CBD

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. This means that the initial symptoms will become more severe over time and new symptoms may also develop.

Initial symptoms of CBD include:

• sudden problems controlling certain limbs
• loss of balance and co-ordination
• slowness and reduced mobility

As CBD progresses, the symptoms will become more wide-ranging and troublesome. They will include:

• muscle spasms and stiffness
• an ongoing decline of mental functions (dementia)
• difficulty swallowing food and liquid (dysphagia)
• difficulty speaking

Read more about the symptoms of corticobasal degeneration.

What causes CBD?

The brain damage associated with CBD is caused by a build-up of a protein in the brain called tau. Tau is usually found in low levels in the brain, but in CBD it forms clumps that kill nearby brain cells.

This damages vital parts of the brain, such as the cortex and basal ganglia, which are responsible for important functions, including:

• movement
• speech
• higher thought processes, such as planning and understanding

Exactly why tau protein builds up and forms clumps isn't known.

Read more about the causes of corticobasal degeneration.

Diagnosing CBD

There's no single test for diagnosing CBD. Instead, a diagnosis will be made based on the type and pattern of symptoms and by ruling out other conditions that can cause similar symptoms, such as a stroke, Parkinson’s disease, motor neurone disease and more common types of dementia.

As CBD shares symptoms with a number of other more common conditions, confirming the diagnosis can be challenging and may take several months, or in some cases years.

Read more about diagnosing CBD.

Treating CBD

There's no cure for CBD. Several medications, such as memantine, have been suggested to slow down the condition's progression and improve the function of the brain, but it's not clear how effective they are.

Most treatments for CBD focus on relieving a person's symptoms and helping them cope with daily life. These include medication to relax muscles and using feeding tubes to overcome swallowing problems.

Read more about treating corticobasal degeneration.

Complications of CBD

CBD isn’t itself life-threatening, but can lead to serious complications.

Difficulty swallowing (dysphagia) is a common symptom of CBD, which increases the risk of a person choking or inhaling food or liquid into their airway (aspiration).

If this happens, aspiration pneumonia can develop. This is a lung infection that's triggered when a small piece of food enters the lungs.

Read more about the complicatons of CBD.