Development of flexion pyramidal signs in preterm infants.
Forty-two babies (20 boys, 22 girls) with birthweights from 800g to 2000g and gestational ages between 25 and 40 weeks were followed-up for several weeks with developmental tests and a conventional neurological examination. Here, only the flexion pyramidal signs are evaluated, i. e. downward flexion of the toes after percussion over the base of the metatarsals (Rossolimo's sign) and of the cuboid bone (Mendel-Bechterew's sign). These reflexes are signs of severe upper motor neuron lesion in children and adults, but also appear in normal newborns and disappear again until the 12th week of life. This study shows that the early response of FPS is  abduction of the toes and extension of the great toe from the 25th up to the 34th to 36th gestational weeks, when it becomes the normal downward flexion of all toes. This developmental course seems to be the same in healthy preterm babies and in small-for-dates babies.
D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007235:Infant, Premature, Diseases / Q000175:diagnosis*; D008297:Male; D011712:Pyramidal Tracts / Q000503:physiopathology*; D012021:Reflex, Abnormal / Q000175:diagnosis*