Unique Distribution of Benzodiazepine Receptors in the Brain during the First Two Years of Life

Pediatr Neurosurg. 2016;51(5):244-8. doi: 10.1159/000445903. Epub 2016 May 19.

Abstract

Background: 123I-iomazenil (IMZ) single-photon emission computed tomography (SPECT) is a tool for evaluating epileptic foci and brain damage. To apply the method to children, information regarding the age-specific expression of benzodiazepine receptors (BDZ-Rs) is required. Unfortunately, there is no information currently available for children <2 years of age.

Methods: We used IMZ SPECT once in infants aged 3-8 months and again at 2 years of age in order to describe the maturational changes in BDZ-R distribution.

Results: No neurological deficits were found in any of the infants at the first examination. The BDZ-Rs were more dominantly distributed in the occipital lobe than in the frontal lobe before the age of 2 years. The frontal-occipital gradients of the distribution were obvious in children <8 months of age. Magnetic resonance imaging showed a spreading of myelination toward the frontal lobes simultaneously with BDZ-R expression.

Conclusion: Information regarding the alteration in the BDZ-R distribution pattern is useful when assessing infantile epilepsy and brain injury. The age-related pattern of BDZ-R distribution could correspond with myelination, cerebral blood flow, metabolism and behavioral development.

MeSH terms

  • Autoradiography / methods
  • Benzodiazepines / metabolism
  • Brain / diagnostic imaging*
  • Brain / metabolism*
  • Child, Preschool
  • Female
  • Flumazenil / analogs & derivatives
  • Flumazenil / metabolism
  • Frontal Lobe / diagnostic imaging
  • Frontal Lobe / metabolism
  • Humans
  • Infant
  • Iodine Radioisotopes / metabolism
  • Male
  • Occipital Lobe / diagnostic imaging
  • Occipital Lobe / metabolism
  • Receptors, GABA-A / metabolism*
  • Tomography, Emission-Computed, Single-Photon* / methods

Substances

  • Iodine Radioisotopes
  • Receptors, GABA-A
  • Benzodiazepines
  • Flumazenil
  • iomazenil