THE CHESTNUT FOUNDATION
WHAT ARE THE BASAL GANGLIA?

The basal ganglia are a group of nuclei in the brains of vertebrates, situated at the base of the forebrain and strongly connected with the
cerebral cortex, thalamus, and other areas. The basal ganglia are associated with a variety of functions, including motor control and learning.

They are functionally important, at a minimum, for controlling voluntary movements and establishing postures. When they are altered - say
in disorders like Huntington disease or Wilson disease - the person has unwanted movements, such as involuntary jerking movements of an
arm or leg, spasmodic movement of facial muscles.
CONDITIONS and DISORDERS ASSOCIATED WITH THE BASAL GANGLIA

The basal ganglia play a central role in a number of neurological conditions, including several movement disorders. Basal ganglia dysfunction
is a problem with these deep brain structures that help start and control movement. The most notable movement disorders affected by the
basal ganglia are Parkinson disease, which involves degeneration of the dopamine-producing cells in the substantia nigra, and Huntington’s
disease, which primarily involves damage to the striatum. Basal ganglia dysfunction is also implicated in some other disorders of behavior
control such as Tourette’s syndrome and obsessive-compulsive disorder, although the neural mechanisms underlying these are not well
understood.

Some, but not all, disorders which are believed to involve the basal ganglia are:
Attention-deficit hyperactivity disorder (ADHD)
Athymhormic syndrome (PAP syndrome)
Cerebral palsy: basal ganglia damage during second and third trimester of pregnancy
Dystonia
Fahr's disease
Foreign accent syndrome (FAS)
Huntington's disease
Lesch-Nyhan syndrome
Obsessive-compulsive disorder
Other anxiety disorders
Parkinson's disease
PANDAS
Sydenham's chore
Tourette's disorder
Tardive dyskinesia, caused by chronic antipsychotic treatment
Stuttering
Spasmodic dysphonia
Wilson disease
Blepharospasm