Kernig’s sign refers to an inability to extend the knees past a right angle without pain. It may occur in some, but not all, people with meningitis. Meningitis can be life threatening and typically occurs with a high fever, stiff neck, sleepiness, and headache.

Meningitis is a life threatening medical emergency characterized by the inflammation of the membranes surrounding your spinal cord and brain.

Prompt diagnosis and treatment of meningitis is important to prevent further complications.

In 1882, a Russian physician named Vladimir Mikhailovich Kernig found that many people with meningitis weren’t able to extend their knees past a 90˚ angle without pain. This was named Kernig’s sign.

However, more recent research shows that many people with meningitis don’t display Kernig’s sign. So here’s what you need to know:

To look for Kernig’s sign:

  1. Lie face up.
  2. Flex your knee and hip in
    a 90˚ angle while someone else slowly extends your knee.

If you feel either resistance or pain, see a doctor right away for treatment.

There are additional signs and symptoms to look out for if you suspect you have meningitis. Early symptoms will be similar to the flu, and they can develop over a matter of hours or even days. Symptoms include:

  • sudden high fever
  • stiff neck
  • severe headache
  • nausea or vomiting
  • confusion and difficulty
  • seizures
  • sleepiness or difficulty
  • sensitivity to light
  • no appetite or thirst
  • skin rash

The Brudzinski sign

The Brudzinski sign is another way to diagnose meningitis. The Brudzinski sign was created by Josef Brudzinski, a Polish pediatrician.

To check for the Brudzinski sign:

  1. Lie flat on your back.
  2. Your doctor will place one
    hand behind your head, and another on your chest to prevent you from rising.
  3. Then, your doctor will
    lift your head, bringing your chin to your chest.

A positive Brudzinski sign occurs when this causes flexion of the hips.

Nuchal rigidity

A third sign used to diagnose meningitis is called nuchal rigidity. Nuchal rigidity is an inability to flex the neck forward due to rigidity of the neck muscles.

Similar to Kernig’s sign, research has shown that many people with meningitis don’t have the Brudzinski sign or nuchal rigidity.

Kernig’s sign, the Brudzinski sign, and nuchal rigidity are typically not successful at diagnosing those with meningitis.

While these tests can be done quickly at home, it’s important to seek immediate medical attention if you suspect you have meningitis. Early and definitive detection is extremely important in the treatment of this condition.

A lumbar puncture, also called a spinal tap, is a common and more effective way to diagnose a person with meningitis. Other diagnostic tools include CT imaging and blood cultures.