West Syndrome

What is West syndrome?

West syndrome is a rare and serious form of epilepsy that begins in infancy. Epilepsy is a condition in which the brain produces repeated bursts of abnormal electrical activity that cause seizures. West syndrome is defined by a combination of three features: a particular type of seizure called infantile spasms (also called epileptic spasms), a distinctive chaotic pattern on a brain-wave test known as hypsarrhythmia, and a slowing or loss of developmental skills. Because the spasms are the most visible sign, many doctors and families use the terms West syndrome and infantile spasms interchangeably, although not every child with spasms shows all three features.

The condition is named after Dr. William James West, a physician who described the spasms in his own son in the 1840s. West syndrome most often starts between about 3 and 12 months of age, with many cases beginning in the middle of the first year. It affects boys somewhat more often than girls. It is considered an epileptic encephalopathy, which means the abnormal electrical activity itself may harm the developing brain over time, not just the underlying cause. This is why early recognition and treatment are considered so important.

West syndrome is usually managed by pediatric neurologists, doctors who specialize in the nervous system of children. At Acibadem, this care is coordinated through the Neurology department together with pediatric specialists.

West syndrome symptoms

The symptoms of West syndrome can be subtle at first, and the spasms are often mistaken for colic, startle reactions, reflux, or normal infant movements. Recognizing them early matters. The main features include:

• Infantile spasms: sudden, brief stiffening of the body lasting about one to two seconds. The baby may bend forward at the waist with the arms flung out or brought together, or the head may drop forward or backward.
• Spasms in clusters: the movements typically come in groups of several to many spasms in a row, often a few seconds apart, and clusters may repeat many times a day.
• Timing around sleep: clusters frequently happen soon after the baby wakes up or when drowsy, and less often during deep sleep.
• Crying or distress: the infant may cry out or seem upset during or after a cluster.
• Loss of skills: a baby who was smiling, rolling, babbling, or reaching may stop doing these things.
• Reduced eye contact and social interaction: parents often notice the child seems less responsive or “not themselves.”
• Poor head control or floppiness: changes in muscle tone may appear.
• Irritability or reduced feeding: general behavior changes are common.

Spasms can be flexor (bending forward), extensor (arching backward), or mixed. Some babies have very subtle spasms, such as a slight head nod, a brief eye roll, or a small shrug of the shoulders. Because the movements are brief, they are easy to miss, and recording a video of the episodes can be very helpful for the doctor.

Symptoms may also differ depending on the underlying cause. Children who already had a known brain injury or genetic condition may have shown developmental delay before the spasms began, while others develop normally until the spasms start and then regress. In some children, the spasms later change into other seizure types as the epilepsy evolves.

Causes and risk factors

West syndrome causes are varied, and in many cases the condition is the result of a problem that affects the developing brain. Doctors usually group the causes into a few broad categories:

• Structural brain abnormalities: these include malformations that formed before birth, brain injury from lack of oxygen around the time of birth (called hypoxic-ischemic encephalopathy), stroke in infancy, bleeding in the brain, and damage from infections such as meningitis or encephalitis.
• Genetic conditions: tuberous sclerosis complex, a genetic disorder that causes non-cancerous growths in the brain and other organs, is one of the best-known causes. Down syndrome (trisomy 21) and changes in specific genes, such as CDKL5, ARX, and STXBP1, are also recognized causes.
• Metabolic disorders: rare inherited conditions that affect how the body processes nutrients or produces energy can trigger spasms. Some, such as a vitamin B6 (pyridoxine) dependency, may respond to specific treatments.
• Unknown cause: in a portion of children, no cause is found even after detailed testing. This group has sometimes been called “cryptogenic” or “idiopathic.”

Risk factors reflect these causes. A baby may be at higher risk if there was a difficult birth with oxygen deprivation, prematurity with brain complications, a serious brain infection in early life, a family history of epilepsy or a known genetic syndrome, or a diagnosis of tuberous sclerosis or another neurodevelopmental disorder. It is important to understand that West syndrome is not caused by anything a parent did or did not do during pregnancy or infancy, and vaccinations are not considered a cause, although spasms may coincidentally first be noticed around the age when routine vaccines are given.

