What is ataxia?
The term “ataxia” refers to a group of disorders that affect coordination, balance and speech.
It can affect any part of the body, but people with ataxia often have difficulties with:
- balance and walking
- tasks that require a higher degree of control, such as writing and eating
The causes of ataxia are many, including head trauma, alcohol abuse, stroke, cerebral palsy, genetic causes, tumor, multiple sclerosis (MS), infections and immune disorders.
Symptoms and severity vary based on the type of ataxia.
Types of ataxia.
Some types of ataxia present in childhood, while others develop at an adult age.
Depending on the type of ataxia, symptoms may remain unchanged, progressively worsen or gradually improve.
The different types of ataxia can be divided into three categories:
- Acquired ataxia: Symptoms appear following a trauma or as a result of problems that cause damage to the brain or nervous system.
- Hereditary ataxia: Symptoms develop gradually over the course of years and are caused by faulty genes inherited from the parents. The most common type is Friedreich’s ataxia.
- Idiopathic late-onset cerebellar ataxia (ILOCA): The brain undergoes progressive damage for reasons that are unknown.
This disorder can strike at any age and usually develops very rapidly, over the course of a few days or even hours. It can improve over time, remain unchanged or gradually worsen.
The potential causes of acquired ataxia include:
- severe head injury (for example as a result of a car accident or a fall)
- bacterial brain infection, such as meningitis or encephalitis
- viral infection (in some rare cases, viral infections such as chickenpox or measles can spread to the brain)
- conditions that disrupt the supply of blood to the brain (e.g. stroke, hemorrhage or transient ischemic attack [TIA])
- cerebral palsy (can occur if the brain develops abnormally or is damaged before, during or after birth)
- multiple sclerosis (a long-term condition that damages the nerve fibers of the central nervous system)
- long-term alcohol abuse
- an underactive thyroid gland
- vitamin B12 deficiency
- brain tumors and other types of cancer
- long-term exposure to certain toxic chemicals, such as mercury and some solvents
- medications such as benzodiazepines, which can occasionally trigger ataxia as a side effect
Hereditary ataxia is caused by a faulty gene.
Ataxia can be inherited in two ways:
- autosomal recessive: Friedreich’s ataxia and ataxia-telangiectasia are inherited in this way.
A person affected by this type of genetic ataxia has inherited the mutated gene from both their mother and their father.
A person who receives only one mutated gene from one of the two parents will be a carrier of the condition; they will not have the condition themselves, but they will be able to pass it on to their children if their partner is also a carrier of the faulty gene.
It is estimated that approximately 1 person in 85 is a carrier of the mutated gene that causes Friedreich’s ataxia. Even fewer are carriers of the mutated gene that causes ataxia-telangiectasia.
- autosomal dominant: Episodic ataxia and some cases of spinocerebellar ataxia are inherited in this way.
A person can develop this type of ataxia if they receive a single faulty gene from either their mother or their father; the mutation is strong enough to override the other healthy gene.
In this case, the children of a person with autosomal dominant ataxia will have a 1 in 2 chance of developing ataxia.
Friedreich’s ataxia is the most common type of hereditary ataxia (caused by inherited genes). It is believed to affect at least 1 person in 50,000.
Symptoms usually develop before the age of 25, but they can also develop in people much older.
Signs and symptoms of Friedreich’s ataxia:
- problems with balance and coordination, which often cause unsteadiness, clumsiness and frequent falls
- problems with speech, caused by motor impairments to the facial muscles (dysarthria)
- progressive weakness in the legs; difficulty in walking, with patients requiring a wheelchair after about 10-20 years
- total or partial loss of vision and hearing
- thickening of the heart muscles (hypertrophic cardiomyopathy), which can cause chest pain, shortness of breath, and an irregular heartbeat
- loss of sensation in the hands and feet (peripheral neuropathy)
Complications may affect the spinal column, feet, heart, muscles, vision and hearing.
Those who suffer from this type of ataxia will require care throughout their lives.
The symptoms of Friedreich’s ataxia usually worsen gradually. People with this condition tend to have a shorter life expectancy. Many are able to live until their 30s or 40s while others live into their 60s and beyond.
Ataxia-telangiectasia (AT) is a rare type of hereditary ataxia. Symptoms usually begin in early childhood but can develop at a later age.
Signs and symptoms of AT:
- difficulty in walking; most children must use a wheelchair by age 10
- small spider-like clusters of red blood vessels at the corners of the eyes and on the cheeks (telangiectasias)
- slow eye movement; patients must move their heads to compensate for this
- a weakened immune system; children with AT are more vulnerable to infections, especially of the sinuses, lungs and airways, such as pneumonia
- an increased risk of cancer, especially leukemia or acute lymphoblastic lymphoma
In addition to appearing “a little wobbly,” affected children may also have spider veins in the whites of their eyes, in their ears or elsewhere on their faces.
The symptoms of AT tend to worsen rapidly. People suffering from AT usually live to age 19-25, but some can live into their 50s.
