Corticobasal Degeneration: Causes, Symptoms & Treatment

Corticobasal degeneration represents a disease that is classified as one of the so-called tauopathies. The disease is sometimes referred to by the abbreviation CBD. In corticobasal degeneration, components of the tau protein are deposited in the human brain. As a result, the brain‘s ability to function becomes increasingly impaired over time. Basically, corticobasal degeneration is a so-called atypical Parkinson’s syndrome.

What is corticobasal degeneration?

In principle, it is easy to confuse corticobasal degeneration and Parkinson’s disease based on the typical symptoms. In fact, corticobasal degeneration represents a form of atypical Parkinson’s syndromes. These diseases are often confused with Parkinson’s. Moreover, corticobasal degeneration ranks third in terms of frequency of atypical Parkinson’s syndromes, after multisystem atrophy as well as progressive supranuclear palsy. Corticobasal degeneration usually develops over a long period of time. In the process, it leads to continuously increasing damage to the brain and its function. For this reason, corticobasal degeneration is a so-called neurodegenerative disease. The tau protein accumulates in the brain, which is also referred to as tauopathy in medical terms. The central symptoms resemble or correspond to the symptoms of Parkinson’s disease. In addition, the cognitive abilities of the affected persons increasingly deteriorate. Basically, corticobasal degeneration is a relatively rare disease. According to current knowledge, the frequency is 1:100,000. With regard to the characteristic symptoms, there are strong similarities to Parkinson’s disease. However, some symptoms of corticobasal degeneration also indicate a dementia-like disorder. However, the causes of corticobasal degeneration are different from those of Parkinson’s disease, which is why it is considered an atypical Parkinsonian syndrome.

Causes

Basically, corticobasal degeneration is a relatively rare disease. According to medical research, the cause of the disease lies in a special gene responsible for coding the so-called tau protein. The name of this gene is MAPT. In the course of corticobasal degeneration, accumulations of the tau protein occur in the brain of the affected person. The protein is primarily deposited in the area of the so-called frontal lobe. In the course of the disease, this deposition in the brain causes symptoms that are particularly associated with the death of so-called glial cells and neurons.

Symptoms, complaints, and signs

Corticobasal degeneration is associated with certain symptoms and complaints in affected patients. For example, apraxia occurs, which is primarily associated with the cerebral cortex. Also, the cognitive performance of the affected individuals decreases over time. Eventually, affected individuals suffer what is known as subcortical dementia. Corticobasal degeneration leads to an increase in muscle reflexes, and myoclonias are also possible. One of the typical symptoms of the disease is that patients perceive their limbs as foreign and not belonging to their body. The English term for this phenomenon is ‘alien limb’. In addition, there are various motor disorders, which also occur in Parkinson’s disease. At the beginning, these symptoms are often only unilateral, for example hypokinesia or rigor. In a few cases, a so-called rest tremor also occurs. In addition, dystonia is possible in the context of corticobasal degeneration, primarily affecting the neck or limbs. Some patients suffer from significant gait disturbance. In addition, some individuals exhibit facultative complaints. These include, for example, movement disorders of the eyes. Especially when dementia develops, anxiety and depression occur.

Diagnosis and disease progression

Corticobasal degeneration is diagnosed using a set procedure. If a person shows symptoms typical of the disease, consultation with a physician is indicated. The physician discusses the presenting symptoms with the patient.In the course of clinical examinations, the suspicion of corticobasal degeneration becomes stronger and stronger until finally a definite diagnosis is made. Histological laboratory tests of the brain, for example, are necessary. Imaging procedures reveal atrophies in the area of the cerebral cortex. So-called ballooned neurons also appear. Accumulations of tau proteins can be detected with appropriate tissue examinations.

Complications

Corticobasal degeneration is one of the rare diseases that rapidly and severely affect the functioning of the brain. It is caused by an increase in the components of the tau protein in the brain. This protein is deposited preferentially in the area of the frontal lobe. As a result of the deposits in the brain, various neurons and cells in the central nervous system become atrophied in affected patients. The course is similar to that of Parkinson’s disease. The complications resulting from neurodegenerative disorders are serious. All cognitive abilities of the affected person deteriorate as the symptom progresses. There is a general disturbance of motor skills, especially walking, movement disorders of the eyes and speech difficulties. This is followed by a rapid increase in muscle reflexes and muscle twitching. In a short time, signs of subcortical dementia become noticeable. Due to the severe physical and mental degeneration, affected persons react with depression and anxiety. In addition, the patient is overcome by the feeling of seeing their own limbs as alien. Corticobasal degeneration can only be detected by clinical procedures as well as imaging methods. So far, there is no therapy against the symptom. It is limited to alleviating the suffering of the affected person and to maintaining cognitive and mental abilities as far as possible. However, diseased patients usually succumb to the symptom within a few years.

