Cerebellar ataxia is a type of ataxia that occurs from abnormalities such as inflammation in the temporal and occipital lobes of the cerebellum. The cerebellum is located at the back of the brain close to the brainstem and below the cerebrum and is responsible for muscle movement, motor learning, and motor control. This type of ataxia causes a loss of balance and coordination and can lead to either symptom like cognitive issues, visual abnormalities, and fatigue.
Cerebellar ataxia can either be chronic or acute. Chronic ataxia is referred to as cerebellitis and is common with people who have multiple sclerosis (MS).
Individuals that have cerebellar ataxia have full cognitive awareness. The physical deterioration is usually the one that is preventing them to do their daily activities or other interests.
Cerebellar ataxia can be caused by a lot of things and it does not have one clear cause.
It may be a result of an underlying condition or a problem that can be treated like alcoholism, stroke, multiple sclerosis, and hyperthyroidism. It may also be caused by genetics because of inherited mutations. For most cases, they are idiopathic wherein the cerebellar degeneration transpires without any obvious cause or reason.
Cerebellar ataxia can also be caused by gluten ataxia which accounts for 30% of all sporadic idiopathic ataxias and 15% of all ataxias.
Other causes of ataxia can include autoimmunity to neural cells in the cerebellum including Purkinje cells, infection, vasculitis, tumors, bleeding, infarction, toxins, direct injury, and the use of a statin.
Alcoholism is a common cause of cerebellar ataxia. Abuse of alcohol for longer periods of time can damage the cerebellum that leads to a loss of proper functioning. Alcohol abuse can also damage subcortical white matter, the connective myelinated fiber tracts of the cerebral cortex, and other parts of the central nervous system. Damage to these parts of the brain leads to ataxia as the systems controlling motor skill become impaired.
The infection causes inflammation in the cerebellum that prevents it from functioning normally. Ataxia is more commonly caused by viral infections such as chickenpox but can also be caused by bacterial infections like Lyme disease. It results in an acute or sudden attack of ataxia which often affects children more than adults. This type of cerebellar ataxia is also known as acute cerebellar ataxia or acute post-infectious ataxia. It might appear in the healing stages of the infection and may last for days or for weeks. Usually, ataxia resolves over time.
Hypothyroidism is another underlying cause of cerebellar ataxia. Hyperthyroidism transpires when the thyroid gland becomes underactive and produces too little hormones. Thyroxine and triiodothyronine are thyroid hormones that control metabolism and energy consumption. Hypothyroidism causes weight gain, lethargy, and weakness. The changes in metabolism that is caused by hypothyroidism lead to cerebellar degeneration and dysfunction. Hypothyroidism can also lead to an increase in antithyroid antibodies which is believed to cause cerebellar degeneration.
- Head trauma and bleeding
A bleeding in the brain or a trauma on the head can also cause cerebellar ataxia.
Head traumas can cause inflammation, direct damage, and injury of the cerebellum.
This causes an impairment in the normal functioning of the cerebellum which could lead to cerebellar ataxia. A bleeding in the cerebellum can also cause ataxia.
- Cerebral palsy
Cerebral palsy is a result of a brain injury that takes place either before, during, or after birth. It is a condition that affects movement. Cerebellar ataxia can transpire if the brain injury damages the cerebellum. Damage to the cerebellum can be a result of an infection in the womb, head traumas during or after birth, loss of oxygen from breaching during birth or placental failure, and brain hemorrhages caused by fetal stroke.
Tumors can lead to ataxia whether they are cancerous or not. Tumors affect the structure of the cerebellum by putting pressure on it or by causing it to become inflamed.
Brain cells die when the blood supply to a part of the brain is interrupted or severely reduced depriving brain tissue of nutrients and oxygen.
- Autoimmune disease
- Paraneoplastic Syndromes
They are degenerative disorders that are rare and are triggered by the immune system’s reaction to a cancerous tumor called neoplasm, which is most common for ovarian, breast, lung, or lymphatic cancer. Ataxia can appear months and years before cancer is diagnosed.
- Toxic reaction
Ataxia can be a potential side effect of certain medicines especially sedatives and barbiturates and also chemotherapy.
Drug and alcohol intoxication, solvent poisoning, and heavy metal poisoning can also cause ataxia.
