coordination caused by damage and/or degeneration
of the cerebellum or connections to it. The
cerebellum is an area in the back, bottom part of the
brain that plays an important role in movement and
Areas connecting to the cerebellum that can cause
acute cerebellar ataxia are the pons, cerebellar
peduncles, red nucleus, and cerebellar peduncles.
The pons is a part of the brainstem that is very important for sleep and arousal. The
brainstem is an area in the lower part of the brain that connects it with the spinal cord.
The cerebellar peduncles are bundles of nerve fibers that connect the brainstem with the
peduncles. The red nucleus is a large, well-defined, reddish-gray, elongated mass of cells
in the midbrain that receive massive amounts of input from the cerebellum. The midbrain
is the top part of the brainstem.
WHAT CAUSES ACUTE CEREBELLAR ATAXIA?
Acute cerebellar ataxia is caused by a disruption in the transmission of nerve signals to
the cerebellum, which affects coordination and muscle reactions. This is often caused by
an infectious viral disease but any other problem that leads to inflammation in the
cerebellum can cause it. Examples of illness that can cause acute cerebellar ataxia are
the chicken pox and a virus known as the Coxsackie virus.
They cause infections by acting as parasites on the outside of cells. A parasite is an organism that lives
in or on another organism to obtain nourishment. Disorders of the blood vessels that supply blood to the
cerebellum can also cause acute cerebellar ataxia.
WHAT ARE SIGNS OF ACUTE CEREBELLAR ATAXIA?
Acute cerebellar ataxia is the most important sign of damage to the cerebellum. Acute cerebellar ataxia
can affect movements of the trunk or limbs (arms or legs). The trunk includes all the parts of the body,
except the head, arms, and legs.
Common signs of acute cerebellar ataxia include sudden writhing movements in the limbs, hypotonia,
incoordination, and action/intention tremors. Hypotonia is abnormally decreased muscle tone (tension).
This can present as poor maintenance of posture, decreased resistance to slight pressure exerted on
the limbs, and delayed motor responses. Incoordination can present as delays in initiating responses in
limbs, errors in the force or range of movement, and errors in the rate and regularity of movements. For
example, when the person tries to reach for something, he or she may miss the target by a significant
There may be an inability to walk without support. Incoordination can cause an impaired ability to perform
rapid, alternating movements - a problem known as dysdiadochokinesia. Action tremors (also known as
intention tremors) are shaking movements that become worse when performing voluntary movements. In
acute cerebellar ataxia, the signs discussed above are not caused by weakness or a loss of the sense
If the cerebellar vermis is involved, an unstable stance, broad-based unsteady walking, and nystagmus
(rhythmic involuntary jerking or swinging movements of the eyes) can also result. The cerebellar vermis
is a narrow, worm shaped structure in between both sides of the cerebellum. The trunk is most likely to
be affected if the cerebellar vermis is involved whereas the limbs are more likely to be affected if the
main part of the cerebellum is involved (known as the cerebellar hemispheres). When the child is sitting,
the trunk of the body may move back and forth and/or from side to side and then return to the vertical
position in a jerky type of motion. When the trunk of the body is involved, this is often called truncal
ataxia (also known as axial ataxia). Dysarthria may also occur in truncal ataxia. Dysarthria is a difficulty
in speech articulation that results from an impaired ability to control the muscles involved in speech.
The most severe disturbances in acute cerebellar ataxia are caused by damage to the superior (top)
cerebellar peduncles and the red nucleus. See the first section for a description of the cerebellar
peduncles and red nuclei.
AT WHAT AGE DOES ACUTE CEREBELLAR ATAXIA OCCUR?
Acute cerebellar ataxia can occur at any age, from childhood to adulthood. When the condition occurs in
childhood, it usually occurs before age 3, several weeks after a viral illness.
HOW IS ACUTE CEREBELLAR ATAXIA DIAGNOSED?
The first step towards diagnosing acute cerebellar ataxia is for the doctor to rule out other causes of the
presenting movement disorder by obtaining a thorough medical history and determining if there have
been any recent illnesses. Some additional tests may include computerized axial tomography (CT) or
causing an abnormality. X-rays may also be requested. CT is an advanced imaging technique that uses
x-rays and computer technology to produce more clear and detailed pictures than a traditional x-ray. MRI
scans produce extremely detailed pictures of the inside of the body by using very powerful magnets and
Another test the doctor may do is a lumbar puncture (also known as a spinal tap) to look for increased
levels of protein in the cerebrospinal fluid. A lumbar puncture is a procedure in which a needle is inserted
into a space inside the spinal canal for the purpose of removing some of the cerebrospinal fluid. The
spinal canal is the space between the spinal cord and the bony structure that surrounds it.
IS THERE ANY TREATMENT FOR ACUTE CEREBELLAR ATAXIA?
There is no specific treatment for acute cerebellar ataxia.
WHAT IS THE PROGNOSIS FOR ACUTE CEREBELLAR ATAXIA?
Full recovery from acute cerebellar ataxia can be expected within a period of weeks to a few months.
However, there are occasional cases where the child will be left with a permanent movement disorder or
WHAT COMPLICATIONS CAN THERE BE FROM ACUTE CEREBELLAR ATAXIA?
Rarely, movement or behavioral disorders can persist in acute cerebellar ataxia.
WHAT ELSE IS ACUTE CEREBELLAR ATAXIA KNOWN AS?
Acute cerebellar ataxia is also known as cerebellitis and acute cerebellar ataxia of childhood.
WHAT IS THE ORIGIN OF THE TERM, ACUTE CEREBELLAR ATAXIA?
Acute cerebellar ataxia comes from the Latin word "acutus" meaning "sharp," the Latin word "cerebellum"
meaning "little brain," the word “a” meaning “no,” and the word “taxis” meaning “order.” Put the words
together and you get “sharp no order little brain.”