Ataxia is a disorder of coordination of movements; a very common violation of motor skills. The strength in the limbs is slightly reduced or completely preserved. Movements become inaccurate, awkward, their continuity and sequence are upset, the balance in the standing and walking position is disturbed. Static ataxia is a violation of balance in a standing position, dynamic form is a violation of coordination during movement. Diagnosis includes neurological examination, EEG, EMG, MRI of the brain, and DNA analysis if the hereditary nature of the disease is suspected. Therapy and prognosis of ataxia development depend on the cause of its occurrence.
ICD 10
R27.0 Unspecified ataxia
Classification
In clinical practice, there are several types:
- sensitive (or posterior—lobed) – a violation of the conductors of deep muscle sensitivity;
- cerebellar is a lesion of the cerebellum;
- vestibular — lesion of the vestibular apparatus;
- cortical is a lesion of the temporal—occipital or frontal cortex.
Symptoms
The occurrence of sensitive ataxia is caused by damage to the posterior pillars (Gaulle and Burdach bundles), less often the posterior nerves, peripheral nodes, the cortex of the parietal lobe of the brain, the visual hillock (funicular myelosis, spinal dryness, tumors, vascular disorders). Its manifestation is possible, both in all limbs, and in one leg or arm. The most significant phenomena of sensitive ataxia, which occurs as a result of a disorder of the articular-muscular feeling in the lower extremities. The patient is unstable, when walking excessively bends his legs in the hip and knee joints, steps too much on the floor (stamping gait). Often there is a feeling of walking on cotton wool or carpet. Patients try to compensate for the disorder of motor functions with the help of vision — when walking, they constantly look at their feet. This allows you to significantly reduce the manifestations of ataxia, and closing the eyes, on the contrary, aggravates them. Severe lesions of the posterior columns practically make it impossible to stand and walk.
Cerebellar ataxia is a consequence of damage to the cerebellar worm, its hemispheres and legs. In the Romberg pose and when walking, the patient collapses (up to a fall) towards the affected hemisphere of the cerebellum. In case of damage to the cerebellar worm, it is possible to fall in any direction or backwards. The patient staggers when walking, puts his legs wide. The flanking gait is sharply disrupted. The movements are sweeping, slow and awkward (mostly from the affected hemisphere of the cerebellum). Coordination disorder is almost invariable with vision control (open and closed eyes). There is a violation of speech — it slows down, becomes stretched, jerky, often chanted. The handwriting becomes sweeping, uneven, macrography is observed. There may be a decrease in muscle tone (to a greater extent on the side of the lesion), as well as a violation of tendon reflexes. Cerebellar ataxia can be a symptom of encephalitis of various etiologies, multiple sclerosis, malignant neoplasm, vascular focus in the brain stem or cerebellum.
Vestibular ataxia develops when one of the sections of the vestibular apparatus is affected — the labyrinth, the vestibular nerve, the nuclei in the brainstem and the cortical center in the temporal lobe of the brain. The main sign of vestibular ataxia is systemic dizziness (it seems to the patient that all the objects around him are moving in the same direction), dizziness increases when the head turns. In this regard, the patient randomly staggers or falls, and makes head movements with noticeable caution. In addition, vestibular ataxia is characterized by nausea, vomiting and horizontal nystagmus. Vestibular ataxia is observed in stem encephalitis, ear diseases, tumors of the IV ventricle of the brain, as well as in Meniere’s syndrome.
The development of cortical ataxia (frontal) is caused by damage to the frontal lobe of the brain caused by dysfunction of the frontal-cerebellar system. With frontal ataxia, the leg that is contralateral to the affected hemisphere of the cerebellum suffers to the maximum extent. When walking, instability is observed (to a greater extent on turns), tilting or falling in the direction ipsilateral to the affected hemisphere. With severe lesions of the frontal lobe, patients cannot walk or stand at all. Vision control does not affect the severity of walking disorders in any way. Cortical ataxia is characterized by other symptoms characteristic of damage to the frontal lobe — grasping reflex, mental changes, impaired sense of smell. The symptom complex of frontal ataxia is very similar to cerebellar ataxia. The main difference of cerebellar lesion is evidence-based hypotension in the atactic limb. The causes of frontal ataxia are abscess, tumors, disorders of cerebral circulation.
Hereditary cerebellar Pierre-Marie ataxia is a hereditary disease of a chronic progressive nature. It is transmitted by an autosomal dominant type. Its main manifestation is cerebellar ataxia. The pathogen has a high penetrance, generation skipping is very rare. A characteristic pathoanatomic sign of Pierre-Marie ataxia is cerebellar hypoplasia, less often — atrophy of the lower olives, the bridge of the brain (varoliev bridge). Often these signs are combined with combined degeneration of the spinal systems (the clinical picture resembles Friedreich’s spinocerebellar ataxia).
The average age of the onset of the disease is 35 years, when there is a gait disorder. Subsequently, it is joined by a violation of facial expressions, speech and ataxia in the hands. There is static ataxia, adiadochokinesis, dysmetria. Tendon reflexes are elevated (to pathological reflexes). Involuntary muscle tremors are possible. The strength in the muscles of the extremities is reduced. Progressive oculomotor disorders are observed — paresis of the abductor nerve, ptosis, lack of inertia, less often — Argyle Robertson’s symptom, optic nerve atrophy, decreased visual acuity, narrowing of the visual fields. Mental disorders manifest themselves in the form of depression, a decrease in intelligence.
