What Is Ataxia?
What Is Ataxia?Ataxia refers to a group of neurological disorders that affect a person’s balance and speech. Ataxia can be inherited, acquired by illness or trauma to the brain, or caused by brain damage of an unknown cause. Additionally, ataxia can develop from vitamin deficiency, tumors, multiple sclerosis, alcoholism, or metabolic disorders.
Ataxia is usually caused by damage to the cerebellum, the part of the brain that controls muscle movement and balance. Patients with ataxia have slurred speech, poor hand coordination, and difficulty with balance and walking. They may also experience problems with speech and swallowing. This progressive illness can significantly affect a person’s quality of life and the lives of those close to them.
Ataxia treatment is determined by the cause of the condition. Walkers, canes, or other adaptive devices can be used to help a person remain somewhat self-sufficient. Physical, occupational, and speech therapy, along with regular exercise, can help a person maintain physical strength.
Apraxia vs. Ataxia
Apraxia and ataxia sound similar and may sometimes be confused for one another. However, these are two distinct neurological conditions.
Apraxia affects the brain, making it difficult to process information. This makes one unable to move or carry out tasks even though the muscles are functioning properly. Someone with apraxia may understand a request but be unable to follow through with the action. Apraxia can be caused by brain damage from a tumor, neurodegenerative disease, dementia, a stroke, hydrocephalus, or a traumatic brain injury.
The four different types of apraxia include:
- Ideomotor apraxia – The inability to plan or complete a voluntary action
- Conceptual apraxia – The inability to figure out the steps of a tasks
- Speech apraxia – The inability to say the right words, or speaking in a jumbled manner (in a person who could previously speak correctly)
- Constructional apraxia – The inability to build, assemble, or draw an object
Ataxia, on the other hand, is the loss of control and coordination of muscle movements. In cases of ataxia, a person has physically lost the ability to perform or control muscle movements because of a defect in the neurological pathways of the cerebellum.
Types of Ataxia
TypesThere are different types of ataxia, which are divided into three categories:
- Cerebellar – Cerebellar ataxia affects the cerebellum — the area of the brain that controls muscular movement. This is the most common form of ataxia.
- Sensory – Sensory ataxia is caused by nerve damage in the spinal cord or peripheral nervous system. People can lose sensation in their hands, legs, and feet. They may find it difficult to touch their nose with their eyes closed, feel vibrations, and have trouble walking in dim light.
- Vestibular – Vestibular ataxia affects the inner ear; this disrupts the brain’s ability to sense balance and coordination.
Types of ataxia include:
Hereditary ataxias
Hereditary ataxias are caused by a defect or abnormality within a gene that is inherited from a parent and is present from birth. Inherited ataxias are broken down further according to dominant and recessive genes.
- Autosomal dominant ataxias are caused by genes that are passed from one generation to the next due to a single copy of an abnormal gene being passed down from parent to child. Each child of a parent possessing an autosomal dominant ataxia gene has a 50% chance of inheriting the ataxia gene. If the gene is passed along to the child from one parent, the child will get the disease. Biological sex does not affect a person’s chance of acquiring the condition.
Types of autosomal dominant ataxias include:- Spinocerebellar ataxia is part of a group of inherited central nervous system diseases. Genetic abnormalities eventually lead to the deterioration of the cerebellum, the area of the brain that controls coordination.
- Episodic ataxia involves episodes of ataxia that can last from minutes to several hours. It is usually brought on by stress. This type of ataxia may respond to medication treatment.
- Autosomal recessive ataxia occurs when a recessive gene is passed along in a single generation. Two copies of the recessive gene must be passed from each parent (the carrier) to the child. Each parent must be a carrier of the ataxia gene, in addition to passing the defective gene along to the child for the disease to present itself. Each child of the carrier parents has a 25 percent chance of developing the disease, a 50 percent chance of inheriting one of the ataxia genes (becoming a carrier themselves), and a 25 percent chance of inheriting no ataxia genes.
