Movement disorders

What are movement disorders?

Movement disorders are conditions that affect your nervous system and change the way your body moves. They can make you move more than you mean to, such as shaking or jerking, or make your movements slower and harder to start.

What are the symptoms of a movement disorder?

Movement disorders affect everyone differently. Some people barely notice their symptoms, while for others they get in the way of everyday activities. Most movement disorders cause one of two things: movement that happens more than you want, or movement that becomes slow and hard to start.

• uncontrolled movements such as tremors, jerks, spasms, twitching or twisting
• trouble with coordination, or keeping your balance
• finding it hard to do things like write, eat or speak clearly
• changes to your walking or gait
• stiffness in your limbs and trunk.

These symptoms can affect one part of your body or several, including your limbs, hands, feet, face, head, neck, trunk or voice. Some movement disorders also affect your mood or thinking, alongside the physical symptoms.

Parkinson's disease is the most common movement disorder, and it shows how these symptoms can build up over time. Doctors look for three signs when diagnosing it:

• slowness of movement (bradykinesia)
• tremor
• stiffness (rigidity).

A fourth sign, trouble with balance, usually shows up further down the line. Only around half of people with Parkinson's disease will ever experience tremor.

What causes movement disorders, and who is at risk?

Movement disorders usually happen because of damage to, or a problem with, the parts of your brain in charge of movement, including regions called the basal ganglia and the cerebellum.

Causes include:

• genetic conditions passed down in families
• damage to your brain or the nerves that carry its signals around your body, including from a stroke or injury
• infections
• toxins
• problems with how your body processes certain substances (metabolic disorders)
• side effects of some medicines.

Not every movement disorder comes from physical damage to the nervous system. Functional movement disorders happen when your body responds to stress or emotional strain with real, physical movement problems, even though your scans and blood tests come back normal.

Age can increase the risk of movement disorders. Essential tremor is most common in adults over 65, and your risk of Parkinson's disease also rises as you get older, although 4% of people with Parkinson's are diagnosed before they turn 50.

Some movement disorders run in families. About half of people with essential tremor have a close relative with the same condition. Huntington's disease passes directly from parent to child: if one of your parents has it, you have a one in two chance of developing it too.

Are there different types of movement disorder?

Movement disorders come in many forms. Doctors often group them by whether they cause too much movement, or too little.

Conditions that cause more movement than usual:

• Tremor: shaking or trembling you can't control, which may affect a single limb or several parts of the body.
• Dystonia: muscles contract without you meaning them to, causing twisting movements or unusual postures.
• Chorea: quick, jerky, dance-like movements you can't control, often seen in people with Huntington's disease.
• Myoclonus: sudden, brief jerks or twitches that you can't control, which may affect a single muscle or several at once.
• Tics: repeated, patterned movements or sounds, such as blinking or throat-clearing, seen in Tourette syndrome.
• Spasticity: muscles tighten all at once, making it hard to move normally.

Conditions that cause slower or reduced movement:

• Parkinsonism: a general term covering slowness, stiffness, tremor and poor balance, most often caused by Parkinson's disease.
• Bradykinesia: your movements become slow, and may hesitate or stop and start as you're doing them.

Specific named conditions:

• Essential tremor: uncontrollable shaking, usually in the hands and arms.
• Huntington's disease: an inherited condition that causes jerky, uncontrollable movements and a gradual decline in mental abilities.
• Multiple system atrophy: a rare condition that damages several brain areas, causing balance problems and a sharp drop in blood pressure on standing.
• Progressive supranuclear palsy: a rare disorder that affects walking, balance, speech, swallowing and how your eyes move.
• Restless legs syndrome: a strong need to move your legs, often with an uncomfortable creeping or tingling feeling.
• Tardive dyskinesia: movements you can't control, such as grimacing, lip-smacking or blinking, that develop after long-term use of certain antipsychotic medicines.
• Tourette syndrome: repeated tics, movements or sounds you can't control, often alongside anxiety or obsessive-compulsive disorder.
• Wilson's disease: a rare inherited condition where copper builds up in your brain and liver, causing tremor and stiff muscles.

Functional movement disorders are a bit different. They can produce the same kinds of movement you'd see with dystonia or tremor, but the trigger is stress or psychological strain, not damage to your brain or nerves.

Scans and blood tests usually come back normal, so a specialist looks for specific clinical signs instead, such as symptoms that ease with distraction or come on suddenly after a stressful event.

How are movement disorders diagnosed?

Because movement disorders can be complex and look like other conditions, your doctor will usually start with a detailed conversation about your symptoms and medical history, followed by a physical and neurological examination.

• blood tests, which can point to a specific cause or rule other conditions out
• electromyography (EMG), which tests how well your muscles and their nerve connections are working
• electroencephalogram (EEG), which picks up the electrical signals produced by your brain
• a lumbar puncture (sometimes called a spinal tap), which takes and tests a small sample of the fluid that cushions your central nervous system
• a muscle biopsy, which takes a small tissue sample to work out whether a nerve or a muscle is behind your symptoms
• a nerve conduction study, which measures how quickly electrical signals travel along a nerve on their way to a muscle
• imaging scans, such as a CT or MRI scan, to get a detailed picture of your brain and the nerves in your body.

If your doctor suspects a functional movement disorder, there's no blood test or scan that can confirm it. Instead, a specialist looks for specific clinical signs, for example, whether your symptoms started suddenly after a stressful event, come and go, ease when you're distracted, or change with a specific suggestion during the examination.

How are movement disorders treated?

For most movement disorders, there's currently no cure. Instead, treatment aims to control your symptoms and help you stay as independent as possible. Some, such as movement problems caused by a medicine you're taking, can improve once the medicine or dose is changed.

Non-surgical treatment

• medicines to ease specific symptoms, such as dopaminergic drugs for Parkinson's disease and restless legs syndrome, or muscle relaxants such as baclofen for spasticity
• physical therapy, to help you manage stiffness, pain and movement problems
• occupational therapy, to help you carry out daily tasks safely
• speech therapy, to help if you're having difficulty speaking, communicating or swallowing
• mobility aids, such as canes, walkers or wheelchairs
• psychotherapy (talking therapy), to help with anxiety, depression or stress that can come with a movement disorder
• botulinum toxin (Botox) injections, to relax specific muscles affected by conditions such as dystonia or spasticity.

If you have a functional movement disorder, treatment usually involves a team of professionals working together, such as a neurologist, a psychologist or psychiatrist, and physiotherapists, alongside talking therapies and, sometimes, antidepressant medicines.

Surgical treatment

If medicines and therapy haven't helped enough, your doctor may discuss surgery. Deep brain stimulation involves placing a thin wire in a specific part of your brain and connecting it to a small device that sends electrical signals to help control your movements. It's used for advanced Parkinson's disease and dystonia, as well as severe tremor.

Other surgical options include thalamotomy and pallidotomy, where a surgeon carefully damages a very small area of the brain to stop the signals causing abnormal movement. This is sometimes used for severe essential tremor or dystonia when other treatments haven't worked.

About three in four people who have a thalamotomy see their symptoms ease on that side of the body. It's rarely carried out on both sides during the same operation, since this raises the chance of losing some speech.

When should I see a doctor?

See a doctor if you notice a change in how you or your child usually move, especially if it's affecting your daily activities or getting worse over time. The sooner a movement disorder is diagnosed, the sooner treatment can start.

• you notice a change in your movement, coordination or balance
• your symptoms are getting worse or affecting your daily activities
• you notice new side effects from a medicine, or your current treatment stops working as well as it used to
• you have a scheduled appointment with your care team to monitor your condition.