When should you see a doctor?

If cramping and numbness in the muscles are noticed, corticobullous degeneration may be underlying. An appointment with a primary care physician is indicated if the signs of disease increase and/or persist over a long period of time. If the characteristic foreign sensation in the muscles develops, medical advice is needed. Signs of rigor or hypokinesia also require prompt evaluation by the primary care physician. Individuals who have been diagnosed with corticobial degeneration should see a doctor regularly. The individual symptoms should be treated by different specialists. Depending on the symptom complex, these may include neurologists, orthopedists, and physical therapists. Due to the severity of the disease and the expected negative prognosis, a psychologist should also be consulted. Even with a positive course, regular visits to the doctor are necessary, as new symptoms can always develop. In addition, the functional capacity of the brain tends to decrease, which is why a neurologist must regularly perform appropriate brain examinations. Externally, corticobullous degeneration is not initially visible. As the genetic disease progresses, it can lead to abnormal posture and motor dysfunction, which must be clarified by a physician.

Treatment and therapy

To date, there are no therapeutic measures capable of halting the progression of corticobasal degeneration. In general, most patients die about one to eight years after the diagnosis of the disease is made. Possibilities for a cure are not yet known. In some cases, the drug levodopa improves symptoms resembling Parkinson’s disease. Basically, corticobasal degeneration progresses in such a way that the affected patients suffer from increasingly severe disturbances in the ability to move. This also leads to akinesia. Numerous individuals suffering from corticobasal degeneration ultimately die from inflammation of the lungs caused by the lack of movement.

Outlook and prognosis

The prognosis for corticobasal degeneration, which progresses slowly but inexorably, is poor. The symptoms of corticobasal degeneration are similar to those seen in Parkinson’s disease. However, as they progress, they are perceived as atypical Parkinson’s symptoms. The cognitive abilities of those affected also increasingly decline. Their movements slow down increasingly. Corticobasal degeneration is caused genetically. It occurs very rarely.Doctors treat it as an atypical Parkinson’s syndrome. However, to date, there are no effective and independent therapeutic approaches to alleviate the symptoms of corticobasal degeneration, which occurs rarely. The disease progresses without being able to be slowed or stopped by medication. A characteristic feature for distinguishing corticobasal degeneration from Parkinson’s disease is that affected individuals perceive their own extremities as not belonging to them. The increasing dementia and the emerging variety of symptoms worsen the prognosis increasingly. There is no treatment option for corticobasal degeneration. At best, the symptoms of Parkinson’s disease can be improved somewhat by drug therapy. However, the drugs administered often have a poor response in this atypical Parkinson’s disease. The increasing movement disorders make the patients less and less mobile. As a result of increasing immobility, many affected individuals die of pneumonia between one and ten years after diagnosis.

Prevention

According to the current state of medical knowledge, corticobasal degeneration cannot be prevented. This is because the development of the disease is related to a genetic component over which affected individuals have no control.

Follow-up

In most cases, only a few measures of aftercare are available to the patient with this disease. First and foremost, this should be a quick and further an early diagnosis of the disease to prevent further complications or discomfort. As a rule, the disease cannot be cured on its own, so that the patient should always consult a doctor if he or she experiences symptoms of the disease. The earlier the disease is detected, the better the further course of the disease usually is. In most cases, patients are dependent on taking various medications. The doctor’s instructions must always be followed, including the correct dosage and also regular intake. If there are any uncertainties, questions or side effects, a doctor should always be consulted first. Furthermore, those affected should protect their lungs particularly well, as this disease can often lead to inflammation. In most cases, the life expectancy of the affected person is severely limited due to the disease. In this context, loving and empathetic conversations with one’s own family are not infrequently very important in order to prevent depression and other psychological complaints.

This is what you can do yourself

Self-help options are relatively limited for individuals with corticobasal degeneration. Affected individuals suffer tremendous impairment of their quality of life and are no longer able to manage their daily lives independently. In particular, the rapid decline in cognitive performance as well as the disturbances in the motor area lead to the fact that patients with corticobasal degeneration are dependent on the help of other people regarding care and nursing. Due to the difficulties in walking, the patients are usually forced to use a wheelchair. In order to improve the quality of life, patients adapt their homes to the use of a wheelchair and redesign the furnishings. In this way, sufferers still retain some of their independence. In addition, patients perform physical therapy with a physical therapist to improve their motor skills and fitness. Sports activities usually have a positive effect on the mental and emotional state. However, these must be coordinated with a physician and, moreover, are not capable of completely halting the progression of corticobasal degeneration. Corticobasal degeneration is still not curable, so that some of the patients suffer from anxiety attacks and depression, which are also caused by the severe physical changes.