The Progressive Supranuclear Palsy Clinical Deficits Scale accurately reflects functional as well as patient- and caregiver-reported outcomes.

BACKGROUND

Progressive supranuclear palsy (PSP) is a common atypical parkinsonian disorder, but a significant gap in clinical and research practice has been the unavailability until very recently of a brief but accurate scale to rate its clinical severity. The 7-item PSP Clinical Deficits Scale (PSP-CDS) offers an efficient method to evaluate PSP clinical severity and can be administered relatively rapidly. However, further validation of this new tool is needed.

METHODS

Patients with PSP (n = 110; 55.5 % with Richardson syndrome [PSP-RS]) were consecutively recruited at a quaternary centre in Malaysia. We examined the correlations between the PSP-CDS and measures of patients' functional status, using the Barthel Index (which is generic, brief, and clinician rated) and the Cortical Basal ganglia Functional Scale (CBFS; which is disease-specific, more comprehensive, and patient/caregiver reported).

RESULTS

There were strong correlations between the PSP-CDS vs. the Barthel Index (rs = -0.81) and the CBFS (rs = 0.64) (both P < 0.001). In a post hoc analysis of individual items of the PSP-CDS and Barthel Index and CBFS, significant (and also mostly strong) correlations were observed, in the motor as well as non-motor domains.

CONCLUSIONS

The strong correlations between PSP disease severity as measured by the PSP-CDS vs. generic and disease-specific measures of functional status, rated by clinicians and patients and caregivers, provide further support for the PSP-CDS as a valid and efficient instrument. More widespread use of such tools can help to address the global gap of inadequate phenotyping of patients in routine clinical and research practice.