People with corticobasal degeneration (CBD) develop a range of difficulties with movement, speech, memory and swallowing.

The condition tends to develop gradually, which means it can be mistaken for another condition at first – such as Parkinson's disease, dementia or a stroke.

The symptoms typically become more severe over several years, although the speed at which they worsen varies.

Some of the main symptoms of CBD are outlined below. Most people with the condition won't experience all of these.

Early symptoms

CBD typically affects one of the limbs at first. This is usually a hand or arm, but sometimes a leg.

Problems affecting the limb can include:

• a clumsy or "useless" hand
• muscle stiffness
• shaking (tremors) and spasms (dystonia)
• loss of feeling
• feeling like the limb doesn't belong to you (an "alien" limb)

Some people also develop problems with walking and co-ordination.

Mid-stage symptoms

As CBD progresses, it may eventually start to cause problems in your other limbs.

Walking, balance and co-ordination may get worse. Many people have problems with their speech, which will become slow and slurred.

Some people with CBD also have dementia, although this doesn't always occur, symptoms may include:

• problems recalling words, reading and using correct language (aphasia)
• short-term memory loss
• problems carrying out tasks that require planning or thinking ahead
• problems coping with sudden and unexpected situations
• difficulty with numbers and counting
• difficulty seeing things, or knowing where they are located (such as furniture)

It's also common for someone with CBD to experience personality changes, such as becoming apathetic, irritable, agitated or anxious.

Advanced stages

As CBD reaches an advanced stage, muscle stiffness will continue to get worse. People with the condition may lose the ability to move 1 or more limbs. Some people are unable to walk and need a wheelchair or assistance to transfer (such as help getting into and out of bed).

Other problems people with advanced CBD can experience include:

• worsening speech problems, which can make it hard for others to understand you
• uncontrollable blinking
• worsening dementia, meaning constant care may be needed
• increasing difficulties swallowing, which may mean a feeding tube is required

As a result of swallowing problems, many people with CBD develop chest infections caused by fluid or small food particles falling down into their lungs (aspiration pneumonia), which can be life-threatening.

It can be difficult to diagnose corticobasal degeneration (CBD), as there's no single test for it, and the condition can have similar symptoms to a number of others.

A diagnosis of CBD will be based on the pattern of your symptoms. Your doctor will also try to rule out conditions that can cause similar symptoms, such as Parkinson's disease, a stroke, motor neurone disease and Alzheimer's disease.

Your doctor will need to carry out assessments of your symptoms, as well as other tests and scans.

The diagnosis must be made or confirmed by a consultant with expertise in CBD. This will usually be a neurologist (specialist in conditions affecting the brain and nerves).

Brain scans

If you have symptoms of CBD that suggest there's something wrong with your brain, it's likely you'll be referred for a brain scan.

Types of scan that you may have include:

• magnetic resonance imaging (MRI) scan – where a strong magnetic field and radio waves are used to produce detailed images of the inside of the brain
• positive emission tomography (PET) scan – a scan that detects the activity of the brain
• a DaTscan – to measure the amount of a chemical called dopamine that your brain is making

These scans can be useful in ruling out other possible conditions, such as brain tumours or strokes.

MRI scans can also detect abnormal changes to the brain that are consistent with a diagnosis of CBD, such as shrinkage of certain areas.

Scans that show the build-up of the tau protein in the brain that's associated with CBD are being developed.

Ruling out Parkinson's disease

A person's symptoms and signs usually help distinguish CBD from Parkinson's disease, but sometimes tests may be used to support the diagnosis and rule out other possible conditions. 

You may be prescribed a short course of a medication called levodopa. This typically works very well in Parkinson's disease, but not so well in CBD.

If it doesn't lead to a significant improvement in your symptoms, it can help your doctor distinguish CBD from Parkinson's disease.

Neuropsychological testing

It's also likely you'll be referred to a neurologist and possibly also a psychologist for neuropsychological testing.

This involves having a series of "memory tests" with words and pictures. They're designed to evaluate the full extent of your symptoms and their impact on your mental abilities.

The tests will look at abilities such as:

• memory
• concentration
• understanding language
• the processing of visual information, such as words and pictures
• numbers and counting

Most people with CBD have a distinct pattern of difficulties on these tests.

The memory of previously learned facts and the person's own life story is generally maintained.

Coping with a diagnosis

Being told that you have CBD can be devastating and difficult to take in.

You may feel numb, overwhelmed, angry, distressed, scared or in denial. Some people are relieved that a cause for their symptoms has finally been found. There's no right or wrong way to feel – everybody is different and copes in their own way.

Support from your family and care team can help you come to terms with the diagnosis.

The PSP Association (PSPA) can give you information and practical advice about living with CBD, as well as providing support to help you cope with the emotional impact of the condition.

You can get in touch with the PSPA by calling their helpline on 0300 0110 122, or by emailing: helpline@pspassociation.org.uk.

You may find that many people – even the doctors you meet – have not heard of CBD. The PSPA has online and printed information for patients, their families and professionals.

There's currently no cure for corticobasal degeneration (CBD) and no treatment to slow it down, but there are lots of things that can be done to help manage the symptoms.

Care will be provided by a team of health and social care professionals working together. This is known as a multidisciplinary team.

