Conference Coverage

Which interventions can treat cognitive fatigue?



– Cognitive fatigue in patients with neurologic disease is a common problem with few objectively studied treatments, according to a systematic review presented at the annual meeting of the Consortium of Multiple Sclerosis Centers. Only one intervention – transcranial direct current stimulation (tDCS) – has been found to counteract cognitive fatigability in a trial with objective outcome measures, the review authors said.

One other objective trial found that Fampridine-SR (Ampyra) did not reduce cognitive fatigue in patients with multiple sclerosis (MS).

The researchers screened for studies across various neurologic conditions, and found that both trials were in patients with MS, “suggesting that more emphasis is given to this issue in this population,” said review author Alyssa Lindsay-Brown, a researcher at Ottawa Hospital Research Institute, and her collaborators. “This review highlighted the paucity of interventions designed to target objectively measured cognitive fatigability and demonstrates the need for further research in this area.”

Investigators have examined self-reported fatigue in patients with neurologic disease, but objective cognitive fatigability, the inability to maintain optimal task performance during a sustained cognitive task, is not well understood, and the best approach to treating cognitive fatigue is unclear, said Ms. Lindsay-Brown and colleagues. To determine how researchers objectively measure cognitive fatigability and summarize currently available treatments, they conducted a systematic literature review.

The researchers registered the review protocol with the PROSPERO international prospective register of systematic reviews and searched databases for studies that objectively measured cognitive fatigability in patients with neurologic disorders aged 18-65 years. They searched for randomized controlled trials, case-control studies, and case reports and case series published in English between 1980 and February 2019.

The authors reviewed the studies using a modified Cochrane Data Extraction Template and assessed their quality and risk of bias. They decided in advance to group studies according to whether they evaluated pharmacologic, procedural, or behavioral interventions.

The search initially yielded 431 records, and the authors assessed 28 full-text articles for possible inclusion. They ultimately included 2 studies in their qualitative synthesis.

A 2017 pharmacologic study by Morrow et al. sought to determine whether Fampridine-SR objectively improves cognitive fatigability in 60 patients with MS (Mult Scler Relat Disord. 2017 Jan;11:4-9.). This study compared the number of responses from the last third to the first third on the Paced Auditory Serial Addition Test (PASAT). Patients performed better with placebo than with Fampridine-SR.

A 2018 procedural study by Fiene at al. assessed tDCS over the prefrontal cortex in 15 patients with MS (J Neurol. 2018 Mar;265[3]:607-17.). The investigators objectively measured P300 event-related potential and reaction times on an alertness test. Compared with sham, anodal tDCS increased P300 amplitude and reduced fatigue-related decrements in reaction time.

The search did not identify any behavioral interventions for objective cognitive fatigability. “Given the known benefit of behavioral interventions at improving subjectively measured fatigue, future research should investigate whether these effects are transferable to objectively measured cognitive fatigability,” the review authors concluded. “If behavioral interventions demonstrate promise, then future studies should evaluate these against the beneficial, but preliminary, outcomes from tDCS.”

The authors had no disclosures.

SOURCE: Lindsay-Brown A et al. CMSC 2019, Abstract NNN10.

Next Article: