The Romberg test is a foundational clinical examination used across medical disciplines to quickly assess a patient’s neurological function, particularly concerning balance and posture. This maneuver helps clinicians identify the root cause of impaired coordination, known as ataxia, by testing the body’s ability to maintain an upright stance under specific conditions. The test is named after the German neurologist Moritz Heinrich Romberg, who first described the phenomenon in the mid-19th century while studying patients with impaired sensory function. The primary utility of this bedside test is to differentiate sensory ataxia from other forms of balance disorder.
The Romberg Test Procedure
The test begins with the patient standing with their feet placed closely together, touching at the heels and toes. The arms are typically positioned at the patient’s sides or crossed over the chest to eliminate their use for balance compensation. The clinician first observes the patient for a period of time, usually 30 seconds, while their eyes are kept open to establish a baseline of postural stability.
After this initial observation, the patient is instructed to close their eyes while maintaining the standing position. The clinician remains close to the patient throughout the entire process, prepared to intervene and prevent any potential falls. The patient is observed for another 30 to 60 seconds to detect any change in stability once visual input is removed.
Defining a Positive Romberg Sign
A result is labeled a positive Romberg sign when the patient exhibits a marked increase in postural sway or unsteadiness, but only when their eyes are closed. The defining characteristic is the stark contrast between the patient’s relative stability with their eyes open and the onset of significant instability when visual input is withdrawn. A small, normal amount of subtle swaying is expected, as the body’s balance mechanisms are constantly making minor adjustments to maintain equilibrium.
The sign is considered positive only if the patient can maintain the stance with eyes open but fails to do so with eyes closed. If the patient is unsteady with both eyes open and closed, the test is not considered a positive Romberg sign, which points the clinician toward a different neurological origin for the balance impairment.
The Neurological Basis of the Sign
Maintaining upright balance requires constant input from three sensory systems: vision, the vestibular system in the inner ear, and proprioception. Proprioception refers to the body’s sense of its own position and movement in space, which is relayed to the brain primarily through the dorsal column pathway in the spinal cord. This pathway transmits fine touch, vibration, and conscious proprioceptive information from the limbs and trunk.
A positive Romberg sign indicates damage to this proprioceptive system, a condition known as sensory ataxia. When the proprioceptive input is faulty, the central nervous system compensates by heavily relying on vision to maintain posture. When the eyes are closed, the compensatory visual input is eliminated, and the impaired proprioceptive system is unmasked, resulting in the sudden loss of balance.
The test is a discriminator between sensory and cerebellar ataxia, which involves the brain’s cerebellum. In cerebellar ataxia, the patient is unsteady and exhibits disequilibrium regardless of whether their eyes are open or closed, meaning the Romberg test would be negative. The inability to maintain the stance only in the absence of vision points specifically to a deficit in the dorsal column pathway.
Conditions Indicated by the Result
One historical condition closely associated with the sign is Tabes Dorsalis, a form of neurosyphilis that specifically causes demyelination and degeneration of the posterior columns. This damage compromises the transmission of proprioceptive signals from the lower body.
Peripheral neuropathy can also lead to a positive result by disrupting the sensory input before it even reaches the spinal cord, often seen in conditions such as uncontrolled diabetes mellitus or chronic alcoholism. Additionally, Vitamin B12 deficiency can cause subacute combined degeneration of the spinal cord, directly affecting the dorsal columns and leading to sensory ataxia. The positive Romberg sign serves as a clinical clue, suggesting a need for further investigation into these specific types of sensory pathway diseases.