Members of your multidisciplinary team may include:

• a neurologist – a specialist in conditions that affect the brain and nerves
• a physiotherapist – who can help with movement and balance difficulties
• a speech and language therapist – who can help with speech or swallowing problems
• an occupational therapist – who can help you improve the skills you need for daily activities at home, such as washing, dressing, or getting around
• a social worker – who can advise you about the support available from social services
• a specialist neurology nurse – who may act as your point of contact with the rest of the team

A care plan will be drawn up in discussion with your team. This will outline the treatments you need to help with the symptoms of CBD, as well as the support and advice you require to make your life easier.

Medicine

There are currently no medicines that treat CBD specifically. Depending on the person's symptoms or complications, the following may be used:

• muscle stiffness of contractions – levodopa, amantadine, clonazepam, baclofen, gabapentin, or botulinum toxin injections to relax the muscles
• jerky movements – clonazepam or levetiracetam
• memory and related mental abilities – the medicines used to treat Alzheimer's disease may also be used in CBD, such as donepezil or memantine
• irritability or depression – medicines such as citalopram or trazodone
• sleep problems – short term use of temazepam, zopiclone, melatonin or others medicines
• bladder problems and incontinence – medicines to relax the bladder, or help it empty more regularly may be needed, such as oxybutynin or miabegron
• pain and anxiety – simple painkillers like ibuprofen, and more specialist medicines like gabapentin
• bone strength – if people are prone to regular falling, osteoporosis (weak bones) and vitamin D problems should be ruled out or treated

In general, people with CBD are sensitive to medicine side effects. Doses may start low and be increased gradually.

Some medicines should be avoided completely, such as haloperidol (a medicine used to treat some mental health problems).

Cognitive stimulation

Cognitive stimulation is a type of therapy used to treat dementia, and it may be helpful if a person with CBD has dementia symptoms.

It involves taking part in activities and exercises designed to improve your memory, problem-solving skills and language ability.

Read more about how dementia is treated.

Physiotherapy

A physiotherapist can give advice about how to remain safely mobile. Regular exercise can help strengthen your muscles, improve your posture and prevent stiffening of your joints.

They can teach you breathing exercises to use when you eat, to reduce your risk of developing aspiration pneumonia (a chest infection caused by food particles falling into your lungs).

Read more about physiotherapy.

Occupational therapy

An occupational therapist can give you advice about the best ways to increase your safety and prevent trips and falls during your day-to-day activities.

For example, a person with CBD may benefit from having bars placed along the sides of their bath to make it easier to get in and out.

The occupational therapist can also arrange access to mobility equipment such as walking frames and wheelchairs. They can also arrange equipment to help the person or their carer manage other everyday activities such as washing, dressing, eating, and using the bathroom safely.

Speech and language therapy

A speech and language therapist can help assess and treat speech and swallowing problems.

They can teach people techniques to help make the voice as clear as possible and can advise you about suitable communication aids or devices that the person may need as CBD progresses.

A therapist can also advise you about different swallowing techniques and, working together with a dietitian, they may suggest altering the consistency of your food to make swallowing easier.

Diet and severe swallowing problems

You may be referred to a dietitian, who will advise you about making changes to your diet, such as including food and liquids that are easier to swallow, while ensuring that you have a healthy, balanced diet.

Feeding tubes may be recommended for severe swallowing problems, where the risk of malnutrition, weight loss, fatigue and dehydration is increased. You should discuss the pros and cons of feeding tubes with your family and care team.

The decision about whether and when to consider a feeding tube depends on the individual and should be discussed with a specialist.

Read more about treating swallowing problems.

Palliative care

Palliative care aims to relieve pain and other distressing symptoms while providing psychological, social and spiritual support. It can be offered at any stage of CBD, alongside other treatments.

Palliative care can be received:

• in a hospice
• at home or in a residential home
• on a day patient basis in a hospice
• in a hospital

Read more about accessing palliative care.

Advanced care planning

Many people with CBD make plans for the future that outline their wishes about medical care and other decisions. They share these plans with both their family and the health professionals involved in their care.

This can be useful in case you're unable to communicate your decisions later on because you're too ill. However, you don't have to do it if you don't want to.

Issues that you may want to cover include:

• if you want to be treated at home, in a hospice or in a hospital when you reach the final stages of CBD
• if you would be willing to use a feeding tube if you were no longer able to swallow food and liquid 
• if you'd be willing to be resuscitated if your heart were to stop

If you decide to discuss these issues, they can be written down in a number of ways:

• Advance decision to refuse treatment
• Advance statement
• Emergency healthcare plan
• Preferred place of care
• Lasting Power of Attorney

Your care team can provide you with more information and advice about these decisions and how best to record them.

Read more about end of life care.

Care and support

If someone you know develops CBD, you may need information and advice about caring for them.

The NHS website guide to care and support has a wide range of useful information about all aspects of caring for others, and advice for carers themselves.

You can also contact the PSP Association (PSPA), who provide help and advice to people living with CBD. Their email address is: helpline@pspassociation.org.uk and you can call their helpline on 0300 0110 122.

The Parkinson's nurse within your local hospital may be able to provide you with useful information and support.