Tremor is most commonly classified by clinical features and cause or origin. Some of the better known forms of tremor, with their symptoms, include the following:

- Cerebellar tremor (also known as intention tremor) is a slow, broad tremor of the extremities that occurs at the end of a purposeful movement, such as trying to press a button or touching a finger to the tip of one’s nose. Cerebellar tremor is caused by lesions in or damage to the cerebellum resulting from stroke, tumor, or disease such as multiple sclerosis or some inherited degenerative disorder. It can also result from chronic alcoholism or overuse of some medicines. In classic cerebellar tremor, a lesion on one side of the brain produces a tremor in that same side of the body that worsens with directed movement. Cerebellar damage can also produce a “wing-beating” type of tremor called rubral or Holmes’ tremor — a combination of rest, action, and postural tremors. The tremor is often most prominent when the affected person is active or is maintaining a particular posture. Cerebellar tremor may be accompanied by other manifestations of ataxia, including dysarthria (speech problems), nystagmus (rapid, involuntary rolling of the eyes), gait problems and postural tremor of the trunk and neck. "Titubation" is tremor of the head and is of cerebellar origin.

- Dystonic tremor occurs in individuals of all ages who are affected by dystonia, a movement disorder in which sustained involuntary muscle contractions cause twisting and repetitive motions and/or painful and abnormal postures or positions. Dystonic tremor may affect any muscle in the body and is seen most often when the patient is in a certain position or moves a certain way. The pattern of dystonic tremor may differ from essential tremor. Dystonic tremors occur irregularly and often can be relieved by complete rest. Touching the affected body part or muscle may reduce tremor severity (a geste antagoniste). The tremor may be the initial sign of dystonia localized to a particular part of the body.

- Essential tremor (sometimes called benign essential tremor) is the most common of the more than 20 types of tremor. Although the tremor may be mild and nonprogressive in some people, in others, the tremor is slowly progressive, starting on one side of the body but affecting both sides within 3 years. The hands are most often affected but the head, voice, tongue, legs, and trunk may also be involved. Head tremor may be seen as a vertical or horizontal motion. Essential tremor may be accompanied by mild gait disturbance. Tremor frequency may decrease as the person ages, but the severity may increase, affecting the person’s ability to perform certain tasks or activities of daily living. Heightened emotion, stress, fever, physical exhaustion, or low blood sugar may trigger tremors or increase their severity. Onset is most common after age 40, although symptoms can appear at any age. It may occur in more than one family member. Children of a parent who has essential tremor have a 50 percent chance of inheriting the condition. Essential tremor is not associated with any known pathology.

- Orthostatic tremor is characterized by fast (>12 Hz) rhythmic muscle contractions that occur in the legs and trunk immediately after standing. Cramps are felt in the thighs and legs and the patient may shake uncontrollably when asked to stand in one spot. No other clinical signs or symptoms are present and the shaking ceases when the patient sits or is lifted off the ground. The high frequency of the tremor often makes the tremor look like rippling of leg muscles while standing. Orthostatic tremor may also occur in patients who have essential tremor, and there might be an overlap between these categories of tremor.

- Parkinsonian tremor is caused by damage to structures within the brain that control movement. This resting tremor, which can occur as an isolated symptom or be seen in other disorders, is often a precursor to Parkinson's disease (more than 25 percent of patients with Parkinson’s disease have an associated action tremor). The tremor, which is classically seen as a "pill-rolling" action of the hands that may also affect the chin, lips, legs, and trunk, can be markedly increased by stress or emotion. Onset is generally after age 60. Movement starts in one limb or on one side of the body and usually progresses to include the other side.

