What are Tremors?
Tremors are involuntary, rhythmic muscle contractions that make a body part appear to be shaking or trembling.
Hand tremors may be more noticeable when a person holds their hands out straight in front of the body or when they are stressed or anxious.
Tremors mostly affect the hands. However, it can also occur in other body parts, such as:
- The head
- The arms
- The legs
- The torso
- The voice box (larynx), which may cause a shaky voice
There are several types of tremors. However, most fall into two categories:
- Resting tremors: These occur when the muscles are relaxed, including when the hands are resting on the lap.
- Action tremors: These occur when the muscles are contracted due to voluntary movement. The majority of tremors are action tremors. They are further divided into:
- Postural tremor – occurs when your hands are outstretched, and gravity is pulling them down. You can’t keep the hands completely steady while they’re outstretched.
- Intention tremor – starts when you’re reaching for a target, like a keyhole as you unlock your door.
- Task-specific tremor – occurs when performing an activity, such as when you’re writing.
What are the causes of tremors?
We all have a little bit of tremor called a physiologic tremor; it’s natural and not usually noticeable. Tremors that aren’t natural include these types:
- Enhanced physiologic tremor. Caffeine use, thyroid disorders, stress, fatigue, or sleep deprivation can intensify physiologic tremor. This tremor may show up as a postural tremor.
- Essential tremor. This is a benign tremor that causes involuntary shaking in various body parts, including the hands, head, and voice box.
A person with essential tremor may have a postural hand tremor or an intention tremor.
- Parkinsonian tremor. It is a resting, pill-rolling tremor can occur with other features of Parkinson’s disease like bradykinesia, rigidity, postural instability.
- Cerebellar tremor. This is an intention tremor caused by damage to the cerebellum in the back of the brain, often from a stroke or multiple sclerosis. The cerebellum helps coordinate movement, like reaching out to grasp a doorknob. Cerebellar damage can cause your hand to miss the doorknob.
- Post-stroke tremor. After a stroke, a person can have a variety of tremors. If there’s damage to the cerebellum there can be an intention tremor. If the damage is in the basal ganglia, the person can have a resting tremor.
- Medication-induced tremor. Some medications can cause tremors, such as the antidepressant bupropion and the anti-arrhythmic drug amiodarone. The resulting tremor is often postural.
- Withdrawal tremor. People suffering alcohol withdrawal can experience postural tremors.
What are steps required in the management of tremors?
First step is diagnosis of tremors: –
Diagnosing requires a physical exam and a careful analysis of medical history. It is important to know if there are any associated features.
Is there balance impairment, stiffness, or slowness of movement as in Parkinson’s disease?
Is there any history of stroke?
Is there a brain lesion?
Is the person taking a certain kind of medication?
Does the person consume a lot of caffeine or have any other underlying conditions?
Depending upon history and examination, lab work-up and neuroimaging may be required that includes CT Head or MRI Brain.
Next step is treatment: –
Some tremors can be eliminated or dramatically reduced.
For enhanced physiologic tremor, you may just need to cut back on caffeine or manage stress.
Tremors caused by thyroid disorder or alcohol withdrawal may be reduced by treating those conditions.
Medication-induced tremors may be resolved by switching to a different type of medication.
Essential tremor is often treated with medications such as the beta blocker propranolol or the antiseizure drug primidone.
Parkinsonian tremors may be reduced with anti-parkinsonian medications or a procedure called deep brain stimulation.