Tremor is an unintentional, rhythmic muscle movement involving to-and-fro
movements (oscillations) of one or more parts of the body. It's the most
common of all involuntary movements and can affect the hands, arms, head,
face, voice, trunk, and legs. Most tremors occur in the hands. In some
people, tremor is a symptom of a neurological disorder or appears as a side
effect of certain drugs. The most common form of tremor, however, occurs in
otherwise largely healthy people. Although tremor is not life-threatening,
it can be embarrassing to some people and make it harder to perform daily tasks.|
Tremor is generally caused by problems in parts of the brain that control muscles
throughout the body or in particular areas, such as the hands. Neurological
disorders or conditions that can produce tremor include multiple sclerosis (MS),
stroke, traumatic brain injury (TBI), and neurodegenerative diseases that damage or
destroy parts of the brainstem or the cerebellum. Other causes include the use
of some drugs, alcohol abuse or withdrawal, mercury poisoning, overactive thyroid,
or liver failure. Some forms of tremor are inherited and run in families, while
others have no known cause.
Clinically tremor can be classified into physiologic tremor, enhanced physiologic
tremor, essential tremor (ET) syndromes (including classical ET, primary orthostatic
tremor, and task- and position-specific tremor), dystonic tremor, parkinsonian
tremor, cerebellar tremor (often associated with MS), Holmes' tremor (rubral
tremor), palatal tremor, neuropathic tremor, toxic or drug-induced tremor, and
For the majority of those that experience a tremor, it's simply annoying and
can even be embarrassing. However, a small percent of people may experience
tremor so severe that it becomes impossible to perform necessary tasks like
eating, drinking or getting dressed. Many people with MS experience some form
of tremor which can occur in a single or multiple parts of the body.
Tremor occurs because there are damaged areas along the nerve pathways that
control coordination of movement. Most tremor associated with MS occur in the
lower arms and hands. Those with MS tremor may also have difficulty with speaking
or swallowing because these activities also require coordination of movement. It's
estimated that up to 50% report extremity ataxia (shaky movements or unsteady gait)
Types Of Tremor
The Type of Tremor is usually classified primarily based on when it occurs:
This is defined as a tremor which occurs in a body part in which the
muscles are not being voluntarily contracted and which is completely
supported against gravity , such as when the hands are lying on the
lap or hanging next to the body while standing or walking. Normally
when the limb is moved, the rest tremor will attenuate or disappear.
Like all tremors, it will be aggravated by stress or anxiety. Rest
tremor is quite separate from other tremors. It's more common in
Parkinson's disease than in MS.
This is any tremor occurring when there is voluntary activation or
contraction of muscles. For example, holding an arm outstretched arm
requires muscle activity to hold the limb against gravity. Action tremor
may or may not change in severity as a target is reached; they can occur
at very different frequencies, but the frequency is always < 13 Hz.
Action tremors include kinetic, intention, and postural tremors.
Kinetic tremor is a subclass of action tremors. This is the tremor which
occurs during movement of a body part (it could equally be called a
movement tremor). Simple kinetic tremor can be brought out by the
clinician by asking the subject to carry out simple rotary movements of
the forearm or flexion and extension movements of the wrist. Those with
postural tremors will often be shown to have tremor during movement.
Complex kinetic tremor is normally referred to as "intention tremor" and
is a subclass of action tremors. It manifests when the affected person is
either making a "purposeful movement" or when they are aiming for a target.
This means there is no shaking at rest. The tremor develops as the person
attempts to reach or grasp something or move a hand or foot to a precise
spot. This is the most common and generally the most disabling form of
tremor that occurs in people with MS. Hand intention tremors are usually
the result of damage to the cerebellum.
Postural tremor is a subclass of action tremors. This is the tremor
which is present while voluntarily maintaining a position against gravity,
like an outstretched arm. Postural tremors require voluntary or purposive
contraction of muscles. A person who has a postural tremor will shake while
sitting or standing, but not while lying down. The most common examples
would be exaggerated physiological tremor and essential tremors. They may
also become exaggerated in specific postures.
Task Specific Kinetic Tremor:
These are tremors which appear only, or become very exacerbated with specific
tasks or activities the individual is asked to carry out. They are sometimes
called occupational tremors and the best example of this is "primary writing
tremor". This is a condition in which tremor is largely or only seen during
the act of writing or acts which mimic writing.
Nystagmus is tremor that produces jumpy eye movements.
Tremors can also be classified by what causes them. Examples include:
Physiologic (the normal tremors that everyone has to some degree)
Essential (a common disorder that rarely causes any other symptoms)
Cerebellar (caused by damage to part of the brain called the cerebellum)
Secondary (caused by a disorder or drug)
Tremor can be described based on frequency of oscillations (rapid or slow)
and amplitude of movement (fine or coarse). Complex tremors can have components
of more than one type of tremor. Other important characteristics of tremors
How fast the shaking is (frequency): Slow to fast
How wide the movement is (amplitude): Fine to coarse
How often the tremor occurs: Intermittent to constant
How severe it is
How rapidly it appears: Sudden to gradual
Tremors are one of the most difficult symptoms of MS to treat and so far there
have been no consistently effective drugs to treat tremors. Varying degrees of
success have been reported with drugs such as the anti-tuberculosis agent,
isoniazid (INH); the antihistamines Atarax and Vistaril; the beta-blocker
Inderal; the anticonvulsive Mysoline; a diuretic Diamox; and anti-anxiety drugs
Buspar and Klonopin.
