Tremors, or involuntary shaking, are a noticeable sign of a movement disorder. While they can occur at any age, they are more common among older adults. When an individual experiences rhythmic trembling in their hands, arms, head, or torso, a doctor will evaluate whether the shaking is a symptom of a common neurological condition like essential tremor or Parkinson's disease. Other causes, such as medications or a thyroid disorder, may also be responsible.
Essential Tremor
Essential tremor (ET) is one of the most common movement disorders and a very frequent cause of involuntary shaking in older adults. It is important to know that ET is distinct from Parkinson's disease, although they are often confused.
Symptoms of essential tremor
Essential tremor is primarily an action tremor, meaning the shaking is most pronounced when the affected body part is being used during voluntary movements.
- Visible shaking: A rhythmic tremor most often affects the hands and arms, but can also involve the head, voice, or trunk.
- Difficulty with tasks: The shaking can interfere with daily activities, making it challenging to write, eat with utensils, or hold a cup.
- Exacerbating factors: Symptoms may worsen with emotional stress, anxiety, fatigue, or caffeine.
- Improved at rest: The tremor tends to decrease or disappear when the hands or arms are at rest.
Parkinson's Disease
Parkinson's disease (PD) is a progressive neurological disorder caused by the degeneration of dopamine-producing cells in the brain. The average age of onset is around 60 years old. While it is also known for causing tremors, they present differently than those seen in essential tremor.
Symptoms of Parkinson's disease
Parkinson's tremors are typically resting tremors, which means they are most noticeable when a limb is not in use.
- Resting tremor: Rhythmic shaking that is most prominent when the hands are resting, and often described as a “pill-rolling” motion of the thumb and forefinger.
- Starts on one side: The tremor often begins on one side of the body and may eventually spread to the other side as the disease progresses.
- Other motor symptoms: In addition to tremors, PD includes other cardinal symptoms such as bradykinesia (slowed movement), muscle rigidity, and balance problems.
- Non-motor symptoms: Other issues like a reduced sense of smell, constipation, sleep problems, depression, and cognitive changes can also occur.
Comparison of essential tremor and Parkinson's disease
Distinguishing between essential tremor and Parkinson's disease requires a careful evaluation of the symptoms and the circumstances under which the tremors occur. Here is a table comparing the two conditions.
| Feature | Essential Tremor (ET) | Parkinson's Disease (PD) |
|---|---|---|
| Primary Symptom | Tremor is often the only symptom. | Tremor is one of several symptoms, along with slowed movement and rigidity. |
| Tremor Type | Action tremor: Occurs during movement, such as writing or eating. | Resting tremor: Occurs when at rest and often lessens with purposeful movement. |
| Body Parts Affected | Commonly affects both hands, head, and voice. | Starts on one side, typically in a hand or finger, and can affect the legs, chin, or other areas. |
| Progression | Typically progresses slowly over many years. | Often progresses more quickly than ET, with a decline in other motor and non-motor functions. |
| Associated Problems | Does not cause cognitive decline, balance issues, or major problems beyond the tremor itself. | Causes other significant symptoms, including balance problems, stiffness, and cognitive or emotional changes. |
| Frequency | More common than Parkinson's disease, especially among those over 65. | Affects about 1% of the population over 60, but is less common than ET. |
Other potential causes of shaking in older adults
While ET and PD are the most common causes of tremors, a proper diagnosis is necessary to rule out other potential factors.
- Side Effects of Medications: Certain drugs, including some antidepressants, asthma medications, and corticosteroids, can cause tremors as a side effect.
- Hyperthyroidism: An overactive thyroid gland can cause a fine, rapid tremor in the hands, along with other symptoms like weight loss and a rapid heartbeat.
- Alcohol Withdrawal: Trembling can be a symptom of alcohol abuse or withdrawal.
- Anxiety and Stress: High anxiety or stress levels can trigger or worsen tremors.
- Enhanced Physiological Tremor: A temporary, fine tremor that is more noticeable than a typical physiological tremor. Causes include hypoglycemia (low blood sugar), caffeine, and alcohol withdrawal.
Diagnosis and treatment
Diagnosing the cause of a tremor involves a comprehensive neurological exam, a review of medical history, and sometimes a DaTscan to help distinguish between ET and PD. Blood and urine tests can rule out other medical conditions like thyroid disease or toxic exposure.
Treatment depends on the underlying cause. For ET and PD, there is no cure, but symptoms can be managed effectively.
- Medications: For ET, beta-blockers like propranolol and anti-seizure medications like primidone are often used. Parkinson's tremors are treated with dopaminergic medications, such as carbidopa-levodopa.
- Surgery: For severe tremors unresponsive to medication, surgical options like Deep Brain Stimulation (DBS) or Focused Ultrasound may be considered.
- Lifestyle Adjustments: Simple changes can help, including avoiding triggers like caffeine, managing stress with relaxation techniques, and using weighted utensils.
- Supplements: Some supplements, such as Vitamin B12 and magnesium, have been anecdotally used for tremors, but their effectiveness is not definitively proven. Always consult a doctor before starting new supplements.
Conclusion
While many people assume any shaking in older age points to Parkinson's disease, the reality is that other conditions, particularly the more common essential tremor, are often the cause. Understanding the specific characteristics of a tremor—such as whether it occurs during movement or at rest—is crucial for an accurate diagnosis. With proper medical evaluation, management strategies can be implemented to significantly improve a person's quality of life, regardless of the underlying cause. If you or a loved one experiences unexplained shaking, consulting a healthcare provider is the most important step towards finding answers and effective treatment.
Learn more about tremors from the National Institute of Neurological Disorders and Stroke (NINDS).
