Congenital cerebellar ataxia due to autosomal recessive GRID2 deficiency is a rare, genetic, progressive neurodegenerative disease that results from GRID2 deficiency. It is characterized by motor, speech and cognitive delay, hypotonia, trunk and appendicular ataxia, eye movement abnormalities (upward gaze tonic deviation, nystagmus, oculomotor apraxia). It can also be associated with intentional tremor. Brain images reveal progressive atrophy of the cerebellum with the cerebellar floc especially affected. The term ataxia is used to refer to a syndrome characterized by symptoms such as imbalance and motor coordination. When these changes are due to dysfunction in the cerebellum, the posterior structure of the brain , the concept of cerebellar or cerebellar ataxia is used . Ataxia can affect the fingers , hands , upper and lower extremities , the body, speech, or eye movements. This loss of coordination can be caused by various and diverse medical and neurological conditions; For this reason, it is important that a person with ataxia seek medical attention to determine the underlying cause of the symptom and to get the proper diagnosis.
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- 1 Types of ataxia
- 2 Origin of ataxia
- 3 Characteristic symptoms and signs
- 4 How it is diagnosed
- 5 Causes of this alteration
- 6 Treatment of cerebellar ataxia
- 7 Sources
Types of ataxia
There are two main types of cerebellar ataxia : acute cerebellar ataxia and chronic cerebellar ataxia . We speak of acute cerebellar ataxia when the symptoms appear abruptly, and we say that it is chronic when they develop progressively. Acute cerebellar ataxia is more frequent than chronic. It usually appears in infants and young children in the period following an illness. The chronic cerebellar ataxia often associated with neurological disorders structural, as caused by trauma , tumors and [[autoimmune diseases.
Origin of ataxia
Often ataxia is caused by loss of function in the part of the central nervous system that serves as the focal point, which is the cerebellum . The cerebellum is located at the back and lower part of the head . The right part of the cerebellum controls coordination on the right side of the body, and the left part controls coordination on the left. The central part of the cerebellum is involved in coordinating the complex movements of walking or walking. Other parts of the cerebellum help coordinate eye movements, speech, and swallowing.
Symptoms and characteristic signs
The main symptoms of cerebellar ataxia are related to the coordination of movements of different parts of the body, since this type of signs are what define the ataxia. However, most commonly, other changes associated with damage to the cerebellum also appear. Scientific research has determined that these symptoms and signs occur on the ipsilateral side of the body, that is, in the same hemisphere where the lesion is located in the cerebellum.
- Lack of coordination (dyssynergia) of the trunk and extremities
- Gait disturbances, frequent trips
- Deficit in fine motor skills
- Difficulty executing fast, alternating movements (dysdiadochokinesia)
- Lack of balance and postural changes
- Ocular nystagmus (involuntary eye movements)
- Gaze instability
- Alterations in speech, mainly in the articulation of phonemes (dysarthria)
- Difficulty swallowing food and liquids
- Symptoms of depression and anxiety
- Changes in behavior and personality
- Delayed development of multiple systemic atrophy (in one third of patients)
How is it diagnosed
Ataxia is a symptom, it is not a diagnosis. If there is clumsiness or loss of coordination in one arm or both legs or speech difficulties, the doctor may say that the patient has an ataxic arm or ataxic gait or non-ataxic way of speaking. Then you have to determine why this happens. To do this, the doctor (or neurologist more specifically) will ask numerous questions: first about the ataxia, how and when it appeared, if it progresses, if there are other symptoms. A very important part of the evaluation is the neurological examination. Normally, by neurological examination the doctor can determine if the ataxia is caused by a problem in the cerebellum and its associated pathways, or by other parts of the nervous system. In addition to this careful neurological examination, A thorough general physical exam can also determine if other parts of the nervous system are damaged and if a medical condition may be causing the ataxia. Blood tests (eg genetic tests), radiographs, radiological tests, can be very useful in the specific diagnosis of the medical or neurological condition that can cause ataxia, or in deciding what are the suspicious causes.
Causes of this alteration
The cerebellum or any other part of the nervous system can be damaged and inflamed by many different causes; therefore, the reasons for the appearance of cerebellar ataxia are also very numerous. Below we will describe some of the most common.
There are different forms of ataxia caused by the inheritance of genetic defects that alter the synthesis of proteins necessary for the normal functioning of the nervous system, and that mainly affect the cerebellum and the spinal cord. Spinocerebellar and episodic ataxias are inherited through an autosomal dominant mechanism, while Wilson’s disease, Friedrich’s ataxia, ataxia-telangiectasia, and congenital cerebellar ataxia are transmitted by autosomal recessive inheritance.
One of the most common causes of cerebellar ataxia is traumatic brain injury; for example, it is common for the cerebellum to be damaged as a result of traffic accidents, by hitting the back of the skull against the seat.
Strokes, like ischemia, can alter circulatory flow to the cerebellum and other regions; If the tissue is devoid of nutrients and oxygen, it can become necrotic, causing damage to the affected area.
Chickenpox, Lyme disease, and other infectious diseases are common causes of this syndrome, especially in young children. It usually appears in the recovery period and usually only lasts a few weeks.
Among the autoimmune diseases that can cause symptoms of cerebellar ataxia are multiple sclerosis and sarcoidosis.
Tumors in the brain
The appearance of tumors near the cerebellum often causes damage to this structure, even in the case of benign tumors. Likewise, paraneoplastic syndromes, caused by pathological responses of the immune system to the development of cancer, have also been associated with cerebellar ataxia.
Substance exposure and use
Exposure to elements toxic to the human body such as lead and mercury can cause symptoms of cerebellar ataxia; the same is true with chemotherapy. The abusive consumption of alcohol or some types of anxiolytics, especially barbiturates and benzodiazepines, can cause harmful reactions in the cerebellum and the rest of the nervous system.
Cerebellar ataxia treatment
Since cerebellar ataxia can appear as a consequence of a large number of causes, the most appropriate treatment for each case will depend on the specific alteration that has caused the symptoms. This multiplicity of causal factors makes identification of the underlying problem particularly important in ataxia. There is no medicine to specifically treat the symptoms of ataxia. If the ataxia is due to a hit, a low vitamin level, or exposure to a toxic or chemical drug, then treatment would consist of shock treatment, vitamin therapy, or avoiding the toxic or chemical drug cause. Many patients with hereditary and idiopathic ataxia have other symptoms besides ataxia. Medication or other therapies may be appropriate for some of these symptoms, which may include tremor, stiffness, depression, spasticity, and sleep disorders, among others. Theacute cerebellar ataxiasthey tend to gradually disappear in a matter of weeks; Conversely, by definition, chronic ataxia is more difficult to treat and may have to be managed only by supportive therapy. Rehabilitation can be effective in reducing posture and motor problems. Therapeutic programs focused on exercises that work coordination and balance are applied with some frequency. Buspirone, an anxiolytic from the group of azapirones, has been shown to be useful in the treatment of mild and moderate symptoms of cerebellar ataxia, although it is not so in more severe cases. Its effects are associated with increased serotonin levels in the cerebellum. In recent years, research has begun into the therapeutic efficacy of transcranial stimulation of the cortex of the cerebellum in order to enhance its inhibitory activity on movement. The results so far are encouraging but more research is required to consolidate these interventions in cases of cerebellar ataxia.