusion tensor MRI. Magn Reson Med 1999;42,37-41.

19. Conturo TE. Tracking neuronal fiber pathways in the living human brain. Proc Natl Acad Sci USA 1999;96,10422-7.

20. Nakada T, Matzusawa H. Three-dimensional anisotropy contrast magnetic resonance imaging on the rat nervous system: MR axonography. Neurosci Res 1995;22,389-8.

21. Behrens TEJ. Non-invasive mapping of connections between human thalamus and cortex using diffusion imaging. Nature 2003;6,7.

22. Matsuzawa H, Nakayama N, Isotropic component trace analysis. J Neuroimaging 2005;15, 233-9.

23. Zhu XL. Magnetic resonance imaging based morphometry and landmarks correlations of the basal ganglia. Acta Neurochir 2002;144, 954-69.

24. Olszewski J. Cytoarchitecture of the human brain stem, 2nd Edition, Ed. Raven, New York, 1982.

25. Schlesinger B. The upper brain stem in the human: its nuclear configuration and vascular supply. Springer-Verlag Berlin Heildelberg New York 1976; pp 19-73.

26. Affifi A, Bergman RA. Neuroanatomía Funcional, Mc-Graw Hill Interamericana 1989; 189-233.

27. Oikawa H, Sasaki M. The substantia nigra in parkinson disease: proton density-weighted spin-echo and fast short inversion time inversion – recovery MR Findings. Am J Neuroradiol 2002;23: 1747-56.