Neonatal Seizures: Understanding, Diagnosis, and Treatment

Overview

Neonatal seizures are a significant and alarming neurological event occurring in newborns, characterized by sudden and uncontrolled electrical disturbances in the brain. These seizures can be indicative of underlying conditions and require prompt and precise medical intervention.

Understanding neonatal seizures is crucial for healthcare providers, parents, and caregivers to ensure timely and effective treatment, thereby improving the long-term prognosis for affected infants.

Introduction of Neonatal Seizures

What is a neonatal seizure?

Neonatal seizure is a common neurological condition in neonates. It is defined as a sudden, paroxysmal, alteration of abnormal electrophysiological activity at any point from birth to the neonatal period.

During this period, the neonatal brain is still developing and is considered immature within the first 28 days after birth. Thus, neonatal seizures have special pathophysiology and electrographic presentations resulting in clinical manifestations that are different compared to older age groups.

Neonatal seizures incidence ranges from 1.5 to 5.5 per 1000 in newborns and maybe even higher in premature infants. Occurrence of seizures increases with decreasing gestational age and birth weight.

Importance of Understanding Neonatal Seizures

Understanding neonatal seizures is crucial for several reasons:

• Early Identification and Treatment: Neonatal seizures can be the first sign of an underlying neurological condition or systemic illness. Prompt recognition allows for early intervention and management, which is critical to preventing further brain injury.

• Differentiation from Normal Neonatal Behavior: Neonatal seizures can present with subtle signs that may be mistaken for normal neonatal behaviour. Knowledge of seizure characteristics helps healthcare providers distinguish abnormal movements or behaviours that warrant further evaluation.

• Etiological Diagnosis: Identifying the cause of neonatal seizures involves a thorough evaluation to determine if they are due to metabolic disturbances, infections, structural brain abnormalities, or genetic disorders. Understanding these etiologies guides appropriate diagnostic testing and treatment.

• Impact on Long-Term Neurodevelopment: Seizures in the neonatal period may affect long-term neurodevelopmental outcomes. Early recognition and management aim to minimize brain injury and optimize developmental outcomes.

• Family Counseling and Support: Educating families about neonatal seizures helps alleviate anxiety and promotes understanding of the condition. It enables families to make decisions regarding their child’s care and management.

• Research and Advancements in Care: Continued research into neonatal seizures’ causes, mechanisms, and treatment advances medical knowledge and improves outcomes for affected infants.

In summary, understanding neonatal seizures is essential for timely diagnosis, appropriate management, and improving outcomes for infants at risk of or experiencing seizures in the early stages of life.

Neonatal Seizure Types and Categories

Neonatal seizures can be classified into different types and categories based on their clinical presentation and underlying causes. Here are the primary types and categories:

• Clinical Seizures:
  1. Subtle Seizures: These are often challenging to recognize as they may present with subtle movements such as eye blinking, sucking, or bicycling movements of limbs.
  2. Generalized Convulsive Seizures: These seizures involve more obvious movements such as tonic (muscle stiffness), clonic (rhythmic jerking), or myoclonic (brief jerks) movements.
• Etiological Categories:
  1. Hypoxic-Ischemic Encephalopathy (HIE) Seizures: Occur due to perinatal asphyxia or birth trauma, leading to decreased oxygen supply to the brain.
  2. Metabolic Seizures: Caused by metabolic disturbances such as hypoglycemia, electrolyte imbalances, or inborn errors of metabolism.
  3. Infectious Seizures: Result from meningitis, encephalitis, or intrauterine infections (e.g., TORCH infections).
  4. Structural Seizures: These are due to structural abnormalities in the brain, such as congenital malformations, haemorrhages, or tumours.
  5. Genetic Seizure Disorders: Result from genetic mutations or syndromes affecting neurological function.
• Electroclinical Syndromes:
  1. Benign Familial Neonatal Seizure: Typically benign and often have a good prognosis.
  2. Benign neonatal seizures
  3. Early Infantile Epileptic Encephalopathies: Severe epileptic syndromes presenting in early infancy with frequent seizures and developmental regression.
  4. Ohtahara Syndrome: Characterized by early onset seizures, often associated with structural brain abnormalities.
• Mixed or Unclassified Seizures: Some neonatal seizures may not fit neatly into one category and may have multiple types or unclear aetiology features.

