Symptoms linked to coordination or cerebellar disorders can be of different kinds. There are :
- Ataxia: unsteady, staggering walking, with legs or even bars spread to maintain balance.
- Dysmetria: Loss of control over range of movement, slower, jerky movements, inability to perform fine movements such as writing.
- Dysarthria: Inability to articulate words correctly, slurred speech with loss of control over the amplitude of the voice and lip movements.
- Nystagmus: rapid, involuntary oscillations of the eyes. The eyes move in all directions and then slowly return to their initial position.
Acquired ataxias
The symptoms of acquired ataxia are highly heterogeneous and depend on the location and type of brain lesion that causes them, such as a tumour, cyst, haematoma or inflammation.
Patients may suffer from neurological disorders such as tremors or dementia, as well as cardiac, skeletal or endocrine disorders.
Acquired ataxia is diagnosed by clinical examination, medical imaging, oculomotor tests and electroencephalograms.
Treatment for acquired ataxia focuses on the cause of the symptoms. These include stopping the consumption of alcohol or reducing the dose of medication in cases of toxic ataxia, surgery on the cyst or tumour, or treatment of the inflammation.
Cerebellar ataxias of genetic origin
Autosomal dominant ataxias
People suffering from these ataxias present the cerebellar symptoms listed above, which indicate damage to the cerebellum.
There are 4 clinical pictures:
Type 1: cerebellar symptoms are accompanied by ocular damage, with a reduction in eye movement which may even lead to paralysis. Muscle stiffness (dystonia) or muscle wasting (alyotrophy) may be observed, as well as sensory disturbances that prevent the patient from being aware of their body position. In some very severe cases, an intellectual deficit may develop.
Type 2: cerebellar symptoms are associated with degeneration of the retinal cells, leading to loss of vision.
Type 3: the patient presents only cerebellar disorders.
Type 4: a combination of cerebellar symptoms and epilepsy.
Diagnosis of these ataxias combines a clinical examination, brain imaging and a family study to look for the genetic mutation.
To date, there is no cure for dominantly inherited ataxias, but treating the symptoms with physiotherapy, occupational therapy, speech therapy and psychomotor re-education can reduce the disability.
Autosomal recessive ataxias
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Friedreich’s ataxia
Friedreich’s ataxia generally begins with cerebellar damage, such as walking problems and instability, followed by problems with coordination of the upper limbs. As the disease progresses, problems with speech (dysarthria), swallowing, vision and hearing may appear.
Patients frequently develop bone deformities of the spine or arch of the foot. In infantile cases, cardiac damage may appear 4 to 5 years after the onset of the disease, and diabetes is observed in 10 to 20% of cases.
The diagnosis is made on the basis of age criteria (the disease generally begins between 7 and 14 years of age), clinical symptoms and, very often, abnormalities on the electromyogram (recording of the electrical signals of the muscles) and cardiac ultrasound. Identification of a genetic mutation confirms the diagnosis.
Treatment for this ataxia is currently being evaluated, in particular to reduce cardiac damage. As with other ataxias, physiotherapy, occupational therapy, speech therapy and psychomotor rehabilitation enable patients to maintain their quality of life for longer.
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Ataxia telangiectasia
The symptoms of ataxia telangiectasia, which appear around the age of 2, are numerous and may involve the nervous system, the skin or the immune system.
In addition to the cerebellar symptoms described above, there is dilation of peripheral vessels, sometimes signs of premature ageing (white hair, thinner skin) and greater susceptibility to infections due to dysfunction of the immune system.
In addition to the clinical examination, which is made difficult by the age of the children affected, the diagnosis is based on biological criteria such as the level of certain proteins or antibodies and identification of the genetic mutation.
