Neonatal Seizures: Types, Causes, Signs, Diagnosis, and Treatment

Creator: Dr. Arpit Varshney
Published: 2023-01-18T12:14:39-04:00

Written by

and medically reviewed by Dr. Arpit Varshney

Published on Jan 18, 2023 and last reviewed on Jul 11, 2023 - 5 min read

Abstract

Neonatal seizures are uncontrolled brain activity during the first 28 days of an infant’s life. This article will elaborate on its causes and management.

Contents

What Are Neonatal Seizures?

What Are the Types of Neonatal Seizures?

What Are the Causes of Neonatal Seizures?

What Are the Signs and Symptoms of Neonatal Seizures?

How to Diagnose Neonatal Seizures?

How to Manage Neonatal Seizures?

What Are Neonatal Seizures?

Seizures are uncontrolled and involuntary electrical activity in the brain. Newborn babies with low birth weight and premature term are more likely to be at risk of getting neonatal seizures. It is a neurological condition that occurs suddenly due to various factors. In the first month of their life, neonates have immature brain development. Due to different pathophysiology and clinical manifestation, it is comparatively difficult to recognize and diagnose its signs and symptoms.

Newborns have immature brain development, which makes them unique and more vulnerable to external and pathological triggers. As a result, if these triggers are given to the brain, it is very much likely to get provoked, resulting in seizures. Seizures can cause severe damage to homeostasis and the brain. In infants, it can cause neurological impairment, developmental growth delay, or in extreme conditions, death. Because of this, it is very important to diagnose them as soon as possible.

What Are the Types of Neonatal Seizures?

There are four main types of neonatal seizures seen in children such as:

Subtle Seizures: It has very mild symptoms, so it is easy to miss them. There is almost a 50 percent chance that seizures are of this type. There are subtle seizures in neonates, such as ocular, oral, apnea-related, autonomic phenomena, and limb movements. An electrocardiogram is required to diagnose this type of seizure.
Clonic Seizures: These types of seizures are commonly related to changes in the electroencephalogram. Almost two to three movements per second are seen with this type of seizure. For instance, a fast contraction is immediately followed by a slow relaxation phase. This type of seizure involves the face, arms, legs, or trunk. This type of seizure can be focal, multifocal, bilaterally symmetrical, or asymmetrical.
Tonic Seizures: This extreme and rigorous kind of seizure causes loss of consciousness. The duration of this type is almost 20 seconds with a sudden contraction of muscles which usually occurs while a person is sleeping. This type of seizure usually affects one extremity, especially eye deviation. This type of seizure can be focal or unilateral or bilaterally symmetrical or asymmetrical. Usually, premature babies are more affected by it.
Myoclonic Seizures: These types of seizures have frequency-like waves and are non-rhythmical. For instance, it occurs in a pattern of sudden shock and relaxation. Usually, this type of seizure occurs due to alcohol consumption, fever, light stimulation, or infectious conditions. This type of seizure is seen in babies due to premature birth or congenital metabolism defect. This type of seizure can be focal, multifocal, bilaterally symmetrical, or asymmetrical.

What Are the Causes of Neonatal Seizures?

There are the following causes behind seizures in neonates:

Sudden decrease or gradual decrease of oxygen level during or before birth owing to premature detachment of the placenta.
Stroke that occurs before or after birth.
Blood clot in the brain.
Bleeding in the brain.
Infectious conditions include bacterial meningitis, viral encephalitis, toxoplasmosis, and syphilis. Also, systemic infections associated with the central nervous system can be the reason behind this condition in neonates.
Developmental birth defects related to the brain.
Electrolyte and sugar imbalances cause many complications.
Metabolic disorders, causing such as hypoglycemia, phenylketonuria, or pyridoxine dependency.
Mothers are addicted to drugs and have drug withdrawal symptoms. These drugs can be alcohol, barbiturates, heroin, cocaine, or methadone. There are chances of babies being born with conditions such as seizures.
Also, it is an autosomal dominant inherited condition. This suggests that either one of the dominant genes can be the reason behind this condition.

What Are the Signs and Symptoms of Neonatal Seizures?

From subtle to severe movements, seizures can be very complex to diagnose. Additionally, neonates with seizures show the same movements as normal babies would. Some symptoms are seen according to their type, such as:

How to Diagnose Neonatal Seizures?

Investigation of seizures should be as immediate as possible after recognizing the sign. The following are investigation options:

1) Physical Examination: If neonates have unusual physical movements at the time of delivery, the doctors should immediately provide them with medical attention.

2) Plasma Examination:

Blood glucose.
Urea and electrolytes examination.
Blood gas- CO2 (carbon dioxide), bicarbonate, and lactate examination.
Liver function test.
Full blood count.
Blood cultures.
Virology tests.

3) Urine Examination:

Cultura- Bacterial.
Virology test.

4) CSF (Cerebral Spinal Fluid) Examination:

Bacterial culture.
Virology.
Glucose.
Protein.

5) Imaging:

Cranial ultrasound.
Magnetic resonance imaging (MRI).
Electroencephalogram is a very useful tool to diagnose the electrical activity of the brain.

6) Other:

Throat swab for viral infection.
Bacterial and viral swabs for skin or other organ infections.

How to Manage Neonatal Seizures?

