After a traumatic brain injury, individuals may experience a movement disorder called dystonia.
To help you better understand dystonia after brain injury, this article will discuss its causes, symptoms, and treatments.
Causes of Dystonia After Brain Injury
Dystonia is a movement disorder caused by disrupted signals between the brain and body. This results in involuntary muscle contractions, typically in the form of repetitive twitching or twisting motions.
The exact cause of dystonia is unknown. However, many scientists believe it is caused by dysfunction of the basal ganglia, a cluster of neurons deep inside the cerebral cortex, or other areas of the brain that play a role in movement.
The basal ganglia play a pivotal role in helping your brain select the correct muscles to move. If they become damaged, then a person may lose coordinated muscle control completely.
To better understand dystonia and how it affects your movement, it will help to have some background on how the basal ganglia work.
How the Brain Controls Movement
For any movement to be executed correctly, two things must happen simultaneously:
- The agonist muscles (the muscles that initiate movement) must contract.
- The antagonist muscles (the muscles that inhibit movement and produce opposing joint torque to the agonist muscles) must relax.
The basal ganglia’s role is to control that process. They are in charge of signaling which muscles need to activate and which need to relax. It does this by passing on inhibitory or excitatory signals to the right muscle groups.
Therefore, if an injury damages the basal ganglia, this normally harmonious process is disrupted. Instead of keeping the muscles balanced, the basal ganglia may not be able to suppress the antagonist muscles any longer.
This can cause them to activate at the same time as the agonist muscles, resulting in uncontrollable twisting movements.
Symptoms of Dystonia After Brain Injury
Dystonia typically does not appear until several months after a brain injury, and the onset is not always immediate.
Some early symptoms of dystonia may include:
- Dropping items frequently
- Loss of fine motor control
Once dystonia fully develops, the characteristic twisting and twitching motions will become more apparent.
In addition, post-traumatic dystonia tends to be paroxysmal. This means symptoms occur in episodes or attacks, rather than all the time. In fact, that is one of the hallmarks of dystonia that distinguishes it from spasticity after TBI.
Sometimes stress and anxiety can trigger dystonia attacks, which is why it’s important to find ways to keep stress down. Some ways to do that are through acupuncture, meditation, and regular exercise.
Types of Dystonia
Dystonia can be characterized into three types: focal dystonia, segmental dystonia, and general dystonia.
Focal dystonia only impacts one part of the body. The most common areas that focal dystonia affects include:
Sometimes dystonia can also cause the torso to bend or writhe, but that is less common.
Segmental dystonia, on the other hand, strikes at two or more adjacent muscle groups at once. So, instead of just your neck acting up, both your neck and jaw would display symptoms.
With both segmental and focal dystonia, the side of your body opposite the brain-injured side is the one affected. In general dystonia, all parts of the body display dystonia.
In the following section, we’ll discuss some interventions that may help individuals better manage their dystonia.
Treating Dystonia After Brain Injury
While there are no true cures for dystonia, there are several options available to help you manage the symptoms of it after brain injury. These include:
- Medications. Oral medications can help keep dystonia flare-ups at bay. Some medications a doctor might prescribe include trihexyphenidyl and oral baclofen.
- Botox injections. For more severe dystonia that causes pain and joint damage, Botox injections are another option. Botox blocks all nerve signals to the targeted muscle, effectively paralyzing it.
- Surgery. In extreme cases, when the patient does not respond to either medication or Botox, doctors will perform a thalamotomy to remove the part of the brain that controls involuntary muscle movements. This should only be done as a last resort, however. Another surgical option is deep brain stimulation.
All of these approaches can help relieve the symptoms of dystonia. Unfortunately, most of them (besides surgery) are only temporary solutions.
That’s because medications do not address the root cause of dystonia, which is poor connection between the basal ganglia and the muscles. The basal ganglia cannot send signals to inhibit the antagonist muscles, which leads to uncoordinated movement.
The good news is, it’s possible to rebuild that connection to your muscles by activating neuroplasticity through physical therapy.
How Neuroplasticity Works to Treat Dystonia
Neuroplasticity refers to your brain’s ability to repair itself and create new neural pathways. These new pathways are formed through repetitive, therapeutic exercise.
This means one of the best ways to treat dystonia after brain injury is to exercise your affected muscles.
Of course, this can be hard to do, especially when dystonia causes abnormal movements. That’s why your best option is to work with both a P.T. and a neurologist, so they can collaborate to find the ideal approach.
For example, you might need medication to get the dystonia under control first. Once the dystonia goes down, you can work on exercising the affected muscles to engage neuroplasticity.
Dystonia and TBI
Dystonia can be a painful condition if left untreated. Fortunately, with the right medication and therapy, it can be effectively managed.
As you participate in physical therapy, your brain will be encouraged to form new neural pathways, which may improve the communication between the basal ganglia and your muscles.
Once that communication is restored, dystonia will decrease, which will let you move your muscles again with ease.
Featured Image: ©iStock/LSOphoto/fizkes