Subthalamic Nucleus (STN)
Disorders Treated with Stimulation
- Primary indications: Parkinson's disease and dystonia [1]
- Investigational applications: The limbic division (anteromedial) STN has been demonstrated as an effective target in severe treatment-refractory OCD [2]. Possibly useful in OCD and Additions therapy [3]
Location
- The STN has a biconvex, almond-shaped appearance well-seen on FGATIR as a hypointense focus in the subthalamic region. It is situated just medial to the posterior limb internal capsule (PLIC), dorsal to the substantia nigra (SN), and anterolateral to the red nucleus (RN).
- The STN is divided into limbic (anterior), associative (middle), and motor (posterior) portions (not shown), each with associated tracts as described below.
Associated Tracts
- Hyperdirect Fibers: The STN is the confluence of the hyperdirect fibers, comprised of the limbic tract (anterior STN), associative tract (middle STN), and motor tract (posterior STN).
- Ansa Subthalamica (AS): Runs between the GPi and STN, thought to contribute to the dystonia treatment effect
- Fasciculus Subthalamicus (FS): Runs between the globus pallidus externus (GPe) and STN, also thought to contribute to the dystonia treatment effect The STN is a key node in the basal ganglia circuitry, receiving cortical input via the hyperdirect pathway and modulating activity in the globus pallidus internus (GPi) and substantia nigra.
References
- Middlebrooks EH, Domingo RA, Vivas-Buitrago T, Okromelidze L, Tsuboi T, Wong JK, Eisinger RS, Almeida L, Burns MR, Horn A, Uitti RJ, Wharen RE Jr, Holanda VM, Grewal SS. Neuroimaging Advances in Deep Brain Stimulation: Review of Indications, Anatomy, and Brain Connectomics. AJNR Am J Neuroradiol. 2020 Sep;41(9):1558-1568. doi: 10.3174/ajnr.A6693. Epub 2020 Aug 13. PMID: 32816768; PMCID: PMC7583111.
- Tyagi H, Apergis-Schoute AM, Akram H, Foltynie T, Limousin P, Drummond LM, Fineberg NA, Matthews K, Jahanshahi M, Robbins TW, Sahakian BJ, Zrinzo L, Hariz M, Joyce EM. A Randomized Trial Directly Comparing Ventral Capsule and Anteromedial Subthalamic Nucleus Stimulation in Obsessive-Compulsive Disorder: Clinical and Imaging Evidence for Dissociable Effects. Biol Psychiatry. 2019 May 1;85(9):726-734. doi: 10.1016/j.biopsych.2019.01.017. Epub 2019 Jan 30. PMID: 30853111; PMCID: PMC6467837.
- Lee DJ, Lozano CS, Dallapiazza RF, Lozano AM. Current and future directions of deep brain stimulation for neurological and psychiatric disorders. J Neurosurg. 2019 Aug 1;131(2):333-342. doi: 10.3171/2019.4.JNS181761. PMID: 31370011.