Definition

Opisthotonos is a condition in which a person holds their body in an abnormal position. The person is usually rigid and arches their back, with their head thrown backward. If a person with opisthotonos lies on their back, only the back of their head and heels touch the surface they are on.

Alternative Names

Back arching; Abnormal posturing - opisthotonos; Decerebrate posture - opisthotonos

Considerations

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

Causes

Opisthotonos may occur in infants with meningitis. This is an infection of the meninges, the membranes that cover the brain and spinal cord. Viruses, malaria, and syphilis are infections associated with opisthotonos. 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
• Cerebral palsy
• Gaucher disease, which causes a buildup of fatty tissue in certain organs
• Growth hormone deficiency (occasionally)
• Poisoning including strychnine, some street drugs, and some medicines
• Metabolic disorders that run in families, such as glutaric aciduria and organic acidemias, Krabbe disease, maple syrup urine disease, and others
• Seizures
• Severe electrolyte imbalance
• Traumatic brain injury
• Stiff-person syndrome (a condition that makes a person rigid and have spasms)
• Bleeding in the brain
• Tetanus

Some antipsychotic medicines 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 opisthotonos due to alcohol withdrawal.

Home Care

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

When to Contact a Medical Professional

Go to the emergency room or call 911 or the local emergency number if symptoms of opisthotonos occur. Typically, opisthotonos is a symptom of other conditions that are serious enough for a person to seek medical attention.

What to Expect at Your Office Visit

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

Your health care provider will perform a physical examination and ask about symptoms to look for the cause of opisthotonos

Questions may include:

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

The physical examination will include a complete checkup 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

Treatment will depend on the cause. For example, if meningitis is the cause, medicines may be given.

References

Berger JR, Price R. Stupor and coma. In: Jankovic J, Mazziotta JC, Pomeroy SL, Newman NJ, eds. Bradley and Daroff’s Neurology in Clinical Practice. 8th ed. Philadelphia, PA: Elsevier; 2022:chap 5.

Birch TB, Bleck TP. Tetanus (Clostridium tetani). In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 9th ed. Philadelphia, PA: Elsevier; 2020:chap 244.

Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM. Defects in metabolism of amino acids. In: Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Textbook of Pediatrics. 21st ed. Philadelphia, PA: Elsevier; 2020:chap 103.