Tremors after brain injury, also known as post-traumatic tremors, are a rare side effect of TBI. They mostly occur after damage to the cerebellum.
Sometimes, however, other movement disorders can cause symptoms that look like tremors but are in fact something else. Therefore, it’s vital to work closely with your doctor to find an accurate diagnosis.
To help you find the best treatment approach, this article will describe the many types of tremors after brain injury, plus show you how to distinguish them from other motor disorders.
Types of Tremors After Brain Injury
Tremors are an uncontrollable, rhythmic shaking of certain parts of the body, usually the hands. Sometimes, tremors also affect a person’s voice.
Most tremors do not appear until several months, even years, after a brain injury. This makes tremors the TBI side effect with one of the longest onset delays.
There are over twenty types and categories of tremors, according to the NIH. Some are caused by brain or nerve damage, while others are triggered by psychological stress.
There are two primary categories that all types of tremors fall into:
- Resting tremors. These tremors occur when the muscles are relaxed, such as when the hands are in the person’s lap.
- Action tremors. These tremors are triggered by voluntary movement. Some occur only when a person is doing a complex task while others happen whenever the person moves
Besides these categories, tremors are also classified by their appearance and origin.
For the purposes of this article, we will focus on the two most common types of tremors that occur after brain injury. These are known as essential tremors and cerebellar tremors.
Essential tremor occurs primarily in the hands and arms, and is present during both action and rest. Sometimes the tremor will affect the person’s voice box, which will cause their voice to quiver.
Stress, exhaustion, and low blood pressure can trigger essential tremors and increase their severity.
Most people who develop essential tremors after brain injury already have a genetic risk factor for it. Though sometimes damage to certain parts of the brain will trigger it, even if the person has no family history.
The most common types of tremors that occur after brain injury are cerebellar tremors.
Their defining feature is a slow, but visible shaking movement in the arms and legs. Unlike essential tremors, cerebellar tremors only happen at the end of purposeful movements.
As the name suggests, these tremors are caused by damage to the cerebellum or its pathways.
Other Movement Disorders Confused for Tremors
There are several other disorders that also cause involuntary movements. However, these conditions all require distinct treatments. That’s why, in order to get the proper treatment, it is important to know how to distinguish tremors from other related problems.
Many people confuse muscle spasms (which are symptoms of spasticity) with tremors, but they are separate issues.
The best way to tell the difference between a spasm and a tremor is to look for a rhythm. With a spasm, the muscle contracts involuntarily, but the rate at which it contracts is somewhat random. With a tremor, there is usually a pattern.
Also, muscle spasms can cause extreme contortions and are accompanied by pain. Tremors, on the other hand, are painless.
Another condition that is commonly mistaken for tremor is clonus.
Clonus symptoms mimic tremor symptoms in many respects: both cause rhythmic shaking, both are painless, and both mainly affect a person’s arms and legs.
However, with clonus, stretching the affected limb will trigger or increase the shaking, which is not the case with tremors.
Now that you know the different types of tremors after brain injury and how to distinguish them from other motor disorders, it’s time to discuss diagnosis and treatment options.
Diagnosing Tremors After Brain Injury
Because there is often such a long delay between the brain injury and tremor onset, it is difficult to tell whether the brain damage is responsible for the tremors or if something else is.
Unfortunately, there are over a dozen possible conditions, besides brain injury, that can cause tremors, and many require different treatment approaches. Therefore, finding the correct diagnosis is crucial.
That is why the doctors will usually order MRIs and other diagnostic tests to see if the areas of the brain that control movement have lesions on them.
They will also run blood tests to rule out any physiological causes of tremors, such as thyroid disease.
If something else is causing your tremors, it is possible that treating that condition will eliminate the tremors.
If the doctors rule out every other cause except brain injury, then the following treatments might help.
Treating Post-Traumatic Tremors
Treatment for tremors after brain injury, unfortunately, doesn’t always eliminate the tremors. Rather, certain therapies can help you manage the symptoms and sometimes even bring down the severity of the tremors.
In some cases, the person’s tremors are mild enough that they do not require treatment.
If your tremors do impair function, however, then the treatments below can provide some relief.
Physical therapy can help you improve muscle strength and control, which might help reduce your tremor. Through PT exercises, you activate the brain’s neuroplasticity, which rewires the brain and strengthens the neural signals the brain sends to your muscles.
If these stronger signals can get to the muscles affected by tremors, it could reduce them.
Therapists can also fit you with orthotic braces or weights, which can stop tremors by keeping the affected muscle stable. It is not a permanent fix, but it is sometimes enough to restore function.
If physical therapy does not work, there are several medications your doctor might prescribe to treat your post-traumatic tremors. These include:
- Beta-blocking drugs. Beta-blockers, such as propranolol, are often successful at treating essential tremors and some forms of kinetic tremors.
- Anti-seizure meds. For those patients who don’t respond to beta-blockers, some anti-seizure meds can reduce tremors. However, some anti-seizure meds also make tremors worse, which is why you should always consult with your physician first.
- Botox injections. Botox injections are extremely effective at treating tremors, especially head tremors. However, they can cause muscle weakness.
As you can see, these medications all come with a downside. It’s up to you to decide whether the possible benefits outweigh the risks.
Also, it is important to note that the above medications are used to treat general tremors, not specifically tremors after brain injury. More research is needed for their effect on post-traumatic tremors.
Deep Brain Stimulation
In severe cases, a doctor might recommend surgical interventions to treat tremors after brain injury.
Deep brain stimulation (DBS) is the most effective surgical treatment for tremors. It uses surgically implanted electrodes to send high-frequency signals to the thalamus, the structure in the brain that controls involuntary movements.
The electrical signals are sent from a small device, similar to a pacemaker, that is placed under the skin in the person’s chest. When the signals reach the thalamus, they disable the tremors.
DBS is effective at eliminating tremor and has been approved by the FDA as a treatment for Parkinson’s. While more studies are still needed before it is approved for post-traumatic tremors, the current research is promising.
However, since deep brain stimulation is an invasive surgery, this makes it the riskiest treatment option. Some possible side effects include dysarthria (slurred speech) and balance problems.
Still, if your tremors are severely affecting your day-to-day function, it might be worth asking your doctor about it.
Stress, anxiety, and certain drinks can all worsen tremors. Therefore, it’s important to reduce stress and eliminate tremor-inducing substances such as caffeine from your diet.
Meditation is a great way to lower your anxiety. Another treatment you can try is behavioral relaxation training, which focuses on labeling feelings and defusing them with the help of a therapist.
If you can get your stress under control, you might find your tremors improve or even disappear completely.
Understanding Tremors After Brain Injury
Tremors after brain injury cause uncontrollable shaking in the hands, arms, and other parts of the body.
Because they are a rare side effect and have a delayed onset, they can easily be mistaken for other conditions, such as clonus or Parkinson’s. Therefore, a thorough diagnosis by your doctor is crucial.
Once you are diagnosed, talk to your therapist to create a treatment plan that fits your needs.