Overview – Corticobasal degeneration
Corticobasal degeneration (CBD) is a rare condition that can cause gradually worsening problems with movement, speech, memory and swallowing.
It’s often also called corticobasal syndrome (CBS).
CBD is caused by increasing numbers of brain cells becoming damaged or dying over time.
Most cases of CBD develop in adults aged between 50 and 70.
The symptoms of CBD get gradually worse over time. They are very variable and many people only have a few of them.
Symptoms can include:
- difficulty controlling your limb on one side of the body (a “useless” hand)
- muscle stiffness
- shaking (tremors), jerky movements and spasms (dystonia)
- problems with balance and co-ordination
- slow and slurred speech
- symptoms of dementia, such as memory and visual problems
- slow, effortful speech
- difficulty swallowing
One limb is usually affected at first, before spreading to the rest of the body. The rate at which the symptoms progress varies widely from person to person.
Read more about the symptoms of CBD.
What causes CBD?
CBD occurs when brain cells in certain parts of the brain are damaged as a result of a build-up of a protein called tau.
The surface of the brain (cortex) is affected, as well as a deep part of the brain called the basal ganglia.
Tau occurs naturally in the brain and is usually broken down before it reaches high levels. In people with CBD, it isn’t broken down properly and forms harmful clumps in brain cells.
CBD has been linked to changes in certain genes, but these genetic links are weak and the risk to other family members is very low.
There’s no single test for CBD. Instead, the diagnosis is based on the pattern of your symptoms. Your doctor will try to rule out other conditions that can cause similar symptoms, such as Parkinson’s disease or a stroke.
You may need to have a brain scan to look for other possible causes of your symptoms, as well as tests of your memory, concentration and ability to understand language.
The diagnosis must be made or confirmed by a consultant with expertise in CBD. This will usually be a neurologist (a specialist in conditions affecting the brain and nerves).
Treatments for CBD
As someone with CBD can be affected in many different ways, treatment and care is best provided by a team of health and social care professionals working together. Treatments may include:
- medication – to improve stiffness and muscle spasms, sleep and mood, pain or memory
- physiotherapy – to help with movement and balance difficulties
- speech and language therapy – to help with communication and swallowing problems
- occupational therapy – to improve the skills and abilities needed for daily activities at home
- palliative care and advanced care planning
There is currently no treatment that has been shown to stop CBD getting gradually worse, although treatments can reduce many of the symptoms.
Good care and assistance can help someone with CBD be more independent and enjoy a better quality of life, but the condition will eventually put them at risk of serious complications.
CBD usually changes very slowly. Many people find it helpful to plan ahead with their doctors (GP and specialist) to make decisions about what to do in later stages of the illness.
Difficulty swallowing can cause choking, or inhaling food or liquid into the airways. This can lead to pneumonia, which can be life-threatening.
As a result of these complications, the average life expectancy for someone with CBD is around 6 to 8 years from when their symptoms start. However, this is only an average and CBD is very variable.
Information about you
If you have CBD, your clinical team will pass information about you on to the National Congenital Anomaly and Rare Diseases Registration Service (NCARDRS).
This helps scientists look for better ways to prevent and treat this condition. You can opt out of the register at any time.
Page last reviewed: 20 August 2018
Next review due: 20 August 2021
Read about corticobasal degeneration (CBD), a rare condition where brain cells become damaged over time and certain sections of the brain start to shrink.
Signs and Symptoms
The gradual loss of brain tissue and symptoms typically begin between ages 45 and 70. Initial symptoms include stiffness; shaky, slow or clumsy movements; and difficulty with speech and comprehension.
Other symptoms include:
- Balance Difficulty walking and balancing
- Memory Short-term memory problems, such as repeating questions or misplacing objects
- Muscle Control Difficulty controlling muscles of the face and mouth
- Speech Progressive difficulty speaking and difficulty comprehending language
Symptoms related to muscle control usually begin on one side of the body and spread gradually to the other.
There may be difficulties in completing specific tasks, such as opening a door or brushing one’s teeth or using tools such as a can opener. When a leg is affected, a patient may have problems with complex movements such as dancing. As the disease progresses, a patient may begin to trip and fall. A patient also may experience uncontrollable movement of an arm or leg.
In the past, patients have been diagnosed on the basis of movement problems that appear similar to Parkinson’s disease. CBD patients also experience many symptoms that are not characteristic of Parkinson’s and it is sometimes referred to as a “Parkinson’s-plus”‘ syndrome.
Some patients experience memory or behavioral problems. They may have difficulty with expression of language, such as finding the right word or name. Reading, writing and simple mathematical calculations also may be impaired. Personality changes, inappropriate behavior and repetitive and compulsive activities similar to those in frontotemporal dementia are common in CBD.
A person with the disease often becomes immobile five years after symptoms emerge. Within 10 years, pneumonia or other bacterial infections may lead to life-threatening complications.
Significant advances in the understanding of CBD have been made and the UCSF Memory and Aging Center is actively involved in researching the cause and course of the disease.
UCSF Health medical specialists have reviewed this information. It is for educational purposes only and is not intended to replace the advice of your doctor or other health care provider. We encourage you to discuss any questions or concerns you may have with your provider.
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Gradual loss of brain tissue and symptoms typically begin between ages 45 and 70. Initial symptoms include stiffness; shaky, slow or clumsy movements; and more.