MSD Manual

Please confirm that you are a health care professional

honeypot link

Overview of Movement and Cerebellar Disorders


Hector A. Gonzalez-Usigli

, MD, HE UMAE Centro Médico Nacional de Occidente

Last full review/revision May 2020
Click here for Patient Education
Topic Resources

Voluntary movement requires complex interaction of the corticospinal (pyramidal) tracts, basal ganglia, and cerebellum (the center for motor coordination) to ensure smooth, purposeful movement without extraneous muscular contractions.

The pyramidal tracts pass through the medullary pyramids to connect the cerebral cortex to lower motor centers of the brain stem and spinal cord.

The basal ganglia (caudate nucleus, putamen, globus pallidus, subthalamic nucleus, and substantia nigra) form the extrapyramidal system. They are located deep in the forebrain and rostral midbrain. The basal ganglia direct their output mainly through the thalamus to the cerebral cortex (see figure Basal ganglia Basal ganglia Parkinson disease is a slowly progressive, degenerative disorder characterized by resting tremor, stiffness (rigidity), slow and decreased movement (bradykinesia), and eventually gait and/or... read more ).

Most neural lesions that cause movement disorders occur in the extrapyramidal system; thus, movement disorders are sometimes called extrapyramidal disorders.

Basal ganglia

Basal ganglia

Classification of Movement and Cerebellar Disorders

Movement disorders are commonly classified as those with

  • Decreased or slow movement (hypokinetic disorders)

  • Increased movement (hyperkinetic disorders)

The classic and most common hypokinetic disorder is

Hyperkinetic disorders refer to

However, this classification does not account for overlap between categories (eg, tremors that occur in Parkinson disease).

Cerebellar disorders are sometimes considered hyperkinetic disorders.

Hyperkinetic disorders

  • Rhythmic

  • Nonrhythmic

Rhythmic disorders are primarily tremors—regular alternating or oscillatory movements, which can occur mainly at rest, while maintaining a position, and/or during attempted movement. However, in some cases, a tremor, though rhythmic, is irregular, as occurs when tremor is associated with dystonic disorders.

Nonrhythmic hyperkinetic disorders can be

  • Slow (eg, athetosis)

  • Sustained (eg, dystonias)

  • Rapid (eg, myoclonus, chorea, tics, hemiballismus)

Rapid nonrhythmic hyperkinetic disorders may be

  • Suppressible (eg, tics)

  • Nonsuppressible (eg, hemiballismus, chorea, myoclonus)

Classification of common hyperkinetic disorders

Classification of common hyperkinetic disorders
Click here for Patient Education
NOTE: This is the Professional Version. CONSUMERS: Click here for the Consumer Version
Professionals also read
Test your knowledge
Cauda Equina Syndrome
Cauda equina syndrome occurs when nerve roots at the caudal end of the spinal cord are compressed or damaged. Of the several causes of this disorder, which of the following is most common?
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Become a pro at using our website 

Also of Interest

Become a pro at using our website