Infantile Spasms in Babies: Seizure Warning Signs After Neonatal Brain Injury or HIE

Infantile spasms are a serious form of epilepsy that typically appears in early infancy and requires urgent medical attention. These brief, repetitive seizures often occur in clusters and can interfere with a baby’s development if not recognized and treated promptly. Parents who notice sudden jerking movements, head drops, or stiffening episodes in their infant should seek immediate medical evaluation. Understanding what infantile spasms look like, how they differ from normal infant movements, and why early diagnosis matters can help families get their child the specialized care they need.

For families whose babies experienced oxygen deprivation during delivery, a NICU stay, or a diagnosis of hypoxic-ischemic encephalopathy, infantile spasms can be one of the most alarming developments in the weeks and months that follow. Research shows that HIE is among the most common identifiable causes of infantile spasms in full-term infants. Understanding what these seizures look like, why early recognition matters so much, and what the connection to birth-related brain injury may mean for your child can help your family navigate an urgent and unfamiliar situation.

What Are Infantile Spasms?

Infantile spasms are a rare type of epilepsy that usually begins in the first year of life, most commonly between 3 and 12 months of age, with most cases presenting between 4 and 8 months. Unlike typical seizures that may last several minutes, infantile spasms are brief episodes that last only one or two seconds. What makes them distinctive is that they tend to happen in clusters, with multiple spasms occurring one after another over several minutes, often when a baby is waking up or falling asleep. This condition is also referred to as West syndrome in medical records and literature — a term parents may encounter after a difficult birth, NICU stay, or neurological evaluation.

This condition is considered a medical emergency because it can affect brain development and cause developmental regression. Babies who were previously meeting milestones may stop making progress or lose skills they had already learned. The American Academy of Pediatrics and the Child Neurology Society recognize infantile spasms as requiring urgent evaluation and treatment, as delays in diagnosis can worsen developmental outcomes.

What Infantile Spasms Look Like in Babies

Parents often describe infantile spasms as sudden, brief movements that repeat in a pattern. The spasms may involve the whole body or just certain muscle groups. Common movements include:

• Sudden forward bending at the waist with the arms extending outward

• Head drops or nodding

• Stiffening of the body with the arms and legs extending

• “Jackknife” movements where the knees pull up toward the chest

These episodes typically occur in clusters of 5 to 30 spasms at a time, with each individual spasm lasting only a second or two. The clusters may happen several times a day, and parents often notice them most frequently when their baby is transitioning between sleep and wakefulness. Some babies cry between spasms or seem irritable during these episodes.

The appearance can vary from one baby to another. Some infants have very subtle spasms that look like brief startles or head nods, while others have more obvious full-body movements. Parents may initially think their baby has colic, reflux, or is just startling easily, which is why video recording suspected episodes can be helpful when seeking medical evaluation.

How Infantile Spasms Are Different From Normal Infant Movements

Many normal infant behaviors can look concerning to parents, so understanding the differences between infantile spasms and typical movements is important. Key distinctions include:

• Normal startle reflexes happen in response to sudden noise or movement and do not occur in repetitive clusters.

• Movements related to reflux or discomfort are usually connected to feeding and do not follow the brief, rhythmic cluster pattern seen with infantile spasms.

• Benign sleep movements (twitching or jerking as a baby falls asleep) are random and do not repeat in clusters.

• Shuddering attacks are brief tremors that occur when a baby is awake and alert, and they do not involve loss of awareness.

What sets infantile spasms apart is their pattern of brief, stereotyped movements that repeat in clusters, often at the same times of day, and their association with developmental concerns. If parents notice repeated episodes of unusual movements, especially if the baby seems to lose developmental skills or stops making progress with milestones, medical evaluation should not be delayed.

What Causes Infantile Spasms?

Infantile spasms can result from many different underlying conditions that affect the developing brain, including:

• Structural brain abnormalities (malformations that occurred during pregnancy)

• Genetic disorders and chromosomal conditions

• Metabolic disorders that affect how the body processes certain substances

• Brain injuries occurring before, during, or after birth

• Infections such as meningitis or encephalitis

In some cases, doctors cannot identify a specific cause despite thorough testing, though this has become less common as diagnostic tools have improved. The underlying cause can affect both the treatment approach and the long-term outlook. Identifying the cause requires careful medical evaluation, including brain imaging, electrical activity monitoring, and often genetic or metabolic testing.

Can Birth Injury Be a Cause in Some Cases?

Birth-related brain injury is one possible cause of infantile spasms, though it represents only a portion of cases. When a baby experiences significant oxygen deprivation during labor and delivery, the resulting brain damage can sometimes lead to seizure disorders, including infantile spasms. This type of injury, known as hypoxic-ischemic encephalopathy, may be identified shortly after birth or may not become fully apparent until seizures develop weeks or months later.

Research published in peer-reviewed literature has found that approximately 4 to 5 percent of term newborns with hypoxic-ischemic encephalopathy go on to develop infantile spasms, and that babies with severe HIE who did not receive therapeutic hypothermia faced substantially higher rates. As many as 10 percent of infants with clinically diagnosed neonatal seizures will develop infantile spasms.

