After the first round of symptoms, multiple sclerosis can stay mild without causing major problems for decades, a 30-year British study indicates.
Karen K. Chung of the University College London Institute of Neurology discussed the findings at the ECTRIMS-ACTRIMS meeting in Paris, which started Oct. 25 and runs until 28. His presentation was titled “Does ‘benign’ multiple sclerosis exist? A 30-year follow-up study of people presenting with clinically isolated syndrome.”
MS affects different people in different ways. Many patients develop nervous system impairments over time, while others remain unaffected.
Scientists refer to cases with no nervous system impairment as benign MS. But its exact definition and characteristics are still a matter of debate. And some researchers contend that benign MS does not exist.
British researchers wanted to know if people with MS can have a benign form of the disease 30 years after the first symptoms appear.
The team’s intent was to follow 132 patients with clinically isolated syndrome, or CIS — a precursor to MS — for 30 years. Some died or dropped out before the study was completed.
Researchers gave the patients magnetic resonance imaging (MRI) scans and disability assessments every five years. The disability yardstick they used was the Expanded Disability Status Scale, or EDSS.
About halfway through the study, the team added an MS functional composite test to the measurements. It assessed leg and arm function, and cognition.
In the very last evaluation, researchers also assessed cognition with a test known as the Brief International Cognitive Assessment for MS.
In addition, the team included patients’ employment history in their analysis.
From the initial pool of 132 participants, 29 had died by the time the study ended 30 years later – 16 of an MS-related cause. Twelve participants dropped out of the study, leaving 91 for the analysis.
Thirty of the 91, or 33 percent, failed to develop MS. Thirty-five, or 44 percent, had relapsing-remitting multiple sclerosis, or RMSS. And 26, or 33 percent, had the more severe secondary progressive multiple sclerosis, or SPMS.
Researchers excluded those with CIS — that is, those who had failed to develop MS — from additional analysis.
They discovered that only 11 of the 61 who had developed MS had received a disease-modifying therapy at some point or other. Eighty-eight percent of the 35 with RRMS had low disability scores, and all were either still working or had retired at a normal retirement age.
Cognition tests showed only mild impairment in three patients.
Researchers said the study suggests that “it is not uncommon for people with relapsing MS “to have only mild or no physical or cognitive dysfunction approximately three decades after clinical onset.”
MS may have a bimodal progression, the team said. Either patients continue to have a mild and stable disease, such as the majority of RRMS patients in the study, or their disease progresses to SPMS.
Nonetheless, based on the results, Chung concluded that “very stable ‘benign’ MS does exist.”