- Physiological tremor occurs in every normal individual and has no clinical significance. It is rarely visible and may be heightened by strong emotion (such as anxiety or fear), physical exhaustion, hypoglycemia, hyperthyroidism, heavy metal poisoning, stimulants, alcohol withdrawal or fever. It can be seen in all voluntary muscle groups and can be detected by extending the arms and placing a piece of paper on top of the hands. Enhanced physiological tremor is a strengthening of physiological tremor to more visible levels. It is generally not caused by a neurological disease but by reaction to certain drugs, alcohol withdrawal, or medical conditions including an overactive thyroid and hypoglycemia. It is usually reversible once the cause is corrected. This tremor classically has a frequency of about 10 Hz

- tremor (also called hysterical tremor) can occur at rest or during postural or kinetic movement. The characteristics of this kind of tremor may vary but generally include sudden onset and remission, increased incidence with stress, change in tremor direction and/or body part affected, and greatly decreased or disappearing tremor activity when the patient is distracted. Many patients with psychogenic tremor have a conversion disorder (see Posttraumatic stress disorder) or another psychiatric disease.

- Rubral tremor is characterized by coarse slow tremor which is present at rest, at posture and with intention. This tremor is associated with conditions which affect the red nucleus in the midbrain, classically unusual strokes.

Tremor can result from other conditions as well

- Alcoholism, excessive alcohol consumption, or alcohol withdrawal can kill certain nerve cells, resulting in a tremor known as asterixis. Conversely, small amounts of alcohol may help to decrease familial and essential tremor, but the mechanism behind it is unknown. Alcohol potentiates GABAergic transmission and might act at the level of the inferior olive.

- Tremor in peripheral neuropathy may occur when the nerves that supply the body’s muscles are traumatized by injury, disease, abnormality in the central nervous system, or as the result of systemic illnesses. Peripheral neuropathy can affect the whole body or certain areas, such as the hands, and may be progressive. Resulting sensory loss may be seen as a tremor or ataxia (inability to coordinate voluntary muscle movement) of the affected limbs and problems with gait and balance. Clinical characteristics may be similar to those seen in patients with essential tremor.

- Tobacco withdrawal symptoms include tremor.

- Most of the symptoms can also occur randomly when panicked.

Holmes tremor is typically characterized by a low frequency tremor (below 4.5 Hz) that has a repeated series of rest and intention tremors. These tremors move slowly and are generally specific to an upper area of the body. They can consist of postural tremors in nearby muscles as well. These tremors involve uncontrollable shaking despite efforts to be still. Holmes tremor is considered a rest-intention posture tremor. These irregular movements occur while muscles are at rest, but worsen during voluntary muscle contractions. Symptoms usually appear delayed one to twenty-four months after the lesion is created.

Tremor can be a symptom associated with disorders in those 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, stroke, traumatic brain injury, chronic kidney disease and a number of neurodegenerative diseases that damage or destroy parts of the brainstem or the cerebellum, Parkinson's disease being the one most often associated with tremor. Other causes include the use of drugs (such as amphetamines, cocaine, caffeine, corticosteroids, SSRIs) or alcohol, mercury poisoning, or the withdrawal of drugs such as alcohol or benzodiazepine. Tremors can also be seen in infants with phenylketonuria (PKU), overactive thyroid or liver failure. Tremors can be an indication of hypoglycemia, along with palpitations, sweating and anxiety.

Tremor can also be caused from lack of sleep, lack of vitamins, or increased stress. Deficiencies of magnesium and thiamine have also been known to cause tremor or shaking, which resolves when the deficiency is corrected. See magnesium in biology. Some forms of tremor are inherited and run in families, while others have no known cause. Tremors can also be caused by some spider bites, e.g. the redback spider of Australia.

Characteristics may include a rhythmic shaking in the hands, arms, head, legs, or trunk; shaky voice; and problems holding things such as a fork or pen. Some tremors may be triggered by or become exacerbated during times of stress or strong emotion, when the individual is physically exhausted, or during certain postures or movements.

Tremor may occur at any age but is most common in middle-age and older persons. It may be occasional, temporary, or occur intermittently. Tremor affects men and women equally.