Other birth complications that can potentially contribute to brain injury include untreated maternal infections, severe prematurity with intracranial bleeding, traumatic delivery with head injury, or delayed recognition and treatment of newborn distress. Not every difficult birth causes lasting brain injury, and not every case of infantile spasms is related to birth events. Medical records from pregnancy, labor, delivery, and the newborn period can help doctors understand whether birth-related factors may have played a role.

When a baby develops infantile spasms and there were complications around the time of birth, a thorough review of the medical timeline can be important. Families may benefit from consultation with both medical specialists who can evaluate the neurological findings and a New York birth injury lawyer who can review whether the standard of care was met during prenatal care, labor, delivery, or newborn treatment.

How Doctors Diagnose Infantile Spasms

Diagnosis begins with a detailed medical history and description of the episodes. Parents may be asked to record video of the suspected spasms, as this can be very helpful for doctors trying to distinguish infantile spasms from other conditions. A thorough physical and neurological examination helps identify any developmental delays or other neurological concerns.

An electroencephalogram (EEG) is the key diagnostic tool for infantile spasms. This test records the brain’s electrical activity and can detect an abnormal pattern called hypsarrhythmia, which is commonly associated with infantile spasms. The EEG may be done while the baby is awake and asleep to capture the full picture of brain activity. In some cases, video EEG monitoring over a longer period helps confirm the diagnosis.

Brain imaging with magnetic resonance imaging (MRI) is typically performed to look for structural abnormalities, brain malformations, or signs of prior injury. Blood tests and other laboratory work may be ordered to check for metabolic disorders or genetic conditions. Genetic testing has become an increasingly important part of the evaluation, as many genetic causes of infantile spasms have been identified in recent years. The diagnostic process is thorough because identifying the underlying cause can guide treatment decisions.

Why Early Treatment Matters

Infantile spasms can interfere with normal brain development during a critical period of growth. The abnormal electrical activity in the brain may disrupt the formation of important neural connections. Babies with untreated infantile spasms often experience developmental regression, losing skills they had previously gained, and may have difficulty acquiring new skills.

Research has shown that early treatment can improve developmental outcomes. When treatment begins soon after symptoms start, babies have a better chance of controlling the seizures and minimizing developmental impact. Delayed treatment may be associated with more significant cognitive and developmental challenges, though outcomes vary depending on the underlying cause and other factors.

The urgency of treatment does not mean parents should panic, but it does mean that suspected infantile spasms should be evaluated quickly. Pediatric neurologists who specialize in childhood epilepsy can provide expert assessment and recommend appropriate treatment. The goal is to stop the spasms, normalize brain electrical activity, and support the child’s development as much as possible.

Common Treatments for Infantile Spasms

Treatment for infantile spasms typically involves medication specifically chosen for this condition. Common options include:

• Hormonal therapy with adrenocorticotropic hormone (ACTH), given by injection. ACTH is a common first-line treatment and can be effective in stopping spasms. Initial ACTH doses are typically given in the hospital for monitoring. Parents are then trained to administer the injections at home for approximately six weeks.

• Oral corticosteroids, which may be used as an alternative hormonal treatment.

• Vigabatrin, an anti-seizure medication particularly effective for spasms caused by tuberous sclerosis.

Some babies may need a combination of treatments or may try different medications if the first approach does not control the spasms. In select cases where spasms are caused by a specific structural abnormality in one area of the brain, surgery may be considered. This is uncommon, but when a focal brain lesion is identified and medication is not effective, surgical removal of the abnormal tissue may stop the seizures.

Other supportive therapies are often important parts of the overall care plan, including developmental services, physical therapy, occupational therapy, and speech therapy.

Treatment decisions are made based on the individual child’s situation, the underlying cause when known, and the response to initial therapy. Close monitoring by a pediatric neurologist is essential to adjust treatment as needed and watch for side effects.

What Parents Can Expect After Treatment

Even when infantile spasms are successfully controlled with treatment, a significant number of children go on to develop other forms of epilepsy and may face intellectual or developmental challenges later in life. Outcomes depend heavily on the underlying cause, the severity of any brain injury, and how quickly treatment begins after symptoms first appear. Babies who were developing normally before spasms began and who respond quickly to treatment generally have better prospects than those whose spasms are related to structural brain injury or severe HIE. Parents should work closely with a pediatric neurologist to monitor for relapse, track developmental progress, and access early intervention services as soon as delays are identified.

What Parents Should Do If They Suspect Infantile Spasms

If you notice your baby having brief, repetitive movements that occur in clusters, especially if these episodes happen multiple times a day or your baby seems to be losing developmental skills, contact your pediatrician immediately. Describe what you are seeing in detail, including:

• When the movements happen

• How long they last

• How many occur in a row

• Whether your baby seems aware during the episodes

Recording video of the episodes on your phone can be extremely helpful for doctors. Try to capture several episodes if possible, and note the time of day they occur. Keep track of any changes in your baby’s behavior, feeding, sleep, or development. If your pediatrician has not seen infantile spasms before or is uncertain about the diagnosis, ask for an urgent referral to a pediatric neurologist.

