[Generalized neonatal hypotonia].

Abstract

Generalized neonatal hypotonia implies a pathologically decreased postural tone involving at least the extremities, trunk and neck occurring during the first month of life. The gestational age of the neonate, the behavioral state of the neonate at the time of the examination, and the possibility of pseudoparalysis (due to generalized pain) should be considered when evaluating a neonate for the possibility of generalized hypotonia. The evaluation of neonates with hypotonia should be guided by the characteristic of the muscular dynamic reflexes, primitive reflexes, the relation between the degree of hypotonia and weakness and findings during several maneuvers (traction, ventral and horizontal suspension, plantar response and response to forward displacement from a lying position). Possible sites of pathology in neonates with hypotonia include: (1) brain, (2) brain stem, (3) cervical spine, (4) cerebellum, (5) lower motor neurons in the brain stem and spine; (6) nerve, (7) myoneural junction, and (8) muscles.