title: Target identification for stereotactic thalamotomy using diffusion tractography.
abstract: BACKGROUND
  Stereotactic targets for thalamotomy are usually derived from population-based coordinates. Individual anatomy is used only to scale the coordinates based on the location of some internal guide points. While on conventional MR imaging the thalamic nuclei are indistinguishable, recently it has become possible to identify individual thalamic nuclei using different connectivity profiles, as defined by MR diffusion tractography.
  
  
  RESULTS
  Here we investigated the inter-individual variation of the location of target nuclei for thalamotomy: the putative ventralis oralis posterior (Vop) and the ventral intermedius (Vim) nucleus as defined by probabilistic tractography. We showed that the mean inter-individual distance of the peak Vop location is 7.33 mm and 7.42 mm for Vim. The mean overlap between individual Vop nuclei was 40.2% and it was 31.8% for Vim nuclei. As a proof of concept, we also present a patient who underwent Vop thalamotomy for untreatable tremor caused by traumatic brain injury and another patient who underwent Vim thalamotomy for essential tremor. The probabilistic tractography indicated that the successful tremor control was achieved with lesions in the Vop and Vim respectively.
  
  
  CONCLUSIONS
  Our data call attention to the need for a better appreciation of the individual anatomy when planning stereotactic functional neurosurgery.
authors.affiliation: Department of Neurology, Albert Szent-György Clinical Center, University of Szeged, Szeged, Hungary. kincsesz@nepsy.szote.u-szeged.hu
authors.forename: Zsigmond Tamás
authors.initials: ZT
authors.lastname: Kincses
authors.forename: Nikoletta
authors.initials: N
authors.lastname: Szabó
authors.forename: István
authors.initials: I
authors.lastname: Valálik
authors.forename: Zsolt
authors.initials: Z
authors.lastname: Kopniczky
authors.forename: Lívia
authors.initials: L
authors.lastname: Dézsi
authors.forename: Péter
authors.initials: P
authors.lastname: Klivényi
authors.forename: Mark
authors.initials: M
authors.lastname: Jenkinson
authors.forename: András
authors.initials: A
authors.lastname: Király
authors.forename: Magor
authors.initials: M
authors.lastname: Babos
authors.forename: Erika
authors.initials: E
authors.lastname: Vörös
authors.forename: Pál
authors.initials: P
authors.lastname: Barzó
authors.forename: László
authors.initials: L
authors.lastname: Vécsei
mesh_terms: D000328:Adult; D001931:Brain Mapping / Q000379:methods; D056324:Diffusion Tensor Imaging / Q000379:methods; D020329:Essential Tremor / Q000175:diagnosis / Q000601:surgery; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000379:methods* / Q000592:standards; D015588:Observer Variation; D011859:Radiography; D016634:Radiosurgery / Q000379:methods* / Q000592:standards; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D013313:Stress Disorders, Post-Traumatic / Q000150:complications / Q000175:diagnosis / Q000601:surgery; D013788:Thalamus / Q000000981:diagnostic imaging / Q000601:surgery*; D014202:Tremor / Q000175:diagnosis / Q000209:etiology / Q000601:surgery; D055815:Young Adult