Underlying Defect | Points to Remember |
|---|---|
Hypoxic–ischemic encephalopathy |
|
Focal ischemia/infarction |
|
Intracranial hemorrhage |
|
Infections of the CNS |
|
Metabolic derangement |
|
Structural defects |
|
Day of Life | Possible Causes | |
|---|---|---|
1 | Hypoxic ischemic encephalopathy Infection Hypocalcemia | Maternal drug use Hypoglycemia |
2–3 | All of the above Inborn errors of metabolism Drug withdrawal | CNS malformation Hypernatremia Hyponatremia |
Seizure Type | Clinical Manifestation | |
Subtle | Oral–buccal–lingual or ocular movements Autonomic dysfunction (Δ in HR, BP, Spo2) | Stereotypical stepping/swimming |
Clonic | Rhythmic, slow jerking Facial, extremity, or axial involvement | Focal or generalized |
Tonic | Sustained limb posturing Asymmetric position of trunk/neck | Focal or generalized |
Myoclonic | Rapid isolated jerks Limb/trunk involvement | Generalized, multifocal, or focal |
Seizure Mimic | Clinical Manifestation |
Jitteriness | Spontaneous or provoked by stimulus Flexion/extension are equivalent Diminished by repositioning Abolished with containment |
Benign neonatal sleep myoclonus | Bilateral or unilateral Synchronous or asynchronous Occurs during sleep Not due to a stimulus |
Stimulus-evoked myoclonus | Focal or generalized Severe CNS dysfunction EEG may show cortical spike-wave discharge |
Hyperekplexia (stiff-man syndrome) | Generalized stiffness Autosomal dominant and recessive forms Excessive startle responses to unexpected stimuli Excessive stiffness following startle response Benzodiazepines reduce symptoms |
- Support respiratory and cardiovascular function (may require endotracheal intubation and mechanical ventilation).
- Place on continuous cardiorespiratory monitoring.
- Correct any known causes of seizures (see above).
- If seizures continue after correction of transient metabolic derangements, load with phenobarbital (20 mg/kg IV); can be followed by repeat doses of 5–10 mg/kg IV to a total dose of 40 mg/kg IV, if needed.
- If seizures continue, load with a benzodiazepine such as midazolam (0.1 mg/kg IV; repeat doses can be given to a total dose of 0.3 mg/kg IV).
- If seizures continue, load with fosphenytoin 20 mg/kg.
- If seizures continue, can consider loading with pyridoxine (100 mg/kg IV), preferably with EEG monitoring. Maintenance dosing can be 50-100 mg/dose once daily (orally)
- Newer agents that are used in older children, adolescents, and adults may sometimes be given (in consultation with the neurology service), but no data exist on the safety and efficacy of these medications in neonates.
- Definition: an intracranial hemorrhage that originates in the paraventricular subependymal germinal matrix and may extend into the lateral ventricular system.
- 50% of IVH occurs in the first 24 h after birth, and 90% by 7-10 days of life..
- Incidence and severity are inversely proportional to gestational age.
- Antenatal steroid administration is associated with a lower incidence.
- Major risk factors:
- Extreme prematurity
- Need for assisted ventilation
- Pneumothorax
- Extreme prematurity
- Clinical presentation can be very diverse:
- May be asymptomatic
- May have nonspecific symptoms (bulging fontanelle, sudden drop in hematocrit, apnea/bradycardia, metabolic acidosis, seizures, change in level of consciousness)
- May present with a catastrophic constellation of symptoms (profound hypotension, severe neurogenic pulmonary edema, rapid deterioration in neurologic exam, decerebrate posturing)
- May be asymptomatic
- All infants with birth weight <1500 g and any infant who the attending physician feels is at risk for IVH should receive a screening head US between 7 and 10 DOL.
- If abnormalities are noted on the initial screening US, follow-up is recommended at weekly intervals to monitor for the development of posthemorrhagic hydrocephalus.
- If no abnormalities are noted on the initial screening US, follow-up cranial imaging can be done at 36–40 wk postmenstrual age to evaluate for evidence of periventricular leukomalacia.
- If abnormalities are noted on the initial screening US, follow-up is recommended at weekly intervals to monitor for the development of posthemorrhagic hydrocephalus.
- 50% of IVH occurs in the first 24 h after birth, and 90% by 7-10 days of life..
Grade I | Germinal matrix hemorrhage |
Grade II | Germinal matrix hemorrhage with intraventricular hemorrhage but without ventricular dilation |
Grade III | Germinal matrix hemorrhage with intraventricular hemorrhage and dilation |
Grade IV | Germinal matrix hemorrhage with parenchymal involvement |
- Prognosis:
- Mortality in severe IVH (grades III/IV) is approximately 20%–50%.
- Incidence of posthemorrhagic hydrocephalus in severe IVH (grades III/IV) is approximately 55%–80%.
- Long-term major neurologic sequelae are related to the extent of parenchymal injury:
- 15%–20% of infants with minor degrees of hemorrhage will have a major neurodevelopmental impairment (slightly higher than those without IVH).
- 50%–80% of infants with severe hemorrhage will have major developmental impairment.
- 15%–20% of infants with minor degrees of hemorrhage will have a major neurodevelopmental impairment (slightly higher than those without IVH).
- Mortality in severe IVH (grades III/IV) is approximately 20%–50%.
Stage 1 (Mild) | Stage 2 (Moderate) | Stage 3 (Severe) | |
|---|---|---|---|
Level of consciousness | Hyperalert | Lethargic | Stuporous, comatose |
Tone | Normal | Hypotonic | Flaccid |
Posture | Normal | Flexed | Decerebrate |
Reflexes | Hyperactive | Hypoactive | Absent |
Pupils | Mydriasis | Miosis | Unequal, poor light reflex, midline |
Oculovestibular | Normal | Overactive | Weak or absent |
Seizures | None | Common | Decerebrate |
EEG | Normal | Low voltage with seizures | Burst suppression to isoelectric |
Duration of symptoms | <24 h | 2–14 d | Hours to weeks |
Outcome | Nearly 100% normal | 80% normal | ∼50% die; survivors have severe sequelae |
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