The Romberg sign is a clinical test used to assess a person’s neurological function, specifically balance and coordination. This bedside maneuver helps clinicians distinguish between different causes of uncoordinated or unsteady movement (ataxia). Named after German neurologist Moritz Heinrich Romberg, the test provides insight into the body’s reliance on various sensory inputs for maintaining an upright posture. The underlying principle is that balance requires input from multiple systems, and removing one input—vision—reveals deficits in others, particularly the body’s sense of position.
Performing the Romberg Test
The test begins with the patient standing erect with their feet placed closely together and their arms resting at their sides or crossed over the chest. The examiner first observes the patient’s stability in this position with their eyes open for approximately 30 seconds. This initial phase establishes a baseline for how well the person can maintain balance when all sensory systems are available.
The second, most telling phase involves instructing the patient to close their eyes while maintaining the narrow stance. The examiner must remain close by to prevent falls or injury if balance is lost. The clinician observes the patient for up to one minute, watching for excessive swaying or the need to move a foot to regain balance. An inability to maintain a stable posture when the eyes are closed constitutes a positive Romberg sign.
The Sensory Components Required for Balance
Maintaining a stable, upright posture requires information from three distinct sensory systems. The first is the visual system, which provides external reference points and spatial orientation, allowing the brain to monitor the body’s position relative to the environment. Vision is a powerful tool for correcting subtle shifts in the body’s center of gravity.
The second component is the vestibular system, located in the inner ear, which detects head movement, angular acceleration, and the body’s position relative to gravity. This system provides continuous feedback about equilibrium and spatial orientation. The third system is proprioception, the body’s internal sense of its own position and movement in space.
Proprioceptive information travels through the dorsal column pathway in the spinal cord, relaying feedback from sensory receptors in the muscles, tendons, and joints up to the brain. The body can generally maintain balance if at least two of these three systems are functioning correctly. The Romberg test removes visual input, forcing the person to rely solely on their proprioceptive and vestibular systems.
Interpreting a Positive Romberg’s Sign
A positive Romberg sign occurs when a person is steady with their eyes open but begins to sway noticeably or loses balance immediately upon closing them. This result suggests a deficit in proprioception, known as sensory ataxia. The inability to stand still once vision is removed indicates the person was using eyesight to compensate for a lack of reliable internal positioning sense.
When the dorsal column pathway is damaged, the brain does not receive accurate information about the position of the feet, legs, and trunk. Closing the eyes removes the compensatory visual feedback, unmasking the underlying sensory deficit and causing instability and a loss of postural control.
This finding helps differentiate sensory ataxia from cerebellar ataxia, which involves dysfunction in the cerebellum, the brain region responsible for motor coordination. A person with cerebellar ataxia will typically be unsteady and lose balance even with their eyes open, as motor control is impaired. In cerebellar ataxia, the lack of vision does not cause a paradoxical increase in unsteadiness. The positive Romberg sign points specifically to a problem with the sensory input pathway, not central processing or motor execution.
Conditions That Result in a Positive Test
A positive Romberg sign indicates a problem affecting the dorsal column-medial lemniscus pathway, which transmits proprioceptive signals. One common cause is Vitamin B12 deficiency, which can lead to subacute combined degeneration of the spinal cord, damaging the dorsal columns.
Peripheral neuropathies affecting the large, heavily myelinated sensory nerves can also produce a positive result. Conditions such as diabetes mellitus frequently cause this type of nerve damage, leading to reduced sensation and proprioceptive feedback from the lower limbs. Historically, the test was associated with Tabes Dorsalis, a late-stage manifestation of neurosyphilis that specifically targets the dorsal columns of the spinal cord.
Other conditions, including Multiple Sclerosis and certain myelopathies (diseases affecting the spinal cord), can also damage the dorsal columns. The presence of a positive Romberg sign prompts a clinician to investigate these specific neurological and systemic disorders.