b'TheauthorsproposeddeterminantsforClinic, and London Health Sciences Center. diagnosing PRIA both in RRMS and progressiveThere were 592 participants recruited during a MS are: 1) baseline EDSS score, 2) event EDSSthree-year span and followed for four-and-a-scorebasedonaclinicallysignicantin- half years. Participants underwent a neurological crease, 3) conrmation EDSS score six to 12assessment and MRIs. The goal of the study months after the initial disability increase,was to determine the frequency of isolated and 4) sustained score measured at 12 or 24cognitive relapses when there is a decline in months from the start of PRIA. The ndingscognitive testing but not documented physical were published in JAMA Neurology.worsening on EDSS. The Symbol Digit Modalities Thrower -One of the more challenging andTest was the primary measure of cognitive frustrating scenarios in MS is the person whodecline. However, the researchers noted there has no new MRI lesions, no relapses, yet stillare scales that may be better suited to recognize has progression of disability. This situationchanges. Even with the limited use of SDMT has been termed progression independent ofin this study, it provides evidence that ICR relapse activity, or PIRA. PIRA has been theoccursinpeoplewithMS.Thestudywas subject of signicant research in recent years.published in Multiple Sclerosis Journal. What mechanisms drive PIRA and how do weThrower- Biomarkers have been a hot topic address them? Two potential causes for PIRAin the MS world. A biomarker is dened as have been identified. First, a loss of neuralsomething that can be measured objectively reserve could contribute to PIRA. Neural(i.e. a blood test or MRI nding) that gives us reserve is the term used to describe how wellinsight into disease progression, pathology, our brain and spinal cord adapt to injuries andor pharmacological responses. Neurolament insults, such as MS. Humans do lose neurallight chain as measured by a blood test would reserve with age and this may contribute tobearecentexample.Measurementsof PIRA. Secondly, smoldering inammation mayneurolament light chain may give us clues drive PIRA. In contrast to acute inammationabout disease progression and responses to resulting clinical relapses and new lesions ontherapy,althoughtheirusehasnotbeen MRI, smoldering inammation may be chronicwidelyaccepted.AnotherMSbiomarker and causes slow progression of disability andwould be optical coherence tomography. OCT more subtle MRI changes. This article focusesis a noninvasive test that uses light waves to on how we dene PIRA. Research is lookingmeasure the thickness of the retinal layers, at ways we address this through rehabilitation,including the retinal nerve ber layer. OCT new classes of disease-modifying therapies,has many clinical uses including glaucoma neural repair, and neural plasticity. andmaculardegenerationmanagement. Cognition changesThe test may also prove useful in monitoring may have relapse linkMS. The RNFL is part of the central nervous system and correlates with things like brain This prospective cohort study assessingvolume on MRI. This study shows that the cognitive change during relapses from threeRNFL as measured by OCT also correlates MS centers: University of Buffalo, Clevelandwith both cognitive and physical disability.47 msfocusmagazine.org'