A new study suggests that the disease course in those who develop MS in childhood takes longer to progress, but that disability occurs approximately 10 years younger than it does in individuals whose MS begins after the age of 16. The study confirmed other important differences, supporting the urgent need to bolster pediatric MS research, an important goal of the National MS Society’s Pediatric MS Centers of Excellence and the primary goal of the International Pediatric MS Study Group.

Christel Renoux, MD (INSERM, Lyon, France) and colleagues from the Kids with Multiple Sclerosis Study Group (KIDMUS) report their findings in the  June 21, 2007 issue of The New England Journal of Medicine (2007;356:2603-13). Supporters of this international study include the Neurological Society of France, the French MS Society, the French Association for Research on Multiple Sclerosis (L’ARSEP), and the Canadian Institutes of Health Research.

Though MS is rare in children, there are estimated to be up to 10,000 persons under the age of 18 who have this disease in the U.S. and up to 15,000 who exhibit symptoms that mimic MS. Because cases of pediatric MS are few and scattered around the world, there were until recently few attempts to conduct research in that form of the disease and its optimal treatment.

In the largest study of its kind,  the investigators identified 394 adults from a French and Belgian MS-related database whose MS had begun at age 16 or younger, and compared data with a control group of 1775 adults whose MS began after age 16 to investigate the course and prognosis of MS onset during childhood.

The study identified several features associated with their cohort of childhood-onset MS in comparison with adult-onset. Those whose MS started before age 16

•  were more likely to be female;
  
  
•  were more likely to have isolated optic neuritis, an inflammation of the optic nerve that is often an initial symptom of MS;
  
  
• were more likely (98% versus 84%) to have a relapsing-remitting course at onset (a course of MS characterized by clearly defined flare-ups followed by partial or complete recovery periods); 
  
  
•  took approximately 10 years longer to “convert” to secondary-progressive MS (a type of MS characterized by an initial period of relapsing-remitting MS, followed by a steadily worsening disease course with or without flare-ups) but they still developed secondary-progressive MS at an age of approximately 10 years younger than adult-onset patients.

Approximately half of the pediatric patients had received disease-modifying therapies that affect the immune system, whereas virtually none of the adult cohort studied in comparison had received such treatment. It is not known what effect this may have had on the outcomes reported in this study. The gender ratio reported in this study also differs from some other studies of pediatric MS, which reported that the youngest patient groups tended to exhibit roughly equal numbers of females and males.

Nevertheless, these results call attention to important potential differences between MS onset during childhood and during adulthood. “Efforts to improve multiple sclerosis have focused on the population with adult-onset disease,” write the authors. “Patients with childhood-onset MS clearly deserve similar attention.”

The National MS Society has begun to address this underserved population in recent years, establishing a nationwide network of Pediatric MS Centers of Excellence as part of its Promise:2010 targeted initiative. The Society also founded the International Pediatric MS Study Group, a multidisciplinary panel that now includes pediatric and adult MS experts from around the world, including some of the authors of this study. The Study Group recently published a comprehensive supplement on pediatric multiple sclerosis, the first publication of its kind, that was funded by the Society. Read more about Pediatric MS at www.nationalmssociety.org/PediatricMS.

-- Research & Clinical Programs

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