Apraxia

What apraxia is

Movement involves two steps: deciding what to do and planning the precise sequence of muscle actions. Apraxia is a failure of the second step. The brain's "motor plan" is damaged or cannot be accessed. A person with apraxia may:

• be unable to wave goodbye when asked, but wave spontaneously when someone leaves
• hold a comb upside down or use a toothbrush as if it were a pen
• know what they want to say but be unable to coordinate the lips and tongue to say it

Apraxia is not caused by weakness, paralysis, poor coordination from cerebellar disease, numbness, or failing to understand the instruction. Doctors check these first.

Types of apraxia

Causes

• Stroke: the most common cause in adults. Damage to the left parietal and frontal lobes often causes limb apraxia and apraxia of speech, frequently together with aphasia (language difficulty).
• Dementia: apraxia develops in Alzheimer's disease as the disease progresses, and is prominent early in corticobasal degeneration, where one hand may feel "alien".
• Traumatic brain injury.
• Brain tumors and infections.
• Primary progressive apraxia of speech: a rare neurodegenerative condition in which speech planning gradually worsens.
• Normal pressure hydrocephalus: causes gait apraxia with memory problems and urinary incontinence.

Developmental forms

• Childhood apraxia of speech (CAS): children have difficulty planning speech movements. Signs include limited babbling, late first words, inconsistent errors on the same word, and difficulty with longer words. It is uncommon and needs diagnosis by a speech-language pathologist.
• Developmental coordination disorder (dyspraxia): difficulty learning motor skills such as handwriting, dressing, riding a bike and ball games, out of keeping with the child's age and intelligence.

Apraxia vs dyspraxia

The terms overlap. In the US, apraxia usually means a loss of ability after brain damage, while dyspraxia describes a developmental difficulty with motor coordination, now formally called developmental coordination disorder. In the UK, "dyspraxia" is the common name for DCD.

Diagnosis

A neurologist, occupational therapist or speech-language pathologist will ask the person to:

• perform gestures on command (wave, salute, blow a kiss)
• pantomime using objects (comb hair, brush teeth)
• use real objects
• copy the examiner's movements and drawings
• repeat words and sentences of increasing length

Brain imaging, usually MRI, identifies the cause, such as stroke, tumor or atrophy. Cognitive testing assesses for dementia.

Treatment

There is no medicine for apraxia itself. Therapy aims to improve function and independence:

• Occupational therapy: breaking tasks into steps, practicing real activities in real settings, using cues, and adapting tools and the environment.
• Physical therapy: for gait apraxia and safe mobility.
• Speech-language therapy: for apraxia of speech, using intensive, repetitive practice of sound sequences, visual and touch cues, rhythm and melody. Augmentative and alternative communication (AAC) devices can support communication.
• For children: frequent individual speech therapy sessions for CAS, and occupational therapy and school support for DCD.
• Treat the cause: stroke rehabilitation, tumor treatment or shunting for normal pressure hydrocephalus.

Outlook

After a stroke, apraxia often improves over weeks to months, especially with rehabilitation. Apraxia from progressive diseases gradually worsens, but therapy and adaptations help maintain independence for longer. Children with CAS usually make good progress with intensive therapy, though some have lasting speech differences.

Frequently asked questions

What is apraxia?

Apraxia is a neurological condition in which a person cannot carry out learned, purposeful movements on command, even though their muscles work and they understand the request. It results from damage to brain areas that plan movement, most often from stroke.

What are the main types of apraxia?

The main types are ideomotor apraxia (difficulty with gestures and pretending to use tools), ideational apraxia (difficulty using objects or sequencing tasks), apraxia of speech, buccofacial apraxia, dressing apraxia and constructional apraxia.

What is the difference between apraxia and aphasia?

Aphasia is a language disorder affecting understanding or producing words. Apraxia of speech is a motor planning disorder affecting the mouth movements needed to say words. They often occur together after a left-sided stroke, but are treated with different approaches.

Can apraxia be cured?

Apraxia caused by stroke or brain injury often improves substantially with therapy, though some difficulties may remain. Apraxia from progressive conditions such as dementia worsens over time. Childhood apraxia of speech usually improves greatly with intensive speech therapy.