Uncovering Neuropathic Pain in CANVAS: Lessons from a Case-Based Literature Review

Area of Science:

• Neuroscience
• Genetics
• Clinical Neurology

Background:

• Cerebellar ataxia with neuronopathy and vestibular areflexia syndrome (CANVAS) is a rare neurodegenerative disorder.
• It is caused by RFC1 gene repeat expansions, with a heterogeneous phenotype.
• The prevalence and significance of neuropathic pain in CANVAS are not well understood.

Purpose of the Study:

• To investigate the prevalence and clinical significance of neuropathic pain in CANVAS.
• To characterize pain as an early manifestation of the syndrome.

Main Methods:

• A genetically confirmed case of CANVAS with predominant neuropathic pain was analyzed.
• A systematic review and meta-analysis of CANVAS cases with pain data were performed (PRISMA guidelines).
• Pooled prevalence of neuropathic pain was calculated from 14 studies including 445 patients.

Main Results:

• The pooled prevalence of neuropathic pain in CANVAS was 43.2% (95% CI: 34.0-52.9%).
• Neuropathic pain showed moderate heterogeneity across studies (I² = 65%).
• Evidence suggests pain can be an early and significant feature of the disease burden.

Conclusions:

• Neuropathic pain is a frequent and potentially early symptom of CANVAS, linked to sensory neuronopathy.
• CANVAS should be considered in idiopathic sensory neuronopathy cases, even with pain.
• Early diagnosis via genetic testing is crucial for patient management.