Deep tendon reflexes in premature infants.
Ten classic deep tendon reflexes (DTRs) were evaluated in 62 premature infants of greater than 27 weeks post-conceptional age. The pectoralis major was the most readily elicitable reflex in all infants (100%), regardless of maturity. Achilles, patellar, biceps, thigh adductors, and brachioradialis reflexes also were obtained in at least 98% of babies of greater than 33 weeks gestation. Among these reflexes, less mature infants (less than 33 weeks gestation) had decreased elicitation rates for patellar and biceps reflexes and overall had diminished reflex intensity when compared to older infants (33-36 weeks gestation). By order of decreasing rate, finger flexors, jaw, crossed adductors, and triceps reflexes were less frequently elicited in both groups. Equal DTRs were obtained often in healthy and previously ill infants of less than 33 weeks gestation. Head position had no apparent affect on the ability to elicit reflexes. Theophylline therapy tended to intensify the Achilles reflex and the quiet, wakeful state appeared to be the most optimal state for the elicitation of DTRs.
D005865:Gestational Age; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007235:Infant, Premature, Diseases / Q000175:diagnosis*; D009422:Nervous System Diseases / Q000175:diagnosis*; D009460:Neurologic Examination / Q000379:methods; D012026:Reflex, Stretch; D012307:Risk Factors