Myoclonus is defined as a sequence of repeated, often nonrhythmic, brief, shock-like jerks due to sudden involuntary contraction or relaxation of one or more muscles. These movements may be asynchronous, in which several muscles contract variably in time, synchronous, in which muscles contract simultaneously, or spreading, in which several muscles contract sequentially. It is characterized by a sudden, unidirectional movement due to muscle contraction, followed by a relaxation period in which the muscle is no longer contracted. However, when this relaxation phase is decreased, as when muscle contractions become faster, a myoclonic tremor results. Myoclonus can often be associated with seizures, delirium, dementia, and other signs of neurological disease and gray matter damage.

Dystonia is a movement disorder in which involuntarily sustained or intermittent muscle contractions cause twisting or repetitive movements, abnormal postures, or both. Such abnormal postures include foot inversion, wrist ulnar deviation, or lordotic trunk twisting. They can be localized to specific parts of the body or be generalized to many different muscle groups. These postures are often sustained for long periods of time and can be combined in time. Dystonic movements can augment hyperkinetic movements, especially when linked to voluntary movements.

Blepharospasm is a type of dystonia characterized by involuntary contraction of the muscles controlling the eyelids. Symptoms can range from a simple increased frequency of blinking to constant, painful eye closure leading to functional blindness.

Oromandibular dystonia is a type of dystonia marked by forceful contractions of the lower face, which causes the mouth to open or close. Chewing motions and unusual tongue movements may also occur with this type of dystonia.

Laryngeal dystonia or spasmodic dysphonia results from abnormal contraction of muscles in the voice box, resulting in altered voice production. Patients may have a strained-strangled quality to their voice or, in some cases, a whispering or breathy quality.

Cervical dystonia (CD) or spasmodic torticollis is characterized by muscle spasms of the head and neck, which may be painful and cause the neck to twist into unusual positions or postures.

Writer's cramp and musician’s cramp is a task-specific dystonia, meaning that it only occurs when performing certain tasks. Writer’s cramp is a contraction of hand and/or arm muscles that happens only when a patient is writing. It does not occur in other situations, such as when a patient is typing or eating. Musician’s cramp occurs only when a musician plays an instrument, and the type of cramp experienced is specific to the instrument. For example, pianists may experience cramping of their hands when playing, while brass players may have cramping or contractions of their mouth muscles.

Holmes tremor, first identified by Gordon Holmes in 1904, can be described as a wing-beating movement localized in the upper body that is caused by cerebellar damage. Holmes tremor is a combination of rest, action, and postural tremors. Tremor frequency ranges from 2 to 5 Hertz and is aggravated with posture and movement. It may arise from various underlying structural disorders including stroke, tumors, trauma, and other cerebellar lesions. Because Holmes tremor is rare, much of the research is based on individual cases.

The formation of tremors is due to two main factors: the over-excited rhythmic movement of neuronal loops and permanent structural changes from neurodegeneration. Two major neuronal networks, the corticostriatothalamocortical hap and the inferior olivary nucleus (ION) specifically target the development of the tremors. When diagnosing a patient with Holmes tremor, one must look at the neurological signs and symptoms, as well as the possibility that the tremor is caused by medications or other stimulants. In most cases, the patient’s history and a targeted neurological examination is enough to give a diagnosis.

Treatment for Holmes tremor is dependent on the characteristics of the tremor. Because the disease is involved with the dopaminergic system, most treatments involve levodopa. Drugs used to treat other types of tremors are applicable to the treatment of Holmes tremor; however, these drugs have a low success rate.

In mild cases, ET can manifest as the inability to stop the tongue or hands from shaking, the ability to sing only in vibrato, and difficulty doing small precise tasks such as threading a needle. Even simple tasks like cutting in a straight line or using a ruler can range from difficult to impossible, depending on the severity of the condition. In disabling cases, ET can interfere with a person's activities of daily living, including feeding, dressing, and taking care of personal hygiene. Essential tremor generally presents as a rhythmic tremor (4–12 Hz) that occurs only when the affected muscle is exerting effort. Any sort of physical or mental stress will tend to make the tremor worse.

