Cerebrolysin: Positive Cognitive Effect in Vascular Dementia

Pauline Anderson

February 05, 2013

Cerebrolysin, a peptide preparation produced from purified pig brain proteins, may have positive effects on cognitive function in older patients with vascular dementia (VaD), according to a new meta-analysis.

The analysis also found that most adverse effects related to Cerebrolysin were mild to moderate in severity.

"However, due to the limited number of included trials, varying treatment durations, and short-term follow-up, there is insufficient evidence to recommend Cerebrolysin as a routine treatment for patients with VaD," write the authors, led by Ning Chen, Department of Neurology, West China Hospital, Sichuan University, Chengdu, China.

They added that the treatment is not widely used because it must be given by intravenous infusion and requires a long-term and demanding treatment schedule.

The study is published online January 30 in The Cochrane Database for Systematic Reviews.

Improved Cognition

Cerebrolysin is a mixture of 80% low-molecular-weight peptides and 20% free amino acids. Various studies have shown that the agent's multiple effects include promotion of neuroprotection, neuroplasticity, and neurogenesis. It is approved in many countries for treatment of Alzheimer's disease (AD), stroke, and/or traumatic brain injury, although not in the United States. A Cochrane review of Cerebrolysin for stroke published in 2010 concluded there was not enough evidence to evaluate its use in stroke, and a review of its use in AD is underway, the authors note.

After searching various literature sources, including ALOIS (the Cochrane Dementia and Cognitive Improvement Group's Specialized Register), as well as MEDLINE and EMBASE, researchers selected 6 randomized controlled clinical trials to include in the review. The analysis involved 507 male and female participants with mild to moderate VaD, which can include dementia caused by ischemic or hemorrhagic cerebrovascular disease or by ischemic hypoxic brain lesions of cardiovascular origin.

Two trials were conducted in multiple centers in Russia and China, and the others were carried out in single centers. Study sample sizes ranged from 29 to 242 patients. The mean age of participants ranged from 60.4 to 70.8 years, and the mean duration of dementia was 4.6 months to 4.3 years in 3 trials (the others did not include this information).

In all trials, Cerebrolysin was administered in an intravenous infusion. Four trials compared Cerebrolysin with placebo, and the others compared Cerebrolysin plus routine treatment with the same treatment only. The dose of the treatment ranged from 10 to 30 mL daily. The length of the treatment period varied between trials, and follow-up ranged from 15 days to 3 years.

The analysis showed significant improvements in cognitive function, as measured by the Mini-Mental State Examination (MMSE) (weighted mean difference [WMD], 1.10; 95% confidence interval [CI], 0.37 - 1.82) or by the Alzheimer's Disease Assessment Scale Cognitive Subpart, extended version (ADAS-cog) (WMD, –4.01; 95% CI, –5.36 to –2.66).

As for global function, the study found improvements in response rates (relative risk, 2.71; 95% CI, 1.83 - 4.00).

Subgroup analysis suggested a larger effect with long-term treatment than with short-term treatment.

No serious adverse events were attributable to the treatment, and nonserious adverse events were not significantly more common with the treatment drug (relative risk, 0.97; 95% CI, 0.49 - 1.94).

No data on quality of life or caregiver burden were available from any of the trials.

No Recommendations

Because of the variation in the trials, the analysis is not conducive to providing recommendations for the optimal treatment schedule, said the authors.

In the western world, VaD is the second most common form of dementia after AD. The prevalence of VaD doubles approximately every 5.3 years, compared with every 4.5 years for AD.

The most typical expression of VaD is executive dysfunction. The widely used MMSE may underestimate the cognitive decline in patients with VaD because it contains few items related to executive function, according to the study authors.

No definitive treatments are currently available for VaD.

The authors have disclosed no relevant financial relationships.

Cochrane Database Syst Rev. Published online January 30, 2013. Abstract