Those with MS who have severe tremors affecting movement may be helped by
surgery known as deep brain stimulation. This treatment is only considered
after other options have failed. Severe and disabling tremor that occurs with
the slightest movement of the limbs may be helped by an implanted device that
stimulates an area of the brain. This type of surgery is performed by a
neurological surgeon to implant the device.
If medications or surgery are not involved, then the remaining options are to
let the shaking begin, tighten the affected muscles to steady it, to "overpower
the tremor" by adding extra weight to a limb (ankle or wrist), or move the rest
of the body to "mask" the specific area.
Those who allow their tremors to remain obvious, which is perfectly fine to do,
may find that they could be looked upon or treated differently by others.
If a fist is kept to steady an arm or hand for instance, the tremors may not be
quite as obvious; however, the area around the arm may become tired quickly.
Now if it's decided to move along with the tremor, it may look as if you can't
sit still but there is nothing wrong with that. No matter what you may choose
for yourself is exactly that - your choice. That choice needs to be what is
most comfortable for you physically and mentally.
Myoclonus describes a symptom that refers to sudden, involuntary jerking of a
muscle or group of muscles. Myoclonic twitches or jerks usually are caused by
sudden muscle contractions, called positive myoclonus, or by muscle relaxation,
called negative myoclonus. Myoclonic jerks may occur alone or in sequence, in a
pattern or without pattern. They may occur infrequently or many times each
minute. Myoclonus sometimes occurs in response to an external event or when a
person attempts to make a movement. The twitching can't be controlled by the
person experiencing it.
In its simplest form, myoclonus consists of a muscle twitch followed by
relaxation. A hiccup is an example of this type of myoclonus. Other familiar
examples of myoclonus are the jerks or "sleep starts" that some people
experience while drifting off to sleep. These simple forms of myoclonus occur in
normal, healthy persons and cause no difficulties. When more widespread,
myoclonus may involve persistent, shock-like contractions in a group of muscles.
In some cases, myoclonus begins in one region of the body and spreads to muscles
in other areas. More severe cases of myoclonus can distort movement and severely
limit a person's ability to eat, talk, or walk. These types of myoclonus may
indicate an underlying disorder in the brain or nerves.
Myoclonus can occur by itself, but most often it is one of several symptoms
associated with a wide variety of nervous system disorders such as MS,
Parkinson's disease, Alzheimer's disease, or Creutzfeldt-Jakob disease (CJD). In
almost all instances in which myoclonus is caused by a central nervous system
(CNS) disease and it's preceded by other symptoms; for instance, in CJD it's
generally a late-stage clinical feature that appears after the patient has
already started to exhibit gross neurological deficits.
Treatment of myoclonus focuses on medications that may help reduce symptoms.
The drug of first choice is clonazepam, a type of tranquilizer. Many of
the drugs used for myoclonus, such as barbiturates, phenytoin, and primidone,
are also used to treat epilepsy. Sodium valproate is an alternative
therapy for myoclonus and can be used either alone or in combination with
clonazepam. Myoclonus may require the use of multiple drugs for effective
Seizures, which are the result of abnormal or excessive electrical discharges in
an injured or scarred area of the brain (usually in the cerebral cortex), are
fairly uncommon among those with MS. The incidence of seizures has been
estimated at 2 to 5%, compared to the estimated 1% incidence of seizures in the
Seizures in those with MS tend to be mild and cause no permanent damage. The
vast majority of people with MS can control or eliminate their seizures with
anti-seizure medication, and many people don't have to take any medications at
all. There are, however, a small percentage that may have seizures that don't
respond to medication at all.
|Several Forms of Seizures:
Several Forms of Seizures
Generalized tonic-clonic seizures are brief episodes of unconsciousness
with uncontrollable jerking movement of extremities.
Generalized absence seizures are momentary lapses of consciousness without
Partial complex seizures are periods of repetitive activity, the person
appears to be awake but doesn't respond to external stimuli.
Tonic-clonic seizures are sometimes referred to as "grand mal" seizures,
although this term is becoming less commonly used. Although they look very
dramatic and scary to observers, people experiencing tonic-clonic seizures don’t
really feel them as they are happening. They may experience different warning
sensations, known as auras. These can include a sudden feeling of anxiety, the
sense that everything is fuzzy or dreamlike or a strange smell or taste. The
person will typically feel very tired and washed-out after experiencing a
|The 2 Phases of Tonic-Clonic Seizures:
The person loses consciousness, the muscles stiffen and the person
falls down. The muscles remain rigid and stiff for a short time.
The stage when convulsions (rhythmic flexing and relaxing of the
muscles) occur, usually lasting less than two minutes.
Simple or Complex Partial Seizures
Simple Partial Seizures - While these seizures
don't cause the person to lose consciousness, they do make things seem
"different" or "off." For example, people may experience strange emotions,
or the way things look, sound, feel, smell or taste may be altered. In some
cases, the person’s muscles may stiffen up or start twitching, usually just
in one side of the face or body.
Complex Partial Seizures - These seizures also
don't cause a loss of consciousness, meaning people don't "pass out" if they
have one. However, this type of seizure does result in a loss of awareness
for a short amount of time. People won't remember what happened during this
time, nor will they be able to respond to anyone. People having complex
partial seizures often stare or move in repetitive ways like rubbing their
hands, swallowing or making sounds.