Late-onset MS linked to faster disability progression: Study
Those whose symptoms start after age 50 also more commonly develop PPMS
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A nurse holds the hand of a patient. (Photo from iStock)
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Late-onset MS (after age 50) is linked to faster disability progression.
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Late-onset MS patients more commonly develop primary progressive MS.
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Further research is needed to understand the mechanisms and risk factors.
People with multiple sclerosis (MS) who experience their first symptoms after age 50 tend to have faster disability progression than those with earlier disease onset, according to a recent study.
The also more commonly develop primary progressive MS (PPMS). In addition, late-onset MS was associated with a higher risk of reaching certain disability milestones and faster transition to secondary progressive MS (SPMS) in those diagnosed with relapsing forms of the disease.
“Disease prognosis was markedly influenced by the age of MS onset, with older patients experiencing more rapid disease progression and shorter survival times to reach disability milestones,” researchers wrote.
The study, “Effect of late‑onset on multiple sclerosis phenotype and outcome: evidence from a multi‑national registry,” was published in the Journal of Neurology.
MS symptoms typically begin before age 40
MS symptoms typically begin before age 40, but some people develop the disease later in life. When symptoms begin after age 50, it is considered late-onset MS (LOMS), and when they start after age 60, it is referred to as very late-onset MS (vLOMS).
Researchers are still working to understand whether people with late-onset disease experience different symptoms, disease courses, and long-term disability outcomes than those diagnosed earlier.
To learn more, a team of researchers in Tunisia analyzed data from 81,236 people enrolled in the international MSBase registry, a large database tracking outcomes from people with MS in a real-world setting.
Participants were grouped by the age at which their symptoms began. Most had adult-onset disease (76.9%), defined as symptom onset between ages 18 and 39, while 16.9% had symptom onset between ages 40 and 49 (transition group). Late-onset disease was less common, with 5.4% of participants classified as LOMS and 1% as vLOMS.
Compared with late-onset disease, people with adult-onset MS were more commonly women, and had a higher prevalence of vision problems and brain-related issues as their first symptoms. By contrast, spinal cord involvement was more frequent in people whose disease began later in life.
Relapse activity tended to decline with increasing age at onset
Disability was greater at the first clinical assessment among people with later disease onset. Average scores on the Expanded Disability Status Scale (EDSS), a standard measure of MS disability, were 2.6 in the AOMS group, compared with 3.54 in LOMS and 4.08 in vLOMS.
Disease course also differed between groups. Relapsing-remitting MS (RRMS), the most common form of the disease, was diagnosed in 67.8% of patients with adult-onset MS but in fewer people with late-onset disease — 44.4% of those with LOMS and 40.5% of those with vLOMS.
PPMS was more frequent among people whose disease began later in life, affecting 21.7% of those with LOMS and 24% with vLOMS compared with 3.8% of those with adult-onset disease.
Overall, this study has shown the complex interplay of age and clinical characteristics in shaping the trajectory of MS. Further research is warranted to explain the underlying mechanisms and risk factors associated with LOMS and vLOMS.
Relapse activity also tended to decline with increasing age at onset, with the adult-onset group experiencing an average of 0.202 relapses per year and the transition group 0.13 relapses per year. Among those with later onset, the rates were lower and similar between groups, at 0.095 for LOMS and 0.084 for vLOMS.
However, people with later onset disease had about a 39% to 80% higher risk of experiencing confirmed disability worsening, defined as sustained increases in EDSS scores lasting at least 24 weeks. These patients were also more likely to reach EDSS scores of 4 and 6, indicating significant disability and the need of a walking aid, than those whose symptoms started earlier.
Finally, later-onset disease was also linked to a higher likelihood of progressing to SPMS in people with RRMS, with risks estimated to be 62% to 138% higher than in people with earlier-onset disease.
“Overall, this study has shown the complex interplay of age and clinical characteristics in shaping the trajectory of MS. Further research is warranted to explain the underlying mechanisms and risk factors associated with LOMS and vLOMS,” the researchers wrote.
