Neonatal Brain Development, Nervous System, and Behavioural States PDF

Neonatal Nervous System Autonomic functions - The neonate's nervous system takes over control of functions e.g. hunger, thirst and satiety (feeling full), which are balanced by hypothalamic centres - Also thought to influence nutritive sucking and swallowing Sensory functions - Neonates are...

Neonatal Nervous System Autonomic functions - The neonate's nervous system takes over control of functions e.g. hunger, thirst and satiety (feeling full), which are balanced by hypothalamic centres - Also thought to influence nutritive sucking and swallowing Sensory functions - Neonates are born with active sensory pathways– smell, taste, see, hear sounds (used in utero). They learn by receiving, processing and responding to a vast range of sensory stimuli Motor functions - Movements may be reflexive or volitional (under control of the motor cortex) - Gradual motor control becomes evident as myelination of the major central and peripheral nerve track progresses - Increased sensory stimulation encourages skeletal muscle movements, and contribute to new dendrites, motor neurons and interneuron connections (Rankin 2017) Image reproduced from Rankin 2017 DD/Month/ Professor/Dr: Topic title: 1 YYYY Reflexes Autonomic 'built-in' motor behaviours which Permanent generally occur in the spinal cord. Involuntary 1. Breathing Reflex 2. Eye Blink Reflex Safety and survival 3. Pupillary Reflex Important in assessing the integrity of the 4. Swallowing Reflex – gag, cough and sneese neurological system reflexes Grasping and Moro reflex are used to assess CNS Primitive – involving brainstem and spinal development of the newborn. Babies also cord demonstrate a strong palmar grasp and a 5. Rooting Reflex – first few weeks rhythmic stepping movement 6. Babinski Reflex – before 12 months Absence of many reflexes may indicate brain 7. Moro Reflex (startle) - 4-6 months damage – severe asphyxia, low apgars, 8. Tonic Neck Reflex (fencing) – 6 months neurological damage. Narcotic used in labour – 9. Galant Reflex – 6 months may cause temporary depression of reflexes 10. Palmar/Plantar Grasp Reflex – 3-4 months 11. Sucking Reflex –3-4 months Reappearance in adulthood of primitive reflexes 12. Stepping/walking Reflex – first 2 months may be due to pathological interference. Further 13. Swimming Reflex – 6 months investigations are necessary DD/Month/ Professor/Dr: Topic title: 2 YYYY  Apgar score – how does the baby respond to handling? Tone and response Neurological examination to stimuli Tone – strength and reflexes of limbs with normal or abnormal movements – neurological damage Level of consciousness – alertness and interaction with mother, eye-to- eye contact Ability to adapt temperature to the environment; and respiratory and heart rates changes with physical activity Cry – tone and its clarity, it should be without hoarseness or nasal tone; Pain – pain perception is more intense as more sensitive to painful stimulus with immature nervous system. Does it have any pain? Hard to assess – facial expressions, irritability, withdrawn and lethargic. Pain relief, change position, offer sucking breast/hand. Feeding – if it does not seem capable of normal feeding responses, need to check reflexes – rooting, sucking and gag as may have cranial nerve damage Facial dysmorphism – genetic syndromes, palsy seen on crying Eyes – how eyes of term baby react to light, how they move and fixate can provide neurological markers Anal wink - contraction of the external anal sphincter in response to touch or blown air – the muscular opening of the anus should have a firm appearance and not be distended and lax Others:- café au lait –neurofibromatosis, naevus simplex over spine, hair tuft - spina bifida, palsies, retinoblastoma (brain tumours) DD/Month/ Professor/Dr: Topic title: 3 YYYY Behavioural states Normal neonatal body posture/ activity:- Well flexed with head usually lying in midline and limbs often held in a roughly symmetrical Often alternately move their arms and legs Hands are tightly closed and often held near chin or upper body ‘Jitter’ or startle in their sleep – myoclonic jerk When limbs are moved, there should be obvious muscle resistance and tone Traction response – held in a sitting position, initial head lag but the baby should be able to demonstr DD/Month/ Professor/Dr: Topic title: 4 YYYY Sleep patterns The normal term baby will usually move between behavioural states, spending most of the time in quiet and active sleep – 16 hours of sleep per day Approx 50 mins per hour will consist of sleep time, which 50% will be spent in quiet sleep (Campbell and Dolby 2018) Sleep patterns are not diurnal and do not follow a Reproduced from Campbell and Dolby 2018 –from Brazelton and light–dark cycle Nugent (2011) define normal sleep pattern as passing through a number of stages or ‘states’ unless this pattern is interrupted Understanding these e.g. baby is picked up different behavioural states DD/Month/ Professor/Dr: Topic title: may lessen anxiety, allow 5 YYYY Key neurological alarm signals - rare Persistent irritability Difficulty in feeding Persistent symmetry of posture and movement Floppiness Opisthotonus Abnormal cry Setting sun eyes Convulsions Respiratory difficulties Apathy or conversely hyperexcitability and jitteriness REQUIRE URGENT NEONATAL REFERRAL/ INVESTIGATIONS DD/Month/ Professor/Dr: Topic title: 6 YYYY What needs to be done next Discuss with your Practice Supervisor Possible referrals – depending on the findings, urgency may be required Discussion with the parents, may require sensitive approach Documentation DD/Month/ Professor/Dr: Topic title: 7 YYYY