Clinical meaning
Infant reflexes are involuntary motor responses present at birth that are controlled by the brainstem and spinal cord. These primitive reflexes are essential for survival and neurological assessment. They emerge during fetal development and normally disappear (integrate) at specific ages as the cerebral cortex matures and assumes voluntary motor control. Persistence of primitive reflexes beyond expected age or absence at birth indicates potential neurological dysfunction. The most clinically important reflexes include Moro (startle), rooting, sucking, palmar grasp, plantar grasp, Babinski, tonic neck (fencing), and stepping reflexes. Assessment of these reflexes is a fundamental component of the newborn neurological examination and ongoing developmental screening.
Exam relevance
Risk factors: - Prematurity (reflexes may be weak or absent) - Birth asphyxia or hypoxic-ischemic encephalopathy - Intracranial hemorrhage - Congenital neurological conditions - Brachial plexus injury (asymmetric reflexes) - Maternal substance use during pregnancy - Kernicterus (bilirubin encephalopathy) - Chromosomal abnormalities