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

Abstract

Introduction Our research aim was to develop a novel clinimetric scale sensitive enough to detect disease progression in primary lateral sclerosis (PLS). Methods A prototype of the PLS Functional Rating Scale (PLSFRS) was generated. Seventy‐seven participants with PLS were enrolled and evaluated at 21 sites that comprised the PLSFRS study group. Participants were assessed using the PLSFRS, Neuro‐Quality of Life (QoL), Schwab‐England Activities of Daily Living (ADL), and the Clinical Global Impression of Change scales. Participants completed telephone assessments at 12, 24, and 48 weeks after enrollment. Results The PLSFRS demonstrated internal consistency as well as intrarater, interrater, telephone test‐retest reliability, and construct validity. Significant changes in disease progression were detected at 6 and 12 months; changes measured by the PLSFRS vs the ALSFRS‐R were significantly higher. Discussion The PLSFRS is a valid tool to assess the natural history of PLS in a shorter study period.

Measuring disease progression in primary lateral sclerosis

“…This 4% difference was also significant (p < 0.0001). The scores in each sub-domain of the PLSFRS (bulbar, fine motor, gross motor, and respiratory) showed significant decreases over one year, which was consistent with the Patient Reported Outcome scores for both upper and lower extremities and the Schwab-England ADL Scale (7).…”

“…. The PLS Functional Rating Scale (reproduced with permission(7)). The PLS Functional Rating Scale (PLSFRS) 1.…”

Upper Motor Neuron Disorders: Primary Lateral Sclerosis, Upper Motor Neuron Dominant Amyotrophic Lateral Sclerosis, and Hereditary Spastic Paraplegia

“…Despite being considered on the spectrum of ALS, PLS clearly has a longer survival and much slower rate of decline, as much as 30 times slower than that of ALS when measured by the ALS functional rating scale-revised (ALSFRS-R). More sensitive clinical trial tools, such as the development of a unique PLS functional rating scale and advanced MRI imaging techniques, may help encourage therapeutic development for PLS therapies and help shorten the time required to study these interventions [ 9 , 43 , 89 ].…”

Primary lateral sclerosis: diagnosis and management

“…The primary outcome measure of survival commonly used in ALS is less relevant (or indeed practical) for a condition with such a dramatically longer natural history. An adapted functional rating scale has been developed for PLS,46 and the development of therapy more selectively targeting spasticity might be the greatest unmet need in this population. Understanding those at risk, to eventually allow preventative strategies, may emerge from rapid developments in the understanding of the pathogenesis of ALS.…”