Primary lateral sclerosis (PLS) functional rating scale: PLS-specific clinimetric scale

Area of Science:

• Neurology
• Clinical Assessment
• Disease Progression

Background:

• Primary Lateral Sclerosis (PLS) is a rare neurodegenerative disorder.
• Assessing disease progression in PLS is crucial for clinical trials and patient management.
• Existing scales may lack the sensitivity to detect subtle changes in PLS.

Purpose of the Study:

• To develop and validate a novel clinimetric scale for Primary Lateral Sclerosis (PLS).
• To create a tool sensitive enough to detect disease progression in PLS.
• To establish the reliability and validity of the PLS Functional Rating Scale (PLSFRS).

Main Methods:

• A prototype of the PLS Functional Rating Scale (PLSFRS) was developed.
• Seventy-seven participants with PLS were enrolled across 21 sites.
• Participants were assessed using PLSFRS, Neuro-QoL, Schwab-England ADL, and CIGC scales, with telephone follow-ups at 12, 24, and 48 weeks.

Main Results:

• The PLSFRS demonstrated strong internal consistency and reliability (intrarater, interrater, test-retest).
• Construct validity was confirmed for the PLSFRS.
• Significant disease progression was detected at 6 and 12 months, with greater sensitivity compared to the ALSFRS-R.

Conclusions:

• The PLSFRS is a valid and reliable tool for assessing the natural history of PLS.
• The PLSFRS enables the detection of disease progression in a shorter study period.
• This scale can facilitate more efficient clinical research in PLS.