- Vitamin e & vitamin b12 or thiamine deficiency
The lack of these nutrients because of an alcohol abuse, a person’s inability to absorb enough of these nutrients, or other reasons, can also result to ataxia.
- Genetic factors
Some conditions that cause cerebellar ataxia are hereditary. You might have been born with a defect in a certain gene that makes abnormal proteins if you have any of these symptoms. The abnormal proteins impede the function of the nerve cells mostly in your spinal cord and cerebellum and cause them to degenerate.
It can also be a result of inherited mutations in the form of triplet repeat expansion.
Triplet repeat expansion is a repeated segment of DNA, also known as trinucleotide repeat, that is unstable and impedes with protein functioning. The mutations are dominant and can be transmitted easily. This kind of ataxia can also be called familial progressive cerebellar ataxia or dentato-rubro-pallido-luysian atrophy which are registered with the National Organization for Rare Disorders.
You can inherit genetic ataxia either from a dominant gene from a parent, also known as an autosomal dominant disorder, or from a recessive gene from each parent, autosomal recessive disorder.
- Idiopathic cerebellar ataxia
Other cerebellar ataxia does not have a clear cause and is the result of cerebellar degeneration that has no genetic factor. This type of ataxia is called idiopathic late onset cerebellar ataxia (ILOCA). There is a variation in the physical changes in the cerebellum of patients that have idiopathic cerebellar ataxia. Some patients reveal cerebellar cortical atrophy where Purkinje cells degenerate in the cerebellar cortex and there is a loss of facultative retrograde cells in the inferior olivary nucleus, the largest nucleus of the olivary body of the medulla oblongata which is very important in motor control.
Olivopontocerebellar atrophy can also cause idiopathic cerebellar ataxia.
These are transneuronal changes in the cerebellar hemispheres that emerge in the pontine and olivary nuclei and result in shrinking of the cerebellar. This may sometimes be inherited but most of the time, this kind of ataxia occurs idiopathically without any obvious cause. Ataxia can also be a result of unexplained changes in the cerebral cortex, thalamus, spinal cord, and basal ganglia of the central nervous system.
- Inability to coordinate balance, eye movements, and extremity
- A wide and unsteady gait when walking
- Difficulty maintaining normal upright posture
- Unsteadiness in moving platforms
- Poor hand-eye coordination
- Difficulty with fine motor tasks such as handwriting, opening jars, cutting food, buttoning clothes, typing, sewing, playing sports or instruments
- A lack of sensory capability
- Double or blurred vision
- Involuntary eye movements
- Slow and imprecise speech
- Cognitive impairment
- Difficulties in swallowing
- Increased fatigue
- Emotional difficulties
- Lack of coordination between body parts and organs
- Dysdiadochokinesia or an inability to perform quick and alternating movements
- Dyschronometria or a difficulty in estimating the passing of time
Symptoms may vary depending on the person and depend on how the cerebellum has been affected.
In order to look for signs of ataxia, clinicians often use visual observation on people while they perform motor tasks.
Another way of diagnosing ataxia is by genetically analyzing the blood samples and assessing medical histories of the family. If someone in the family has had cerebellar ataxia or there is a pattern in the family tree, the patient most likely has ataxia and is suffering from inherited autosomal dominant ataxia.
MRI Scanning is also used to diagnose cerebellar ataxia to assess inflammation or damage in the brain and cerebellum in particular.
Ataxia can be diagnosed by looking at the patient’s medical history, checking for signs and symptoms of hypothyroidism or alcoholism, and assessing the presence and severity of ataxia symptoms.
There is currently no cure for ataxia. Since cerebellar ataxia is more of a symptom rather than an actual illness, the ultimate cure is by treating the underlying condition. This is for cerebellar ataxia that is caused by an underlying condition such as alcoholism, infections, and hypothyroidism. For example for cerebellar ataxia caused by infection, simply treating the infection would also lead to recovery from ataxia. If it is caused by alcoholism, the patient should stop and stay away from drinking liquor. For hypothyroidism, the patient should undergo hormone therapy to treat the disease and to also remove the symptoms of ataxia.
Therapies and exercises are also a good idea in order to reduce the intensity of cerebellar ataxia. Occupational therapy, physical therapy, speech therapy, physiotherapy and regular aerobic exercise can alleviate cerebellar ataxia.