Cerebral Palsy and Muscle Tone: Risks of Having High vs. Low Muscle Tone

Wondering how too much or too little muscle tone due to cerebral palsy can affect your child’s growth and development?

This article will explain the risks associated with extremes in muscle tone and the best ways to manage them.

How Cerebral Palsy Affects Muscle Tone

Cerebral palsy is caused by damage to areas of the brain that control motor functions like movement, balance, and coordination.

Although there’s nothing directly wrong with the muscles of the body,  movements are negatively affected by the brain damage.

Movement occurs through the regular contracting and relaxing of our muscles.

When there’s irregular muscle tone, movements get harder to control.

Normally, the brain will send signals down the spinal cord and through peripheral nerves in response to stimuli for your muscles to appropriately contract and relax.

However, the brain damage that caused cerebral palsy can negatively affect communication to the body, resulting in abnormal muscle tone.

Types of Abnormal Muscle Tone That Can Be Caused By Cerebral Palsy

There are two types of abnormal muscle tone that a child with cerebral palsy may experience: hypertonia and hypotonia.

Hypertonia describes high muscle tone, which causes stiff, rigid movements due to continuously contracted muscles.

In contrast, hypotonia describes low muscle tone. Individuals with hypotonia generally have floppy, loose limbs due to constantly relaxed muscles.

Next, we’ll further differentiate between the two.

Hypertonia

Hypertonia is most evident in individuals with spastic cerebral palsy, which is the most common type of CP and makes up over 75% of CP cases.

Signs of High Muscle Tone

Depending on the severity of one’s cerebral palsy, experiences with high muscle tone can vary.

Some of the most common signs of high muscle tone include:

• Spasticity
• Slow, firm movements
• Rigid positioning
• Musculoskeletal deformities when growing due to an uneven muscle pull
• Joint and muscle pain
• Spasms and other involuntary movements
• Delays in motor development
• Lack of flexibility
• Abnormal walking patterns

Treatments for High Muscle Tone

Depending on the severity of high muscle tone, various treatments may be recommended.

Common treatment interventions for high muscle tone include:

• Rehabilitation therapy. Physical therapy hones in on your child’s gross motor skills through exercise while occupational therapy will work on your child’s fine motor skills through practical activities of daily living. Stretching and manual therapy can help lengthen contracted muscles to ease movement.
• Braces. Braces can help passively lengthen muscles. Because it creates a mold around the limb, bracing makes it difficult to compromise form when performing affected movements, such as walking.
• Muscle relaxants. Muscle relaxants can be taken orally, through injections, or from a pump. The most commonly used medications for high muscle tone are baclofen and Botox.
• Surgery. The main surgical intervention to treat high muscle tone is Selective Dorsal Rhizotomy. Nerve fibers are selectively cut, and because they can’t grow back, the procedure results in permanent spasticity reduction. Conservative treatment is usually attempted before surgery.

Hypotonia

Hypotonia from cerebral palsy is generally associated with damage to the cerebellum (which is responsible for balance and coordination), but not always.

It’s most commonly observed in cases of ataxic cerebral palsy, but also in athetoid and mixed cerebral palsy, in which a combination of both high and low muscle tone is apparent.

Signs of Low Muscle Tone

It’s generally agreed among PTs and OTs that children with hypotonia display:

• Lack of strength
• Low activity tolerance
• Delays in motor skill development (rolling, sitting, crawling, walking)
• Rounded shoulder posture
• Tendency to lean forward
• Joint hypermobility
• Increased flexibility
• Poor head control

Treatments for Low Muscle Tone

Physical and occupational therapy for low muscle tone will focus on activating and strengthening muscles to improve posture and coordination.

Speech therapy can help children who have feeding or speech difficulties develop muscle strength in the face and oral muscles.

Severe hypotonia can make it difficult to chew or swallow, so it’s important to pay extra attention to nutritional intake and ensure that your child is consuming enough calories to prevent malnourishment.

Some individuals may even need to use a feeding tube.

Additionally, orthotics like braces and compression garments can help improve low muscle tone by promoting proper alignment and form. However, consistent reliance on a device to support the muscles may worsen muscle tone over time, so attempting to improve muscle tone through strengthening is a better long-term solution.

Cerebral Palsy and Muscle Tone

Cerebral palsy is nonprogressive, meaning that it will not get worse over time.

However, if not properly managed, abnormal muscle tone can worsen and further impair movement.

Both high and low muscle tone can cause your child to develop poor posture, control, strength, and balance.

Now that you know the symptoms of irregular cerebral palsy muscle tone, make sure to keep an eye out for them in your child and don’t hesitate to seek a professional evaluation. Good luck!