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Tremor & Shaking
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 psychogenic tremor.

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) or tremors.

Types Of Tremor

The Type of Tremor is usually classified primarily based on when it occurs:

Rest Tremor:

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.

Action Tremor:

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:

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.

Intention Tremor:

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:

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 Tremor:

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 include:
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

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 treatment.
Seizures
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 general population.

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 abnormal movements.
Partial complex seizures are periods of repetitive activity, the person appears to be awake but doesn't respond to external stimuli.

Tonic-Clonic Seizures

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 seizure.

The 2 Phases of Tonic-Clonic Seizures:
Tonic The person loses consciousness, the muscles stiffen and the person falls down. The muscles remain rigid and stiff for a short time.
Clonic 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.