Spinocerebellar ataxias (SCAs) are a group of hereditary ataxias that often appear during adulthood, affecting people between the ages of 25 and 80, depending on the type of SCA.
Occasionally, some types of SCAs begin during childhood.
Symptoms vary depending on the type of SCA. In addition to dysphagia and dysarthria, patients can present with:
- problems with balance and coordination
- difficulty in walking, with patients requiring a wheelchair after a few years
- muscle stiffness and cramps
- loss of sensation in the hands and feet (peripheral neuropathy)
- memory loss and difficulty in speaking
- slow eye movement; patients must move their heads to compensate for this
- reduced bladder control (urinary urgency or incontinence)
When ataxia strikes the spinocerebellum region of the brain, gait becomes unusual, with unequal sideways steps and stuttering starts and stops. The spinocerebellum regulates body and limb movements.
This type of ataxia is caused by a dysfunction of the cerebellum, a region of the brain that plays a role in the assimilation of sensory perception, coordination and motor control.
Cerebellar ataxia may cause neurological symptoms, such as:
- jerking or shaking of the body or limbs while moving
- a reduction in muscle tone
- a lack of coordination between organs, muscles, limbs and joints
- trouble controlling distance, power and speed of movements of the arms, hands, legs or eyes
- trouble accurately estimating time
- inability to perform rapid alternating movements
Its impact on the body depends on which part of the cerebellum is damaged and if the lesions occur on only one side (unilateral) or both (bilateral).
Ataxia may affect posture. If it occurs in the vestibulocerebellum, it will affect balance and eye movement control.
This type of ataxia develops due to a loss of proprioception (a person’s sense of the positions of the various parts of their own body), which indicates whether the body is moving with the appropriate effort.
Sensory ataxia usually causes:
- an unsteady gait with a heavy tread
- postural instability that worsens in environments with low light
If a person who suffers from sensory ataxia stands still with their eyes closed and their feet together, their unsteadiness worsens. Furthermore, they could have trouble performing accurately coordinated voluntary movements with their limbs, trunk, pharynx, larynx and eyes.
Other types of ataxia
Ataxia caused by vitamin E deficiency: Similar to Friedreich’s ataxia, it is caused by problems in assimilating vitamin E or a deficiency due to a poor diet. It is often possible to control the symptoms with vitamin E supplements.
What causes ataxia?
Ataxia is usually the result of damage to the cerebellum, but can also be caused by damage to other parts of the nervous system, such as the spinal cord or other nerves.
The spinal cord is a long bundle of nerves that runs the length of the spine and connects the brain to various parts of the body.
The cerebellum is located at the base of the brain and is responsible for controlling:
- balance when walking and sitting
- limb coordination
- eye movements
The damage to the nervous system may be linked to a progressive disease such as MS (Multiple Sclerosis) or be caused by a head injury, a lack of oxygen supply to the brain a lesion or long-term alcohol abuse. This type of ataxia is called acquired ataxia.
Hereditary ataxia, on the other hand, is caused by a mutated gene passed down from one or both parents, who may or may not be affected by it.
The reasons why the cerebellum and spinal cord are damaged are sometimes unclear; this is the case for patients with idiopathic late-onset cerebellar ataxia.
If unexplainable symptoms appear, such as problems involving balance and coordination or difficulty in walking, speaking or swallowing, the person is advised to see their primary care physician. After consulting the primary care physician, the specialist who deals with ataxia is a neurologist specialized in brain and nervous system disorders. In the case of children, the specialist to consult is a pediatrician.
Family and medical history
The primary care physician may ask whether there have been cases of ataxia in the patient’s family and want to know about the progression of the symptoms. He or she may perform a simple test of balance, walking and coordination.
Alcohol abuse or the use of certain medications may cause symptoms similar to those of ataxia in some individuals.
Certain tests (such as blood and urine tests) can be performed in order to rule out other possible causes for the symptoms, such as an infection.
A genetic test involves taking a sample of blood and testing the DNA to look for any genetic mutation known to be a cause of ataxia.
Brain scans check for any physical anomalies in the brain, which could be caused by certain types of hereditary ataxia, as well as for the presence of any other problems which could affect the brain (such as a tumor).
The two types of brain imaging scans most commonly used are:
- Magnetic Resonance Imaging (MRI): this uses a strong magnetic field and radio waves to generate detailed scans of the brain’s soft tissue.
- Computerized Tomography (CT): a series of X-rays are used to create a detailed three-dimensional image of the brain.