Usually, the management of seizure activity has three main components such as observing, assessing, and managing. The following are the options to manage seizures in neonates:

It is essential to first identify the signs of seizures in neonates. Moreover, identifying the underlying reason behind this condition is equally essential.
Anticonvulsant medication is prescribed to control seizures. Additionally, doctors prescribed Phenytoin, Phenobarbital, or Lorazepam.
If the diagnosis suggests a condition such as low or not enough oxygen in the brain hypothermia treatments are recommended. This involves cooling down the newborn’s body and brain by a few degrees, along with close monitoring. As the vitals get back to normal, the body temperature is brought back to normal.

Conclusion:

Neonatal seizures can be fatal if not diagnosed at an early stage. Moreover, it is a condition that requires interdisciplinary medical care and attention. It is very important for parents and doctors to recognize the first sign of this condition. If a seizure lasts more than five minutes in children patients should immediately seek medical attention. A delay of a few minutes can be life-threatening in severe cases.

Frequently Asked Questions

1. Does Neonatal Seizure Occur as a Result of Xantheine Oxidase Deficiency?

Xantheine oxidase refers to the type of enzyme that helps in the process of oxidative conversion of hypoxanthine to xanthine which in turn converts to uric acid. A deficiency of the xantheine oxidase enzyme can result in hereditary xanthinuria. This condition is characterized by kidney symptoms causing increased levels of xanthine in the urine. Some of the clinical features of this condition lead to intractable seizures in neonates.

2. What Is the Duration of Medical Intervention in Neonatal Seizures?

Neonatal seizures are usually treated with anti-seizure medications to control the seizures. Even though the symptoms of neonatal seizures subside within three days, they are at higher risk of chronic, unprovocative seizures. Hence, the anti-seizure medications are maintained for several months to avoid the risk of seizures and early-life epilepsy. Long-term use of anti-seizure medications is associated with potentially toxic neurological effects.

3. Explain Neonatal Focal Seizure?

It is referred to as a focal neonatal seizure because the abnormality in the brain's electrical activity occurs in one or more areas of only one side of the brain. Genetic mutations commonly cause them. The clinical presentation of a focal seizure depends on the side of the brain affected. Hence, focal seizure of the brain's right side affects the body's left part.

4. Is Phenobarbital the Drug of Choice in Neonatal Seizures?

Phenobarbital is one of the most preferred medications for neonatal seizures. They are usually preferred for their long exposure to use in neonates and their intravenous absorption. They have been shown to decrease the duration and severity of the seizure. However, the effectiveness of this medication is still controversial.

5. Explain Benign Neonatal Seizure?

Benign neonatal seizures refer to a rare genetic condition with autosomal dominant inheritance. It affects newborns within the first few days of life, and the episodes of seizures stop after 15 weeks. Seizures usually last for a minute and are tonic-clonic seizures. This condition is often controlled with the administration of phenobarbital. The management of this condition depends on the severity of the seizures.

6. How Are Neonatal Seizures Treated?

Immediate diagnosis and prompt treatment are necessary in cases of neonatal seizures. The healthcare provider will initially work on identifying the condition's underlying cause. The affected child is prescribed anti-convulsant medication to control the seizures. In severe cases, when the affected child lacks oxygen supply to the brain, they are managed with hypothermia treatment.

7. Are Neonatal Seizures a Serious Condition?

Neonatal seizures can occur for a short period and may not even reoccur. But rarely, in severe cases, it can result in neurological impairment, delay in growth, and rarely, in extreme cases, it may even be fatal. This condition can cause some serious impairments in the affected child’s brain. Hence, this condition requires immediate diagnosis and appropriate treatment.

8. What Is the Normal Duration of a Neonatal Seizure?

Seizures that affect neonates are generally momentary and impermanent, and it may be difficult to evaluate the condition during this stage of life. The episodes of seizures usually last about ten seconds to two minutes. A longer duration of episodes in neonates can also occur during this age. They are shown to occur during the first 28 days of the affected child's life.

9. Is It Possible to Identify Neonatal Seizures?

It is extremely difficult to identify and diagnose a neonatal seizure. The symptoms of neonatal seizures are not obvious and may even mimic the normal movements of healthy babies. Confirming a neonatal seizure only through an electrical brain recording is possible. The commonly noted movements during a seizure are bicycling, continuous eye deviations, and frequent changes in muscle tone.

10. What Causes Neonatal Seizures?

Neonatal seizures can occur due to various causes, such as when the affected child has a cerebrovascular accident before or after birth. Other causes are bleeding or dislodged blood clots in the brain. It can also occur when there are brain defects, electrolyte imbalances, infections obtained before birth, or a lack of oxygen to the child during birth. Rarely it may occur due to genetic reasons.

11. What Are the Common Signs and Symptoms of Neonatal Seizures?

The signs and symptoms of neonatal seizures are difficult to identify. The common signs and symptoms are pedaling movements of the legs, struggling movements, breathing difficulties, and tongue protrusion. The symptoms of clonic seizures are rapid jerking movements of the body. The body, legs, and arms stiffen in tonic seizures.

12. What Is the First Line of Medication in Neonatal Seizures?

The first medication preferred in neonatal seizures is anti-epileptic drugs, especially phenobarbital. They are generally given at 25 micrograms per milliliter (mg/mL). The second choice of drug is phenytoin at a dosage of 3 mcg/mL (micrograms per millimeter). The affected babies are closely monitored when they are on these medications. These medications may be continued for many months.