Opisthotonos is a condition in which the body is held in an abnormal position. The person is usually rigid and arches the back, with the head thrown backward. If a person with opisthotonos lies on his or her back, only the back of the head and the heels touch the supporting surface.

See: Abnormal posturing

Opisthotonos is much more common in infants and children than in adults. It is also more exaggerated in infants and children because of their less mature nervous systems.

Opisthotonos may occur in infants with meningitis. It may also occur as a sign of reduced brain function or injury to the nervous system.

Other causes may include:

• Arnold-Chiari syndrome (a problem with the structure of the brain)
• Brain tumor
• Gaucher disease
• Growth hormone deficiency (occasionally)
• Glutaric aciduria and organic acidemias (forms of chemical poisoning)
• Krabbe Disease
• Seizures
• Severe electrolyte imbalance
• Severe head injury
• Stiff-person syndrome (a condition that makes a person rigid and have spasms)
• Subarachnoid hemorrhage (bleeding in the brain)
• Tetanus

Drugs such as phenothiazines and other antipsychotic medications, can cause a side effect called acute dystonic reaction. Opisthotonos may be part of this reaction.

In rare cases, infants born to women who drink large amounts of alcohol during pregnancy may have opisthotonus due to alcohol withdrawal.

A person who develops opisthotonos will need to be cared for in a hospital.

Go to the emergency room or call your local emergency number (such as 911) if this symptom occurs. Typically opisthotonos is a symptom of other conditions that are serious enough for a person to seek medical attention.

This condition will be evaluated in a hospital, and emergency measures may be taken.

The health care provider will take a medical history and perform a physical examination to look for the cause of opisthotonos

Medical history questions may include:

• When did this behavior start?
• Is it always the same type of posturing?
• What other symptoms came before or with the abnormal posturing (such as fever, stiff neck, or headache)?
• Is there any recent history of illness?

The physical examination will include a complete check of the nervous system.

Tests may include:

• Blood and urine tests
• Cerebrospinal fluid (CSF) culture and cell counts
• CT scan of the head
• Electrolyte analysis
• Lumbar puncture (spinal tap)
• MRI of the brain

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