Facial sparing as a feature of prenatal-onset hemiparesis.
The presence of facial weakness was prospectively correlated with age of onset of hemiparesis. Facial weakness was not associated with prenatal-onset hemiparesis, but sometimes occurred with onset of hemiparesis during the first year of life. In contrast, facial weakness was generally present when all patients with postnatal-onset hemiparesis were considered as a group. With double hemiparesis, facial weakness was common, regardless of age at onset. These findings suggest that facial sparing results from plasticity of the developing corticobulbar tract, the critical period ending during the first year of life. Decreased synapse elimination of uninjured, ipsilateral terminals is suggested as the mechanism of facial sparing. Facial weakness accompanying double hemiparesis thus would be a reflection of absence of an uninjured pathway.
Lenn
N J
NJ
Department of Neurology, University of Virginia Health Sciences Center, Charlottesville 22908.
Freinkel
A J
AJ
D000375:Aging / Q000502:physiology; D005152:Facial Muscles / Q000503:physiopathology*; D005260:Female; D005315:Fetal Diseases / Q000503:physiopathology*; D006429:Hemiplegia / Q000503:physiopathology*; D006801:Humans; D011247:Pregnancy