The tremor may also occur in the head (neck), jaw and voice as well as other body regions, with the general pattern being that the tremor begins in the arms and then spreads to these other regions in some people. Women are more likely to develop the head tremor than are men. Other types of tremor may also occur, including postural tremor of the outstretched arms, intention tremor of the arms and rest tremor in the arms. Some people may have unsteadiness and problems with gait and balance.

ET-related tremors do not occur during sleep, but people with ET sometimes complain of an especially coarse tremor upon awakening that becomes noticeably less coarse within the first few minutes of wakefulness. Tremor and disease activity/intensity can worsen in response to fatigue, strong emotions, low blood sugar, cold and heat, caffeine, lithium salts, some antidepressants, and other factors. It is typical for the tremor to worsen in "performance" situations, such as when writing a check for payment at a store or giving a presentation.

Parkinson's disease and Parkinsonism can also occur simultaneously with ET. In those cases the degree of tremor, rigidity, and functional disability does not differ from those people with idiopathic Parkinson's disease. Hand tremor predominates (as it does in Parkinson’s disease), and occurs in nearly all cases, followed by head tremor, voice tremor, neck, face, leg, tongue and trunk tremor. Most other tremors occur in association with hand tremor. Walking difficulties in essential tremor are common. About half of patients have associated dystonia, including cervical dystonia, writer's cramp, spasmodic dysphonia, and cranial dystonia, and 20% of the patients had associated parkinsonism. Olfactory dysfunction (loss of sense of smell) is common in Parkinson’s disease, and has also been reported to occur in patients with essential tremor. A number of patients with essential tremor also exhibit many of the same neuropsychiatric disturbances seen in idiopathic Parkinson's disease.

Essential tremor with tremor onset after the age of 65 is associated with Mild cognitive impairement and dementia.

Initial symptoms of spasmodic torticollis are usually mild. Some feel an invisible tremor of their head for a few months at onset. Then the head may turn, pull or tilt in jerky movements, or sustain a prolonged position involuntarily. Over time, the involuntary spasm of the neck muscles will increase in frequency and strength until it reaches a plateau. Symptoms can also worsen while the patient is walking or during periods of increased stress. Other symptoms include muscle hypertrophy, neck pain, dysarthria and tremor. Studies have shown that over 75% of patients report neck pain, and 33% to 40% experience tremor of the head.

This type of tremor is often referred to as "kinetic tremor".

Essential tremor has been known as "benign essential tremor", but the adjective "benign" has been removed in recognition of the sometimes disabling nature of the disorder.

Though it is often most associated with Parkinson's disease, hypokinesia can be present in a wide variety of other conditions.

Intention tremors are common among individuals with multiple sclerosis (MS). One common symptom of multiple sclerosis is ataxia, a lack of coordinated muscle movement caused by cerebellar lesions characteristic of multiple sclerosis. The disease often destroys physical and cognitive function of individuals.

Intention tremors can be a first sign of multiple sclerosis, since loss or deterioration of motor function and sensitivity are often one of the first symptoms of cerebellar lesions.

Intention tremors have a variety of other recorded causes as well. These include a variety of neurological disorders, such as stroke, alcoholism, alcohol withdrawal, peripheral neuropathy, Wilson's disease, Creutzfeldt–Jakob disease, Guillain–Barré syndrome and fragile X syndrome, as well as brain tumors, low blood sugar, hyperthyroidism, hypoparathyroidism, insulinoma, normal aging, and traumatic brain injury. Holmes tremor, a rubral or midbrain tremor, is another form of tremor that includes intention tremors, among other symptoms. This disease affects the proximal muscles of the head, shoulders, and neck. Tremors of this disease occur at frequencies of 2–4 Hz or more.