Do not wait to see if the movements go away on their own. While some normal infant movements can look unusual, the cluster pattern and repetitive nature of infantile spasms, combined with any developmental concerns, warrant prompt evaluation. Early diagnosis and treatment can make a meaningful difference in outcomes.

When to Seek Emergency Medical Care

Most cases of suspected infantile spasms should be evaluated urgently but do not require an emergency room visit if you can reach your pediatrician or a pediatric neurologist quickly. However, seek immediate emergency care if any of the following occur:

• A seizure lasting more than five minutes

• Difficulty breathing during or after an episode

• Unresponsiveness or failure to wake normally after spasms

• Repeated clusters that are much more frequent or severe than usual

Also seek emergency care if your baby develops a fever along with the spasms, shows signs of serious illness such as extreme lethargy or poor feeding, or if you are unable to reach your doctor and are concerned about the episodes. Emergency room doctors can perform initial testing and arrange for urgent pediatric neurology consultation.

Parents should trust their instincts. If something about your baby’s movements or behavior seems seriously wrong, it is always better to seek medical evaluation than to wait.

Questions Parents Often Ask About Infantile Spasms

What Do Infantile Spasms Look Like in a Baby?

Infantile spasms typically appear as brief, sudden movements that happen in clusters. Common patterns include the baby suddenly bending forward at the waist with arms extending outward, head nodding or dropping forward, body stiffening with arms and legs extending, or knees pulling up toward the chest. Each spasm lasts only one or two seconds, but multiple spasms occur in a row, often 5 to 30 in a single cluster. These clusters may happen several times throughout the day, frequently when the baby is waking up or falling asleep.

Are Infantile Spasms the Same as Seizures?

Yes. Infantile spasms are a type of seizure — a specific form of epilepsy that occurs in infancy. Unlike prolonged convulsive seizures, infantile spasms are very brief but occur in repetitive clusters. They result from abnormal electrical activity in the brain and typically require treatment tailored to this condition.

What Causes Infantile Spasms?

Infantile spasms can be caused by many different conditions affecting the developing brain, including structural abnormalities, genetic disorders, metabolic conditions, brain injuries, and infections. In some cases the cause remains unknown despite thorough testing. The underlying cause can influence treatment choices and long-term outcomes.

Can Infantile Spasms Be Related to a Birth Injury?

Birth-related brain injury is one possible cause of infantile spasms, though many cases have other causes. Significant oxygen deprivation during labor and delivery (hypoxic-ischemic encephalopathy), traumatic delivery, untreated maternal infections, or severe prematurity with brain bleeding may contribute to later seizure disorders. Medical records from pregnancy, labor, delivery, and the newborn period can help determine whether birth-related factors played a role. Research has found that approximately 4 to 5 percent of term newborns with hypoxic-ischemic encephalopathy develop infantile spasms, making HIE one of the most common identifiable causes in full-term infants.

When Should Parents Seek Urgent Care for Possible Infantile Spasms?

Parents should seek urgent medical evaluation if they notice brief, repetitive movements that occur in clusters, especially if these episodes happen multiple times a day or if the baby seems to be losing developmental skills. Emergency care is needed for prolonged seizures (more than five minutes), breathing difficulty, unresponsiveness, or other signs of serious illness.

How Medical Records Can Help Explain the Cause

When a baby is diagnosed with infantile spasms, doctors often review the complete medical history to understand potential contributors. Important records include:

• Prenatal records (ultrasounds, maternal health issues, pregnancy complications)

• Labor and delivery records (fetal heart rate monitoring, interventions, newborn condition)

• Newborn hospital records (resuscitation, APGAR scores, NICU care)

• Later pediatric records documenting developmental progress and when concerns first arose

This documentation helps specialists piece together the timeline and identify potential causes. For families who had complications during pregnancy, labor, or delivery, a thorough review of medical records may reveal whether the standard of care was met. When birth injury is suspected, families may want records reviewed by both medical experts and a legal professional experienced in New York birth injury cases.

What Comes Next for Your Child and Your Family

A diagnosis of infantile spasms can feel overwhelming, especially when it follows a difficult birth, an HIE diagnosis, or a NICU stay. Working closely with a pediatric neurologist experienced in early-onset epilepsy is the most important step, and many children benefit significantly from early intervention services including physical therapy, occupational therapy, and speech therapy started as soon as developmental concerns are identified. If your child’s infantile spasms may be connected to complications during labor, delivery, or newborn care in New York, understanding your medical records and your legal options is part of making fully informed decisions for your family’s future.

NYBirthInjury.com is an educational resource and does not provide medical or legal advice. If your baby shows signs of infantile spasms, seek immediate evaluation from a pediatrician or pediatric neurologist. If you have questions about whether a birth injury may have contributed to your child’s condition, consider consulting with a qualified New York birth injury attorney who can review your family’s specific situation and medical records.