title: Functional brain mapping of patients with arteriovenous malformations using navigated transcranial magnetic stimulation: first experience in ten patients.
abstract: BACKGROUND
  Intracranial arteriovenous malformations (AVM) are known to be potent inductors of functional plasticity, and their vasculature makes standard functional imaging difficult. Here we conducted functional mapping of both primary motor cortex and speech related areas in patients with AVM using navigated transcranial magnetic stimulation (nTMS), which has been recently proven as a reliable noninvasive modality of preoperative functional brain mapping.
  
  
  METHODS
  nTMS mapping was performed in ten patients with unruptured intracranial AVMs located in or near eloquent areas. Motor mapping was conducted for six patients with AVMs near the rolandic region, and speech mapping was performed for four patients with left perisylvian AVMs. After the examination, all patients were treated with surgery, radiosurgery or observed with best medical treatment on case-by-case basis.
  
  
  RESULTS
  Motor mapping allowed for delineation of the primary motor cortex, even if the anatomy was severely obscured by the AVM in all cases with rolandic AVMs. No plastic relocation of the primary motor cortex was observed. Repetitive stimulation of the left ventral precentral gyrus led to speech impairments in all four cases that underwent speech mapping. Right hemispheric involvement was observed in one out of four cases and potentially indicated plastic changes. No side effects were observed.
  
  
  CONCLUSIONS
  nTMS allowed for detailed delineation of eloquent areas even within hypervascularized cortical areas. Our observations indicate that nTMS functional mapping is feasible not only in tumorous brain lesions, but also in AVMs.
authors.affiliation: Department of Neurosurgery, Charité - Universitätsmedizin Berlin, Berlin, Germany, nao-kth@jikei.ac.jp.
authors.forename: Naoki
authors.initials: N
authors.lastname: Kato
authors.forename: Sarah
authors.initials: S
authors.lastname: Schilt
authors.forename: Heike
authors.initials: H
authors.lastname: Schneider
authors.forename: Dietmar
authors.initials: D
authors.lastname: Frey
authors.forename: Markus
authors.initials: M
authors.lastname: Kufeld
authors.forename: Peter
authors.initials: P
authors.lastname: Vajkoczy
authors.forename: Thomas
authors.initials: T
authors.lastname: Picht
mesh_terms: D000328:Adult; D000368:Aged; D001164:Arteriovenous Fistula / Q000503:physiopathology*; D001931:Brain Mapping / Q000379:methods*; D019054:Evoked Potentials, Motor / Q000502:physiology; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology*; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000503:physiopathology*; D038361:Neuronavigation / Q000379:methods*; D010865:Pilot Projects; D013060:Speech / Q000502:physiology; D050781:Transcranial Magnetic Stimulation / Q000379:methods*; D055815:Young Adult