Neonatal Seizures ✅ Flashcards
How does the incidence of seizures in the neonatal period compare to at other times of life?
They are more common in neonatal period than any other time
What is the incidence of neonatal seizures in term babies?
1.5-3.5 per 1000 live births
What is the incidence of neonatal seizures in premature babies?
10-130 per 1000 live births
When do seizures occur, in terms of electrical activity in the brain?
When a large group of neurons undergo excessive, synchronised depolarisation
What can cause depolarisation of neurones?
- Excessive excitatory amino acid release
- Deficient inhibitory neurotransmitter
Give an example of an excitatory amino acid that may be excessively released in seizures
Glutamate
Give an example of an inhibitory neurotransmitter that may be deficient in seizures
Gamma amino butyric acid (GABA)
What is the biochemical effect of neonatal seizures?
Derangements of energy metabolism
What do derangements in energy metabolism lead to in neonatal seizures?
Compromise of energy-dependent ion pumps and consequent rise of adenosine diphosphate (ADP) levels
What does the rise in ADP in neonatal seizures do?
Stimulates glycolysis, with the ultimate increase in pyruvate
What happens to pyruvate produced due to neonatal seizures?
It accumulates due to compromised mitochondrial function
What is the role of adenosine triphosphate (ATP)-dependent resting membrane potentials in seizures?
Seizures can be caused by disruption in ATP-dependent resting membrane potentials
What pump is important in ATP-dependent resting membrane potentials?
ATP-dependent sodium-potassium pump
What condition causes disruption of the ATP-dependent sodium-potassium pump?
Hypoxic-ischaemic encephalopathy
What is the effect of HIE on the ATP-dependent sodium-potassium pump?
It appears to cause excessive depolarisation leading to seizures
What is the function of the ATP-dependent sodium-potassium pump?
It allows sodium to flow into the neuronal and potassium to flow out of the neuron
How may seizures present in the neonatal period?
- Clonic or tonic involuntary movements of one or more limbs
- Apnoea, transient cyanosis, and episodes of oxygen desaturation
- Lip smacking
- Altered consciousness
- Floppiness
What is the problem with seizures in the developing brain?
- Poorly classified
- Frequently under-diagnosed
- Difficult to treat
What can the causes of neonatal seizures be classified into?
- Cerebral
- Metabolic
- Infectious
- Drugs
- Other
What are the cerebral causes of neonatal seizures?
- Hypoxic-ischaemic
- Subarachnoid or subdural haemorrhage
- Parenchymal haemorrhage in preterm infants
- Cerebral malformations of the brain, including vascular anomalies
What are the hypoxic-ischaemic causes of neonatal seizures?
- Hypoxic-ischaemic encephalopathy/birth trauma
- Focal ischaemia (arterial/venous)
What are the metabolic causes of neonatal seizures?
- Hypoglycaemia
- Hypocalcaemia
- Hypomagnesaemia
- Hyponatraemia
- Hypernatraemia
- Inborn errors of metabolism
What are the infectious causes of neonatal seizures?
- Septicaemia
- Meningitis
- Encephalitis
What are the drug causes of neonatal seizures?
- Drug withdrawal
- Side-effect of drugs
What are the other causes of neonatal seizures?
- Kernicterus
- Pyridoxine deficiency
- Idiopathic benign neonatal seizures
What is the most common cause of seizures in a term infant?
HIE
What % of preterm infants with intraventricular haemorrhage or periventricular leukomalacia have seizures?
Up to 70%
How can early recognition of neonatal seizures be assisted?
aEEG or EEG monitoring, preferably with video recording
What investigations are done in neonatal seizures?
- Comprehensive biochemical, infective, and metabolic screening
- Neurophysiological studies
- Imaging
Give a neurophysiological study that may be done in the investigation of neonatal seizures
EEG
What neuroimaging may be done in the investigation of neonatal seizures?
- Cranial USS
- CT
- MRI
What is the purpose of CT head in the investigation of neonatal seizures?
Identify haemorrhage or traumatic injury
What is the purpose of MRI in the investigation of neonatal seizures?
Identify ischaemia or malformations
What conditions may be screened for in the investigation of neonatal seizures?
- Inborn errors of metabolism
- Congenital infection
When are neonatal seizures treated?
If prolonged
What anticonvulsant is best in neonatal seizure?
No anticonvulsant has been shown to be superior to others
What is the limitation of anticonvulsant medications in neonatal seizures?
Evidence that some anticonvulsant medication, while reducing the abnormal movements, does not reduce the electrical discharge
What is it called when there is a reduction in abnormal movements but not electrical discharge in seizures?
Electroclinical dissociation
What is the prognosis of neonatal seizures?
Depends on cause
What are neonatal seizures an independent risk factor for?
Adverse neurodevelopment outcome
