Effect of neuromodulation on neurotrophic factors in patients with chronic disorders of consciousness

Iazeva  EG, Legostaeva LA, Bakulin IS, Poydasheva AG, Abaimov DA, Suponeva NA, Shabalina AA, Ryabinkina YuV, Piradov MA
About authors

Research Center of Neurology, Moscow, Russia

Correspondence should be addressed: Elizaveta G. Iazeva
Volokolamskoye shosse, 80, Moscow, 125367; ur.ygoloruen@avezay

About paper

Funding: the study was supported by Russian Science Foundation (RSF) grant 16-15-00274.

Compliance with ethical standards: the study was approved by the Ethics Committee of the Research Center of Neurology (protocol No. 9-5.16 dated October 26, 2016). Patients were included in the study after obtaining the informed consent from their legal representatives.

Author contribution: Iazeva EG — clinical practice, clinical assessment, collecting biomaterials, manuscript writing; Legostaeva LA — clinical practice, clinical assessment, collecting biomaterials; Bakulin IS, Poydasheva AG — рТМС, manuscript writing; Abaimov DA, Shabalina AA — laboratory tests; Suponeva NA, Ryabinkina YV, Piradov MA — study planning and management.

Received: 2020-08-19 Accepted: 2020-09-05 Published online: 2020-09-23

Transcranial magnetic stimulation (TMS) is one of rehabilitation approaches for patients with chronic disorders of consciousness (DOC). The aim of our study was to assess neurotrophic factors and the changes of those after TMS course in patients with chronic DOC. We enrolled 26 patients with chronic DOC of various etiology and 21 heathy volunteers. Blood serum and cerebrospinal fluid (CSF) were collected from all patients before and after the TMS course, the levels of BDNF, NSE, NGF, РDGF, GDNF and NT3 were assessed in the biomaterial. The blood BDNF, NSE, PDGF, GDNF and NT3 in patients with chronic DOC were higher compared to healthy volunteers (p < 0.05). We found no correlations between the type of DOC and neurotrophic factors concentrations in blood and CSF. The CSF level of BDNF in patients after traumatic brain injury (TBI) was higher compared to patients with non-traumatic chronic DOC (p < 0.05). We also found the increase of CSF BDNF after the TMS course in patients after TBI (p < 0.05). No other significant differences between groups and another blood and cerebrospinal fluid biomarker levels were detected. Thus, the serum BDNF, NSE, PDGF, GDNF and NT3 levels in patients with chronic DOC were higher compared to healthy volunteers. The BDNF level in CSF was higher in patients with traumatic DOC, and it also increased after the course of high-frequency TMS in this group. This fact may indicate the long-term neuronal plasticity processes in patients after TBI, as well as more favorable rehabilitation prognosis.

Keywords: disorders of consciousness, vegetative state, unresponsive wakefulness syndrome, minimally consciousness state, BDNF, NSE, PDGF, NT3, neurotrophic factors, transcranial magnetic stimulation