Impact of Intensive Therapy on the Salivary Proteomic Profile in Ischemic Stroke Patients: Relationships with Expressive Aphasia, Language Assessment, and Stress

• Grant number: 25/00922-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: July 01, 2025
• End date: June 30, 2026
• Field of knowledge: Health Sciences - Dentistry
• Principal Investigator: Marília Afonso Rabelo Buzalaf
• Grantee: Beatriz Campos Melo
• Host Institution: Faculdade de Odontologia de Bauru (FOB). Universidade de São Paulo (USP). Bauru , SP, Brazil

Abstract

Stroke is a serious global public health issue and, in Brazil, it is the second leading cause of death. Stroke is a neurological disorder that occurs due to the obstruction of blood vessels, causing damage to brain tissue and potentially resulting in loss of function and permanent disability. The most common type is ischemic stroke, which often results in expressive aphasia-a language disorder that impairs an individual's ability to speak. Intensive speech therapy is an effective approach to treat this condition, focusing in improving communication skills and, consequently, the quality of life of the patients. The present study aims to evaluate and compare the proteomic profile of saliva from patients who have suffered an ischemic stroke-whether treated with thrombolysis or not-before and after intensive speech therapy. Additionally, the study seeks to correlate the proteomic findings with the stress level and language assessment of these patients, in order to elucidate the underlying mechanisms behind these changes by comparing them with a group of healthy volunteers. Healthy volunteers (control group), patients with thrombolysed ischemic stroke, and patients with non-thrombolysed ischemic stroke, diagnosed within up to one year and aged between 30 and 60 years, will be recruited. The number of patients will be determined based on the pilot study. Unstimulated saliva from these participants will be collected between 9 a.m. and 11 a.m., before and after intensive speech therapy, in Falcon tubes immersed in ice. The saliva samples will be prepared and individually analyzed by nanoLC-ESI-MS/MS. Differential statistical analysis will be carried out using Progenesis software, employing analysis of variance (ANOVA) with consideration of p-value (p<0,05), fold-change, q-value (adjusted for multiple comparisons), and power analysis. Stress levels will be evaluated using the Perceived Stress Scale (PSS), and language will be assessed by the Montreal-Toulouse Language Assessment Battery-MTL-Brazil. For the correlation regarding language evaluation and stress level, the data will be subjected to a normality test (Kolmogorov-Smirnov). Subsequently, to assess the strength and direction of the association between the data, Pearson's correlation test (for parametric data) or Spearman's correlation test (for non-parametric data) will be used.