Stanford Doctor Neurologic Assessment of a Newborn

Summary

This video provides a comprehensive guide to performing a neonatal neurologic exam, emphasizing the importance of understanding a baby’s gestational age and mental state. It covers key components such as mental status, cranial nerve assessment, tone, strength, sensory responses, deep tendon reflexes, and primitive reflexes. The video demonstrates techniques for assessing reflexes like the Moro, rooting, and grasp reflexes, along with muscle tone and response to stimuli. The aim is to equip healthcare professionals with the knowledge to assess a neonate's neurologic health, adjusting the approach depending on the baby’s state and development.

Takeaways

• 😀 Gestational age is crucial when performing a neonatal neurologic exam, as full-term and pre-term infants have different expected results.
• 😀 Neonatal neurologic exams are highly state-dependent, with a baby's alertness, sleep state, and feeding status influencing their response.
• 😀 The neurologic exam must be assessed in context—individual reflexes or findings should not be interpreted in isolation.
• 😀 To evaluate mental status, gently stimulate the baby to check if they are awake and alert. A baby may need to be re-examined if too sleepy.
• 😀 Cranial nerve function is checked by testing eye movements, pupillary response, the rooting reflex, sucking, and gag reflexes.
• 😀 Tone is assessed by observing the baby's posture at rest and active movements when the baby is awake and alert.
• 😀 Both central (trunk and neck) and peripheral (arms and legs) tone are tested, with head position kept midline to avoid asymmetry in tone.
• 😀 Strength testing in neonates is done by observing whether the baby can maintain anti-gravity positions or resist passive movements.
• 😀 Sensory exam involves checking the baby’s response to stimuli like light touch, pinch, or nail bed pressure, as babies cannot verbally communicate sensation.
• 😀 Reflex testing includes deep tendon reflexes (e.g., patella, Achilles) and primitive reflexes (e.g., Moro, rooting, grasp, stepping) to assess neurologic development.
• 😀 Clonus may be observed in neonates but is considered normal if it’s not sustained, indicating a possible sign of hyperreflexia.
• 😀 Primitive reflexes like the asymmetric tonic neck reflex, Moro reflex, and grasp reflex provide insight into the maturity of the baby's nervous system.

Q & A

Why is it important to know the gestational age when performing a neonatal neurologic exam?

Gestational age is crucial because a full-term infant will have a very different neurologic exam than a pre-term baby. Knowing the gestational age helps in understanding what is considered normal or abnormal for the baby's neurologic state.

How does the baby's state (awake, asleep, or in active sleep) affect the neurologic exam?

A baby's state significantly influences the neurologic exam. For example, a baby who has just had a meal may be very sleepy and hard to arouse, which could alter the findings. It's essential to know the baby’s most awake state to accurately assess the exam.

What is the importance of considering all components of a neonatal neurologic exam together?

It is important to evaluate all components of the neurologic exam in context because a single reflex or tone finding on its own is not sufficient to fully understand the baby's neurologic status. A comprehensive view of all factors provides a clearer picture.

What is the first step in assessing the mental status of a neonate during a neurologic exam?

The first step is to lightly stimulate the baby by gently placing a hand on their abdomen and chest and moving the arms and legs slightly. This helps determine the baby's level of alertness and responsiveness.

What cranial nerves are assessed during the neonatal neurologic exam, and how are they tested?

Cranial nerves II, III, IV, VI, V, VII, IX, X, and XII are assessed. Testing includes eye movements, the doll’s eye reflex, checking the pupils, rooting reflex, sucking reflex, gag reflex, and responses to light touch or sound.

What is the difference between resting and active tone in a neonate?

Resting tone refers to the baby's relaxed state, where the limbs may be slightly flexed. Active tone refers to the tone when the baby is more awake or stimulated, during which the baby shows more purposeful movement and stronger muscle tone.

How is central tone evaluated in a neonatal neurologic exam?

Central tone is assessed by lifting the baby and checking if they can support their head or hold it up briefly, as well as testing vertical and horizontal suspension to observe how much the baby can support themselves with their trunk and neck.

What is the significance of checking appendicular tone during the exam?

Appendicular tone is assessed by gently moving the baby's arms and legs to test the range of motion and passive stretch of the muscles. This helps determine if the baby has normal tone in the limbs, which is important for overall neurologic development.

Why is clonus considered a sign of increased reflex activity in a neonate?

Clonus, which is the involuntary rhythmic contraction of muscles, can be a sign of increased reflex activity in a neonate. If clonus is present and sustained, it might indicate abnormal neurologic function, but it can also be normal if it is not sustained.

What are primitive reflexes, and why are they important in a neonatal neurologic exam?

Primitive reflexes are automatic movements that are present in neonates but disappear as the nervous system matures. These reflexes, such as the Moro reflex, rooting reflex, and grasp reflex, provide insight into the development and function of the baby's nervous system.