Causes of an Isolated Positive Romberg Sign
An isolated positive Romberg sign indicates dysfunction of the dorsal-column proprioceptive pathways of the spinal cord or large-fiber peripheral sensory nerves, and specifically excludes cerebellar disease as the primary cause. 1
Understanding the Romberg Sign
A positive Romberg occurs when balance is lost only with eyes closed, demonstrating that the patient relies on visual input to compensate for impaired proprioception. 1 This pattern distinguishes sensory ataxia (positive Romberg) from cerebellar ataxia (instability persists regardless of eye position). 1, 2
The test specifically assesses dorsal-column function, which transmits peripheral proprioceptive information from joints and muscles to the brain. 1 When these pathways are damaged, patients cannot sense their body position in space without visual feedback. 1
Primary Causes by Category
Spinal Cord Pathology (Dorsal-Column Lesions)
These are the most critical causes to identify urgently:
- Subacute combined degeneration from vitamin B12 deficiency is the single most important reversible cause that must be identified early, as it progresses rapidly but responds to treatment. 1
- Copper-deficiency myelopathy mimics B12 deficiency clinically but requires distinct copper replacement therapy. 1
- Multiple sclerosis involving the posterior columns produces a positive Romberg when demyelinating plaques affect proprioceptive pathways. 1
- Spinal cord infarction in the posterior spinal artery distribution can present acutely with a positive Romberg. 1
- HIV-associated myelopathy is a recognized cause of dorsal-column dysfunction in immunocompromised patients. 1
- Transverse myelitis can lead to a positive Romberg sign when inflammation affects the posterior columns. 1
- Neurosyphilis (tabes dorsalis) produces a classic positive Romberg sign and should be considered in at-risk populations. 1
Peripheral Sensory Neuropathies
Large-fiber sensory neuropathies impair proprioception at the peripheral nerve level:
- Diabetic polyneuropathy with large-fiber sensory loss is one of the most common causes in clinical practice. 1
- Chronic inflammatory demyelinating polyneuropathy (CIDP) affects proprioceptive fibers and yields a positive test. 1
- Guillain-Barré syndrome (particularly sensory variants) may present with a positive Romberg and areflexia. 1
- Chemotherapy-induced peripheral neuropathy from platinum agents, taxanes, or vinca alkaloids can impair dorsal-column function. 1
- Medication-induced neuropathy from metronidazole, isoniazid, or other drugs is a reversible cause. 1
- Hereditary sensory neuropathies produce chronic proprioceptive deficits. 1
- Lyme disease with peripheral nerve involvement can lead to a positive Romberg. 1
Metabolic and Nutritional Causes
- Vitamin B12 deficiency remains the most important reversible metabolic cause—delay in treatment can lead to permanent neurological damage. 1, 3
- Copper deficiency increasingly recognized as mimicking B12 deficiency but requiring separate management. 1, 3
- Hypothyroidism may contribute to proprioceptive loss through peripheral neuropathy. 1
- Heavy-metal toxicity (lead, arsenic, mercury) can affect dorsal-column integrity. 1
Infectious Etiologies
- Neurosyphilis (tabes dorsalis) remains a classic cause, particularly in high-risk populations. 1
- HIV myelopathy should be considered in immunocompromised patients. 1
- Lyme disease may involve dorsal-column pathways in endemic areas. 1
Neoplastic and Paraneoplastic
- Paraneoplastic sensory neuronopathy can lead to profound proprioceptive loss, often preceding cancer diagnosis. 1
- Spinal cord compression from tumor frequently presents with a positive Romberg before motor symptoms develop. 1
- Leptomeningeal carcinomatosis may involve posterior columns. 1
Critical Clinical Pitfalls to Avoid
Never attribute a positive Romberg to cerebellar disease—cerebellar ataxia produces instability with eyes both open and closed (Romberg-negative pattern). 1, 2 This is the most common misinterpretation in clinical practice.
Assess vitamin B12 immediately—subacute combined degeneration can progress to irreversible spinal cord damage within weeks if untreated. 1, 3
Always check copper status when B12 deficiency is suspected, as copper deficiency presents identically but requires copper supplementation rather than B12. 1, 3
Obtain a thorough medication history—many commonly prescribed drugs (metronidazole, isoniazid, chemotherapy agents) cause sensory neuropathy. 1, 3
Use MRI, not CT—CT lacks sensitivity for dorsal-column lesions and posterior fossa pathology. 3
Temporal Pattern Recognition
The timeframe of symptom onset guides the differential diagnosis:
Acute onset (hours–days): Prioritize spinal cord stroke, acute transverse myelitis, or Guillain-Barré syndrome; obtain urgent MRI of brain and spine. 1, 3
Subacute onset (weeks–months): Focus on nutritional deficiencies (vitamin B12, copper), inflammatory disorders, and infections—this timeframe is classic for subacute combined degeneration. 1, 3
Chronic progressive course: Consider hereditary neuropathies, paraneoplastic syndromes, or degenerative spinal conditions. 1, 3
Distinguishing from Vestibular Ataxia
While not a cause of isolated positive Romberg, vestibular dysfunction can confuse the clinical picture:
- Vestibular ataxia presents with instability, nystagmus, and vertigo that may worsen on compliant surfaces (foam), helping differentiate it from sensory ataxia. 3, 4
- Standing with eyes closed on foam rather than firm surface is more a test of vestibular than proprioceptive function. 5
- Vestibular patients show greater trunk sway on foam surfaces, while proprioceptive patients show greater sway on firm ground with eyes closed. 4
Special Considerations
Hepatic encephalopathy does not typically cause a true positive Romberg sign because it does not primarily affect dorsal-column proprioception. 1
Cervical myelopathy may present with a "walking Romberg" (instability when walking with eyes closed) before the traditional standing Romberg becomes positive. 6