Friedreich’s familial ataxia is a hereditary disease of a chronic progressive nature. It is transmitted by an autosomal dominant type. Its main manifestation is a mixed sensetive—cerebellar ataxia resulting from a combined lesion of the spinal systems. Blood marriages are very common among the parents of patients. A characteristic pathoanatomic sign of Friedreich’s ataxia is the increasing degeneration of the lateral and posterior columns of the spinal cord (up to the medulla oblongata). To a greater extent, the Gaulle bundles are affected. In addition, the cells of Clark’s pillars are affected, and with them the posterior spinocerebellar pathway.
The main symptom of Friedreich’s ataxia is ataxia, expressed in an uncertain, awkward gait. The patient walks with a flourish, deviating from the center to the sides and placing his legs wide. Sharko designated such a gait as tabetic-cerebellar. With the development of the disease, discoordination spreads to the arms, chest muscles and face. Facial expressions change, speech becomes slow, jerky. Tendon and periosteal reflexes are significantly reduced or absent (primarily on the legs, and later on the upper extremities). In most cases, hearing is reduced.
With the development of Friedreich’s ataxia, extraneural disorders manifest themselves — heart lesions and skeletal changes. On the ECG — deformation of the atrial tooth, rhythm disturbance. There is paroxysmal pain in the heart, tachycardia, shortness of breath (as a result of physical exertion). Changes in the skeleton are expressed in a characteristic change in the shape of the foot — a tendency to frequent dislocations of the joints, an increase in the arch and extension of the fingers, as well as kyphoscoliosis. Among the endocrine disorders accompanying Friedreich’s ataxia, diabetes, hypogonadism, infantilism are noted.
Ataxia-telangiectasia (Louis-Bar syndrome) is a hereditary disease (a group of phacomatoses) transmitted by an autosomal recessive type. Very often accompanied by dysgammaglobulinemia and hypoplasia of the thymus gland. The development of the disease begins in early childhood, when the first ataxic disorders appear. In the future, ataxia progresses and by the age of 10 walking is almost impossible. Louis-Bar syndrome is often accompanied by extrapyramidal symptoms (myoclonic and athetoid hyperkinesis, hypokinesia), mental retardation, damage to cranial nerves. A tendency to repeated infections (rhinitis, sinusitis, bronchitis, pneumonia) is characteristic, which is primarily due to the insufficiency of immunological reactions of the body. Due to the deficiency of T-dependent lymphocytes and class A immunoglobulins, the risk of malignant neoplasms is high.
Complications
- Tendency to recurrent infectious diseases.
- Chronic heart failure.
- All types of respiratory failure.
Diagnostics
The diagnosis of ataxia is based on the identification of diseases in the patient’s family and the presence of ataxia. EEG of the brain in Pierre Marie’s ataxia and Friedreich’s ataxia reveals the following disorders: diffuse delta and theta activity, reduction of alpha rhythm. In laboratory studies, there is a violation of amino acid metabolism (the concentration of leucine and alanine is reduced, their excretion in urine is also reduced). Brain MRI reveals atrophy of the trunks of the spinal cord and brain, as well as the upper parts of the worm. With the help of electromyography, axonal-demyelinating lesion of sensory fibers of peripheral nerves is detected.
When differentiating ataxia, it is necessary to take into account the variability of the clinical picture of ataxia. In clinical practice, rudimentary varieties of ataxia and its transitional forms are observed, when clinical manifestations are similar to the symptoms of familial paraplegia (spastic), neural amyotrophy and multiple sclerosis.
To diagnose hereditary ataxia, direct or indirect DNA diagnostics is necessary. With the help of molecular genetic methods, ataxia is diagnosed in the patient, after which indirect DNA diagnostics is performed. With its help, the possibility of inheritance of the pathogen of ataxia by other children in the family is established. It is possible to conduct a comprehensive DNA diagnosis, it will require a biomaterial of all family members (the biological parents of the child and all other children of this parent couple). In rare cases, prenatal DNA diagnostics is indicated.
Treatment and prognosis
Ataxia is treated by a neurologist. It is mainly symptomatic and should include: general restorative therapy (B vitamins, ATP, anticholinesterase agents); a special set of gymnastic exercises of physical therapy aimed at strengthening muscles and reducing discoordination. In Friedreich’s ataxia, taking into account the pathogenesis of the disease, drugs that support mitochondrial functions (succinic acid, riboflavin, coenzyme Q10, vitamin E) can play an important role in treatment.
For the treatment of ataxia-telangiectasia, in addition to the above algorithms, correction of immunodeficiency is necessary. To do this, a course of treatment with immunoglobulin is prescribed. Radiation therapy in such cases is contraindicated, in addition, excessive X-rays and prolonged exposure to the sun should be avoided.
The prognosis of genomic hereditary diseases is not favorable. There is a slow progression of neuropsychiatric disorders. Working capacity is reduced in most cases. However, thanks to symptomatic treatment and prevention of repeated infectious diseases, injuries and intoxication, patients have the opportunity to live to an advanced age. For preventive purposes, it is necessary to avoid the birth of children in families where there are patients with hereditary ataxia. In addition, it is recommended to exclude the possibility of any related marriages.