Spasticity After TBI: Causes, Symptoms, and Treatments

Spasticity is an uncontrolled stiffening of muscles caused by a disruption of signals from the brain. The onset of spasticity after TBI is often rapid, occurring as early as one week following the brain injury.

Because spasticity is rooted in problems with the brain, effective treatments must involve neuroplasticity, the brain’s natural repair mechanism.

In this article, you will learn more about the causes of spasticity after TBI, plus the best ways to treat it. You will also discover how to treat muscles that have been effectively paralyzed by spasticity.

Causes Spasticity After TBI

Spasticity is associated with a condition called hyperreflexia, which causes increased activity of the muscle stretch reflex. The muscle stretch reflex (myotatic reflex) is a muscle contraction that occurs in response to stretching within the muscle.

When you stretch a muscle, the muscle spindle lengthens and its nerve activity increases. The increased neural activity triggers a contraction in the muscle fibers to resist the stretching. This prevents muscles from stretching too far and tearing.

The myotatic reflex is controlled by the central nervous system (i.e. the brain and spinal cord). Normally, the muscles and the brain send neural messages to each other through the spinal cord, enabling the brain to know when to contract the muscles and when to release them.

However, after a brain injury, this communication is disrupted, which leads to an imbalance of signals to the muscles. As a result, the myotatic reflex can never deactivate, and the muscles will stay in a constant state of flexion. This state is what doctors call spasticity.

Symptoms of Spasticity

Spasticity after TBI primarily causes muscle stiffness. If the spasticity persists, the muscle fibers can permanently shorten, leading to contractures and loss of mobility.

Other symptoms of spasticity can include:

• Muscle spasms
• Joint deformity
• Muscle fatigue
• Involuntary crossing of legs

Fortunately, you can prevent many of these symptoms with early and effective treatment.

Engaging Neuroplasticity to Treat Spasticity after TBI

The most effective way to overcome spasticity after TBI is to address the root cause. Since the cause of spasticity is poor communication between the brain and muscles, treating it must involve restoring that connection. You can do this by engaging a process known as neuroplasticity.  

Neuroplasticity refers to the brain’s ability to rewire itself and create new neural pathways. This allows undamaged areas of the brain to take over functions from damaged ones.

These new pathways are formed through repetitive, therapeutic exercise. This means the best way to treat your spasticity is to exercise your affected muscles.

The more you activate your muscles, the more you will reinforce those new neural pathways. This in turn will lead to easier communication between your brain and muscles and, eventually, less spasticity.

But what if your spasticity is so severe you cannot even move your muscles at all? Fortunately, there are still alternatives.

Treating Severe Spasticity After TBI

Spasticity can often resolve on its own as the brain heals. But in some cases, spasticity is so severe that the muscle is effectively paralyzed. This can make engaging neuroplasticity much more difficult.

However, there are still two other options available, which we will examine below:

Option 1. Stretching and Passive Range-of-Motion

Stretching and passive range of motion exercises can help minimize the effects of spasticity after TBI. Stretches are important for preventing contractures, which preserves joint mobility.

Passive exercises come with an additional benefit though, in that they can also activate neuroplasticity. In fact, neuroimaging studies have found that passive movement exercises activate the primary motor cortex, the part of the brain responsible for voluntary movement.

Therefore, having a therapist move your arm or leg for you can help repair the brain’s connection to your muscles. And the stronger the communication, the less spasticity you will experience.

Option 2. Botox Injections and Baclofen Pumps

For patients with spasticity in a single location, Botox injections can prove useful. Botox is a nerve blocking agent that prevents the release of acetylcholine, a neurotransmitter that causes your muscles to contract.

This medication can almost instantly stop painful spasms, which makes it a popular treatment. For people with severe and painful spasticity, it is often the best option.

If, on the other hand, your spasticity is more systemic, a baclofen pump will probably prove more effective. A baclofen pump refers to a small, hockey-puck sized device implanted beneath the skin. The device then releases small amounts of baclofen into the space surrounding the spinal cord. This allows the medication to reach multiple muscle groups at once.

However, both baclofen and Botox are only temporary solutions. Once their effects wear off, the spasticity will return. For the most effective approach, patients should combine these medications with passive motion exercises or active exercise when possible.

Understanding Spasticity After TBI

Spasticity after TBI can be a painful condition. However, it is treatable.  

If your spasticity does not allow you to move on your own, combine passive range-of-motion exercises with medication. Although you are not moving yourself, the passive exercise still engages cortical plasticity. This will help repair the neural connections between the brain and muscles.

As communication improves between the central nervous system improves, your spasticity should decrease. With enough persistance, you can hopefully relearn to relax your muscles again.

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