Neonatal Seizures Symptoms and Signs

Neonatal seizure symptoms can be categorized as follows:

• Common Symptoms: Here are some common symptoms:
  • rhythmic jerking of the limbs
  • stiffening of the body
  • sudden eye movements
• Uncommon Symptoms: Uncommon symptoms may include subtle behaviours such as
  • lip-smacking
  • tongue thrusting
  • sudden cessation of movement.
• Behavioral Signs: Behavioral signs can involve periods of unresponsiveness, irritability, or excessive crying.
• Physical Manifestations: Physical manifestations often include;
  • abnormal posturing
  • apnea (pauses in breathing)
  • changes in heart rate.
• Duration and Frequency of Seizures: The duration and frequency of seizures can vary, ranging from brief, isolated episodes to frequent and prolonged seizures.

Neonatal Seizure Causes and Risk Factors

Neonatal seizure causes and risk factors are the following;

• Genetic Factors: Genetic mutations and inherited conditions can predispose newborns to seizures.
• Perinatal Factors: Complications during pregnancy and childbirth, such as preterm birth and low birth weight, are significant risk factors.
• Infections: Infections like
  • meningitis (Group B Streptococcus, Listeria monocytogenes, Escherichia coli)
  • viral encephalitis (Herpes simplex encephalitis, Enteroviruses)
  • intrauterine infection (Toxoplasmosis, Cytomegalovirus, Zica virus, Varicella)
• Metabolic Disorders: Metabolic imbalances, including
  • hypoglycemia
  • hypocalcemia
  • hypomagnesemia
  • hyponatremia
  • hypernatremia
• Hypoxic conditions: Lack of oxygen during birth (birth asphyxia) and Hypoxic-ischemic encephalopathy can result in brain injury and seizures.
• Brain Malformations: Structural brain abnormalities can also be a cause of neonatal seizures.
  • schizencephaly
  • hydranencephaly
  • lissencephaly
  • holoprosencephaly
• Intracranial hemorrhage
  • intraventricular hemorrhage
  • intraparenchymal hemorrhage
  • subdural hemorrhage
  • subarachnoid hemorrhage
• Inborn error of metabolism: deficiency of vitamin and cofactor
  • Paroxidine deficiency
  • Molybdenum contactor deficiency
• Inborn error of metabolism– deficiency of a selected enzyme
  • urea cycle defects
  • amino acid disorders
  • peroxisomal disorders
  • organic acidemias
• Thromboembolic
  • arterial ischemic stroke
  • sinus venous thrombosis

Diagnosis and Tests

Approach to Neonatal Seizures

Details history Taking

• Seizure History:

When assessing neonatal seizures, it’s crucial to gather information about associated eye movements, any attempts to stop the seizure by bending the affected limb, changes in skin colour (such as mottling or cyanosis), autonomic symptoms, and whether the infant was awake or asleep during the seizure.

The timing of seizures in the first days of life can provide valuable diagnostic clues. Seizures occurring from day 0 to 3 may indicate perinatal asphyxia, intracranial hemorrhage, or metabolic issues. Seizures occurring from day 4 to 7 could be related to sepsis, meningitis, metabolic disorders, or developmental abnormalities.

• Antenatal History:

Obtaining a history that suggests intrauterine infection, maternal diabetes, or narcotic use is essential for understanding potential underlying causes.

• Perinatal History:

It’s important to explore the circumstances surrounding delivery, including signs of fetal distress, reduced fetal movement, the need for resuscitation in the delivery room, Apgar scores, and abnormalities in cord pH and base deficit.

• Feeding History:

Observing symptoms like lethargy, poor activity, drowsiness, or vomiting after breastfeeding initiation may indicate inborn errors of metabolism. Late-onset hypocalcemia should be felt if the baby is fed with cow’s milk.

• Family History:

A family history of seizures in parents or siblings during the neonatal period might suggest benign familial neonatal convulsions (BFNC).

Thorough Examination

During the examination, it’s important to record vital signs such as heart rate, respiration, blood pressure, capillary refill time, and temperature. General observations should include gestation status, birth weight, and weight for age, which can provide insights into possible causes such as subarachnoid hemorrhage in the term “well babies” or hypoglycemia in large-for-date babies.

