Corticobasal degeneration (CBD) is a rare condition where brain cells become damaged over time and certain sections of the brain start to shrink.
CBD is a progressive condition, which means that the initial symptoms will become more severe over time, and new symptoms may also develop.
Initial symptoms of CBD include:
- sudden difficulties in controlling certain limbs
- loss of balance and co-ordination (the medical term for this is ataxia)
As the condition progresses symptoms become more wide ranging and troublesome, such as:
- muscle spasms and stiffness
- ongoing decline of mental functions (dementia)
- difficulties swallowing food and liquid (dysphagia)
- difficulties with speaking
Read more about the symptoms of corticobasal degeneration
What causes CBD?
In CBD, brain damage occurs because a protein called tau, which is normally found in low levels inside the brain, starts to build up and form clumps which kill nearby brain cells.
This damages vital parts of the brain, such as the cortex and the basal ganglia, that are responsible for important functions such asincluding:
- movement
- speech
- higher thought processes such as planning and understanding
Exactly why there is an excess of tau protein that forms clumps is still unknown.
Read more about the causes of corticobasal degeneration.
Treating CBD
There is no cure for CBD. A number of medications, such as memantine, have been suggested to slow the progression of CBD symptoms and improve the function of the brain, but it is still unclear how effective they are.
Most of the treatments for CBD focus on relieving symptoms and helping people cope better with daily life, such as medication to relax muscles and using feeding tubes to overcome dysphagia.
Read more about treating corticobasal degeneration.
Who is affected
CBD is a rare condition.
It is difficult to be entirely accurate as it is often misdiagnosed as another condition, such as a stroke, or progressive supranuclear palsy, which share similar symptoms.
A recent estimate was that 1 in every 20,000 people are currently living with CBD.
Most cases of CBD affect people who are 60-80 years of age and it may be more common in women than in men, but because the condition is so rare, it is difficult to be entirely certain.
The number of reported cases of CBD have risen sharply in the last twenty years. It is unclear whether this is due to CBD becoming more widespread or doctors being better at diagnosing the condition.
Outlook
Although CBD itself isn’t life-threatening, it can lead to serious complications. One of the most common complications is difficulties with swallowing (dysphagia) which can cause a person to choke or inhale food or liquid into the airway (aspiration). Aspiriation can develop into pneumonia, which can be fatal.
Read more about the complications of CBD.
Most people with CBD will not live longer than ten years after the symptoms start.
