ICAs are a group of rare, complex neurodegenerative diseases primarily affecting the cerebellum
Introduction and Overview
- Definition: ICAs are a group of rare, complex neurodegenerative diseases primarily affecting the cerebellum
- Additional involvement: Often affects spinal cord and peripheral nerves
- Primary clinical feature: Progressive cerebellar syndrome leading to significant disability
- Genetic basis: Over 100 new entities described in the past 25 years, with up to 500 genes related to ataxias
Diagnosis and Initial Approach
Patient Assessment
- Collect detailed family medical history (three generations minimum)
- Perform thorough physical examination
- Exclude acquired causes of cerebellar ataxia
Key Clinical Features
- Gait and balance difficulties
- Cerebellar dysarthria
- Dysmetria (nose-finger and heel-shin tests)
- Hypotonia
- Cerebellar eye signs (often earliest clinical features)
Diagnostic Algorithm
- Determine age at onset and disease progression speed
- Assess functional disability
- Look for associated symptoms and signs
Genetic Testing
- Initial screening for most frequent expansions
- Next-Generation Sequencing (NGS) for comprehensive genetic analysis