Shakiness, or tremor, is not inevitable with aging but it occurs more often in the elderly. The most common causes are related to the body's normal (physiologic) function and its disturbance by certain drugs and medical problems. Other causes include pathologic dysfunctions of the brain and nervous system. Specific features of the tremor help make the diagnosis.
Physiologic tremor is the most frequent cause of shakiness in the elderly. According to the Merck Manual, Consumer Version, (expand the "Types of Tremor" section) it is the benign "normal tremor that everyone has," and it reflects the normal rhythm of control of muscles by the nervous system.
Characteristics of the tremor include:
- It primarily affects the hands, but the shaking can be present in the arms as well as all other muscle groups.
- The fine, rapid shaking is a so-called postural, action tremor, meaning a doctor can see it with a specific movement.
- You may notice this type of tremor when you point to an object or a word on paper.
Enhanced Physiologic Tremor
Physiologic tremor is normally barely visible but can become so in the elderly under certain conditions, including:
- Anxiety, depression, fear, and other causes of stress such as elder abuse
- Sleep deprivation, fatigue, fever
- Certain medicines, drugs, and other medical problems
These situations can enhance the underlying physiologic shaking. If the tremor is significant, treatment depends on the cause.
As with younger people, drugs that affect the central nervous system can cause shakiness in the elderly or make a physiologic tremor more visible. According to MedlinePlus, the drugs and other substances that can enhance physiologic tremors include:
- Prescription drugs, such as
- Theophylline or albuterol (used to treat asthma)
- Epinephrine (a catecholamine)
- Corticosteroids, (used to treat a variety of medical disorders)
- Anticonvulsants, such as Depakote, for seizure disorders
- Treatment for mood disorders, including lithium, antidepressants (for example, Zoloft or Prozac), and antipsychotic medicines
- Overuse, side effects, or withdrawal from certain drugs that depress the central nervous system, such as benzodiazepines and opioids
- Abuse or withdrawal from alcohol use (the "shakes"} or nicotine
- Abuse, side effects, or withdrawal of caffeine or recreational drugs, such as cocaine and methamphetamines
Substance abuse or addiction can also cause a pathologic tremor by the permanent damaging effects on the central nervous system. The substances include alcohol, opioids, cocaine and methamphetamines.
Management of drug-induced tremor is directed at treating substance abuse, or withdrawing from or adjusting the doses of prescription medications.
Older people are more vulnerable to drugs and are more likely to be taking multiple prescribed medicines that lead to shakiness. They benefit from fewer medications and the smallest dose necessary.
Systemic Disease-Induced Tremors
Systemic diseases that affect the brain or peripheral nervous system can cause shakiness or enhance physiologic tremor in the elderly. Based on the Merck Manual, Professional Version (expand the table, "Some Causes of Tremor" in section "Etiology"), health conditions include metabolic, hormonal, or toxic disturbances such as:
- Liver or kidney disease
- Diabetes or low blood sugar (hypoglycemia)
- Low blood oxygen (anoxic encephalopathy)
- Symptomatic overactive thyroid gland (hyperthyroidism)
- Overactive parathyroid gland (hyperparathyroidism)
- Heavy metal poisoning such as with mercury or lead
The shakiness that occurs with movement can be complex and variable.
Treatment of the underlying medical problem can improve the resulting tremors. In addition, physical and rehabilitative therapy can also be helpful to optimize a senior's daily function.
Essential tremor is the most common type of pathologic shaking, the Cleveland Clinic notes. It can occur at any age, but it tends to affect those over 40, according to the Mayo Clinic. The cause of essential tremor is uncertain, but in some people, it might be due to a genetic inheritance passed down in their families, according to a report in Genetics in Medicine.
Some people might confuse essential tremor for Parkinson's disease. However, an essential tremor is less limiting than Parkinson's. In addition, both types of tremors have other distinguishing features.
The Mayo Clinic reference states that the shaking of essential tremor:
- Is a tremor primarily of the hands and often the head and voice
- Can be seen, for example, when keeping the arms lifted straight out against gravity (postural). The typical head movements are the vertical nodding, "yes-yes," or the horizontal shaking, "no-no"
- The tremors can progress to affect other body parts, such as the arms and legs.
