Newborn and Infant Neurological Assessment: Why is it important?!
Neurological examination is commonly carried out by Pediatric Neurologists and Pediatricians for babies and infants, and in some countries monthly visit to a Pediatric Neurologist is mandatory in the first year of life. As a Consultant Pediatric Neurologist and Pediatrician, I have the privilege of carrying out neurological examinations in newborn babies and Infants. However, every now and then I get asked from parents and expecting families, “We have been asked to get a regular neuro exam, but we don’t know what it entails!”. Hence the reason to write this simple and easy to understand blog.
“Neuro exam” or Complete Neurological Examination is basically assessment/evaluation of your baby’s or infant’s nervous system. Most people tend to think that nervous system comprises only brain, which is partially correct. The human nervous system consists of brain, the spinal cord, nerves arising from the spinal cord and muscles, so in essence neurological examination is from “Head-to-Toe” evaluation. This assessment can be carried out by a pediatrician when the baby is born and if it needs to be detailed then the newborn or the infant must visit a Pediatric Neurologist. Part of my daily job is to carry out detailed “neuro exams” on babies and infants to pick up any subtle abnormalities which may have been overlooked or have presented as the baby matures. The common aspects involve assessing the baby’s motor and sensory skills, level of awareness, interaction with the environment, newborn reflexes, muscle tone and nerve functions etc.
Now to the second common question, “Why is a regular neuro exam performed on babies and infants?” A complete neurological assessment and examination is important in babies to make sure there is no underlying neuro-developmental or neurological problem which may have long term implications on the overall growth and development of the baby. If there is damage to the developing nervous system, early identification may help to identify the cause and management strategies can be put in place for early “course correction”.
Let’s now have a look at the aspects of the neuro exam commonly undertaken by the doctor on a newborn baby or an infant. The examining doctor carries out “Head-to-Toe” exam looking for any clues which may suggest problem with the nervous system of the baby. It usually starts with the measuring the Head Circumference (also called OFC) and thereafter the OFC, weight and length are plotted on a growth chart to make sure there are no major discrepancies in the vital parameters. The doctor will then look at the general muscle tone of the baby, because if the baby is “floppy” it will point towards various neurological and neuromuscular problems. Various newborn or “primitive reflexes” are also checked, as lack of these reflexes may also point towards problem with the baby’s nervous system (listed later). The doctor will also look at the anterior fontanalle (soft spot) on the head to ensure it is open and not too large or bulging. A quick examination of the back and lower end of spine is done to look for any spinal disorders like Spina Bifida. If there are “distinct facial features”, these may point towards various chromosomal or Neurogenetic disorders eg Down syndrome and these need urgent Genetic referrals. He/She will also use a “tendon/knee hammer” to check the joint reflexes to ensure that nerves supplying the arms and legs are intact. These reflexes are different from the primitive reflexes and lack of these reflexes, or abnormally frisky reflexes can both point to various neurological disorders.
The common primitive reflexes tested in newborn and infants are as follows (list not exhaustive):
- Blinking reflex - an infant will close his/her eyes in response to bright lights.
- Moro's reflex - a quick change in the infant's position will cause the infant to throw the arms outward, open the hands, and throw back the head.
- Palmar and plantar grasp - the infant's fingers or toes will curl around a finger placed in the area
- Plantar or Babinski reflex - as the infant's foot is stroked, the toes will extend upward.
- Stepping reflex- when the baby’s shin is touched at the edge of bed, it raises the leg as if to step.
- Startle - a loud noise will cause the infant to extend and flex the arms while the hands remain in a fist.
Another common question I get asked by parents is, “Doctor, when can my baby see?”, “What toys can I use to improve vision?”
When a doctor examines a newborn child, he/she grossly assesses the cranial nerves which supply the face, head, and eye muscles to make sure there no gross neurological deficit or anomaly. The babies usually start to focus around 4 weeks of age to nearby faces and social smiling starts around 6 weeks of age i.e they look at you and smile. I always encourage contrasting coloured toys, initially black and white (as colour vision recognition starts around 5-6 months of age) followed by coloured toys to improve baby’s visual pathways.
When the infant is bit older, it is easy to gauge their interaction with the environment e.g reaching out for toys, responding to commands etc.
Finally, it is imperative for parents to visit their paediatricians or Pediatric Neurologist on a regular basis, particularly in the first year of life so that the doctors can spot any early signs of Neurological disorder and put management strategies in place as soon as possible to avoid development problems.