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Neuro

Judy Philbrook, NNP-BC

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Development

!   Primary neurulation !   Prosencepahlic !   Neuronal

proliferation !   Neuronal migration !   Organization !   Myelination

!   3-4 weeks !   2-3 months !   3-4 months

!   3-5 months !   5 months to years

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Associated disorders !   Primary neurulation !   Prosencepahlic !   Neuronal proliferation !   Neuronal migration !   Organization !   Myelination

!   Anencephaly, myelomeningocele

!   Holoprosencephaly, midline defects

!   Sturge-Weber !   Agenesis of the corpus

callosum !   Retardation !   Acquired/inherited

diseases

Anatomy

Verklan, et. al.; Core Curriculum for Neonatal Intensive Care Nursing, Elsevier, Philadelphia, 2004

Physiology

!   Brain needs glucose and oxygen l  Preterm has minimal glucose stores l  Cerebral blood flow is affected by pH,

oxygenation, osmolarity, and calcium ion and potassium levels

l  Hypotension – ischemia l  Hypertension - hemorrhage

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Neuro Assessment

!   History !   Observation

l  State, posture, movement, respiratory activity

!   Physical exam l  Skull size and shape, face, spine, cranial

nerve function, muscle tone, reflexes

Neurological disorders

Anencephaly

!   Failure of the anterior neural tube closure

!   Skull bones absent, absent cerebellum !   Identified with prenatal ultrasound !   Outcome – 75 % are stillborn, survival

unlikely beyond neonatal period

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Microcephaly

!   Occipital-frontal circumference > 2 SD below the mean

!   Risk factors !   Pathophysiology

l  Occurs between 3-4 months gestation l  Neuronal proliferation defect

!   Presentation !   Outcome

Up To Date

Hydrocephalus !   Excess CSF in the ventricles

l  Decrease in reabsorption l  Overproduction (rare)

!   Pathophysiology l  Aqueductal outflow obstruction – obstructive,

noncommunicating l  Most common l  May progress rapidly

l  Communicating, nonobstructive - Flow between ventricles and subarachnoid space

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Up To Date

Congenital Hydrocephalus – Risk Factors

!   Aqueductal stenosis !   Dandy Walker cyst !   Myelomeningocele with Arnold-Chiari

malformation !   Congenital masses and tumors !   Congenital infection

l  Toxo l  CMV

Up ToDate

Up To Date

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Congenital Hydrocephalus

!   Presentation – large head, widened sutures, full fontanel, sun setting eyes

!   Needs head ultrasound and/or CT !   VP shunt

l  Signs of infection or blockage l Irritability, vomiting, increasing head

size, lethargy, changes in feeding patterns, bulging fontanel

Posthemorrhagic Hydrocephalus

!   Caused by dilatation of the ventricles after IVH – occurs in ~50% of infants with IVH

!   Care l  Weekly OFC l  Ultrasound

!   Serial LP, Reservoir placement, VP shunt

Myelomeningocele

!   Neural tube defect l  Meningocele (protrusion of meninges) l  Myelocele (spinal cord or nerve roots) l  Myelomeningocele (both)

!   Risk factors !   Pathophysiology

l  Failure of the neural tube to close l  80% lumbar

Up To Date

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Myelomeningocele !   Management

l  Prenatal diagnosis l  Wrap with sterile gauze moistened with

warm NS l  Maintain in prone position l  Obtain neuro and urology consults

!   Outcome l  Survival – 90% l  80% or more have normal intelligence and

85% are ambulatory

Encephalocele

!   Neural herniation with or without brain tissue

!   Prenatal ultrasound !   Outcome: Early surgery recommended !   50% complicated with hydrocephalus

Up To Date

Craniosynostosis

!   Premature closure of the sutures !   Cause unclear !   1 in 2000 to 2500 births !   Presentation: abnormal skull shape,

suture line has bony prominence !   Treatment: surgery

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Verklan, et. al.; Core Curriculum for Neonatal Intensive Care Nursing, Elsevier, Philadelphia, 2004

Birth Injuries

!   Any injury that occurs during the birth process !   Caused by:

l  cephalopelvic disproportion l  prolonged labor l  abnormal presentation (face, brow

presentation)

Which one?

