Cerebellar ataxia, neuropathy, and vestibular areflexia syndrome: a slowly progressive disorder with stereotypical presentation

Cerebellar ataxia, neuropathy and vestibular areflexia syndrome (CANVAS) is a newly described condition with onset in adulthood, characterized by progressive balance impairment and sensory disturbances in the lower limbs, which can severely affect patients' quality of life. Its pathogenesis remains obscure and the diagnosis challenging. We described four patients complaining of slowly progressive gait unbalance and sensory disturbances at the feet followed, after a period ranging 2-6 years, by cerebellar dysfunction. All patients showed gait and limb ataxia, positive Romberg sign, cerebellar dysarthria, gaze-evoked nystagmus, absent deep tendon reflexes, and impaired vibratory sensation. Nerve conduction studies revealed axonal sensory neuropathy, brain magnetic resonance imaging showed cerebellar atrophy, and otoneurological investigation demonstrated bilateral vestibular areflexia with impaired vestibulo-ocular reflexes. The diagnosis of CANVAS should be suspected on clinical ground based on homogeneous course of symptoms and signs, and addressed by video-oculography eye movement recording.