Opisthotonos is a condition in which the body is held in an abnormal posture. It usually involves rigidity and severe arching of the back, with the head thrown backward. If a person with opisthotonos lays on his or her back, only the back of the head and the heels would 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, where it is a sign of irritation of the membranes surrounding the brain and spinal cord (meninges).

It may also occur as a sign of depressed brain function or injury to the nervous system.

Other causes may include:

• Brain tumor
• Growth hormone deficiency (occasionally)
• Glutaric aciduria and organic acidemias (forms of chemical poisoning)
• Krabbe Disease (disorder of metabolism)
• Meningitis
• Seizures
• Severe head injury
• Stiff-person syndrome (a condition that involves worsening rigidity and spasms)
• Subarachnoid hemorrhage (bleeding in the brain)
• Tetanus
• Arnold-Chiari syndrome (a brain structure problem)
• Gaucher disease (disorder of metabolism)

Drugs, particularly phenothiazines and other antipsychotic medications, can cause a side effect known as 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.

Hospital care is required for a person who develops opisthotonos.

Go to the emergency room or call your local emergency number (such as 911) if this symptom occurs. Typically opisthotonos is a symptom that follows late in the course of other conditions, which are serious enough that medical attention will likely have already been sought.

This condition will be evaluated in a hospital setting. Emergency measures will be taken as appropriate.

The medical history will be obtained, and a physical examination will be performed.

Medical history questions documenting opisthotonos in detail may include:

• When did this behavior start?
• Is it always the same type of posturing?
• What other symptoms preceded or accompanied the abnormal posturing (particularly fever, stiff neck, headache, but also any others)?
• Is there any significant medical history (such as a recent illness)?

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

The cause of the opisthotonos will be suggested by the history and physical examination. Diagnostic tests may include:

• Lumbar punctureand analysis of the cerebrospinal fluid (CSF culture, CSF cell counts, and similar studies), electrolyte analysis
• CT scan of the head
• MRI of the head
• Blood and urine tests

Chiriboga CA. HIV, fetal alcohol and drug effects, and the battered child. In: Rowland LP, ed. Merritt's Neurology. 11th ed. Baltimore, Md: Lippincott Williams & Wilkins; 2005:chap 168.

Haemophilus influenzae meningitis is a bacterial infection of the membranes covering the brain and spinal cord (meninges).

See also:

• Aseptic meningitis
• Meningitis
• Meningitis - cryptococcal
• Meningitis - gram-negative
• Meningitis - meningococcal
• Meningitis - pneumococcal
• Meningitis - staphylococcal
• Meningitis - tuberculous

H. influenzae meningitis; H. flu meningitis

H. influenzae meningitis is caused by Haemophilus influenzae bacteria. This bacteria should not be confused with the disease influenza, an upper respiratory infection caused by the influenza virus.

Before the Hib vaccine became available, H. influenzae was the leading cause of bacterial meningitis in children under 5 years of age. Since the introduction of the vaccine in the U.S., H. influenzae now occurs in less than 2 in 100,000 children. It still causes 5% - 10% of bacterial meningitis cases in adults.

H. influenzae meningitis may come after an upper respiratory infection. The infection usually spreads from the respiratory tract to the bloodstream, and then to the meninges. At the meninges, the bacteria produce infection and inflammation, causing serious illness and sometimes death.

Risk factors include:

• Ear infection (otitis media)
• Family member with an H. influenzae infection
• Native American race
• Placement in day care
• Sinus infection (sinusitis)
• Sore throat (pharyngitis)
• Upper respiratory infection

• Fever (in young infants the temperature may actually be below normal)
• Irritability, poor feeding in infants
• Nausea and vomiting
• Pain in back when neck is bent forward and chin is brought toward chest (older children)
• Sensitivity to light (photophobia)
• Severe headache(older children)
• Stiff neck or pain in neck
• Unusual body positions

Signs include:

• Bulging of the fontanelles in an infant
• Lying with the back arched, head, back, and chin up (opisthotonos)
• Mental status changes (such as irritability, reduced consciousness, coma)
• Poor blood flow (circulation)
• Seizures

For any patient with meningitis, it is important to perform a lumbar puncture ("spinal tap"), in which spinal fluid (known as cerebrospinal fluid, or CSF) is collected for testing.

Other tests include:

• Antibodies in blood (serology)
• Blood culture
• Spinal fluid culture
• White blood cell count

Treatment must be started as soon as meningitis is suspected. H. influenzae meningitis should be treated with antibiotics given through a vein (IV).

Steroid medication may also be used, mostly in children. Steroids are given to reduce hearing loss, which is a common complication of meningitis in children.

The likely outcome is good with early treatment. However, 3 - 5% of patients do not survive.

• Abnormal speech and language development
• Behavioral problems
• Hearing loss
• Hydrocephalus
• Learning disorders
• Mental retardation
• Seizures

Contact your health care provider or go to an emergency room if you experience symptoms of H. influenzae or if you notice these symptoms in your child. Meningitis can quickly become life-threatening.

To protect infants and young children:

• Hibimmunizations for infants and children are recommended by the American Academy of Pediatrics, the National Institutes of Health, and many other health agencies.
• Several types of Hib vaccine are available for children ages 2 months and older.

To prevent infection after being exposed to H. influenzae meningitis:

• All family contacts of people with this type of meningitis who have not been vaccinated should begin drug therapy to prevent infection as soon as possible.
• Ask your health care provider about this treatment during the first visit.

Swartz MN. Meningitis: bacterial, viral, and other. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007: chap 437.