Generalized hypotonia

Horizontal suspension response is elicited by placing the neonate face down and lifting the neonate by the trunk. A hypotonic neonate bends ventrally and the head and limbs drop straight down like a rag doll (Figure 90.1 [A]). A normal neonate straightens the torso, briefly lifts the head up, and flexes the elbows, hips, knees, and ankles (Figure 90.1 [B]).

Figure 90.1.— [A] Hypotonic horizontal suspension response (Click on figure). [B] Normal horizontal suspension response.

DIFFERENTIAL DIAGNOSIS OF HYPOTONIA

Generalized hypotonia must be differentiated from decreased generalized movements due to pain. Neonates with generalized hypotonia and neonates with decreased movement due to pain have the same posture, yet during arm traction and during vertical and horizontal suspensions the typical hypotonic responses are not present in neonates with decreased generalized movement due to pain. Neonates with decreased generalized movement due to pain become stiff and cry during any of these maneuvers.