Muscle Spasms In Newborns: What's Normal And What's Not?

It is common for newborns and infants to startle, flinging their arms and legs wide, and then bringing them together. This is a normal reflex known as the startle or Moro reflex. However, in some cases, these movements may be a sign of a more serious condition called infantile spasms, a rare type of epilepsy that can impact a child's development. So, is it normal for newborns to have muscle spasms?

Infantile spasms are a type of seizure that can be a sign of epilepsy

It is common for newborns and infants to startle, flinging their arms and legs wide, then bringing them together. This is usually a normal reflex known as the startle or Moro reflex. However, in some rare cases, these movements may be a sign of a serious condition called infantile spasms, which are a type of seizure that can indicate epilepsy.

Infantile spasms are a rare form of childhood epilepsy, affecting around 1 in 2,000 to 4,000 infants and children in the US each year. They are characterised by brief (one- to three-second) seizures that can have a significant impact on a baby's development. The spasms typically consist of sudden stiffening, with the baby's arms, legs, or head bending forward. They may also cry during or after the seizure.

These seizures often occur in a series of short spasms, sometimes called jackknife seizures, and can happen several times a day. They usually occur in clusters, with a few seconds between each spasm, and often occur when the baby is waking up from sleep.

The underlying cause of infantile spasms can vary and is sometimes unknown. They may be associated with specific disorders, such as tuberous sclerosis, certain genetic abnormalities, brain injuries, or infections. Structural changes in the brain, issues with brain development, gene mutations, and metabolic conditions are also possible causes.

If you suspect your baby is experiencing infantile spasms, it is crucial to seek medical advice as soon as possible. Early diagnosis and treatment are critical to improving long-term outcomes and reducing the risk of developmental issues.

They can be caused by brain injuries, infections, or abnormal blood vessels

Infantile spasms are a rare type of epilepsy that affects babies under 12 months old. They are characterised by brief spells of tensing or jerking, typically lasting one to two seconds, and occurring in a cluster or series. These spasms can happen at any time but are most common after a baby wakes up from sleep.

Infantile spasms can be caused by various conditions affecting a baby's brain, including:

• Brain injuries: Any type of brain injury can cause infantile spasms, including hypoxic-ischemic encephalopathy (lack of oxygen or blood flow to the brain), meningitis, and perinatal stroke.
• Infections: Infections such as meningitis can lead to infantile spasms by affecting the brain.
• Abnormal blood vessels in the brain: Conditions like arteriovenous malformations or other central nervous system malformations can cause infantile spasms.

It is important to note that in about one-third of cases, the cause of infantile spasms cannot be determined. If you suspect your baby is experiencing infantile spasms, it is crucial to seek medical advice from a pediatrician or a pediatric neurologist as soon as possible.

They can also be caused by metabolic or genetic disorders

Infantile spasms are a rare but serious type of epilepsy that affects babies, typically under 12 months old. They are characterised by brief spells of tensing or jerking and often happen in a cluster or series. They can be caused by problems with the way the brain developed in the womb, infections, brain injury, or abnormal blood vessels in the brain.

In addition, infantile spasms can also be caused by metabolic or genetic disorders. Metabolic disorders, or inborn errors of metabolism (IEM), are genetic conditions that block metabolic pathways involved in the breakdown of nutrients and the generation of energy. Genetic or metabolic disorders can cause infantile spasms, and children with conditions such as Down syndrome or tuberous sclerosis are at a higher risk.

Several metabolic conditions can cause infantile spasms. Inborn errors of metabolism (IEM) are genetic conditions that block or disrupt the normal metabolic pathways involved in breaking down nutrients and generating energy. These disruptions can lead to a build-up of harmful substances in the body or a shortage of essential ones, affecting the brain and nervous system.

There are a variety of metabolic disorders that can contribute to infantile spasms. For example, in rare cases, a vitamin B6 deficiency can be the cause. This is because vitamin B6 is essential for the proper functioning of the nervous system, and a deficiency can lead to neurological issues, including seizures and infantile spasms.

Furthermore, gene mutations are increasingly being linked to infantile spasms. Some of the specific gene mutations associated with infantile spasms include trisomy 21 (Down syndrome), tuberous sclerosis, Miller-Dieker syndrome, and CDKL5 deficiency disorder. These mutations can affect the development and function of the brain, increasing the risk of seizures and infantile spasms.

It is important to note that infantile spasms can have serious, permanent effects on a child's developing brain if left untreated. Therefore, if you suspect your baby is experiencing infantile spasms, it is crucial to seek medical advice as soon as possible.

Symptoms include a sudden stiffening of muscles, with arms and legs bent forward

Infantile spasms are a form of epilepsy that affects babies, typically under 12 months old. They are a series of short spasms, about one to two seconds in length, and can happen in a cluster or series. Infantile spasms are often mistaken for startles, colic, reflux, or hiccupping.

During an infantile spasm, a baby may stiffen and extend their arms, while scrunching up their knees or bending their neck forward. Specifically, a baby's body may suddenly jerk, flex, or extend. Their arms may fling out, their knees may pull up, and their body may bend forward. This is described as a "jackknife" seizure.

While infantile spasms can look similar to a normal startle reflex in babies, they are different. The startle reflex, or Moro reflex, happens when a loud sound or sudden movement startles a baby. They typically throw their head back and extend their arms and legs with the palms of their hands facing upward. They may also cry and often pull their arms and legs back in.

If you think your baby is having infantile spasms, it is important to talk to their pediatrician as soon as possible. Early diagnosis and treatment are critical to managing infantile spasms and reducing their impact on your baby's development.

Treatment options include medication, steroids, and surgery

While it is common for newborns and infants to startle, with their arms and legs flinging wide and then brought together, in rare cases, these movements may be a sign of a serious condition called infantile spasms. Infantile spasms are a rare type of epilepsy affecting approximately 1 in 2,000 infants and children in the US each year. The spasms are tiny seizures that can have a big impact on a baby's development. They can cause serious, permanent changes to a child's developing brain without early diagnosis and treatment.

Medication, steroids, and surgery are the three main treatment options for infantile spasms. Adrenocorticotropic hormone (ACTH) is a major medication used to treat infantile spasms. ACTH is a naturally produced hormone injected into the child's muscles and has been proven to be very effective in stopping spasms. However, due to its powerful nature and potential side effects, it is typically administered in low doses for a short duration. Edema, or swelling from fluid retention, and low potassium in the blood are common side effects. More severe side effects may include mental status changes due to high blood pressure and gastrointestinal bleeding.

Vigabatrin (Sabril), an anti-seizure medication, and steroid therapies such as prednisone are alternative treatments. Steroid therapies can be a better option due to ACTH's limitations, such as high costs, availability issues, and side effects. However, it is important to note that both alternative medications can also cause significant side effects.

The success rates of initial treatments are comparable for oral steroids and vigabatrin. Oral steroids have a 44% success rate, while vigabatrin has a 37% success rate in preventing additional seizures after 30 days of starting therapy.

In cases where drug therapies fail to stop the spasms, surgery may be recommended to remove the brain region causing the seizures. A ketogenic diet, which is high in fat and low in carbohydrates, has been studied as a potential treatment, but more research is needed to understand its benefits fully.

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