A systematic review of available drugs for treating multiple sclerosis failed to identify interventions effective for treating cognitive symptoms, Kessler Foundation researchers suggest, in a study published in CNS Drugs.

The researchers identified 87 articles, using the PubMed and PsycINFO databases and the 2017 American Academy of Neurology (AAN) criteria for therapeutic trials. Standardized effect sizes were calculated for comparison across trials.

Agents from the following therapeutic categories were represented: Disease-modifying therapies (DMTs) (interferon B-1a, B1b, glatiramer acetate, natalizumab, fingolimod); Symptomatic therapies (dalfampridine; cognition enhancers: rivastigmine, Gingko biloba, donepezil; Stimulants: modafinil, armodafinil, methylphenidate, amphetamine sulfate, amantadine); and ‘Other’ therapies that were neither DMTs nor stimulants (eg, estrogen, methylprednisolone, simvastatin, human erythropoietin).

Their review of the studies of DMTs failed to support the effectiveness for treating cognitive deficits, with a majority of class III and IV evidence, a media release from Kessler Foundation explains.

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“We found no class I evidence, and class II evidence was minimal to none,” said Michelle H. Chen, PhD, postdoctoral fellow in the Center for Neuropsychology and Neuroscience Research at Kessler Foundation.

Although most of the studies of symptomatic therapies were randomized controlled trials with primary cognitive outcomes (ie, higher-quality evidence), there were contradictory findings, resulting in inconclusive evidence for the cognitive efficacy of symptomatic therapies. For studies involving “other” agents, there was again insufficient evidence to support their use to treat cognitive problems.

“Given the impact of cognitive dysfunction on individuals with MS, it is prudent to explore the potential for cognitive efficacy of available pharmaceuticals,” Helen Genova, PhD, director of the Center for Neuropsychology and Neuroscience Research explains.

The design of future studies, especially of DMTs, must focus on cognitive outcomes and follow standardized criteria such as the AAN’s,” she concludes. “Randomized, controlled studies with cognition as the primary outcomes will provide clinicians with the information they need to choose optimal treatments for patients.”

[Source(s): Kessler Foundation, EurekAlert]