Central Nervous System (CNS) Examination:

A detailed neurological assessment should include checking the anterior fontanel for signs of bulging, which could indicate meningitis or intracranial hemorrhage. It’s also crucial to assess consciousness levels (alert, drowsy, comatose), and muscle tone (low or high), and perform a fundus examination to look for chorioretinitis.

Systemic Examination:

Examining the presence of hepatosplenomegaly or uncommon urine colour can help identify inborn errors of metabolism. The skin should be checked for neuro-cutaneous markers such as hypopigmented macules or ash-leaf spots, which might indicate conditions like tuberous sclerosis.

Investigation

• Electroencephalography (EEG): EEG is a critical tool for detecting and characterizing seizure activity in the brain.
• Neuroimaging: Neuroimaging techniques such as MRI and CT scans help identify structural abnormalities and brain injuries.
• Blood Tests: Blood tests help doctors find problems in your body, like metabolic disorders and infections, which can lead to seizures.
• Genetic Testing: Genetic testing can find inherited conditions that make babies more likely to have seizures.

Neonatal seizure guidelines (WHO-2011)

Neonatal seizure guidelines (2011) outline the recommended approach to diagnosing and managing seizures in newborns, addressing both immediate care and long-term considerations. Key aspects typically covered in these guidelines include:

• Recognition and diagnosis
• Initial Management
• Investigation
• Monitoring and follow-up
• Family education and support

Neonatal seizures treatment

Neonatal seizure treatment options are given below;

Initial Medical Management (Emergency Management)

• Ensure airways, breathing, and circulation
• Oxygen should be started, IV access should be secured, and blood should be collected for glucose and other investigations
• A brief relevant history should obtained and a quick clinical examination should performed.

Correction of hypoglycemia and hypocalcemia

• Hypoglycemia: 2 ml/Kg of 10% dextrose should be given as a bolus injection followed by a continuous infusion of 6-8 mg/kg/min.
• Hypocalcemia:
  • 2 ml/kg of 10% calcium gluconate IV over 10 minutes under strict cardiac monitoring
  • If ionized calcium levels are suggestive of hypocalcemia, the newborns should receive calcium gluconate at 8 ml/kg/day for 3 days
  • If seizures continue despite correction of hypocalcemia, 0.25 ml/kg of 50% magnesium sulfate should be given intramuscularly

Anti-epileptic Drugs (AED)

There are the following anti-epileptic drugs include:

• Phenobarbitone
  • It is a drug of choice for neonatal seizures. The following doses should be given and maintained accordingly.
    • Loading dose of Phenobarbitone is 20 mg/Kg over 30 to 60 minutes
    • The maintenance dose of Phenobarbitone is 3 to 5 mg/Kg/day twice a day.
    • The maximum dose of Phenobarbitone is 40 mg per Kg per dose.
• Phenytoin
  • It is another choice of a drug for seizure that can be given accordingly.
    • The loading dose of Phenytoin is 20 mg per Kg over 30 to 60 minutes.
    • The maintenance dose of Phenytoin is 3 to 8 mg per Kg per day two times a day.
    • The maximum dose of Phenytoin is 40 mg per Kg per dose.
• Sodium Valproate
  • It is another treatment option for seizures that can be given accordingly.
    • The dose of sodium valproate is 20 to 25 mg per kg per day followed by 5 mg per Kg every 12 hours.
    • Uncertain risk of hepatotoxicity following its use.
• Vigabatrin
  • It had been used in neonates for refractory seizures, primarily for infantile spasms.
  • The dose of Vigabatrin is 50 mg per Kg per day.

WHEN TO DISCONTINUE AED

• Discontinue all medication at discharge if a clinical examination is normal, irrespective of aetiology and EEG.
• If a neurological examination is persistently abnormal at discharge, AED is continued and the baby is reassessed at one month.
• If the baby is normal on examination and no seizures at 1 month, phenobarbitone is discontinued over 2 weeks.
• If neurological assessment is not normal an EEG is obtained.
• If EEG is not overtly paroxysmal, phenobarbitone is tapered and stopped.
• If EEG is overtly abnormal, the infant is reassessed in the same manner at 3 months and then the age of 3 monthly till 1 year.
• The goal is to discontinue phenobarbitone as early as possible.

