What is Cerebellar ataxia ?
Cerebellar ataxia is caused by disease or injury to the cerebellum, located in the brain. This disease is characterized by incoordination in muscle movements. (1)
Ataxia is the term grouping together a number of disorders affecting coordination, balance and language.
All parts of the body can be affected by the disease, however people with ataxia generally have impairments in:
– balance and walking;
– in performing tasks which require a certain degree of control, such as writing or eating;
There are different types of ataxia which are characterized by various symptoms and severity: (2)
– acquired ataxia is the form corresponding to the development of symptoms following trauma, stroke, sclerosis, brain tumor, nutritional deficiencies or other problems damaging the brain and nervous system;
– hereditary ataxia, corresponds to the form in which the symptoms develop slowly (over several years). This form is the cause of genetic abnormalities inherited by parents. This form is also called Friedreich’s ataxia.
– idiopathic ataxia with the late onset of cerebellar ataxia, in which the brain is affected progressively over time for reasons that are often unknown.
Regarding autosomal recessive cerebellar ataxia, it is part of a group of rare neurological diseases that impact the central and peripheral nervous system. These pathologies can also affect other organs. The origin of this type of disease is autosomal recessive inheritance. Or a transmission of a mutated gene of interest from the parents. The presence of only one copy of the gene is necessary for the development of the disease.
The development of the disease often occurs before the age of 20.
It is a rare disease, the prevalence of which (number of cases in a given population at a given time) is between 1 and 4 cases per 100,000 people. (3)
Symptoms associated with cerebellar ataxia are neurological and mechanical.
Cerebellar ataxia generally affects the trunk: from the neck to the hips, but also the arms and legs.
The general symptoms of cerebellar ataxia include: (1)
– a configuration of Clumsy speech (dysarthria): joint disorders;
– nystagmus: repetitive eye movements;
– uncoordinated eye movements;
– an unstable gait.
The origins of the disease
Cerebellar ataxia mainly affects young children of average age 3 years.
The disease can develop after a few weeks following a viral infection. These viral infections in question include: chickenpox, infection with the Eptein-Barr virus, Coxsackie’s disease or an infection with echovirus.
Other origins may be associated with this pathology, in particular: (1)
– abscess in the cerebellum;
– consumption of alcohol, certain drugs or contact with insecticides;
– internal bleeding in the cerebellum;
– multiple sclerosis: development of connective tissue in an organ, causing it to harden;
– a cerebral vascular accident ;
– certain vaccines.
Ataxia is usually associated with damage to the cerebellum. However, abnormalities in other parts of the nervous system can be the cause.
This damage to the brain is associated with certain conditions, such as: a head injury, a lack of oxygen in the brain or even too much alcohol consumption.
In addition, transmission of the disease can also be carried out through hereditary transfer of the autosomal dominant form. Or, the transfer of a mutated gene of interest, present on a non-sexual chromosome, from the parents. The presence of only one of the two copies of the mutated gene is sufficient in the development of cerebellar ataxia. (2)
The risk factors associated with cerebellar ataxia are genetic, in the context of autosomal dominant inheritance. In the latter case, the transmission of a single copy of the mutated gene of interest is sufficient for the development of the disease to the offspring. In this sense, if one of the two parents is affected by the pathology, the child has a 50% risk of so too.
Other factors also come into play in the development of this pathology. These include viral infections: chickenpox, Eptein-Barr virus infection, Coxsackie’s disease or an echovirus infection.
The most widely found risk factor in cerebellar ataxia is brain and nervous system disorders.
Prevention and treatment
The primary diagnosis of the disease is often combined with a differential diagnosis, in which the doctor asks the patient a number of questions to determine if he or she has recently been ill. This first point of view also makes it possible to eliminate other potential causes relating to the presence of symptoms.
Following this first glimpse, examinations of the brain and the central nervous system are carried out in order to identify the regions of the cerebral cortex affected by the disease. Among these tests, we can cite:
– the scanner of the head;
– MRI (Magnetic Resonance Imaging) of the head.
The treatment of the disease depends directly on the cause of it: (1)
– surgery is necessary in the event that ataxia arises from brain bleeding;
– drugs that thin the blood during a stroke;
– antibiotics and antivirals during infections;
– steroids for the treatment of inflammation of the cerebellum.
In addition, in the case of ataxia caused by a recent viral infection, no medication is required.
In most cases of the disease, there is no cure for it. Only treatments that control and limit symptoms are prescribed if necessary.
Language aids can also be associated, physiotherapy in the resolution of deficiencies in movements, occupational therapy sessions allowing the relearning of daily actions or drugs allowing the control of striated muscles, caridaque muscle, movements ocular and urinary control. (2)
(1). SHELAT. AM. 2016. Acute cerebellar ataxia. [In line]. https://www.nlm.nih.gov/medlineplus/ency/article/001397.htm.
(2). NHS CHOICES. 2015. Ataxia. [In line]. http://www.nhs.uk/Conditions/Ataxia/Pages/Introduction.aspx.
(3). PALAU.F. 2006. Autosomal recessive cerebellar ataxia. [ Online]. http://www.orpha.net/consor/cgi-bin/OC_Exp.php?Lng=FR&Expert=1172.