Internal tremors are shaking sensations felt inside the body. They occur without visible movement, which external tremors produce.
A person may experience internal tremors in the trunk, arms, legs, or internal organs.
In this article, we look at the causes and treatment of internal tremors.
Internal tremors can occur in the trunk or the limbs.
The causes of internal tremors are not well understood, and current research is limited. However, doctors tend to believe that these tremors stem from the same neurological causes of external tremors.
Authors of a 2016 study have suggested that internal tremors are early, unusual symptoms of movement disorders, such as PD. Other researchers have proposed that anyone can experience internal tremors, but they are more pronounced in people with PD, MS, and ET.
Below, find more information about PD, MS, and ET, the three most common causes of internal tremors.
PD is a neurological disease that results from the loss of dopamine-producing brain cells. It usually occurs in people over 60 years old.
People with PD may experience some of the following symptoms:
- slowness of movement
- external tremors, including visible trembling in the hands, limbs, face, and jaw
- internal tremors
- stiffness of the arms, legs, and trunk
- poor coordination and balance
These symptoms may progress quickly or slowly, and they can make daily activities difficult. Tremors are not always the most evident symptom of PD, though many people with the condition have tremors.
Initially, a person may only experience a tremor in one limb. As the condition progresses, the tremor can spread to both sides of the body. Strong emotions and stress can make tremors worse.
Treatments for PD
There is no cure for PD. It is a chronic condition that progresses over time. However, there are several treatment options.
A doctor may prescribe a combination of levodopa and carbidopa to replenish the brain's dopamine supply. This can help to treat advanced PD.
Other drug-related options include bromocriptine, pramipexole, and ropinirole.
A doctor may recommend surgery for people who do not respond to medication. The primary type is called deep brain stimulation (DBS).
During the procedure, a surgeon implants electrodes in a person's brain. These stimulate targeted areas to alleviate some symptoms of PD. DBS can also reduce the need for certain drugs, and this may especially benefit people experiencing unpleasant side effects.
Multiple sclerosis (MS)
Damage to the nerves characterizes multiple sclerosis.
MS is a chronic condition that affects the central nervous system.
Many experts believe that in a person with MS, the immune system attacks and damages the body's nerves.
This can affect many parts of the body, and it can have a significant impact on a person's quality of life.
Symptoms of MS usually develop between the ages of 20 and 40. They can include:
- blurred or double vision
- color blindness
- blindness in one eye
- muscle weakness
- poor coordination and balance
- a sensation of numbness or pins and needles
- speech difficulties
- internal and external tremors
Around half of the people with MS also experience difficulty with:
A person may also experience tremor.
Treatment of MS
There is currently no cure for MS, and its severity varies from person to person.
Disease-modifying therapies (DMTs)
In the past, doctors considered MS untreatable, but new drugs and treatment options are changing the outlook.
Current guidelines from the American Academy of Neurology (AAN) advise doctors to start prescribing a type of medication known as disease-modifying therapy (DMT) as soon as possible after a diagnosis.
With early use, these drugs appear to reduce the numbers of flares that a person experiences in relapsing-remitting MS (RRMS), and they may slow the progression of the disease.
- injectable interferon beta-1a and 1-b, such as Avonex and Extavia
- injectable glatiramer acetate, for example, Copaxone and Glatopa
- oral medications, such as siponimod (Mayzent) and fingolimod (Gilenya)
- infusions, including alemtuzumab (Lemtrada) and ocrelizumab (Ocrevus)
Mitoxantrone is an older DMT that can have severe adverse effects. A doctor will only prescribe it if a person has severe symptoms and if the possible benefits outweigh the risks for the individual.
Anyone who has been using mitoxantrone for some time should ask their doctor about newer drugs that may be safer and more effective.
Flares and symptoms
A person will take a DMT regularly, whether they are experiencing a relapse or not.
When flares occur, a doctor may prescribe:
- steroid injections to reduce inflammation and help manage severe symptoms
- specific medications to help with specific symptoms, such as weakness and muscle spasms
A doctor may prescribe muscle relaxers or tranquilizers for people with sustained muscle stiffness and spasticity.
Treatment for tremor
Drugs to help relieve tremor include:
- isoniazid, for example, Laniazid or Nydrazid
- clonazepam, for instance, Klonopin, Rivotril or Syn-Clonazepam
Exercise, occupational therapy, and physical therapy can also help. A doctor can advise on an exercise plan to suit an individual's needs.
They may also advise on assistive devices that may help, such as a walking cane.
The symptoms and progress of MS vary widely between individuals. Each person will make a treatment plan with their doctor to suit their needs.
ET is the most common type of abnormal tremor.
The condition is sometimes associated with mild degeneration of some of the cerebellum. This is the part of the brain that receives information needed to regulate the quality of a person's movements.
The cerebellum receives this information from other parts of the brain, the spinal cord, and the body's sensory systems.
People with ET may experience unintentional, rhythmic movements, most commonly a hand tremor. The tremor may also affect the head, tongue, limbs, trunk, and the ability to speak.
Symptoms can develop at any age, but they usually become noticeable in people over the age of 40. Triggers of ET can include:
- stress and anxiety
- heightened emotions
- feeling physically tired
- low blood sugar
The tremor usually appears on both sides of the body, but it is often more noticeable in the dominant hand.
Treatment of ET
While there is no cure for ET, medications can help to reduce symptoms. These can include beta-blockers or anticonvulsants.
Some people with ET find physical, occupational therapy, and DBS helpful. Treatment plans often involve reducing triggers, such as caffeine and other stimulants.
A doctor will prescribe treatment for internal tremors according to the cause.
There are currently no diagnostic tests for internal tremors. However, anyone experiencing a tingling sensation, shaking, muscle weakness, or poor coordination should speak with a doctor.
For people with internal tremors, doctors may recommend treatments similar to those for other movement or neurological disorders.
However, the severity of internal tremors can vary from person to person, and some may find that no treatment is necessary.
When PD, MS, or ET is responsible for internal tremors, doctors will aim to treat the underlying condition.
Treatments for internal tremors can include:
- reducing anxiety and stress
- avoiding dietary stimulants, such as caffeine
- avoiding intense exercise and heat
For some people, doctors may recommend DBS or medications similar to those for PD, MS, and ET.
While internal tremors are not harmful, they can be disconcerting and may interfere with daily activities.
PD, MS, and ET are the most common causes of internal tremors. For many people, treatments for tremors will be similar to treatments for these neurological conditions.
Avoiding known triggers, such as stress or stimulants, can also help.