Cerebellar Ataxia and the Romberg Test
Patients with cerebellar ataxia typically have a negative Romberg test, as their unsteadiness persists regardless of whether their eyes are open or closed. 1
Understanding Cerebellar Ataxia and Romberg Testing
- Cerebellar ataxia results from damage to the cerebellum and/or its connections, causing impaired coordination of voluntary movements that persists regardless of visual input 1
- The Romberg test specifically evaluates sensory ataxia (dorsal column dysfunction) by testing if a patient's balance worsens significantly when visual input is removed 1
- In cerebellar ataxia, patients demonstrate unsteadiness that does not significantly worsen with eye closure, making the Romberg test negative 1, 2
- This distinguishes cerebellar ataxia from sensory ataxia, where balance dramatically worsens when visual compensation is removed 1
Clinical Manifestations of Cerebellar Ataxia
- Patients with cerebellar ataxia typically present with disequilibrium, loss of muscle coordination, gait and limb ataxia, dysarthria, and ocular dysmetria 2
- Truncal ataxia (difficulty maintaining posture) is particularly common with cerebellar vermian pathology 3, 2
- Cerebellar ataxia includes various clinical conditions characterized by neurodegeneration of the cerebellum and/or brainstem from inherited or sporadic etiologies 3
- Some patients with cerebellar ataxia may have coexisting symptoms of central or peripheral vestibulopathy, which can further complicate the clinical picture 3
Diagnostic Approach
- MRI of the head without IV contrast is the preferred initial imaging modality for evaluating cerebellar ataxia 3, 1, 2
- MRI can detect morphologic changes and signal alterations primarily involving the cerebellum and brainstem 1
- If inflammatory or neoplastic causes are suspected, contrast-enhanced MRI should be included 1
- Advanced MRI techniques such as diffusion-weighted imaging and spectroscopy may help detect early changes and distinguish between ataxia subtypes 1, 2
Clinical Pearls and Pitfalls
- A common pitfall is confusing cerebellar ataxia with sensory ataxia; the key distinction is that cerebellar ataxia patients are unsteady regardless of visual input, while sensory ataxia patients worsen significantly with eye closure 1
- The presence of a positive Romberg test in a patient with suspected cerebellar ataxia should prompt consideration of additional or alternative diagnoses, such as sensory neuropathy or posterior column dysfunction 4, 5
- In some conditions like CANVAS (Cerebellar Ataxia, Neuropathy, and Vestibular Areflexia Syndrome), patients may have both cerebellar and sensory components, resulting in a positive Romberg sign despite having cerebellar ataxia 4, 5
- Quantitative assessment using inertial sensors during the Romberg test may provide objective measurements of postural instability in cerebellar ataxia patients 6, 7