!   Which crosses the suture lines? !   Which resolves the quickest? !   Which may lead to shock and hypovolemia? !   Answer choices:

a)  caput succedaneum b)  cephalohematoma c)  subgaleal hemorrhage

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newborns.stanford.edu

newborns.stanford.edu

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Other birth injuries

!   Skull fractures !   Brachial nerve plexus injuries

l  Erb’s palsy l  Klumpke l  Erb-Duchenne-Klumpke

!   Facial nerve palsy

Intracranial Hemorrhages

Types

!   Subdural !   Subarachnoid !   Intracerebellar !   Periventricular-intraventricular !   Periventricular leukomalacia

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Periventricular-Intraventricular

!   Bleeding into the brain’s ventricular system (graded)

!   Incidence l  30-40% of < 1500 grams l  50% occur in first 24 hours, 80% by 48

hours, 90% by 72 hours !   Presentation

l  Unnoticeable to dramatic !   Diagnosis: Head ultrasound

Verklan, et. al.; Core Curriculum for Neonatal Intensive Care Nursing, Elsevier, Philadelphia, 2004

IVH Risk Factors

!   <34 weeks !   Asphyxia !   Low 5 min Apgar !   Acidosis !   Hypo or

hypertension !   Low Hct

!   RDS – on vent !   Rapid administration

of bicarb or volume expansion

!   Coagulopathy !   Pneumothorax !   PDA ligation !   Transport

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PVL

!   Ischemic and necrotic white matter !   Hypotension impairs cerebral blood flow !   Outcome

l  Spastic dysplasia l  Motor deficits l  Visual impairment

Up To Date

Subdural Hemorrhage !   Definition

l  Laceration of major veins and sinuses !   Incidence - < 10% of ICH’s !   Risk Factors

l  Large head compared to birth canal l  Breech delivery (vaginal) l  Malpresentation l  Forceps, vacuum

!   Pathophysiology l  Excessive molding, elongation – stretching and

tearing of venous sinuses

!   Presentation l  Decreased level of consciousness l  Seizure activity l  Asymmetry of motor reflexes l  Day 2-3: signs of increasing intracranial pressure/

signs of brainstem disturbance !   Diagnosis

l  CT, MRI !   Outcome

l  Poor prognosis with major laceration of tentorium and falx

l  Mortality – 45% l  May develop hydrocephalus and other sequelae

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Subarachnoid Hemorrhage

!   Definition l  An intracranial hemorrhage into the CSF space

between the arachnoid and pial membranes on the surface of the brain

!   Pathophysiology l  Bleeding (venous origin) into the subarachnoid

space l  May be caused by trauma

!   Common type of intracranial hemorrhage

!   Presentation l  No symptoms l  Seizure activity may begin on day 2, esp.

term l  Apnea more common in preterm

!   Diagnosis l  By exclusion – other forms of ICH are

eliminated by CT scan !   Outcome

l  Usually normal – 90% of babies who had seizures have normal follow-up

Intracerebellar Hemorrhage

!   Definition l  Hemorrhage within the cerebellum from

primary bleeding or extension of IVH l  Associated with resp distress, hypoxic

events, prematurity and traumatic delivery !   Diagnosed via CT !   Outcome

l  Better in term than preterm l  Probable neuro deficits

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Seizures

!   Not a disease, but a symptom !   Results from excessive electrical discharge of

neurons

Seizures - Presentation

!   Subtle – most common (lip smacking, blinking)

!   Tonic – tonic extension of extremities or extension of lower extremities and flexion of upper extremities

!   Multifocal clonic – clonic movements – one limb to another with no pattern

!   Myoclonic – rare; jerks

Seizures

!   Diagnostic eval l  Physical l  Lab work l  Sepsis workup l  EEG, CT, head ultrasound l  Neuro consult

!   Medications l  Phenobarbital l  Phenytoin l  Fosphenytoin l  Lorazepam

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HIE !   Brain injury due to asphyxia !   Clinical presentation – staging

l  Stage I (mild encephalopathy) l  Hyperalert state, normal muscle tone, no

convulsions l  Stage 2 (moderate encephalopathy)

l  Lethargy, hypotonia, increased reflexes, weak suck

l  Critical period – improves or deteriorates (seizures, cerebral edema, lethargy)

l  Stage 3 (severe encephalopathy) l  Loss of consciousness l  Seizures appear within 12 hours

!   Care l  Prevent perinatal hypoxia, ischemia and asphyxia l  Maintain oxygenation and acid base balance l  Treat seizures l  Hypothermia (head cooling)

l  > 35 weeks with pH ≤7, base deficit ≥16 OR l  Cord pH or first gas pH 7-7.15 OR base deficit

-10 to -15.9, OR no blood gas and a history of an acute perinatal event and wither a 10 min Apgar ≤5 or continued need for ventilation support for at least first 10 postnatal minutes

!   Outcome l  Based on severity of brain insult

Meningitis

!   Infection in the CNS (viral, bacterial, fungal)

!   Diagnosis: CSF (low glucose, organism present, elevated WBC and protein)

!   Treatment l  Antibiotics l  Repeat LP

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References

!   Verklan, et. al.; Core Curriculum for Neonatal Intensive Care Nursing, Elsevier, Philadelphia, 2004.