Abnormal posturing

Definition:

A tendency to assume a particular body position, or to move or hold one or more parts of the body in a particular way. Certain abnormal posturing behaviors can indicate specific injuries to the nervous system.

Considerations:

Abnormal posturing is a sign of serious central nervous system damage.

Normally, when a muscle contracts, the muscles on the opposite side of the joint provide some resistance to contraction. Abnormal posturing occurs when damage to the central nervous system (brain or spinal cord) results in complete or partial lack of opposition to muscle contraction in various muscle groups.

See the following types of abnormal postures:

• decerebrate posture
• decorticate posture
• opisthotonos

An affected person may alternate between different postures as his or her condition fluctuates.

Injury or inflammation of a portion of the brain, spinal cord, or nervous system is the most common cause of abnormal posturing. The particular type of posturing can reflect the type and area of nervous system involvement.

Common causes:

• increased intracranial pressure
• injury to nerves
• Reye's syndrome
• severe head injury
• uncal herniation
• transtentorial herniation
• cerebral edema

Note: There may be other causes of abnormal posturing. This list is not all inclusive, and the causes are not presented in order of likelihood. The causes of this symptom can include unlikely diseases and medications. Furthermore, the causes may vary based on age and gender of the affected person, as well as on the specific characteristics of the symptom such as quality, time course, aggravating factors, relieving factors, and associated complaints. Use the Symptom Analysis option to explore the possible explanations for abnormal posturing, occurring alone or in combination with other problems.