Intention tremor is also known to be associated with infections, West Nile virus, rubella, H. influenza, rabies, and varicella. A variety of poisons have been shown to cause intention tremor, including mercury, methyl bromide, and phosphine. In addition, vitamin deficiencies have been linked to intention tremor, especially deficiency in vitamin E. Pharmacological agents such as anti-arrhythmic drugs, anti-epileptic agents, benzodiazepine, cyclosporine, lithium, neuroleptics, and stimulants have been known to cause intention tremor. Some ordinary activities including ingesting too much caffeine, cigarettes, and alcohol, along with stress, anxiety, fear, anger and fatigue

have also been shown to cause intention tremor by negatively affecting the cerebellum, brainstem, or thalamus, as discussed in mechanisms.

Intention tremor, also known as cerebellar tremor, is a dyskinetic disorder characterized by a broad, coarse, and low frequency (below 5 Hz) tremor. The amplitude of an intention tremor increases as an extremity approaches the endpoint of deliberate and visually guided movement (hence the name intention tremor). An intention tremor is usually perpendicular to the direction of movement. When experiencing an intention tremor, one often overshoots or undershoots their target, a condition known as dysmetria. Intention tremor is the result of dysfunction of the cerebellum, particularly on the same side as the tremor in the lateral zone, which controls visually guided movements. Depending on the location of cerebellar damage, these tremors can be either unilateral or bilateral.

A variety of causes have been discovered to date, including damage or degradation of the cerebellum due to neurodegenerative diseases, trauma, tumor, stroke, or toxicity. There is currently no established pharmacological treatment; however, some success has been seen using treatments designed for essential tremors.

The most commonly used scale to rate the severity of spasmodic torticollis is the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS). It has been shown that this rating system has widespread acceptance for use in clinical trials, and has been shown to have “good interobserver reliability.” There are three scales in the TWSTRS: torticollis severity scale, disability scale, and pain scale. These scales are used to represent the severity, the pain, and the general lifestyle of spasmodic torticollis.

Stress causes alterations of cerebral circulation, increasing blood flow in the supramarginal gyrus and angular gyrus of the parietal lobe, the frontal lobe, and the superior temporal gyrus of the left hemisphere. Also, an increase in cardiac activity and change in the tonus of the heart vessels occurs, which is an elementary indication of stress development. In patients with normal stress, an adaptive fight-or-flight response is usually triggered by sympathetic nervous system activation. Hypokinesia patients experience these typical stress symptoms on a regular basis because of damage to the basal ganglia system. Therefore, when a hypokinesia victim is under stress, he or she does not display a typical fight-or-flight response, placing the patient under greater danger from potentially harmful stimuli. Low-impact exercise, elimination of drug and alcohol use, and regular meditation can help to restore normal stress responses in hypokinesia patients.

Asterixis (also called the flapping tremor, or liver flap) is a tremor of the hand when the wrist is extended, sometimes said to resemble a bird flapping its wings. This motor disorder is characterized by an inability to maintain a position, which is demonstrated by jerking movements of the outstretched hands when bent upward at the wrist. The tremor is caused by abnormal function of the diencephalic motor centers in the brain, which regulate the muscles involved in maintaining position. Asterixis is associated with various encephalopathies due especially to faulty metabolism. The term derives from the Greek "a", "not" and "stērixis", "fixed position".

Asterixis is the inability to maintain posture due to a metabolic encephalopathy. This can be elicited on physical exam by having the patient extend their arms and bend their hands back.

With a metabolic encephalopathy, the patient is unable to hold their hands back resulting in a “flapping” motion consistent with asterixis. It can be seen in any metabolic encephalopathy e.g. chronic renal failure, severe congestive heart failure, acute respiratory failure and commonly in decompensated liver failure.

Usually there are brief, arrhythmic interruptions of sustained voluntary muscle contraction causing brief lapses of posture, with a frequency of 3–5 Hz. It is bilateral, but may be asymmetric. Unilateral asterixis may occur with structural brain disease.

- It can be a sign of hepatic encephalopathy, damage to brain cells presumably due to the inability of the liver to metabolize ammonia to urea. The cause is thought to be predominantly related to abnormal ammonia metabolism.