West syndrome diagnosis

West syndrome diagnosis is usually made by a pediatric neurologist based on the description of the events, direct observation, and an electroencephalogram (EEG). An EEG is a painless test in which small sensors placed on the scalp record the brain’s electrical activity. In West syndrome, the EEG often shows hypsarrhythmia, a very disorganized pattern of high-voltage slow waves mixed with spikes. Because this pattern may appear mainly during sleep, doctors often request a prolonged or overnight video-EEG that captures both sleep and wakefulness and records any spasms on camera.

Once the diagnosis of spasms is confirmed, the next step is to look for the underlying cause, because this guides treatment and helps predict outlook. Tests your child’s doctor may order include:

• Video-EEG monitoring: to confirm the spasms and the EEG pattern.
• Brain MRI (magnetic resonance imaging): a detailed scan that can show malformations, scarring, tumors, or the growths seen in tuberous sclerosis. Infants usually need sedation for this scan.
• Genetic testing: blood tests that look for chromosome changes or specific gene variants; this may include an epilepsy gene panel or broader sequencing.
• Metabolic testing: blood and urine tests, and sometimes a spinal fluid sample, to look for inherited metabolic disorders.
• Skin and eye examination: some genetic conditions leave clues such as pale skin patches or eye findings.
• Developmental assessment: to document the child’s current skills and track changes over time.

There is no single blood test for West syndrome itself. The diagnosis rests on the clinical picture and the EEG, while the additional tests aim to identify the cause. Many specialists treat suspected infantile spasms as an urgent condition and try to complete the EEG within days rather than weeks.

West syndrome treatment options

West syndrome treatment aims to stop the spasms completely and clear the hypsarrhythmia from the EEG as quickly as possible, because prolonged spasms are thought to affect development. Treatment is individualized, and your child’s neurologist will consider the likely cause, the child’s overall health, and the risks of each medication. Standard options include:

• Hormonal therapy: adrenocorticotropic hormone (ACTH), given by injection, and high-dose oral corticosteroids such as prednisolone are widely used first-line treatments. Corticosteroids are powerful anti-inflammatory hormones. They can be very effective for spasms but require close monitoring for side effects such as irritability, increased appetite, high blood pressure, elevated blood sugar, increased infection risk, and stomach irritation. Treatment is usually given for a limited number of weeks and then tapered.
• Vigabatrin: an oral antiseizure medication that is often chosen first when tuberous sclerosis is the cause and is also used when hormonal therapy is unsuitable or ineffective. Its main long-term concern is a risk of permanent narrowing of the visual field, so eye monitoring is recommended and the duration of use is kept as short as reasonable.
• Combination therapy: in some centers, hormonal treatment and vigabatrin are given together.
• Other antiseizure medications: drugs such as topiramate, valproate, zonisamide, clobazam, or levetiracetam may be tried when first-line treatments do not work, although they are generally considered less effective for spasms.
• Vitamin therapy: a trial of pyridoxine (vitamin B6) may be given, particularly if a vitamin-dependent condition is suspected.
• Ketogenic diet: a carefully supervised high-fat, very low-carbohydrate diet that can reduce seizures in some children. It requires a specialized dietitian and regular monitoring.
• Epilepsy surgery: when imaging shows a single, well-defined abnormal area responsible for the spasms, surgical removal or disconnection of that region may be considered. Surgery is evaluated by a specialized epilepsy team and is not suitable for every child.
• Treatment of the underlying cause: where a treatable metabolic disorder is found, specific dietary or medication measures may be needed.

Alongside seizure control, supportive care is essential. Early intervention services, including physical therapy, occupational therapy, speech and feeding therapy, and developmental programs, help children make the most of their abilities. Regular follow-up EEGs check whether the treatment has cleared the abnormal pattern. Observation without treatment is not usually recommended once spasms are confirmed, given the potential impact on development.

Living with West syndrome and outlook

The long-term outlook for a child with West syndrome depends largely on the underlying cause, how quickly the spasms were controlled, and how the child was developing before the spasms began. Children with no identified cause who were developing normally and who respond promptly to treatment tend to have better outcomes than children with significant brain injury or certain genetic conditions. Even so, no doctor can predict an individual child’s future with certainty.

Many children with West syndrome have some degree of developmental delay or intellectual disability, and a proportion later develop other forms of epilepsy, including Lennox-Gastaut syndrome, a difficult-to-treat epilepsy of childhood. Some children also show features of autism spectrum disorder, movement difficulties, or vision and hearing problems. On the other hand, a number of children achieve full spasm control, and some go on to develop within or near the typical range.

