Immature pattern of brain activity in Rett syndrome
J. B. Nielsen, L. Friberg, H. Lou, N. A. Lassen and I. L. Sam
John F. Kennedy Institute, Glostrup, Denmark.
Seven girls with Rett syndrome, a progressive degenerative encephalopathy
affecting girls, were studied with single photon emission computed
tomography and compared with an aged-matched control group of nine normal
children. Global cerebral blood flow was significantly lower in Rett
syndrome (54 vs 69 mL/100 g per minute), and the flows in prefrontal and
temporoparietal association regions of the telencephalon were markedly
reduced, whereas the primary sensorimotor regions were relatively spared.
The flow distribution in Rett syndrome is very similar to the distribution
of brain metabolic activity in infants of a few months of age. The abnormal
regional cerebral blood flow distribution most likely reflects the
widespread functional disturbances in the brain of patients with Rett
syndrome, whereas computed tomographic and neuropathologic examination only
reveal slight changes when compared with normal children.