Effects of Cerebrolysin on Language Ability in Non-fluent Aphasia Patients After Stroke: A Randomized, Placebo-controlled, Double-blinded, Single Center Study

" This study aims to measure changes in language ability after adding cerebrolysin to standard treatment for non-fluent aphasia patients with post-stroke language impairment. The patients are divided into two groups: the experimental group, which receives a combination of standard treatment (speech therapy) and cerebrolysin, and the control group, which only receives standard treatment (speech therapy). By comparing the PK-WAB scores before and after drug administration, the study seeks to analyze the impact of cerebrolysin on language improvement. According to various stroke registries, 15-42% of patients in the subacute phase of stroke and 25-50% of patients with chronic stroke show symptoms of aphasia. Language therapy for stroke-related aphasia has become increasingly important due to its association with prolonged hospitalization, increased healthcare costs, mortality, and other negative prognostic factors .

After central nervous system damage such as stroke and traumatic brain injury, the administration of growth hormones and neurotrophic factors such as brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF), nerve growth factor (NGF), and ciliary neurotrophic factor (CNTF) has been reported to influence nerve regeneration.

Cerebrolysin (EVER Neuro Pharma GmbH, AUSTRIA) is a multi-modal drug composed of low-molecular peptides and amino acids, which shows neuroprotective and neurotrophic effects similar to endogenous neurotrophic factors. Analysis of cerebrolysin using ELISA revealed that it contains CNTF, GDNF, IGF1, IGF2, and other factors structurally and functionally similar to neurotrophic factors (NTFs). Cerebrolysin activates the same PI3K/Akt pathway as BDNF, playing a crucial role in the growth, proliferation, differentiation, and migration of nerve cells, and promoting the maintenance, protection, and repair of neural networks. Additionally, it activates the SHH pathway, facilitating neuroplasticity and neurogenesis, thereby aiding the brain's self-repair process and functional recovery. Recent studies have shown that cerebrolysin reduces inflammation in the cerebral vasculature and improves the integrity of the blood-brain barrier by increasing tight junctions.

Cerebrolysin has shown excellent effects on motor function improvement in moderate-to-severe stroke patients in studies by Muresanu et al. 2016. and Chang et al. 2016. Based on these results, cerebrolysin has been included in stroke rehabilitation guidelines in Austria (2018), Germany (2020), Canada (2020), the European Neuroscience Society (2021), and the Korean Brain and Neurorehabilitation Society (2022). Furthermore, cerebrolysin has been included in the Canadian TBI guidelines for improving attention in patients with moderate-to-severe traumatic brain injury, and it is expected to be beneficial in the rehabilitation of both stroke and traumatic brain injury patients.

Although there is strong evidence that cerebrolysin improves motor function, attention, and consciousness levels after stroke or brain injury, its effect on language abilities remains unclear. Moreover, previous studies have limitations, including the use of the Western Aphasia Battery Test and heterogeneity in language assessments. Therefore, this study plans to conduct additional research using a well-designed, double-blind, placebo-controlled, randomized study to assess the effect of cerebrolysin on non-fluent aphasia, using a variety of evaluation tools to accurately measure improvements in language abilities."