There are two published assessment scales for use in patients with Wilson disease: the Global Assessment Scale (GAS) and the Unified Wilson Disease Rating Scale (UWDRS). Both scales have promising initial results but require further evaluation.6,8
GAS uses a two-tier scale to grade multisystemic manifestations:6
- Tier 1 is a disability scale covering the liver, cognition and behavior, motor, and osseomuscular domains
- Tier 2 is a detailed neurologic assessment of seven different aspects with 14 items:
- Wilson facies
- Cognition and behavior
- Movement disorders
- Bulbar symptoms
- Posture and gait impairment
- Kayser–Fleischer rings
- Uncommon
GAS is a comparatively broad, general scale; more specialized scales may be required to assess some aspects of Wilson disease, such as gait or swallowing.6 In addition, a neurologist is required to carry out the tier 2 assessment, making the scale less accessible for use in clinical practice.6
UWDRS was developed to assess the entire spectrum of clinical symptoms associated with Wilson disease and consists of three subscales:8,27
- Neurologic (27 items; 208 points)
- Hepatic (9 items; 36 points)
- Psychiatric (19 items; 76 points)
The UWDRS neurologic subscale contains many steps and, therefore, requires a relatively long duration to complete, while the hepatic subscale has been shown to have poor correlation with established scales, meaning that the results do not accurately reflect the liver status of the patient.8