title: Functional magnetic resonance imaging of the sensorimotor system in preterm infants.
abstract: OBJECTIVE
  Preterm birth at <32 weeks' gestational age has a specific predilection for periventricular white matter injury. Early prediction of concomitant motor sequelae is a fundamental clinical issue. Recently, functional MRI was introduced as a noninvasive method for investigating the functional integrity of the neonatal brain. We aimed at implementing a unilateral passive forearm extension/flexion functional MRI paradigm in a routine clinical MRI setup to allow noninvasive mapping of the sensorimotor system in preterm infants and to relate the functional data to structural and behavioral data.
  
  
  METHODS
  Eight patients (median gestational age: 26.5 weeks; median birth weight: 885 g) were included. The functional MRI was performed at term-equivalent age (median: 39 weeks' postconceptional age) under chloral hydrate (50 mg/kg) sedation. In 5 of 8 patients, functional MRI data acquisition was successful. This resulted in 10 functional data sets (5 for passive stimulation of each forearm).
  
  
  RESULTS
  Unilateral stimulation was associated with mainly bilateral activation of the primary sensorimotor cortex (n = 7 of 10 data sets), the prevailing hemodynamic response being a negative blood oxygenation level-dependent signal. Positive blood oxygenation level-dependent response or failure to activate the sensorimotor cortex (n = 3 of 10 data sets) were seen in those patients with aberrant structural/behavioral indices.
  
  
  CONCLUSIONS
  Our data show the feasibility of passive unilateral sensorimotor stimulation during neonatal clinical MRI protocols. The bilateral activation pattern observed at this age is compatible with a bilaterally distributed sensorimotor system. Our data validate initial accounts for a raised incidence of negative blood oxygenation level-dependent responses in the primary sensorimotor cortex at this developmental stage. The negative blood oxygenation level-dependent response is likely to reflect a reduction of the oxy/deoxy-hemoglobin ratio during a maturational stage characterized by rapid formation of synapses, yet ineffective processing. Positive blood oxygenation level-dependent responses or failure to activate the sensorimotor cortex may be an early indicator of abnormal development and will have to be followed up carefully.
authors.affiliation: University of Bonn, Department of Neonatology, Bonn, Germany. axel.heep@ukb.uni-bonn.de
authors.forename: Axel
authors.initials: A
authors.lastname: Heep
authors.forename: Lukas
authors.initials: L
authors.lastname: Scheef
authors.forename: Jakob
authors.initials: J
authors.lastname: Jankowski
authors.forename: Mark
authors.initials: M
authors.lastname: Born
authors.forename: Nadine
authors.initials: N
authors.lastname: Zimmermann
authors.forename: Deborah
authors.initials: D
authors.lastname: Sival
authors.forename: Arie
authors.initials: A
authors.lastname: Bos
authors.forename: Jürgen
authors.initials: J
authors.lastname: Gieseke
authors.forename: Peter
authors.initials: P
authors.lastname: Bartmann
authors.forename: Hans
authors.initials: H
authors.lastname: Schild
authors.forename: Henning
authors.initials: H
authors.lastname: Boecker
mesh_terms: D000367:Age Factors; D001931:Brain Mapping / Q000379:methods; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature / Q000378:metabolism / Q000502:physiology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009044:Motor Cortex / Q000378:metabolism / Q000502:physiology; D011597:Psychomotor Performance / Q000502:physiology*; D013003:Somatosensory Cortex / Q000378:metabolism / Q000502:physiology*