If a single recessive ataxia gene is inherited, it can be passed along in families for generations without being expressed.
Types of autosomal recessive ataxia include:- Friedreich’s ataxia was the first form of ataxia to be distinguished as a hereditary ataxia. Friedreich’s ataxia is caused by a single gene called the Frataxin (FXN) gene. Two copies of each gene are inherited: one from the mother and one from the father. A person who has one copy of the defective FXN gene will not develop neurological symptoms but is a carrier of the gene.
- Ataxia telangiectasia is a rare form of childhood ataxia that begins around the time a child learns to walk. Small, red, spider veins appear in the corner of the child’s eyes, and the areas of their ears and cheeks that are exposed to the sun. Hence, the name “ataxia telangiectasia.” Though the child may begin to walk at the normal age, they waver back and forth when walking, sitting, or standing.
- Mitochondrial ataxia can be inherited from mother to child through damaged mitochondria in the mother’s eggs.
- X-linked ataxias (XLCA) are a group of conditions characterized by cerebellar dysgenesis — a neurological condition in which the cerebellum, the part of the brain that coordinates movement — is not completely developed or is smaller than usual.
Acquired ataxias
This type of ataxia is not inherited. It happens when a person develops a condition during their life that leads to ataxia symptoms. Known factors that affect acquired ataxias are vitamin deficiencies, infections, exposure to toxins, autoimmune diseases, and drug and alcohol use.
Idiopathic late onset cerebellar ataxia patients have no known inheritance from a family member. Doctors usually rule out other causes of ataxia before they will diagnose a person with idiopathic late onset cerebellar ataxia. This type of ataxia is a form of neurodegeneration; the neurons in the cerebellum begin to dissipate with no known cause.
Signs & Symptoms of Ataxia
SymptomsAtaxia is a term used to describe brain disorders affecting a person’s balance, muscle coordination, and speech. Symptoms vary according to the type of ataxia affecting a person; however, the most common signs and symptoms of ataxia include:
- Uncoordinated gait (walk)
- Lack of balance
- Involuntary eye movements
- Speech problems
- Trouble eating or swallowing
- Difficulty maintaining normal posture
- Difficulty performing daily activities
- Tremors
What Causes Ataxia?
CausesAtaxia is either inherited from genetic mutations or acquired from injury, infection, or other degenerative changes to the central nervous system.
Ataxia as a symptom
Although “ataxia” can describe a group of specific degenerative diseases, it is also often used to describe a symptom of incoordination caused by infections, injuries, or other degenerative diseases of the central nervous system. Many conditions can cause ataxia, such as alcohol misuse, stroke, tumor, brain degeneration, multiple sclerosis, some medications, and genetic disorders.
Trust NewYork-Presbyterian for Ataxia Care
NewYork-Presbyterian’s world-renowned neurologists and neurosurgeons, in collaboration with the distinguished neurological experts from Columbia University and Weill Cornell Medicine, implement the most innovative diagnostic treatments available to patients throughout the metropolitan New York area.
The Kuo Lab at Columbia University Medical Center is dedicated to studying the role of the cerebellum in neurological disorders, focusing specifically on ataxia and tremor. We use diverse methodologies to investigate the disease pathophysiology in order to advance the knowledge of the cerebellar function and develop therapies for ataxia and tremor.
The Initiative for Columbia Ataxia and Tremor (ICAT) is a collaborative effort between renowned physicians, scientists, and engineers to advance the understanding and treatment of ataxia and tremor. We aim to quickly turn laboratory discoveries and technological advances into clinical applications, so we can help people living with ataxia and tremor.
Our clinical scientists and research team continue to explore the causes of ataxia and strive for the most effective ways to diagnose and treat this debilitating condition. Genetic testing and counseling are available to families concerned about the possibility of having a genetic ataxia gene.