Dietary Therapies

Dietary therapies, such as the ketogenic diet, play a significant role in the management of specific seizure types. The ketogenic diet is particularly effective in reducing seizures in conditions like epilepsy, where other treatments may not be as effective. It involves a high-fat, low-carbohydrate, and adequate protein intake, which helps in altering the brain’s metabolism and reducing seizure frequency. This therapy requires careful monitoring and adherence to ensure its effectiveness and safety for patients.

Non-pharmacological treatments

• Physical therapy
• Neurostimulation

Non-pharmacological treatments encompass a range of interventions beyond medication. These can include physical therapy, which focuses on improving motor skills, strength, and coordination through exercises tailored to the individual’s needs. Neurostimulation therapies involve devices that deliver electrical impulses to specific nerves or brain areas to modulate neural activity and reduce seizure frequency. These treatments are often considered when medications alone are insufficient or when minimizing drug side effects is a priority. They require careful evaluation and monitoring by healthcare professionals to ensure their effectiveness and safety for each patient.

Management of Metabolic disorder

For Hypomagnesemia

• Hypomagnesemia, or low magnesium levels in the blood, requires appropriate management to prevent complications.
• Treatment typically involves magnesium supplementation through oral or intravenous routes, depending on the severity of the deficiency and the patient’s ability to absorb magnesium.
• Oral magnesium supplements such as magnesium oxide or magnesium chloride are commonly used for mild cases.
• In severe or acute cases, intravenous magnesium sulfate may be administered under medical supervision to raise magnesium levels rapidly.
• Monitoring magnesium levels and clinical symptoms is essential during treatment to adjust dosages as needed and to prevent potential side effects such as diarrhoea or cardiac arrhythmias.

For Hyponatremia

• Hyponatremia refers to low sodium levels in the blood and requires careful management to restore electrolyte balance.
• Treatment depends on the underlying cause and severity of hyponatremia.
• Mild cases may be managed by adjusting fluid intake and dietary sodium intake.
• In more severe cases, especially those causing symptoms like confusion or seizures, intravenous saline solution may be administered to raise sodium levels quickly.
• Diuretics may also be used cautiously to help increase sodium concentration in the blood by promoting water excretion.
• Monitoring sodium levels closely during treatment is crucial to avoid rapid fluctuations, which can lead to complications such as osmotic demyelination syndrome (ODS).

For Hypernatremia

• Hypernatremia, or high sodium levels in the blood, requires management to lower sodium levels and correct the underlying cause.
• Treatment involves addressing water deficit by providing adequate hydration. This may be achieved through oral rehydration solutions or intravenous fluids, depending on the severity of hypernatremia and the patient’s ability to drink fluids.
• Rapid correction of hypernatremia should be avoided to prevent cerebral oedema and other neurological complications.
• The underlying cause of hypernatremia, such as dehydration or excessive sodium intake, should also be identified and treated accordingly.
• Close monitoring of sodium levels and clinical status is essential during treatment to ensure effective and safe correction of hypernatremia.

Treatment for Inborn error of metabolism:

Preventive Measures

Preventing neonatal seizures involves a combination of prenatal care and early intervention strategies.

Prenatal Care: Regular prenatal care and monitoring can help reduce the risk of conditions leading to neonatal seizures.

Managing High-Risk Pregnancies: High-risk pregnancies require specialized care to prevent complications that could result in seizures.

Early Detection and Intervention: Early detection of potential risk factors and timely intervention can prevent the onset of seizures.

Genetic Counseling: Families with a history of neonatal seizures or related conditions are advised to seek genetic counseling.

Infection Control: Preventing infections through vaccination and hygiene practices is essential in reducing seizure

Conclusions

In summary, neonatal seizures are a complex and critical condition requiring early detection, accurate diagnosis, and comprehensive treatment. By understanding the causes, symptoms, and treatment options, healthcare providers and caregivers can improve outcomes for affected infants. Continued research and education are essential to advance our knowledge and improve care for this vulnerable population.

Neonatal seizure ppt

Frequently Asked Questions (FAQs)