Living with the condition often means regular appointments with a neurology team, medication schedules, and ongoing therapies. Families frequently find it helpful to keep a seizure diary or video log, learn seizure first aid, and connect with support groups for parents of children with epilepsy. Caring for a child with a complex condition can be exhausting, and attention to the wellbeing of parents and siblings is an important part of long-term care. As the child grows, the care plan is usually adjusted to address school support, behavior, sleep, and any new seizure types.

Frequently asked questions

What are the first west syndrome symptoms parents usually notice?

Parents most often notice brief, repeated jerks or stiffening episodes, usually soon after waking, in which the baby’s head drops and the arms fling out or the body bends forward. The movements come in clusters and may be mistaken for startles or colic. A loss of previously gained skills, such as smiling or eye contact, is another early clue. If you observe these patterns, recording a video and describing them to your child’s doctor is helpful.

What are the most common west syndrome causes?

The most frequently identified causes are structural brain problems present from before birth or caused by injury around birth, genetic conditions such as tuberous sclerosis complex and Down syndrome, and rare metabolic disorders. In a portion of children, no cause is found despite thorough testing. The condition is not caused by parenting choices or by vaccines.

How is west syndrome diagnosis confirmed?

Diagnosis is confirmed with an electroencephalogram (EEG), ideally a prolonged video-EEG that includes sleep, which typically shows the chaotic hypsarrhythmia pattern and may capture the spasms themselves. A brain MRI, genetic tests, and metabolic tests are then used to search for the underlying cause. There is no single blood test that diagnoses West syndrome.

What does west syndrome treatment usually involve?

First-line treatment is usually hormonal therapy with ACTH or oral corticosteroids, or the medication vigabatrin, particularly when tuberous sclerosis is the cause. If these do not work, other antiseizure medications, the ketogenic diet, or, in selected cases, epilepsy surgery may be considered. Developmental therapies are started alongside medical treatment. The choice depends on the child’s cause, health, and response, and requires close monitoring for side effects.

Can west syndrome be cured?

In many children the spasms can be stopped with treatment, and in some the EEG returns to normal and no further seizures occur. However, West syndrome is often linked to an underlying brain condition that cannot be reversed, and developmental effects may persist. Doctors therefore usually speak of controlling the spasms and supporting development rather than of a cure, and outcomes vary widely from child to child.

Is west syndrome the same as infantile spasms?

The terms are closely related and often used interchangeably. Infantile spasms refers to the seizure type, while West syndrome classically refers to the combination of spasms, the hypsarrhythmia EEG pattern, and developmental slowing or regression. Some children have spasms without every element of the classic triad, which is why many specialists now simply use the term infantile epileptic spasms syndrome.

Will my child grow out of west syndrome?

The spasms themselves often stop or change by early childhood, either because of treatment or because of the way the brain matures, but this does not necessarily mean the epilepsy has resolved. Some children develop other seizure types later, and many need ongoing support for development and learning. Regular follow-up with a neurology team helps identify and manage any changes as your child grows.

When to see a doctor

Any baby who has repeated, clustered jerking or stiffening episodes, especially around waking, should be evaluated by a doctor promptly, ideally within days, because early treatment of infantile spasms is considered important for development. A child who has stopped smiling, making eye contact, or using skills they previously had should also be assessed without delay.

Seek emergency medical care immediately if your child has any of the following:

• A seizure lasting longer than five minutes, or repeated seizures without recovery in between.
• Difficulty breathing, blue or gray color around the lips, or unresponsiveness after an episode.
• A seizure together with a high fever, a stiff neck, a bulging soft spot on the head, or a rash that does not fade.
• A seizure following a head injury or fall.
• Persistent vomiting, extreme sleepiness, or inability to wake the child.
• Signs of a serious medication side effect during treatment, such as severe irritability with vomiting, very high blood pressure readings, signs of infection, or black or bloody stools.

For children already diagnosed with West syndrome, contact the treating neurology team if spasms return after a period of control, if new types of seizures appear, if development stalls again, or if you have concerns about vision changes while on vigabatrin. Keeping a written or video record of events helps the medical team make timely decisions.