- Asterixis is seen most often in drowsy or stuporous patients with metabolic encephalopathies, especially in decompensated cirrhosis or acute liver failure.

- It is also seen in some patients with kidney failure and azotemia, and in carbon dioxide toxicity.

- It can also be a feature of Wilson's disease.

- Asterixis is also seen in respiratory failure.

- Some drugs are known to cause asterixis, particularly phenytoin (when it is known as phenytoin flap). Other drugs implicated include benzodiazepines, barbiturates, valproate, gabapentin, lithium, ceftazidime, and metoclopramide.

Scanning speech, like other ataxic dysarthrias, is a symptom of lesions in the cerebellum. It is a typical symptom of multiple sclerosis, and it constitutes one of the three symptoms of Charcot's neurologic triad.

Scanning speech may be accompanied by other symptoms of cerebellar damage, such as gait, truncal and limb ataxia, intention tremor, inaccuracies in rapidly repeated movements and sudden, abrupt nausea and vomiting. The handwriting of such patients may also be abnormally large.

Onset of symptoms usually occur in early adulthood and is characterized by intention tremor, progressive ataxia, convulsions, and myoclonic epileptic jerks.

Tremors usually affect one extremity, primarily the upper limb, and eventually involve the entire voluntary motor system. Overall, the lower extremity is usually disturbed less often than the upper extremity.

Additional features of the syndrome include: an unsteady gait, seizures, muscular hypotonia, reduced muscular coordination, asthenia, adiadochokinesia and errors with estimating range, direction, and force of voluntary movements. Mental deterioration can occur, however it is rare.

Blocq's disease was first considered by Paul Blocq (1860–1896), who described this phenomenon as the loss of memory of specialized movements causing the inability to maintain an upright posture, despite normal function of the legs in the bed. The patient is able to stand up, but as soon as the feet are on the ground, the patient cannot hold himself upright nor walk; however when lying down, the subject conserved the integrity of muscular force and the precision of movements of the lower limbs. The motivation of this study came when a fellow student Georges Marinesco (1864) and Paul published a case of parkinsonian tremor (1893) due to a tumor located in the substantia nigra.

In the third paper published by Paul Blocq, he was trying to determine the neurophysiology behind this disease by relating the cerebral cortex (the decision making) and the spinal cord (the decision executer). His hypothesis was that there would exist an inhibitory influence which exerted and influenced the cortical or spinal centers for standing and walking.

Scanning speech, also known as explosive speech, is a type of ataxic dysarthria in which spoken words are broken up into separate syllables, often separated by a noticeable pause, and spoken with varying force. The sentence "Walking is good exercise", for example, might be pronounced as "Walk (pause) ing is good ex (pause) er (pause) cise". Additionally, stress may be placed on unusual syllables.

The name is derived from literary scansion, because the speech pattern separates the syllables in a phrase much like scanning a poem counts the syllables in a line of poetry.

There is no universal agreement about the exact definition of this term. Some sources require only a noticeable pause between syllables, while others require other speech abnormalities, such as the unusual stress pattern on syllables. Some sources consider it a common, but not necessary, feature of ataxic dysarthria; others consider it exactly synonymous with ataxic dysarthria.

Dysmetria () refers to a lack of coordination of movement typified by the undershoot or overshoot of intended position with the hand, arm, leg, or eye. It is a type of ataxia. It is sometimes described as an inability to judge distance or scale.

Hypermetria and hypometria refer, respectively, to overshooting and undershooting the intended position.

Differentiating some kinds of atypical Parkinson: Northwest Parkinson Foundation

Before Parkinson's disease is diagnosed, the differential diagnoses include:

- AIDS can sometimes lead to the symptoms of secondary parkinsonism, due to commonly causing dopaminergic dysfunction. Indeed, parkinsonism can be a presenting feature of HIV infection.

