Brain Sciences (May 2021)

Serotonin Levels and Cognitive Recovery in Patients with Subacute Stroke after Rehabilitation Treatment

  • Mariacristina Siotto,
  • Marco Germanotta,
  • Massimo Santoro,
  • Valeria Cipollini,
  • Giulia Guardati,
  • Dionysia Papadopoulou,
  • Elisa Bray,
  • Alessia Mastrorosa,
  • Irene Aprile

DOI
https://doi.org/10.3390/brainsci11050642
Journal volume & issue
Vol. 11, no. 5
p. 642

Abstract

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Post-stroke depression and cognitive impairment are common conditions affecting patients after stroke. Serotonin is a neurotransmitter involved in modulating, among others, mood, cognition, learning, and memory. Sub-optimal serotonin activity may be in part responsible for cognitive deficits seen in depression. In this pilot study serotonin levels were evaluated in 29 patients with sub-acute stroke before and after a rehabilitation treatment (consisting of a program of upper limb robotic rehabilitation in addition to conventional physical therapy treatment). We employed the Back Depression Inventory scale to evaluate symptoms of depression, and specific tools to evaluate cognitive functions. We found a significant reduction of the serotonin levels after rehabilitation in the whole group (T0: 85.9 ± 92.4 ng/mL; T1: 61.9 ± 58.4 ng/mL; p = 0.0018), as well as in the subgroup of patients untreated with Selective Serotonin Reuptake Inhibitors (SRRI), (mean serotonin at T0: 154.0 ± 102.3 ng/mL; mean serotonin at T1: 92.9. ± 68.7 ng/mL at T1; p = 0.005). We also found a correlation with cognitive assessment: in particular, the change from baseline of the serotonin (ΔSerotonin) was correlated with the changes from baseline of the Rey’s Figure (ΔROCF) (r = 0.535; p r = 0.621; p p n = 16) we found only a positive correlation between ∆Serotonin and ∆ToL (subscore point: r= 0.587; p = 0.045), whereas in patients untreated with SSRIs (n = 13) we found a positive correlations between ΔSerotonin and ΔROCF (r = 0.700; p = 0.036), ∆Stroop (subscore time: r = 0.750; p = 0.020) and ∆Tol (subscore point: r = 0.740; p = 0.023) and a negative correlation between ΔSerotonin and ∆Tol (subscore time: r= −0.833; p = 0.005). These results suggest that variation of serotonin levels should be monitored in patients during a rehabilitation program, not only for their relationship with depression symptoms, but also for the correlation with cognitive performance.

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