What is hypertonia?
Hypertonia is too much muscle tone. Infants and newborns diagnosed with hypertonia have stiff muscles, especially their arms, legs and neck, which can be difficult to move.
Muscle tone is the amount of resistance (tension) to movement in your muscles. You can feel your muscle tone if you pinch your bicep while it’s relaxing. The resistance you feel is your muscle tone.
Muscle tone allows you to maintain good posture when sitting, controls your reflexes and helps regulate the function of your organs in your body.
If you have too much muscle tone, your movements will be robotic because you’re unable to relax your muscles and you have limited flexibility. Children with hypertonia have poor balance, trouble walking, difficulty reaching and grabbing objects, and sometimes they need help eating.
What are the types of hypertonia?
There are two types of hypertonia that describe muscle tone:
- Spastic hypertonia (spasticity): Exaggerated reflexes and muscle spasms increase with movement.
- Dystonic hypertonia (rigidity): Muscle stiffness doesn’t change with movement.
To identify which type of hypertonia your baby has, your healthcare provider will move your baby’s arm or leg from a relaxed position at different speeds in a range of directions.
Who does hypertonia affect?
Hypertonia can affect both babies and adults who experience damage to their central nervous system. The diagnosis could occur after an injury or as a symptom of an underlying condition that is congenital (present at birth). It’s normally diagnosed in babies before two years of age.
How common is hypertonia?
Hypertonia is less common than hypotonia (weak muscle tone) in babies, which is the most common condition that affects a newborn’s motor skills. The rate of occurrence is unknown, as hypertonia can be a symptom of another condition.
How does hypertonia affect my child’s body?
Hypertonia will make it difficult for your child to move their arms and legs, as there’s a disconnect between how their brain communicates to their nerves and muscles, telling them when to contract (relax) their muscles. Your child may have a hard time walking because their muscles are stiff and they may be off-balance and fall, as their body doesn’t respond quickly enough so they can regain their balance.
Symptoms and Causes
What are the symptoms of hypertonia?
Symptoms of hypertonia are the result of muscles being too stiff. Symptoms vary from person to person diagnosed with hypertonia. The severity of symptoms depends on the location of the injury to the brain and spinal cord.
Symptoms of hypertonia include:
- Decreased range of motion.
- Difficulty moving arms, legs or neck.
- Loss of balance and frequent falls.
- Limited joint movement and very little flexibility.
- Throbbing pain or soreness in muscles.
- Involuntary muscle twitching or jerking (myoclonus).
Severe cases of hypertonia result in contracture, when joints freeze in place and muscles, tendons, tissues and skin permanently tighten, making your joints short and extremely stiff. Contracture makes it difficult to move affected body parts.
What causes hypertonia?
A communication error in your central nervous system (brain and spinal cord), which regulates how nerves and muscles interact, causes hypertonia.
Pathways that connect nerves to your brain manage and control muscle tone. If there’s damage or any interference in your brain’s pathways, your muscles are unable to hear what the nerve signals are telling them to do. If your muscle tone is too high, your brain is unable to tell your nerves to let your muscles relax.
Causes of pathway damage that lead to a hypertonia diagnosis include:
- Birth injury like lack of oxygen when moving down the birth canal.
- Brain tumor.
- Conditions that affect how nerves communicate with muscles.
- Injury to your central nervous system.
- Problems with how your baby’s brain formed during fetal development.
What conditions have hypertonia as a symptom?
Several conditions affect how your brain communicates with your body’s nerves and muscles, leading to a symptom of hypertonia. If your baby receives a diagnosis of hypertonia, your healthcare provider will also examine your baby for other conditions that also affect their central nervous system, including:
Diagnosis and Tests
How is hypertonia diagnosed?
To diagnose your child, your healthcare provider will examine your baby for physical symptoms of the condition by observing their:
- Balance and coordination.
- Motor skills (grasping, moving arms and legs, sitting up).
- Nerve function.
This examination is painless and usually involves instruments like a reflex hammer.
