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Neonatal Reflexes, HIE, and Neonatal Seizures Explained in Detail

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Frequently Asked Questions

What are neonatal reflexes?

Neonatal reflexes are primitive automatic responses present at birth that indicate normal neurological function and brainstem integrity. They gradually disappear as cortical control develops.

Why are neonatal reflexes clinically important?

They help assess CNS maturity, detect neurological injury such as hypoxic ischemic encephalopathy, and identify peripheral nerve injuries like brachial plexus palsy.

What is the Moro reflex and when does it disappear?

The Moro reflex is a startle response where the infant abducts and then adducts the arms after sudden head movement. It disappears by 4–6 months of age.

What does an absent Moro reflex indicate?

Absent Moro reflex may indicate severe CNS depression, hypoxic ischemic encephalopathy, prematurity, or significant neurological injury.

What does an asymmetric Moro reflex suggest?

An asymmetric Moro reflex suggests peripheral injury such as brachial plexus injury (Erb palsy) or clavicle fracture.

What is the rooting reflex and its significance?

Rooting reflex is turning of the head toward cheek stimulation. It is important for feeding and disappears by 3–4 months. Absence suggests CNS depression.

What is hypoxic ischemic encephalopathy (HIE)?

HIE is neonatal brain injury caused by reduced oxygen supply and impaired cerebral blood flow around the time of birth, leading to neuronal damage.

What are the common causes of HIE?

Common causes include placental abruption, cord prolapse, uterine rupture, prolonged labor, severe maternal hypotension, and neonatal shock or respiratory failure.

What are the main clinical features of HIE?

Features include low Apgar scores, poor tone, weak reflexes, lethargy or coma, poor feeding, respiratory depression, and seizures.

What is the Sarnat staging system in HIE?

Sarnat staging classifies HIE into Stage I (mild), Stage II (moderate with seizures), and Stage III (severe coma with absent reflexes and poor prognosis).

When do seizures typically occur in HIE?

Seizures in HIE most commonly occur within the first 24 hours, often during the secondary energy failure phase.

What is therapeutic hypothermia and when is it used?

Therapeutic hypothermia is controlled cooling to 33–34°C for 72 hours. It is used in moderate to severe HIE if started within 6 hours of birth.

What is the most common type of neonatal seizure?

Subtle seizures are the most common, presenting as eye deviation, lip smacking, apnea, or bicycling movements.

What are the most common causes of neonatal seizures?

The most common causes include hypoxic ischemic encephalopathy, hypoglycemia, hypocalcemia, intracranial hemorrhage, infections, and neonatal stroke.

How can jitteriness be differentiated from seizures in newborns?

Jitteriness is stimulus-sensitive and stops with gentle restraint, while seizures are not suppressible and may have abnormal EEG activity.

What is the first step in evaluating a neonate with seizures?

The first step is to check blood glucose immediately, as hypoglycemia is a reversible and common cause.

What is the first-line anticonvulsant for neonatal seizures?

Phenobarbital is the first-line anticonvulsant, given as a 20 mg/kg IV loading dose followed by maintenance therapy.

Which drug is commonly used as second-line therapy for neonatal seizures?

Levetiracetam is increasingly used as second-line therapy due to its safety profile and minimal respiratory depression.

What investigation is the gold standard for confirming neonatal seizures?

EEG is the gold standard for seizure confirmation, especially because many neonatal seizures are clinically subtle.

What factors determine prognosis in neonatal seizures?

Prognosis depends mainly on the underlying cause. Metabolic seizures have excellent outcomes, while seizures due to severe HIE or structural brain injury have poorer prognosis.

MCQ Test - Neonatal Reflexes, HIE, and Neonatal Seizures Explained in Detail

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1 A term newborn is delivered after prolonged obstructed labor. Apgar scores are 2 at 1 minute and 4 at 5 minutes. At 3 hours of life, the baby is lethargic, hypotonic, has a weak suck reflex, and absent Moro reflex. Seizures begin at 5 hours. What is the most appropriate neuroprotective intervention?