- Corticobasal degeneration

- Creutzfeldt–Jakob disease

- Dementia pugilistica or "boxer's dementia" is a condition that occurs in athletes due to chronic brain trauma.

- Diffuse Lewy body disease

- Drug-induced parkinsonism ("pseudoparkinsonism") due to drugs such as antipsychotics, metoclopramide, sertraline, fluoxetine or the toxin MPTP

- Encephalitis lethargica

- Essential tremor, an illness which has some diagnostic overlap with Parkinson's disease

- Orthostatic tremor

- MDMA addiction and frequent use has been linked to Parkonsonism. Several cases have been reported where individuals are diagnosed with the syndrome after taking MDMA.

- Multiple system atrophy

- Pantothenate kinase-associated neurodegeneration, also known as neurodegeneration with brain iron accumulation or Hallervorden-Spatz syndrome

- Parkinson plus syndrome

- Progressive supranuclear palsy

- Toxicity due to substances such as carbon monoxide, carbon disulfide, manganese, paraquat, mercury, hexane, rotenone, Annonaceae, and toluene (inhalant abuse: "huffing")

- Vascular parkinsonism, associated with underlying cerebrovascular disease

- Wilson's disease is a genetic disorder in which an abnormal accumulation of copper occurs. The excess copper can lead to the formation of a copper-dopamine complex, which leads to the oxidation of dopamine to aminochrome. The most common manifestations include bradykinesia, cogwheel rigidity and a lack of balance.

- Paraneoplastic syndrome: neurological symptoms caused by antibodies associated with cancers

- Genetic

- Rapid onset dystonia parkinsonism

- Parkin mutation

- X-linked dystonia parkinsonism

- Autosomal recessive juvenile parkinsonism

RHS type 1 is caused by the impairment of a regulatory mechanism between cerebellar and brainstem nuclei and has been associated with a wide range of diseases, including Lafora disease, dentatorubropallidoluysian atrophy, and celiac disease.

The actual cause of dysmetria is thought to be caused by lesions in the cerebellum or by lesions in the proprioceptive nerves that lead to the cerebellum that coordinate visual, spatial and other sensory information with motor control. Damage to the proprioceptive nerves does not allow the cerebellum to accurately judge where the hand, arm, leg, or eye should move. These lesions are often caused by strokes, multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), or tumors.

According to the research article cited above, motor control is a learning process that utilizes APPGs. Disruption of APPGs is possibly the cause of ataxia and dysmetria and upon identification of the motor primitives, clinicians may be able to isolate the specific areas responsible for the cerebellar problems.

There are two types of cerebellar disorders that produce dysmetria, specifically midline cerebellar syndromes and hemispheric cerebellar syndromes. Midline cerebellar syndromes can cause ocular dysmetria, which is a condition in which the pupils of the eye overshoot. Ocular dysmetria makes it difficult to focus vision onto one object. Hemispheric cerebellar syndromes cause dysmetria in the typical motor sense that many think of when hearing the term dysmetria.

A common motor syndrome that causes dysmetria is cerebellar motor syndrome, which also marked by impairments in gait (also known as ataxia), disordered eye movements, tremor, difficulty swallowing and poor articulation. As stated above, cerebellar cognitive affective syndrome (CCAS) also causes dysmetria.

The doctor will review the person's medical history and perform a complete physical and neurological examination that will include an evaluation of the gait. The doctor may ask the patient to walk in a corridor or climb stairs to observe specific features including:

1. Stance, posture, and base (wide or narrow).

2. Gait initiation (including start hesitation or freezing).

3. Walking speed, stride length, step height, foot clearance.

4. Continuity, symmetry, trunk sway, path deviation, arm swing.

5. Involuntary movements.

6. Ability to turn.

7. Ability to rise from a chair (without using the arms).

8. Chair Testing: Each patient was asked to walk 20–30 feet forward and backward toward the examiner. Patients were then asked to sit in a swivel chair with wheels and to propel the chair forward and backward.