title: Non-invasive continuous EEG-fNIRS recording of temporal lobe seizures.
abstract: OBJECTIVE
  Functional near-infrared spectroscopy (fNIRS) is a technique that allows continuous non-invasive monitoring of tissue oxygenation and haemodynamics in the brain. By using combined EEG-fNIRS recordings, we sought to better understand the pathophysiology of temporal lobe seizures.
  
  
  RESULTS
  Nine patients (5 males; mean age 35 years; range 11-56 years) with refractory mesial temporal lobe epilepsy underwent combined EEG-fNIRS recordings. Eight complex partial seizures from 3 patients were successfully recorded. All seizures were associated with significant local and remote haemodynamic changes which outlasted the duration of seizures. Over the epileptogenic temporal lobe, increased oxygenation [increase in cerebral blood volume (CBV) and oxyhaemoglobin (HbO), decrease in deoxyhaemoglobin (HbR)] was followed by a deoxygenated state [increase in HbR]. A similar haemodynamic profile was seen over the contralateral temporal lobe (even without evidence of epileptic propagation) though variations generally had lower amplitudes. Heterogeneous haemodynamic changes in remote frontal and/or parietal areas were also noted early on when epileptic activity was limited to the temporal lobe.
  
  
  CONCLUSIONS
  EEG-fNIRS reveals complex local and remote oxygenation changes during temporal lobe seizures.
authors.affiliation: Service de Neurologie, Centre Hospitalier Universitaire de Montréal (Hôpital Notre-Dame), 1560 rue Sherbrooke Est, Montréal (Québec) H2L 4M1, Canada. d.nguyen@umontreal.ca
authors.forename: Dang Khoa
authors.initials: DK
authors.lastname: Nguyen
authors.forename: Julie
authors.initials: J
authors.lastname: Tremblay
authors.forename: Philippe
authors.initials: P
authors.lastname: Pouliot
authors.forename: Phetsamone
authors.initials: P
authors.lastname: Vannasing
authors.forename: Olivia
authors.initials: O
authors.lastname: Florea
authors.forename: Lionel
authors.initials: L
authors.lastname: Carmant
authors.forename: Franco
authors.initials: F
authors.lastname: Lepore
authors.forename: Mohamad
authors.initials: M
authors.lastname: Sawan
authors.forename: Frédéric
authors.initials: F
authors.lastname: Lesage
authors.forename: Maryse
authors.initials: M
authors.lastname: Lassonde
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D004569:Electroencephalography / Q000379:methods; D004833:Epilepsy, Temporal Lobe / Q000175:diagnosis / Q000378:metabolism* / Q000503:physiopathology*; D005260:Female; D059907:Functional Neuroimaging / Q000379:methods; D006801:Humans; D008297:Male; D008875:Middle Aged; D019265:Spectroscopy, Near-Infrared / Q000379:methods; D055815:Young Adult