Symptoms develop gradually, starting on one side of the body, and can worsen under stress or fatigue. The shakiness can become more severe and affect daily functions, such as handwriting, threading a needle, or using eating utensils.
Essential tremor may not need to be treated if the symptoms are not bothersome. If a patient and her doctor feel like treatment is appropriate, medicines include:
- Propranolol (a beta-blocker used to treat high blood pressure)
- Primidone, an anti-seizure medicine
- A tranquilizer such as Xanax
- Botox injections, for example for tremors of the head, voice and hands
A doctor might also suggest surgery on the thalamus of the brain, or deep brain stimulation (DPS) of the thalamus with electrodes if the tremor is difficult to treat.
Parkinson's disease (PD) is also a common cause of pathologic shakiness in older people. It is the condition that most people think of when they see a senior with shakiness, although it is a lot less common than an essential tremor. PD can also occur in young people with an inherited form of the disease.
According to MedlinePlus, features of Parkinson's include:
- It occurs more frequently in people over 60 years and is more common in men than in women.
- The shakiness or tremor is caused by slow degeneration of nerve cells in the substantia nigra of the brain, according to Clinical Neurology of Aging, (page 251).
- Death of the nerve cells decreases dopamine in the basal ganglia (which helps control fine movement), interfering with the transmission of signals from the brain to muscles.
- A Parkinson's-like tremor can be seen with drugs such as some antipsychotics and anti-nausea medicine that affect the basal ganglia.
- Symptoms usually start in the hands but can also affect the voice, chin, leg, and other parts of the body.
Unlike essential tremor, the shakiness of PD occurs when the affected body part is at rest instead of with movement (resting tremor). Typical PD movements that are different from essential tremor include:
- Pill-rolling - rolling of the thumb and forefinger together
- Holding the body stiff (rigidity) with a stooped posture
- Shuffling while walking (shuffling gait)
The slow, coarse tremor of Parkinson's improves with movement so, unlike essential tremor, it does not affect daily functions and activities. A few people with Parkinson's will also have shaking with movement. In addition, sometimes essential tremor and PD can appear together, although the occurrence is rare.
The cerebellum, located at the base of the brain, is responsible for balance and coordination. Diseases that create dysfunctions in the cerebellum can cause cerebellar tremor.
Neurology Review for Psychiatrists (page 89) states that the most common causes are multiple sclerosis, stroke, and brain injury. Other causes include:
- Abscess, tumor, or inherited degenerative disorders
- Alcoholism and overuse of sedatives, anticonvulsants, or other drugs
You can see a cerebellar tremor when the patient moves. It is a so-called intention tremor, meaning it appears at the end of a directed movement, such as reaching to touch your nose or hold a cup. In addition, those affected are unable to do rapid, alternating movements, such as touching finger to nose, or finger to finger, and have difficulty walking and keeping balance.
Symptoms can be unilateral, affecting the side of the body on which the cerebellum is damaged, or both sides if there is bilateral dysfunction.
There is no effective drug for cerebellar tremor. Physical therapy, occupational and assistive therapy can improve a person's ability to function.
Other causes of shaking in seniors include:
- Orthostatic tremor, which occurs when a person stands. There is unsteadiness and shaking in the legs while standing, which disappears when the patient sits or walks. There is no effective treatment, but doctors usually treat with clonazepam, gabapentin, or dopamine-like drugs.
- Psychogenic tremor, which is unpredictable and has changing characteristics. The shakiness improves when the person is distracted from the symptom and gets worse when given attention. The tremor results from an underlying psychological problem in the affected person.
When to Seek Help
Any elderly person who suddenly develops shakiness should see a doctor immediately. Seniors also need to see a doctor if an existing tremor appears to be worsening. A complete history and physical exam can identify the type of tremor and likely cause. Primary treatment is based on the cause. Directed physical and occupational therapy and aging assistive products can also be helpful as indicated.