Other tests to diagnose ataxia and determine its degree of severity are:
- a lumbar puncture: a sample of cerebrospinal fluid is taken from the base of the spine to check for infection or other anomalies
- nerve conduction studies and electromyography (EMG): tests to evaluate the electrical activity of nerves and muscles
- videofluoroscopy: a continuous moving X-ray taken while the patient swallows different types of food and beverages
- an electrocardiogram (ECG): a test to assess the electrical activity of the heart
- an echocardiogram: an ultrasound scan of the heart
In most cases, there is no cure for ataxia. The following treatments can be used to control ataxia symptoms:
- working with a speech and language therapist, who can help with problems speaking and swallowing
- physical therapy for movement problems
- occupational therapy to help deal with problems of everyday life
- medications to control muscle, bladder, heart and eye problems
- medical devices such as GONDOLA AMPS
In some cases, it is possible to treat the underlying cause of ataxia so that it improves or does not worsen. However, this is not possible in most cases, so treatment aims to alleviate the symptoms (palliative care).
Ataxia treatments will vary based on the type of ataxia.
The treatment plan
A multidisciplinary team of medical professionals, typically including a neurologist, a physical therapist and a specialist nurse, will work with the patient to devise a care plan; this plan will play an important part in managing the condition.
The patient’s physical, social and psychological needs will be evaluated, as will the ways to best satisfy them. The plan will also address any possible future needs.
Regular appointments with physicians will serve to monitor the patient’s progress. In some cases, these appointments may take place at a specialized ataxia clinic.
Treating the symptoms
The patient’s physician may suggest a specific treatment for the following ataxia symptoms:
- Trouble with coordination and balance: Adaptive devices such as canes, crutches, walkers or wheelchairs may help patients to maintain their independence.
- Tremor, rigidity, muscle spasms and weakness: A physician may prescribe drugs and physical or occupational therapy to help improve strength, maintain mobility and help find new ways to perform everyday tasks.
- Curvature of the spine: A physician may recommend orthopedic care.
- Depression: Psychotherapy and medications may help.
- Speech problems: A speech and language therapist can help with speech problems and with muscle control to improve swallowing and avoid coughing and choking.
- Deficiencies: Vitamin supplements and a special diet can help in cases of deficiencies.
- Immune problems: Treatment for ataxia-telangiectasia may include injections of gamma-globulin to boost the immune system.
- Uncontrollable eye movements: Medications may help.
Speech therapy and language
A speech and language therapist can help with two of ataxia’s most common symptoms: language impairments (dysarthria) and trouble swallowing (dysphagia).
If speech problems worsen, patients may consider speech aids such as a portable computer connected to a voice synthesizer.
To treat dysphagia, the therapist may teach the patient exercises to stimulate the nerves used to trigger the swallowing reflex and strengthen the muscles used for swallowing.
In cases of ataxia, physical therapy can help patients to maintain the use of their arms and legs and prevent muscles from weakening or becoming locked in one position (contractures).
A physical therapist can teach the patient a number of physical daily exercises to strengthen and lengthen the muscles. He or she may also be able to recommend walking aids for moving around.
The goal of occupational therapy is to teach the patient how to adapt to their progressive loss of mobility and develop new skills in order to perform daily activities.
An occupational therapist can teach a patient how to use a wheelchair and other mobility devices. He or she can also recommend modifications to make in patients’ home environments to simplify their lives, such as installing guide rails or a stair lift.
Individuals suffering from ataxia feel extremely tired and lacking in energy. It is thought that this is caused in part by disturbed sleep and by the physical effort required to cope with coordination loss.
A physical therapist can help to increase stamina, while an occupational therapist can suggest ways to adapt daily activities to better manage fatigue.
Muscle relaxant drugs such as baclofen or tizanidine can be used to control symptoms such as muscle spasms, cramps and rigidity.
If these are not effective, an injection of botulin toxin (Botox) can be administered; it functions by blocking the signals from the brain to the affected muscles. The injection’s effects usually last up to 3 months.
Damage to nerve endings can cause nerve pain. The medical term for nerve pain is neuropathic pain, which often manifests as a burning or shooting pain or as a tingling in certain parts of the body.
Traditional pain medications, such as paracetamol or ibuprofen, usually are not effective in treating neuropathic pain, so drugs such as amitriptyline, gabapentin or pregabalin may be prescribed.
Cardiomyopathy (damage to the heart muscle) is a common problem in certain types of ataxia. It can be serious, as it can put the heart under great strain, affect the normal flow of blood through the heart and cause heartbeat irregularities (arrhythmias).
If the patient presents with cardiomyopathy, it could be necessary for them to take medications to treat any problems as they develop.
Treating the underlying cause
In some cases of ataxia, it is possible to improve the condition or prevent it from worsening by treating the underlying cause.
- Ataxia due to vitamin E deficiency can often be controlled or improved with vitamin E supplements.
- Episodic ataxia can often be controlled using the drug acetazolamide and by avoiding triggering factors such as stress, alcohol and caffeine.
- Acquired ataxia can occasionally be treated based on its specific cause (for example, if it is caused by an infection, antibiotics or antiviral drugs can help).
If acquired ataxia is caused by severe underlying brain damage, such as a stroke or a severe head injury, it may not be possible to improve the condition. In such cases, treatments can be used to control the symptoms.