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Overview of Movement Disorders


Hector A. Gonzalez-Usigli

, MD, HE UMAE Centro Médico Nacional de Occidente

Last full review/revision Sep 2020| Content last modified Sep 2020
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Every body movement, from raising a hand to smiling, involves a complex interaction between the central nervous system (brain and spinal cord), nerves, and muscles. Damage to or malfunction of any of these components may result in a movement disorder.

Different types of movement disorders can develop, depending on the nature and location of the damage or malfunction, as in the following:

The basal ganglia help initiate and smooth out voluntary muscle movements, suppress involuntary movements, and coordinate changes in posture.

The cerebellum coordinates the body’s movements, helps the limbs move smoothly and accurately, and helps maintain balance.

Locating the Basal Ganglia

The basal ganglia are collections of nerve cells located deep within the brain. They include the following:

  • Caudate nucleus (a C-shaped structure that tapers to a thin tail)

  • Putamen

  • Globus pallidus (located next to the putamen)

  • Subthalamic nucleus

  • Substantia nigra

The basal ganglia help smooth out muscle movements and coordinate changes in posture.

Locating the Basal Ganglia


Classifying movement disorders often helps doctors identify the cause.

Movement disorders are commonly classified as those that cause

  • Decreased or slow movement

  • Increased movement

The most common disorder that decreases and/or slows movement is

Disorders that increase movement include

Coordination problems are sometimes classified as disorders that increase movement. They are often caused by malfunction of the cerebellum.

In some disorders, movement is increased and decreased. For example, Parkinson disease causes tremors—increased unintended (involuntary) movements—and slow intended (voluntary) movements.

Disorders that increase movement can be

  • Rhythmic, which are primarily tremors (although tremors are sometimes irregular, as occurs in dystonia)

  • Nonrhythmic, which may involve slow or rapid movements and/or a sustained position

Some rapid, nonrhythmic movements, such as tics Tourette Syndrome and Other Tic Disorders in Children and Adolescents Tics are rapid, purposeless, repetitive but not rhythmic, involuntary movements (muscle or motor tics) or involuntary, abrupt, often repetitive sounds and/or words (vocal tics). They can be... read more , can be temporarily stopped (suppressed). Others, such as hemiballismus, chorea, myoclonus, may be difficult to suppress or impossible to suppress completely.

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