Ataxia

When a person is not able to coordinate his body and its movements, either in its entirety or in specific parts, such as hands, fingers, arms, legs, eyes or complex mechanisms in speech or swallowing, we say that he suffers from ataxia.

Coordination of body movements depends on various structures, including the cerebral cortex, cerebellum, spinal cord, and the senses of sight and hearing. These structures process the information they receive and the orders that are produced to be able to carry out a movement are the complex result of the interaction of all these parts, so that all of them must be correctly integrated to be able to carry out those movements in a coordinated and precise way.

When, due to different causes, one of these structures fails and movements are uncoordinated, it is said that the patient suffers from ataxia.

How is it produced?

Ataxia is more of a symptom than a disease in itself. It appears as a consequence of different diseases, especially those that affect the cerebellum, part of the brain that, among other things, is responsible for coordinating complex movements and body balance.

Some of the most common causes of ataxia are:

• Focal lesions such as tumors, strokes, or multiple sclerosis.
• Lack of vitamin B12.
• Peripheral neuropathies.
• Degenerative diseases.
• Substances such as antiepileptics, lithium, ethanol, cannabis, or other drugs.
• Arnold-Chiari malformation.
• Wilson's disease, caused by an alteration in the metabolism of copper.
• Hereditary ataxias:
  • Spinocerebellar ataxia.
  • Episodic ataxia.
  • Friedreich's ataxia.
  • Niemann Pick disease.
  • Ataxia telangiectasia.
  • Fragile X-associated ataxia.

Symptoms

The symptoms are varied. In general, the inability to maintain balance characterizes patients with ataxia. They walk with their legs wider apart to achieve a greater base of support and thus compensate for the lack of balance; It is what is known as ataxic march.

When the alteration occurs at the level of the cerebellum, the symptoms are:

• Lack of balance
• Uncoordinated movements.
• Difficulty speaking (dysarthria) or swallowing liquids or solids (dysphagia).
• Inability to make repeated counter movements (dysdiadochokinesia), such as turning the hands up and down alternately.

If there is an alteration at the sensory level, that is, at the level of the dorsal spinal cord, which is responsible for carrying the information that makes us aware of our own position (which is called proprioception), the symptoms are:

• Loss of balance, especially if vision, which provides a lot of information about position, is limited, so that in poorly lit situations or in cases of uncorrected visual disturbances, patients with sensory ataxia experience a worsening of their symptoms.
• Balance also depends on the inner ear and if there are alterations in this structure, ataxia can occur. If the lesion is unilateral, nausea, vomiting and a certain imbalance appear, which becomes more marked when the problem is bilateral.

Types

Spinocerebellar ataxia is an autosomal dominant hereditary disease that encompasses many types of ataxias with a wide range of symptoms, patients being able to present alterations in balance, trembling of the hands, incoordination of eye movements or sudden and abrupt muscular movements (myoclonus) , among other symptoms.

• Episodic ataxia is also an autosomal dominant disease in which patients present with occasional episodes of ataxia triggered by stress, exercise, or fatigue. It is an entity that also encompasses different types of diseases.
• Friedreich's ataxia is an autosomal recessive disease in which neuronal degeneration occurs and the patient presents with gait disturbances, dysarthria, and nystagmus, as well as tachycardia, diabetes, and visual and auditory disturbances.
• Niemann Pick disease is also autosomal recessive and is caused by an alteration in the metabolism of lipids, which accumulate in cells and prevent their normal functioning.
• Ataxia telangiectasia is inherited in an autosomal recessive manner and patients present with ataxia, dilations of small capillaries and superficial cutaneous vessels (telangiectasias), immunological alterations that make them prone to infections, skin lesions and an increased risk of suffering neoplastic processes

Diagnosis

The diagnosis of ataxia will be based on the symptoms that the patient presents, the alteration of balance, dysarthria, lack of coordination of movements, etc. A thorough questioning of the patient should be carried out to assess accompanying symptoms and investigate the taking of substances that can cause these symptoms, as well as the family history to rule out ataxias of hereditary origin. A thorough neurologic evaluation of the patient is essential on physical examination.

A blood test will be necessary to assess the patient's immune status and the possible absence of vitamin B12. Also, a urinalysis will be done to detect drug use.

The computerized axial tomography (CT) and will allow to evaluate possible focal lesions at the level of the brain, cerebellum and spinal cord.

Different neurophysiological studies, such as or, will make it possible to assess possible encephalic nerve injuries or peripheral nerves.

Treatment

Ataxia is a symptom within a disease rather than a disease itself. For this reason, treatment will be directed at the cause if possible, as in the case of brain tumors, strokes, substance intoxication, or hypovitaminosis.

Many of the ataxias are part of inherited diseases for which there is no treatment. Some of the patients will benefit from some drugs to try to control ataxia. On the other hand, physiotherapy and rehabilitation are essential to try to improve the motor capacity of these patients.

PREVENTIVE MEASURES There are no specific preventive measures for ataxia given the varied origin it can have. In case of presenting symptoms of incoordination of movements, it is essential to put yourself in the hands of the specialist as soon as possible.

• Ataxia is the incoordination of movements of the whole body or of some of its parts.
• Lack of balance or incoordination of movements are some of the symptoms of ataxia.
• Many of the ataxias are part of inherited diseases for which there is no treatment.