Apraxia

Excerpt

Apraxia is the inability to perform skilled movements, whether they have been previously learned or can be immediately imitated by observing or carrying out the instructions of another individual. Diagnosis involves ruling out weakness, sensory dysfunction, comprehension deficits, or incoordination as potential causes. Initially, Hugo Karl Liepmann classified apraxia into 3 types—limb-kinetic, ideomotor, and ideational. Liepmann's descriptions laid the groundwork for today's characterizations. However, the concept of apraxia now comprises a broader spectrum of subtypes compared to those originally identified by Liepmann. Broadly, apraxia can be classified based on specific tasks performed or general actions taken. Unfortunately, the subtypes of apraxia are not defined consistently in the literature.

Major forms of apraxia are listed below.

1. General

   1. Ideational: Loss of neural encoding of the concept of a previously known skill

   2. Ideomotor: Impaired connection between the concept of a skill and its motor output

   3. Limb-kinetic: Loss of the motor output associated with a given skill

   4. Conceptual: Loss of ability to use tools

1. Task-specific

   1. Speech

   2. Specific constructional: Difficulty in drawing, constructing, or copying

The term "ideational apraxia" is sometimes alternatively used to describe the loss of the ability to perform a sequence of movements. In contrast, "conceptual apraxia" refers to the loss of the concept itself. However, a thorough discussion of usage differences is beyond the scope of this article.

Praxis, or the ability to carry out skilled actions, involves the activation or inhibition of neural networks in the brain. The type of apraxia manifested can vary depending on the involved neural network. Apraxia can be diagnosed by performing a comprehensive examination on patients, which includes a detailed history, neurological examination, and apraxia-specific testing. However, consensus on the best operational practices for assessing apraxia does not exist.

The management of apraxia involves addressing its underlying causes through physical, occupational, or other task-specific therapies, alongside counseling. Long-term outcomes depend on the type of apraxia and its effect on the patient's activities of daily living. Associated deficits can vary from acalculia, agraphia, and aphasia to confusion, social anxiety, and low self-esteem. Some individuals with apraxia may necessitate long-term assisted nursing care.