Explanation:

Moderate to severe HIE requires therapeutic hypothermia started within 6 hours of birth to reduce secondary neuronal injury and improve outcomes.

2 A preterm infant born at 30 weeks gestation has incomplete Moro reflex, weak rooting, and poor coordinated sucking but otherwise stable vitals and normal tone for gestational age. There are no seizures. What is the best interpretation of these findings?

Explanation:

Primitive reflexes may be weak or incomplete in premature infants because brainstem maturation is incomplete.

3 A term neonate shows an asymmetric Moro reflex: the left arm abducts normally, but the right arm does not move. The infant otherwise appears alert with normal tone. What is the most likely cause?

Explanation:

Asymmetric Moro reflex strongly suggests peripheral injury such as brachial plexus palsy or clavicular fracture.

4 A newborn develops repetitive eye deviation, chewing movements, and episodic apnea at 10 hours of life. EEG confirms abnormal ictal activity. What seizure type is most typical in neonates?

Explanation:

Subtle seizures are the most common neonatal seizure type and often manifest as ocular, oral-buccal, or autonomic phenomena.

5 A newborn presents with seizures at 2 hours of life. Blood glucose is 22 mg/dL. What is the immediate first-line management step?

Explanation:

Hypoglycemia is a reversible cause of neonatal seizures and must be corrected immediately before anticonvulsants.

6 A neonate develops seizures on day 2. Serum calcium is 6.8 mg/dL with prolonged QT interval. What is the most appropriate urgent treatment?

Explanation:

Hypocalcemia is an important metabolic cause of neonatal seizures requiring urgent IV calcium replacement.

7 A term newborn with suspected HIE is comatose, flaccid, has absent primitive reflexes, irregular breathing, and no response to stimulation. Which Sarnat stage best fits this presentation?

Explanation:

Stage III HIE is characterized by coma, absent reflexes, apnea, and very poor prognosis.

8 A newborn with moderate HIE undergoes cooling therapy. Seizures persist despite phenobarbital loading. Which drug is the best second-line agent?

Explanation:

Levetiracetam is increasingly preferred second-line due to fewer adverse respiratory and cardiovascular effects.

9 A newborn has tremulous movements that stop when the limb is held. EEG is normal. What is the most likely diagnosis?

Explanation:

Jitteriness is stimulus-sensitive and suppressible, unlike seizures, and is often due to hypoglycemia or hypocalcemia.

10 A neonate develops seizures on day 3 with CSF showing neutrophilic pleocytosis, low glucose, and high protein. What is the most likely etiology?

Explanation:

CSF findings indicate bacterial meningitis, a major infectious cause of neonatal seizures.

11 A newborn with seizures has normal metabolic labs. MRI shows focal arterial infarction. What is the most likely diagnosis?

Explanation:

Focal infarction on MRI suggests neonatal stroke, an important cause of focal seizures.

12 A baby shows repetitive jerks only during sleep that stop immediately when awakened. EEG remains normal. What is the most likely diagnosis?

Explanation:

Benign neonatal sleep myoclonus occurs only during sleep, resolves with arousal, and has a normal EEG.

13 A neonate with refractory seizures has already received phenobarbital and levetiracetam. What is the next appropriate anticonvulsant?

Explanation:

Fosphenytoin/phenytoin is commonly used as third-line therapy for refractory neonatal seizures.

14 A newborn with HIE has severely suppressed background activity on EEG. What does this finding indicate?

Explanation:

Background suppression is associated with severe HIE and adverse neurodevelopmental prognosis.

15 A child continues to demonstrate tonic neck reflex beyond 9 months of age. What is the most concerning implication?

Explanation:

Persistence of primitive reflexes beyond expected age suggests upper motor neuron pathology such as cerebral palsy.

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