The Romberg’s sign is a straightforward neurological assessment tool used to evaluate a person’s balance and coordination. This non-invasive test helps pinpoint the root cause of a patient’s unsteadiness, or ataxia, by selectively eliminating one source of sensory information. Named after German neurologist Moritz Heinrich Romberg, the test’s primary function is to distinguish between two main types of coordination impairment: those caused by sensory loss and those originating in the cerebellum, the brain’s coordination center.
The Three Pillars of Maintaining Balance
Maintaining a stable, upright posture relies on the brain integrating information from three distinct sensory systems. The first is the visual system, which provides external reference points, helping orient the body in relation to the environment. When the eyes are open, this system can compensate for deficits in other areas, acting as a powerful stabilizer.
The second system is the vestibular apparatus, located in the inner ear. It functions like the body’s internal gyroscope, detecting head movement and position relative to gravity, and providing feedback on motion and equilibrium.
These two systems work in concert with the third pillar: proprioception, the body’s sense of its own position and movement in space. Proprioception involves sensory receptors in the muscles, joints, and skin that transmit information up to the brain via the dorsal columns of the spinal cord. To remain stable while standing, the body requires at least two of these three sensory inputs to be functioning effectively.
Performing the Romberg Test
The Romberg test is executed in a controlled setting, often with a clinician standing nearby to prevent a fall. The patient is instructed to stand with their feet together, touching at the heels and toes, and their arms resting at their sides. This narrow stance is maintained for approximately 30 seconds while the patient’s eyes are open.
The examiner observes the patient during this initial phase for any signs of swaying or instability. This eyes-open stage establishes a baseline of stability while all three sensory systems are operational. Instability even with eyes open suggests a severe balance issue not dependent on vision.
The patient is then asked to close their eyes and maintain the stance for another 30 seconds. Removing the visual input forces the patient to rely solely on their proprioceptive and vestibular systems for balance. The loss of stability or significant swaying during this eyes-closed phase defines a positive Romberg’s sign.
Interpreting a Positive Sign
A positive Romberg’s sign indicates a loss of proprioception, which is a form of sensory ataxia. This occurs because the patient’s damaged proprioceptive pathway—often due to a lesion in the dorsal columns of the spinal cord or large sensory nerves—cannot send accurate position information to the brain. While their eyes are open, the visual system compensates for this proprioceptive deficit, allowing them to remain stable.
When the eyes close, the visual crutch is removed, unmasking the underlying sensory problem. The patient begins to sway or lose balance because the two remaining systems are insufficient for maintaining a stable posture. The increased unsteadiness is a direct result of the body’s inability to sense where it is in space without visual guidance.
This contrasts with cerebellar ataxia, which involves incoordination due to damage to the cerebellum. A patient with cerebellar ataxia exhibits unsteadiness and a wide-based stance even with their eyes open. Because their motor control system is impaired, removing vision does not significantly worsen their instability, resulting in a negative Romberg test. The test’s value lies in its ability to isolate a deficit in the proprioceptive pathway.
Medical Conditions Revealed by the Test
The presence of a positive Romberg’s sign suggests a condition that has damaged the sensory nerves responsible for transmitting positional feedback. One historically significant cause is Tabes Dorsalis, a late-stage manifestation of neurosyphilis that specifically targets the dorsal columns of the spinal cord. This damage interrupts the proprioceptive signals traveling from the lower body to the brain.
Another common cause is severe Vitamin B12 deficiency, which can lead to subacute combined degeneration. This deficiency causes demyelination and damage to the spinal cord’s dorsal columns, resulting in profound proprioceptive loss. Various peripheral neuropathies, particularly those affecting large, heavily myelinated sensory fibers, can also produce a positive sign.
These neuropathies, which may stem from conditions like diabetes or certain autoimmune disorders, disrupt the sensory information before it reaches the spinal cord. In all these cases, the integrity of the proprioceptive pathway is compromised, making the patient dependent on vision to maintain balance. The Romberg test demonstrates this sensory reliance.