One-Third of Patients With RIS Had an Attack
Dr. Okuda and colleagues performed a retrospective analysis of individuals with RIS in the United States, Spain, France, Italy, and Turkey. The researchers’ goal was to collect cases and assess for risk factors for first symptom onset. They identified 451 subjects with RIS, the majority of whom were from the US. Most patients were young (mean age, 37.2), Caucasian, and female.
The most common reason the patients underwent MRI was for headache evaluation. Approximately 10% of subjects had a family history of MS, and about 65% had an abnormal CSF profile. These results indicate the specificity of the criteria that the researchers used to identify subjects, said Dr. Okuda. Approximately 17% of patients were exposed to a DMT before first symptom onset.
During the five-year study period, 34% of the cohort had a first attack suggestive of MS. This result “provided further validation that asymptomatic MS exists,” said Dr. Okuda. The investigators identified spinal cord lesions within the cervical or thoracic region, age younger than 37, and male sex as risk factors for a first attack. Having more than one risk factor was associated with a greater risk than having only one risk factor.
Among patients who had a first attack, 11% were identified with a primary progressive MS phenotype. This finding provides evidence for an asymptomatic form of progressive MS, said Dr. Okuda. In addition, for those subjects with an initial MRI study performed after 2008 that revealed anomalies suggestive of MS, 40% demonstrated worsening on MRI and had an increased risk for a seminal clinical event, but further scientific efforts would be needed to confirm these data, said Dr. Okuda.
—Erik Greb