Conference Coverage

Manual dexterity may decline more rapidly in pediatric-onset MS



As disease duration increases, patients with pediatric-onset multiple sclerosis (POMS) have an increased rate of impairment in manual dexterity, compared with patients with adult-onset MS (AOMS), according to an analysis presented at the meeting held by the Americas Committee for Treatment and Research in Multiple Sclerosis.

Dr. Sarah Planchon, Mellon Center for Multiple Sclerosis, Cleveland Clinic

Dr. Sarah Planchon

When MS onset occurs before the patient is age 18 years, the patient is considered to have POMS. Compared with AOMS, POMS is less prevalent and has distinct features. To determine whether changes in physical performance differ between POMS and AOMS, Sarah M. Planchon, PhD, a project scientist at the Mellen Center for MS at the Cleveland Clinic, and colleagues analyzed data cut 9 from the MS PATHS (MS Partners Advancing Technology and Health Solutions) initiative. As part of this initiative, which is sponsored by Biogen, investigators collect MS performance measures longitudinally at each patient visit. Among these measures are the manual dexterity test (MDT), an iPad version of the Nine-Hole Peg Test, and the walking speed test (WST), which is the iPad version of the Timed 25-Foot Walk.

Dr. Planchon and colleagues matched each patient with POMS to five patients with AOMS according to disease duration. They calculated descriptive statistics for the sample and performed Tukey’s honestly significant difference test to compare patient groups on several categorical variables.

Overall, function was better in POMS than in AOMS

The investigators included 3 years’ worth of data from 6,457 patients in their analysis. The average age was approximately 50 years for patients with AOMS and 31 years for patients with POMS. The time elapsed since diagnosis was approximately 14 years in the AOMS group and 17 years in the POMS group. The proportion of female patients was about 74% in the AOMS group and 73% in the POMS group. Compared with the AOMS group, the POMS group had higher proportions of patients who were Asian (0.5% vs 2.6%), black (9.3% vs 11.5%), and other race (2.8% vs 9.3%).

Overall, patients with POMS performed better than patients with AOMS by 1.39 seconds on the MDT and by 0.79 seconds on the WST. Regression analyses indicated that with increasing age, patients with AOMS declined more quickly on the MDT and the WST than patients with POMS did. When the investigators stratified the results by disease duration, however, patients with POMS declined more rapidly on the MDT than did patients with AOMS. There was no significant difference between groups in WST in this analysis. When Dr. Planchon and colleagues performed linear regression and adjusted for variables such as age, sex, race, education, insurance, employment, MS phenotype, disease duration, number of relapses, and Patient-Determined Disease Steps (PDDS), the MS onset type did not significantly affect outcomes. Age, sex, PDDS, and MS type were significant covariates for both tests.

The role of occupational and physical therapy

“POMS patients tend to have a greater dysfunction of the cerebellar and brainstem regions of the brain, both of which may impact motor skills to a greater degree than other regions of the brain,” said Dr. Planchon. The increased rate of manual impairment in POMS, compared with AOMS, does not necessarily indicate more severe disease, she added. Getting a true picture of disease severity would require consideration of factors such as ambulation, cognitive functioning, vision, fatigue, and depression.

“We would recommend introducing POMS patients to occupational and physical therapy early in their disease course, before significant deficits accrue,” said Dr. Planchon. “Early familiarity with rehabilitation services should help the patient and family optimize what exercises are being done to improve and maintain function.”

The optimal pharmacologic treatment for POMS is unknown. One therapy (i.e., fingolimod) has Food and Drug Administration approval, and clinical trials of other treatments are ongoing. Some MS treatments not indicated for a pediatric population are used off label in children.

“We plan to delve deeper into the data set, including using regression modeling to try to better define differences between individuals with POMS and AOMS that may lead to the functional outcome changes we have already observed,” said Dr. Planchon. “We also plan to investigate further the impact of POMS on cognition and quality of life measures and to better understand disease-modifying therapy prescribing patterns and benefits in individuals with POMS. We will look for associations in the MRI imaging findings and various biomarkers to help us understand the disease process in this special population of MS.”

Dr. Planchon has received research support from the Guthy-Jackson Charitable Foundation. Her coinvestigators received funding from Biogen, Genentech, Genzyme, MedImmune, Novartis, Serono, and Teva.

SOURCE: Planchon SM et al. ACTRIMS 2020. Abstract P043.

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