Your healthcare provider will also review your family’s medical history and identify if the condition was the result of any complications that occurred before your baby was born or during delivery.
What tests diagnose hypertonia?
If your healthcare provider suspects hypertonia, they’ll likely perform additional tests to confirm the diagnosis. Tests could include:
- Imaging tests to observe their brain and spinal cord like an MRI or CT scan.
- Electromyograms to measure muscle and nerve function.
Management and Treatment
How is hypertonia treated?
Treatment varies based on the severity of the hypertonia diagnosis and focuses on managing symptoms. Treatment for hypertonia could include:
- Exercising regularly within personal limits.
- Participating in physical therapy to improve range of motion.
- Receiving localized injections (botulinum toxin) in affected muscles to turn off nerve signals.
- Taking muscle relaxant medicine to reduce muscle spasms.
- Treating any underlying conditions that have hypertonia as a symptom.
Treatment is also available to improve mobility and the safety of people diagnosed with hypertonia, especially to reduce the risk of falls, which could lead to bone fractures and breaks. Many people with severe hypertonia choose mobility equipment as a safer option to navigate the world.
How soon after treatment will I feel better?
Hypertonia is a lifelong condition that can improve over time with treatment. Treatment aims to reduce symptoms and improve muscle function. The timeline as to when you’ll feel better is dependent on the cause and severity of your diagnosis.
How can I reduce my risk of having a child with hypertonia?
It’s difficult to reduce your risk of having a child with hypertonia because, often, the cause cannot be prevented, especially if the diagnosis is related to an underlying condition. Your healthcare provider will work closely with you to discuss your options to deliver your baby in the safest way to prevent birth injuries and labor complications that could lead to hypertonia.
Outlook / Prognosis
What can I expect if I have a child with hypertonia?
Hypertonia is a lifelong condition and the prognosis is dependent on the cause of the diagnosis. Some children will feel better after long-term treatment and the condition will have no consequences on their overall health. Severe cases of hypertonia can get worse over time and impact your child’s overall health and wellbeing, sometimes leading to permanent immobility, putting them at risk of falls, infection and bedsores. Treating the cause of hypertonia can improve your child’s outlook.
How do I take care of my baby with hypertonia?
It’s important to support your baby during their diagnosis. It may take longer for your baby to build their motor skills, like grasping objects, reaching for objects and crawling, but working closely with your baby’s healthcare provider and following recommended treatment will alleviate their symptoms and allow them to reach developmental milestones for their age. As your child gets older, long-term care will be necessary, like continuing physical therapy, to improve their mobility as they engage more with the world around them.
When should I see my healthcare provider?
If your baby shows signs or symptoms of hypertonia, you should visit your healthcare provider. Signs include:
- Difficulty moving arms, legs or neck.
- Muscles feel tight to the touch, especially when your baby is resting.
- Muscles uncontrollably twitch or jerk.
What questions should I ask my doctor?
- Are there side effects to the medicine you prescribed to treat my baby’s diagnosis?
- How often should my child see a physical therapist?
- Is my child’s diagnosis the result of an underlying condition?
Frequently Asked Questions
What is the difference between hypertonia and hypotonia?
Hypertonia is too much muscle tone and hypotonia is the opposite, with too little muscle tone. Hypotonia is also known as “floppy infant syndrome” since a baby’s muscles don’t show resistance when their body moves, giving children a limp appearance.
What is the ICD-10 code for hypertonia?
The diagnostic ICD-10-CM (International Classification of Diseases, Tenth Revision, Clinical Modification) code for congenital hypertonia is P94.1. For healthcare providers, this code describes the diagnosis, symptoms and necessity for treatment. The code is used by all healthcare providers in the U.S.
A note from Cleveland Clinic
It may feel discomforting to lift your baby and they feel stiff like a statue, but treatments are available. As your baby’s muscles are unable to relax due to hypertonia, they might need a little extra help as they grow and accomplish developmental milestones for their age, though. Having patience with your child’s treatment, as it’ll likely be long-term, will be critical in supporting your child with their hypertonia diagnosis.
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