NEWBORN: ABNORMAL EXAM
Behavior
This baby is 3 weeks old. When the exam begins, he has his eyes closed and appears to be in a drowsy state. Within a few seconds he transitions to an awake state and maintains eye opening but his movements are not vigorous. He responds to light and sound and has some habituation. One has to decide if this is just a sleepy baby or if this baby’s mental status is abnormal. His lack of spontaneous facial and extremity movement is abnormal although he has grimace to light so he has reflexive movements.
Cranial Nerves
The baby has full conjugate eye movements. The face has a bland appearance, but tickling the feet produces a full grimace and facial muscles are normal. The baby’s cry is not high pitched but is softer and not as sustained as one would expect. (The baby has a poor suck, which is demonstrated in the primitive reflex section of the exam.)
Tone - Resting Posture
Although this baby’s resting posture shows some flexion of the lower extremities, the upper and lower extremities are in more extension than flexion. The hips are fully abducted and there is little spontaneous movement. There are some gravity opposing movements but they are infrequent. This baby has a “flat on the mat” appearance reflecting low tone and possible weakness.
Tone - Upper Extremity Tone
On passive range of motion of the upper extremities there is some tone, but the tone is significantly less than expected. Shaking the hand back and forth demonstrates the decreased tone in the hand.
Tone - Arm Traction
With the arm traction maneuver there is less resistance and the arm is more extended than normal. There should be more flexion at the elbow.
Tone - Arm Recoil
When arm recoil is tested there is very little recoil. This indicates decreased tone in the biceps muscles.
Tone - Scarf Sign
The scarf maneuver demonstrates low shoulder girdle tone. The hand actually can be pulled beyond the opposite shoulder and the elbow goes past the midline.
Tone - Hand Position
The baby’s hand is not in the typical closed or fisted position. It is open with more extension of the fingers and thumb than is usually seen at this age. This is consistent with hypotonia.
Tone - Lower Extremity Tone
There is increased range and less resistance on passive range of motion at the hips, knees, and ankles. The hips can be abducted almost to the mat. The leg can be extended too far at the hip and knee. Ankle tone is diminished, which can be demonstrated by flexing and extending the ankle and shaking the foot.
Tone - Leg Traction
Although there is some tone on leg traction it is less than normal. The leg should not be straightened to the degree that it is. There should be more flexion at the knee.
Tone - Leg Recoil
There is some leg recoil for this baby but it is not as strong as it should be because of the low tone.
Tone - Popliteal Angle
The popliteal angle is about 160 degrees and should be about 90 degrees. This indicates low tone in the hamstring muscles.
Tone - Heel to Ear
This baby’s tone is low enough that the heel can almost be drawn up to the level of the ear. The heel in a normal baby would only come to mid chest.
Tone - Neck Tone
On passive rotation of the head from shoulder to shoulder, the chin goes past the shoulder on each side. This confirms low tone in the neck muscles.
Tone - Head Lag
Pulling the baby from the supine to the sitting position demonstrates significant head lag. Also the arms are fully extended so there is no pulling or resistance with traction. The baby fails to bring the head to the upright position once he is in the sitting position.
Tone - Head Control
The baby has a significant problem with head control. With the neck flexed, the baby cannot raise his head, which indicates weakness of the neck extensors. With the neck extended, the baby cannot raise his head, which indicates weakness of the neck flexors.
Positions - Prone
When placed in the prone position with his face on the mat, he is able to turn the head to one side, but he doesn’t turn his head from side to side which he should be able to do. His hips are too abducted so his pelvis is flat on the mat and he doesn’t bring his arms forward. Overall he has fewer spontaneous movements than he should have.
Positions - Ventral Suspension
In ventral suspension the baby is draped over the supporting hand. His head is on his chest and is not kept in the same plane as the trunk. The trunk is too rounded and the extremities are extended. The baby makes some effort to straighten his back so there is some strength, but the effort is less than it should be.
Positions - Vertical Suspension
In vertical suspension there is the feeling that the baby is slipping through the examiner’s hands because of the low tone in the shoulder girdle muscles.
Reflexes - Deep Tendon Reflexes
Testing deep tendon reflexes on this baby demonstrates that they are present. This is important in trying to sort out if the baby has low tone from an upper motor neuron lesion or if he has a lower motor neuron or muscle disorder.
In older children and adults, an upper motor lesion causes spasticity but in babies an upper motor neuron lesion can cause hypotonia. A disease of the lower motor neuron is unlikely with the deep tendon reflexes being present.
The baby could still have a muscle disorder but inspection of the muscles does not show diminished mass and the baby’s behavior and the rest of the neurological exam indicates an upper motor neuron problem.
Reflexes - Plantar Reflex
On stroking the lateral aspect of the plantar surface of the foot the toes are up going which is a normal finding for the baby.
Primitive Reflexes - Suck, Root
There is some sucking but it is not as vigorous or sustained as it should be. The pacifier can be easily pulled from the mouth. There is no root reflex, which is a definite abnormality, and this baby has had problems with feeding.
Primitive Reflexes - Moro
The baby has a Moro reflex with the arms fully abducted and extended but he doesn’t bring the arms back to the midline. So the Moro is present, but not as complete as it should be.
Primitive Reflexes - Galant
The baby has a normal Galant or trunk incurvation reflex. The trunk and hips move towards the side of the stimulus.
Primitive Reflexes - Stepping
With the baby held in vertical suspension and his feet touching the mat, he does not have the expected reciprocal flexion and extension of the legs. The stepping or walking reflex is absent in this baby.
Primitive Reflexes - Grasp
The baby has grasp reflex of both the hand and the foot but both are weaker and not as pronounced as they should be.
Head Shape and Sutures
The baby’s head shape is noted and the sutures palpated. The only abnormality noted is that the bifrontal diameter is less than the biparietal diameter. In the normal infant they are usually the same.
Head Circumference
The head circumference for the baby is 34.6 cm, which is the 25th percentile. Measuring the head circumference in this baby is very important because of his findings of central or cerebral hypotonia, which reflects that the hypotonia is from an upper motor neuron problem. If the baby had microcephaly, then that would indicate a process that had affected brain growth in utero. The main diagnostic considerations for this baby are a congenital brain malformation, a chromosomal abnormality or an inborn error of metabolism.