Table 1.

The Unified Huntington Disease Rating Scale diagnostic confidence level and Q80 diagnostic criteria.

A. Diagnostic confidence level
To what degree are you confident that this person meets the operational definition of the unequivocal presence of an otherwise unexplained extrapyramidal movement disorder (e.g., chorea, dystonia, bradykinesia, rigidity) in a subject at risk for HD?
0 = normal (no abnormalities)
1 = non-specific motor abnormalities (less than 50% confidence)
2 = motor abnormalities that may be signs of HD (50–89% confidence)
3 = motor abnormalities that are likely signs of HD (90–98% confidence)
4 = motor abnormalities that are unequivocal signs of HD (≥99% confidence)
B. Q80 diagnostic criteria
Based on the entire UHDRS (Motor, Cognitive, Behavioral, and Functional components) do you believe with a confidence level ≥99% that this participant has manifest HD? (0 = No, 1 = Yes)