Ataxia

Definition

Definition of Ataxia
Ataxia is a neurological sign consisting of lack of voluntary coordination of muscle movements, as in walking. Ataxia is a non-specific clinical manifestation implying dysfunction of the parts of the nervous system that coordinate movement, such as the cerebellum. Several possible causes exist for these patterns of neurological dysfunction. The term "dystaxia" is a rarely-used synonym.

Symptoms

Symptoms of Ataxia
Ataxia can develop over time or come on suddenly, depending on the cause. Ataxia, actually a symptom of a number of neurological disorders, may cause:

1. Poor coordination
2. Unsteady walk and a tendency to stumble
3. Difficulty with fine-motor tasks, such as eating, writing or buttoning a shirt
4. Change in speech
5. Involuntary back-and-forth eye movements (nystagmus)
6. Difficulty swallowing

Causes

Causes of Ataxia
Damage, degeneration or loss of nerve cells in the part of your brain that controls muscle coordination (cerebellum), results in loss of coordination or ataxia. Your cerebellum comprises two pingpong-ball-sized portions of folded tissue situated at the base of your brain near your brainstem. The right side of your cerebellum controls coordination on the right side of your body; the left side of your cerebellum controls coordination on the left side of your body.

Diseases that damage the spinal cord and peripheral nerves that connect your cerebellum to your muscles also may cause ataxia. Ataxia causes include:

1. Head trauma: Damage to your brain or spinal cord from a blow to your head, such as might occur in a car accident, can cause sudden-onset ataxia, also known as acute cerebellar ataxia.
2. Stroke: When the blood supply to a part of your brain is interrupted or severely reduced, depriving brain tissue of oxygen and nutrients, brain cells begin to die.
3. Transient ischemic attack (TIA): Caused by a temporary decrease in blood supply to part of your brain, most TIAs last only a few minutes. Loss of coordination and other signs and symptoms of a TIA are temporary.
4. Cerebral palsy: This is a general term for a group of disorders caused by damage to a child's brain during early development - before, during or shortly after birth - that affects the child's ability to coordinate body movements.
5. Multiple sclerosis (MS): MS is a chronic, potentially debilitating disease that affects your central nervous system, which comprises your brain and spinal cord.
6. Chickenpox: Ataxia can be an uncommon complication of chickenpox and other viral infections. It may appear in the healing stages of the infection and last for days or weeks. Normally, the ataxia resolves completely over time.
7. Paraneoplastic syndromes: These are rare, degenerative disorders triggered by your immune system's response to a cancerous tumor (neoplasm), most commonly from lung, ovarian, breast or lymphatic cancer. Ataxia may appear months or years before the cancer is diagnosed.
8. Tumor: A growth on the brain, cancerous or noncancerous (benign), can damage the cerebellum.
9. Toxic reaction: Ataxia is a potential side effect of certain medications, such as barbiturates, such as phenobarbital, and sedatives, such as benzodiazepines. Alcohol and drug intoxication; heavy metal poisoning - from lead or mercury, for example - and solvent poisoning - from paint thinner, for example - also can cause ataxia.

Diagnosis

Diagnosis of Ataxia
Besides conducting a physical exam and a neurological exam, including checking your memory and concentration, vision, hearing, balance, coordination and reflexes, your doctor may request these laboratory tests:

1. Blood Tests: Certain blood tests can confirm or exclude the suspected condition. A sample of your blood will be drawn from your arm through a needle. You may be required to fast from midnight the night before your appointment until after your blood is drawn. The specific tests will depend on the suspected cause, but most likely will include a complete blood count (CBC), which helps evaluate your overall health and detect a range of disorders, including infection and heavy metal poisoning.
2. Urine Tests: Examining a sample of your urine under a microscope (urinalysis) may suggest certain systemic abnormalities that can be related to some forms of ataxia. If your doctor suspects Wilson's disease, you may be asked for a 24-hour urine collection to help determine the amount of copper in your system.
3. Imaging Studies: A computerized tomography (CT) scan or magnetic resonance imaging (MRI) of your brain may help determine potential causes.
4. Lumbar Puncture (spinal tap): A needle is inserted into your lower back (lumbar region) between two lumbar bones (vertebrae) to remove a sample of cerebrospinal fluid. The fluid, which surrounds and protects your brain and spinal cord, is sent to a laboratory for testing.
5. Genetic Testing: Your doctor may recommend genetic testing to determine whether you or your child has the gene mutation that causes one of the hereditary ataxic conditions. Gene tests are available for many but not all of the hereditary ataxias.

Treatment

Treatment of Ataxia
The treatment of ataxia and its effectiveness depend on the underlying cause. Treatment may limit or reduce the effects of ataxia, but it is unlikely to eliminate them entirely. Recovery tends to be better in individuals with a single focal injury (such as stroke or a benign tumour), compared to those who have a neurological degenerative condition. A review of the management of degenerative ataxia was published in 2009.

The movement disorders associated with ataxia can be managed by pharmacological treatments and through physical therapy and occupational therapy to reduce disability. Some drug treatments that have been used to control ataxia include: 5-hydroxytryptophan (5-HTP), idebenone, amantadine, physostigmine, L-carnitine or derivatives, trimethoprim–sulfamethoxazole, vigabatrin, phosphatidylcholine, acetazolamide, 4-aminopyridine, buspirone, and a combination of coenzyme Q10 and vitamin E. Physical therapy requires a focus on adapting activity and facilitating motor learning for retraining specific functional motor patterns. Gait, coordination, and balance training are large components of therapy. Training will likely need to be intense and focused-as indicated by one study performed with stroke patients experiencing limb ataxia who underwent intensive upper limb retraining. Their therapy consisted of constraint-induced movement therapy which resulted in improvements of their arm function. Treatment will likely include strategies to manage difficulties with everyday activities such as walking. Gait aids (such as a cane or walker) can be provided to decrease the risk of falls associated with impairment of balance or poor coordination. Severe ataxia may eventually lead to the need for a wheelchair.

In order to obtain better results, possible coexisting motor deficits need to be addressed in addition to those induced by ataxia. For example, muscle weakness and decreased endurance could lead to increasing fatigue and poorer movement patterns.

Prognosis

Prognosis of Ataxia
Consult with your doctor.

Prevention

Prevention of Ataxia
Consult with your doctor.