If a brain injury damages the basal ganglia, you may experience problems with balance, posture, and certain movements.
Today you will learn all about the effects that basal ganglia damage can cause plus what you can do to overcome it.
What are the Basal Ganglia?
The basal ganglia are a group of structures found deep within the base of the brain. The structures that make up the basal ganglia include the:
- Globus pallidus
- Subthalamic nucleus
Each part of the basal ganglia plays its own separate role in the brain, but they also form a network with each other. This network helps control physical movement.
In particular, the basal ganglia are linked to the initiation and execution of skilled movements.
How the Basal Ganglia Control Movement
To execute any type of movement, two things must happen at once:
- The agonist muscles (the muscles that initiate movement) must contract.
- The antagonist muscles (the muscles that inhibit movement) must relax.
The basal ganglia control that process. They are in charge of directing which muscles should activate and which need to relax. They do this by sending inhibitory or excitatory signals to the right muscle groups.
For example, to pick up a fork, you must extend your arm first, which means your bicep muscle cannot fire while this is happening. Otherwise, your arm would just contract and your elbow would stay bent, not allowing you to reach forward.
The basal ganglia, therefore, will send signals to your bicep, telling it to relax. This allows you to extend your arm easily.
Unfortunately, if an injury damages the basal ganglia, this normally harmonious process is disrupted. This can cause the antagonist muscles to activate at the same time as the agonists, leading to various movement disorders.
Symptoms of Basal Ganglia Brain Damage
Damage to the basal ganglia can cause many serious movement problems.
Below are some of the most common effects of basal ganglia damage after brain injury.
1. Chorea and Athetosis
Chorea and athetosis are conditions that cause strange, involuntary movements.
- Chorea is characterized by small, random, repetitive movements that start in one body part and move abruptly and unpredictably to another part.
- Athetosis, on the other hand, refers to a stream of slow, flowing, writhing movements, usually in the hands and feet.
Chorea and athetosis tend to occur together, which causes the person to display odd, almost dancelike movements. Both conditions are caused by dysfunction in the basal ganglia.
A secondary type of chorea, called hemiballismus, involves a violent, involuntary flinging of one arm. The movements are wider and more vigorous than the movements associated with chorea. It is caused by damage to the subthalamic nucleus.
Dystonia refers to sustained, involuntary muscle contractions that force people into abnormal positions. It occurs when the basal ganglia cannot suppress the antagonist muscles
Dystonia can be divided into two types: focal dystonia and segmental 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.
Parkinsonism occurs when a person displays symptoms similar to that of Parkinson’s disease. However, these symptoms are not caused by the disease itself, but by an external condition, such as head injury.
The symptoms of Parkinsonism may include:
- Resting tremor
- Stiff muscles
- Slow or delayed movements and difficulty initiating movements
- Difficulty with balancing and walking, including shuffling gait
Parkinsonism can also cause people to perform uncontrolled, repetitive movements, such as tics. They may also make involuntary noises, like those displayed in patients with Tourette’s syndrome.
Parkinsonism is a rare side effect of brain injury and typically only occurs after repeated head trauma.
4. Obsessive-Compulsive Disorder
While the basal ganglia are primarily involved in movement, they are also connected to the prefrontal cortex.
Since the prefrontal cortex helps regulate our behavior, it seems that the basal ganglia may play a role in that as well.
This explains why many people with basal ganglia damage develop obsessive-compulsive disorder. Some theories suggest that just as the basal ganglia inhibit certain muscles, it might also inhibit certain thoughts and behaviors.
Therefore, if it becomes damaged, people can experience intrusive thoughts and other compulsions.
Treating Basal Ganglia Damage
There are several options available to help you manage the symptoms of basal ganglia damage. These include:
- Medications. Oral medications can help keep muscle spasms and dystonia 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. This removes the part of the brain that controls involuntary muscle movements. It should only be done as a last resort.
All of these options can help relieve the more painful symptoms you may experience. Unfortunately, most of them (besides surgery) are only temporary solutions.
That’s because they do not address the root cause of these problems, which is poor communication between the basal ganglia and the muscles.
The good news is, it’s possible to rebuild that connection to your muscles. You can do so by activating neuroplasticity through physical therapy.
Engaging Neuroplasticity to Treat Basal Ganglia Damage
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 the many effects of basal ganglia damage is to exercise your affected muscles.
Of course, this can be hard to do, especially when the basal ganglia causes abnormal movements. That’s why your best option is to work with both a P.T. and a neurologist. They can collaborate and help you find the ideal approach.
For example, you might need medication to get dystonia under control first. Once the dystonia goes down, you can work on exercising the affected muscle to engage neuroplasticity.
Basal Ganglia Damage After Brain Injury
Basal ganglia damage can cause serious, painful side effects. Different types of movement disorders can develop depending on which part of the basal ganglia was affected.
Fortunately, you can reverse most of these secondary effects by engaging neuroplasticity. You will do this by exercising your affected muscles.
With enough practice, you can help your brain rewire itself until eventually, you regain better control of your body again.