title: Improving recorded volume in mesial temporal lobe by optimizing stereotactic intracranial electrode implantation planning.
abstract: OBJECTIVE
  Intracranial electrodes are sometimes implanted in patients with refractory epilepsy to identify epileptic foci and propagation. Maximal recording of EEG activity from regions suspected of seizure generation is paramount. However, the location of individual contacts cannot be considered with current manual planning approaches. We propose and validate a procedure for optimizing intracranial electrode implantation planning that maximizes the recording volume, while constraining trajectories to safe paths.
  
  
  METHODS
  Retrospective data from 20 patients with epilepsy that had electrodes implanted in the mesial temporal lobes were studied. Clinical imaging data (CT/A and T1w MRI) were automatically segmented to obtain targets and structures to avoid. These data were used as input to the optimization procedure. Each electrode was modeled to assess risk, while individual contacts were modeled to estimate their recording capability. Ordered lists of trajectories per target were obtained. Global optimization generated the best set of electrodes. The procedure was integrated into a neuronavigation system.
  
  
  RESULTS
  Trajectories planned automatically covered statistically significant larger target volumes than manual plans [Formula: see text]. Median volume coverage was [Formula: see text] for automatic plans versus [Formula: see text] for manual plans. Furthermore, automatic plans remained at statistically significant safer distance to vessels [Formula: see text] and sulci [Formula: see text]. Surgeon's scores of the optimized electrode sets indicated that 95% of the automatic trajectories would be likely considered for use in a clinical setting.
  
  
  CONCLUSIONS
  This study suggests that automatic electrode planning for epilepsy provides safe trajectories and increases the amount of information obtained from the intracranial investigation.
authors: McConnell Brain Imaging Center, Montreal Neurological Hospital and Institute, McGill University, 3801 University Street, Montreal, QC, H3A 2B4, Canada. rina.zelmann@mail.mcgill.ca.
authors: R
authors: R
authors: Zelmann
authors: McConnell Brain Imaging Center, Montreal Neurological Hospital and Institute, McGill University, 3801 University Street, Montreal, QC, H3A 2B4, Canada.
authors: S
authors: S
authors: Beriault
authors: Neurology and Neurosurgery, Montreal Neurological Hospital and Institute, McGill University, 3801 University Street, Montreal, QC, H3A 2B4, Canada.
authors: M M
authors: MM
authors: Marinho
authors: Neurology and Neurosurgery, Montreal Neurological Hospital and Institute, McGill University, 3801 University Street, Montreal, QC, H3A 2B4, Canada.
authors: K
authors: K
authors: Mok
authors: Neurology and Neurosurgery, Montreal Neurological Hospital and Institute, McGill University, 3801 University Street, Montreal, QC, H3A 2B4, Canada.
authors: J A
authors: JA
authors: Hall
authors: McConnell Brain Imaging Center, Montreal Neurological Hospital and Institute, McGill University, 3801 University Street, Montreal, QC, H3A 2B4, Canada.
authors: N
authors: N
authors: Guizard
authors: LTSI - U1099 INSERM, CS34317, Université Rennes 1, 35043, Rennes, France.
authors: C
authors: C
authors: Haegelen
authors: Neurology and Neurosurgery, Montreal Neurological Hospital and Institute, McGill University, 3801 University Street, Montreal, QC, H3A 2B4, Canada.
authors: A
authors: A
authors: Olivier
authors: McConnell Brain Imaging Center, Montreal Neurological Hospital and Institute, McGill University, 3801 University Street, Montreal, QC, H3A 2B4, Canada.
authors: G B
authors: GB
authors: Pike
authors: McConnell Brain Imaging Center, Montreal Neurological Hospital and Institute, McGill University, 3801 University Street, Montreal, QC, H3A 2B4, Canada.
authors: D L
authors: DL
authors: Collins
mesh_terms: D004567:Electrodes, Implanted; D004569:Electroencephalography / Q000379:methods*; D004827:Epilepsy / Q000601:surgery*; D006801:Humans; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging; D012189:Retrospective Studies; D013702:Temporal Lobe / Q000601:surgery*
keywords: Automatic target segmentation; Depth electrode implantation; Intracranial EEG recording; Stereoelectroencephalography (SEEG); Trajectory optimization