Alien Hand Syndrome

What is alien hand syndrome?

Alien hand syndrome occurs when your hand or limb (arm) acts independently from other parts of your body. It can feel like your hand has a mind of its own. Though rare, it can also sometimes affect your legs.

With this condition, you aren’t in control of what your hand does. Your hand doesn’t respond to your direction and performs involuntary actions or movements.

Your hand may lift and levitate in the air. It may grab objects and not let them go. Your hand can undo previously completed actions, like untying your shoes after you just finished tying them. Your leg may move or step involuntarily.

This phenomenon can be a terrifying experience. You might feel like you’ve entered a horror movie and someone or something else is controlling this part of your body.

Alien hand syndrome can happen with several underlying conditions or trauma, as well as after some types of brain surgery.

This condition isn’t common. You may hear a healthcare provider refer to it as alien limb syndrome or “Dr. Strangelove syndrome” (named after a character in a 1964 film of the same name).

What are the types of alien hand syndrome?

There are five types of alien hand syndrome:

• Diagnostic dyspraxia (intermanual conflict). One of your hands acts independently from the other.
• Alien hand sign. You believe that your hand isn’t your own.
• Anarchic hand syndrome. Your hand performs a task that you have no control over.
• Supernumerary hand. You feel like you have an extra limb.
• Levitating hand. Your hand raises on its own.

What are the symptoms of alien hand syndrome?

The symptoms of alien hand syndrome vary but could include the following involuntary actions or tasks performed by one hand outside of your control:

• Touching parts of your body, clothing, objects, etc.
• Holding objects and not being able to release them
• Raising your hand
• Waving or moving your fingers
• Difficulty performing tasks using both hands
• Walking or stepping (if it affects a leg)

You might try to turn on a light switch with one hand, and your affected hand turns it off. Your affected hand might pick up an object, and you need to use your unaffected hand to pry the object out of it. You could be reading a book, and your affected hand lifts up from the binding and rests in the air like it’s floating above your head. Your affected hand could slap you repeatedly and potentially cause injury.

Other symptoms that can happen with alien hand syndrome may include:

• Weakness in an arm or leg
• Difficulty speaking (aphasia)
• Trouble identifying touched and seen objects (anomia)
• Difficulty reading and writing (when previously able to)

Which hand does alien hand syndrome affect?

The affected hand varies based on the location of a lesion or injury in your brain, for example:

• Left medial frontal lobe: Right hand
• Corpus callosum: Left hand
• Right parietal lobe: Left hand

Some cases can affect a leg. Other cases can affect both hands.

What causes alien hand syndrome?

A lesion or injury to one of the following areas of the brain causes alien hand syndrome:

• Corpus callosum: The middle of your brain between the right and left hemispheres
• Parietal region: The top, back part of your brain, under the crown of your skull
• Frontal region: The part of your brain behind your forehead

Any type of trauma to these areas of your brain may happen after:

• Surgery (like a corpus callosotomy, deep brain stimulation or removing a tumor in the frontal lobe)
• An underlying condition

When you want to move your hand, a network of neurons (nerve cells) in your brain turn on (activate). If you have alien hand syndrome, the activation only happens in certain areas of the brain (isolated activation). This shows that nerve cells aren’t activating or communicating as they should.

What conditions cause alien hand syndrome?

Several conditions can lead to alien hand syndrome, including but not limited to, the following:

• Alzheimer’s disease
• Brain tumor
• Corticobasal syndrome (CBS)
• Creutzfeldt-Jakob disease (CJD)
• Intracranial hemorrhage
• Migraine aura
• Multiple sclerosis
• Parkinson’s disease
• Parry-Romberg syndrome
• Subdural hematoma

While extremely rare, a few reported cases occur with stroke.

What are the risk factors for alien hand syndrome?

You may be more at risk of developing alien hand syndrome if you have a condition that targets:

• Nerve cells (neurodegeneration)
• The protective cover (myelin) around nerve cells (demyelination)
• Prion proteins (prion disease)

Most cases of alien hand syndrome affect adults, but it can also affect children.

What are the complications of alien hand syndrome?

Involuntary actions can have a major effect on how you feel about your body and your mental health. When you can’t regulate the actions of part of your body, you might stop recognizing the affected hand or limb as your own. This can cause:

• Depression
• Anxiety
• Fear or paranoia

In addition, alien hand syndrome can cause injury. Your affected hand may grab objects that you shouldn’t touch, such as a hot pan or a sharp knife blade. You may also physically injure yourself with a slapping or punching movement.

How is alien hand syndrome diagnosed?

There isn’t a specific test to diagnose alien hand syndrome. A healthcare provider will review your symptoms and observe your movements during a physical exam. Let them know if you had brain surgery or a head injury.

Several medical conditions can cause involuntary movements. Tests can rule out conditions with similar symptoms. Your provider may order an imaging test like an MRI (magnetic resonance imaging) to look for lesions in your brain.

How is alien hand syndrome treated?

A healthcare provider may offer treatment options to manage any underlying conditions or reduce symptoms of alien hand syndrome, like:

• Medications. A provider may treat involuntary movements with antiseizure medications or neuromuscular blocking agents. Other medications may be an option depending on what symptoms you experience.
• Botulinum toxin injections. Botulinum toxin (Botox^®) can temporarily prevent muscle movement in an area of your body. This can help with involuntary movements, but repeat treatment is necessary after several months.
• Mirror box therapy. A mirror can create an illusion to convince your brain to believe that one of your limbs moved voluntarily and is within your control.
• Distractions. If your affected hand grasps objects often, you can place a ball or soft object within reach to distract it. You can also place this hand in a pocket to prevent any unanticipated actions.
• Therapies. A provider may recommend physical therapy, occupational therapy or cognitive behavioral therapy to improve your physical and mental health.

Can alien hand syndrome be prevented?

There isn’t a known way to prevent alien hand syndrome. It happens after conditions, surgeries or injuries to your brain. You can protect yourself from injury by wearing a helmet when applicable, for example.

You may be able to reduce how often symptoms affect you by:

• Occupying your affected hand (giving it something to hold on to)
• Putting your hand in your pocket or wearing a glove or mitten
• Giving your affected hand verbal commands
• Following muscle relaxation techniques

Some of these may work better than others. Each person’s body reacts differently.

Is there a cure for alien hand syndrome?

There is no known cure available for alien hand syndrome.

How long does alien hand syndrome last?

The length of this phenomenon varies from person to person. The shortest reported case lasted for 30 minutes. Other reports note alien hand syndrome can last for several days to years. Treatment can help you manage symptoms and better your mental health.

When should I see a healthcare provider?

If you experience involuntary movements, contact a healthcare provider. While rare, some cases of alien hand syndrome can indicate a stroke. If you experience stroke-like symptoms (one-sided weakness, vision changes, confusion, etc.), contact 911 or your local emergency services number.

What questions should I ask my healthcare provider?

• What caused this condition?
• What treatment options do you recommend?
• Are there side effects of treatment?
• How can I improve my mental health?
• How can I distract my affected hand?