Romberg's test

Romberg's test is a neurological test that is used to assess the dorsal columns of the spinal cord, which are essential for joint position sense (proprioception).

A positive Romberg test suggests that ataxia is sensory in nature, i.e. depending on loss of proprioception. A negative Romberg test suggests that ataxia is cerebellar in nature, i.e. depending on localised cerebellar dysfunction instead.

It is sometimes used as an indicator for a possible drunk driving.

Procedure
Ask the subject to stand erect with feet together and eyes closed. Stand close by as a precaution in order to stop the person from falling over and hurting themselves. Watch the movement of the body in relation to a perpendicular object behind the subject (corner of the room, door, window etc). A positive sign is noted when a swaying, sometimes irregular swaying and even toppling over occurs. The essential feature is that the patient is unsteadier than with open eyes.

The essential features of the test are as follows:
 * 1) the subject stands with feet together, eyes open and hands by the sides.
 * 2) the subject closes the eyes while the examiner observes for a full minute.

Because the examiner is trying to elicit whether the patient falls when the eyes are closed, it is advisable to stand ready to catch the falling patient. For large subjects, a strong assistant is recommended.

Romberg's test is positive if, and only if, the following two conditions are both met:
 * 1) The patient can stand with the eyes open; and
 * 2) The patient falls when the eyes are closed.

The test is not positive if either:
 * The patient falls when the eyes are open; or
 * The patient sways but does not fall when the eyes are closed.

Patients with a positive result are said to demonstrate Romberg's sign or Rombergism. They can also be described as Romberg's positive.

Physiology
Maintaining balance while standing in the stationary position relies on intact sensory pathways, sensorimotor integration centres and motor pathways.

The main sensory inputs are:
 * 1) Joint position sense (proprioception), carried in the dorsal columns of the spinal cord;
 * 2) Vision

Crucially, the brain can obtain sufficient information to maintain balance if either the visual or the proprioceptive inputs are intact.

Sensorimotor integration is carried out by the cerebellum. The motor pathway is the corticospinal (pyramidal) tract.

The first stage of the test (standing with the eyes open), demonstrates that at least one of the two sensory pathways is intact, and that sensorimotor integration and the motor pathway are intact.

In the second stage, the visual pathway is removed by closing the eyes. If the proprioceptive pathway is intact, balance will be maintained. But if proprioception is defective, both of the sensory inputs will be absent and the patient will sway then fall.

Positive Romberg
Romberg's test is positive in conditions causing sensory ataxia such as:
 * Conditions affecting the dorsal columns of the spinal cord, such as tabes dorsalis (neurosyphilis), in which it was first described.
 * Conditions affecting the sensory nerves (sensory peripheral neuropathies), such as chronic inflammatory demyelinating polyradiculoneuropathy (CIDP).

Romberg and cerebellar function
Romberg's test is not a test of cerebellar function, as it is commonly misconstrued. Patients with cerebellar ataxia will, generally, be unable to balance even with the eyes open; therefore, the test cannot proceed beyond the first step and no patient with cerebellar ataxia can correctly be described as Romberg's positive. Rather, Romberg's test is a test of the proprioception receptors and pathways function.

History
The test was named after the German neurologist Moritz Heinrich Romberg (1795-1873), who also gave his name to Parry-Romberg syndrome.