title: Role of Intraoperative Neurophysiologic Monitoring in the Resection of Thalamic Astrocytomas.
abstract: BACKGROUND
  The thalamus is a deep-seated and crucial structure for the sensorimotor system. It has been long considered a surgically inaccessible area because of the morbidity associated with surgical resections. Astrocytomas of the thalamus are usually treated with bioptic procedures followed by adjuvant treatments. Intraoperative neurophysiologic monitoring (IONM) allows safe and satisfactory resections of lobar gliomas, but few data are available for thalamic lesions. The aim of this study was to review the outcome of a small series of patients with thalamic astrocytomas that were treated with surgical resection with the aid of IONM.
  
  
  METHODS
  Surgical resection with IONM was performed in 5 patients with thalamic astrocytomas (1 grade I, 1 grade II, 2 grade III, 1 grade IV). Two astrocytomas were in the dominant hemisphere. Preoperative and postoperative neuropsychological assessments were performed in 3 patients. IONM was tailored to the individual patient and consisted of transcranial motor evoked potential monitoring, cortical motor evoked potential monitoring, somatosensory evoked potential monitoring, direct electrical stimulation, electroencephalography, and electrocorticography.
  
  
  RESULTS
  None of the patients experienced permanent motor deficits; 2 patients had a transient hemiparesis requiring rehabilitation; 1 patient had a transient aphasia, and 1 patient had permanent aphasia. None of the patients had intraoperative seizures, but 1 patient experienced postoperative transient status epilepticus. The extent of resection on postoperative volumetric magnetic resonance imaging was >70% in all cases.
  
  
  CONCLUSIONS
  Surgical resection of thalamic astrocytomas appeared to be effective and relatively safe when guided by IONM. Larger series of patients are required to confirm these preliminary data.
authors.affiliation: Unit of Neurosurgery, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy. Electronic address: giorgiocarrabba@yahoo.it.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Carrabba
authors.affiliation: Unit of Neurosurgery, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
authors.forename: Giulio
authors.initials: G
authors.lastname: Bertani
authors.affiliation: Unit of Neurophysiopathology, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
authors.forename: Filippo
authors.initials: F
authors.lastname: Cogiamanian
authors.affiliation: Unit of Neurophysiopathology, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
authors.forename: Gianluca
authors.initials: G
authors.lastname: Ardolino
authors.affiliation: Unit of Neurosurgery, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
authors.forename: Barbara
authors.initials: B
authors.lastname: Zarino
authors.affiliation: Unit of Neurosurgery, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy; Department of Pathophysiology and Organ Transplantation, University of Milan, Milan, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Di Cristofori
authors.affiliation: Unit of Neurosurgery, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Locatelli
authors.affiliation: Unit of Neurosurgery, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
authors.forename: Manuela
authors.initials: M
authors.lastname: Caroli
authors.affiliation: Unit of Neurosurgery, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Rampini
mesh_terms: D000293:Adolescent; D000328:Adult; D001037:Aphasia / Q000453:epidemiology; D001254:Astrocytoma / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D001932:Brain Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D002648:Child; D004558:Electric Stimulation; D000069280:Electrocorticography; D004569:Electroencephalography; D019054:Evoked Potentials, Motor; D005073:Evoked Potentials, Somatosensory; D005260:Female; D006801:Humans; D064795:Intraoperative Neurophysiological Monitoring / Q000379:methods*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D019635:Neurosurgical Procedures / Q000379:methods*; D010291:Paresis / Q000453:epidemiology* / Q000534:rehabilitation; D011183:Postoperative Complications / Q000453:epidemiology* / Q000534:rehabilitation; D013226:Status Epilepticus / Q000453:epidemiology*; D013786:Thalamic Diseases / Q000000981:diagnostic imaging / Q000601:surgery*; D013788:Thalamus / Q000000981:diagnostic imaging / Q000601:surgery*; D055815:Young Adult
keywords: Brain mapping; Glioma surgery; Gliomas; Neurophysiologic monitoring; Thalamic glioma; Thalamus