Neonatal hypertonia: I. Classification and structural-functional correlates

Neonatal hypertonic states can be encountered as expressions of abnormal tone and posture. It would be useful for the neonatal neurointensivist to more precisely describe the various presentations of neonatal hypertonia, taking into consideration a classification scheme adopted for hypertonia in children at older ages. An understanding of the ontogeny of muscle tone and posture during fetal and postnatal preterm time periods with maturation to full-term ages will help conceptualize the developmental structural-functional correlates that subserve the evolving expression of this abnormal clinical sign. In the future, a more accurate description of neonatal hypertonic states should be part of the complete clinical examination to help integrate etiology, timing of injury, and neurologic localization before choosing the appropriate therapeutic intervention.