Grasp Placing finger in infant’s palm results in flexing of infant’s fingers Birth 6 mo
Rooting Tactile stimulus about infant’s mouth results in the mouth pursuing the Birth 4–6 mo stimulus
Trunk incurvation Stroking the skin along the edge of vertebrae produces curvature of the Birth 4 mo (Gallant) spine with concavity on the side of the stroke
Placing When dorsum of foot is brought into contact with the edge of a surface, Birth 4–6 mo infant places foot on the surface
Asymmetrical tonic With infant supine, turning of the head results in ipsilateral extension of the Birth 3 mo neck arm and leg with flexion of opposite extremities in a “fencing” posture
Parachute Infant is suspended face down by the chest. When infant is moved toward 8–10 mo Never a table, the arms extend as if to protect self
Babinski Stroking lateral aspect of sole from heel up results in dorsiflexion of the Birth 12–18 mo great toe and fanning of the remaining toes
Irritability, lethargy, or more severely depressed consciousness are nonspecific signs of abnormal brain function.
Examination of the primitive reflexes provides assessment of the functional integrity of the brainstem and basal ganglia (Table 179-1). Many of these stereotyped motor responses are present at birth. They are symmetrical and disappear at 4 to 6 months of age, indicating the normal maturation of descending inhibitory cerebral influences. The grasp and rootingreflexes are inhibited by maturation of frontal lobes but may reappear later in life with acquired frontal lobe lesions. Asymmetry or persistence of the primitive reflexes may indicate focal brain or peripheral nerve lesions.
Posture is the position that a calm infant naturally assumes when placed supine. An infant at 28 weeks of gestation shows an extended posture. By 32 weeks, there is a slight trend toward increase in tone and flexion of the lower extremities. At 34 weeks, the lower extremities are flexed; the upper extremities are extended. The term infant flexes lower and upper extremities. Recoil, the readiness with which an arm or leg springs back to its original position after passive stretching and release, is essentially absent in very premature infants but is brisk at term. Because of the asymmetric tonic neck reflex, it is essential to maintain the infant’s head in a neutral position (not turned to the side) during assessment of posture and tone.
Spontaneous movements of premature infants are slow and writhing; those of term infants are more rapid.
The purpose of the neurologic examination is to localize or identify the region within the neuraxis from which the symptoms arise. The mental status examination assesses the cerebral cortex. The cranial nerve examination evaluates the integrity of the brainstem. The motor examination evaluates upper and lower motor neuron function. The sensory examination assesses the peripheral sensory receptorsand their central reflections. Deep tendon reflexes assess upper and lower motor connections. Gait assessment evaluates the motor system in a dynamic state for better functional assessment.
Alertness is assessed in infants by observing spontaneousactivities, feeding behavior, and visual ability to fix and follow objects. Response to tactile, visual, and auditory stimuliis noted. If consciousness is altered, the response to painful stimuli is noted. Observation of toddlers at play allowsa nonthreatening assessment of developmentally appropriate skills. In addition to language function, older childrencan be tested for reading, writing, numerical skills, fundof knowledge, abstract reasoning, judgment, humor, and memory.