RESUMO
Abstract Background: Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive technique that acts on the activity of the cerebral cortex employing electrical currents. Aim: The objective of this project is to evaluate the effectiveness of rTMS on pain and quality of life in patients with chemotherapy-induced peripheral neuropathic pain. Method: Ten patients with chemotherapy-induced peripheral neuropathic pain received 20 sessions of rTMS, consisting of 15 minutes of treatment repeated 5 times per week for four weeks (10 Hz, 20s, 30 trains with 81% intensity). Patients were evaluated using the Brief pain inventory (BPI) and the Functional Assessment of Cancer Therapy and neurotoxicity (FACT-GOG-NTX 13). Results: There were significant differences in BPI mean severity, interference score and FACT-GOG-NTX 13 (p<0,05). Conclusion: The pilot study results suggest that rTMS is potentially beneficial for the treatment of chemotherapy-induced peripheral neuropathy. rTMS over the M1 had an important reduction in pain severity, interference with daily activities, and quality of life scores. However, results should be taken with caution due to the small sample size, absence of a control group and short period of follow-up.
Resumen Antecedentes: La estimulación magnética transcraneal repetitiva (EMTr) es una técnica no invasiva que actúa sobre la actividad de la corteza cerebral, empleando corrientes eléctricas. Objetivo: El objetivo de este proyecto es evaluar la eficacia de la EMTr sobre el dolor y la calidad de vida en pacientes con dolor neuropático periférico inducido por quimioterapia. Métodos: Diez pacientes con dolor neuropático periférico inducido por quimioterapia recibieron 20 sesiones de EMTr que consistieron en un tratamiento de 15 minutos repetido 5 veces por semana durante cuatro semanas (10 Hz, 20 s, 30 trenes con 81 % de intensidad). Los pacientes fueron evaluados mediante el Inventario Breve de Dolor (BPI) y la Evaluación Funcional de la Terapia del Cáncer y la neurotoxicidad (FACT-GOG-NTX 13). Resultados: Hubo diferencias significativas en la severidad media del dolor del BPI, la puntuación de interferencia y el FACT-GOG-NTX 13 (p<0,05). Conclusión: Los resultados del estudio piloto sugieren que la rTMS es potencialmente beneficiosa para el tratamiento de la neuropatía periférica inducida por la quimioterapia. La rTMS sobre M1 tuvo una reducción importante de la severidad del dolor, la interferencia con las actividades diarias y las puntuaciones de calidad de vida. Sin embargo, los resultados deben tomarse con cautela debido al pequeño tamaño de la muestra, la ausencia de un grupo de control y el corto período de seguimiento.
RESUMO
Chemotherapy-induced peripheral neuropathic pain (CIPNP) is a frequent and devastating side effect of cancer therapy. No preventive strategies are currently available. We investigated the use of resveratrol (RESV) in the prevention of CIPNP and evaluated key components of the antioxidant defense system and neuroinflammatory factors as possible mediators contributing to RESV actions. Male rats were injected with oxaliplatin (OXA) and received daily oral RESV. Paw mechanical and thermal allodynia, oxidative stress, antioxidant, pro-inflammatory and neuronal injury/activation markers were evaluated in the sciatic nerve (SN), lumbar dorsal root ganglia (DRG) and spinal cord (SC). OXA-injected animals developed mechanical and thermal allodynia, while those receiving OXA + RESV showed patterns of response similar to control animals. Higher TBARS levels and lower GSH/GSSG ratios were observed in the SN of animals receiving OXA. The mRNA levels of the transcription factor NFκB and the pro-inflammatory cytokine TNFα were found to be upregulated both in lumbar DRG and SC. In addition, the antioxidant enzymes NQO-1 and HO-1 and the neuronal injury marker ATF3 showed increased levels of expression in lumbar DRG. In the dorsal SC the neuronal activation marker c-fos and the transcription factor Nrf2, main regulator of antioxidant defenses, were found to be upregulated. RESV early and sustained administration prevented NFκB, TNFα, ATF3 and c-fos upregulation, while increasing the expression of Nrf2, NQO-1, HO-1 and the redox-sensitive deacetylase SIRT1. RESV treatment was also able to restore TBARS levels and GSH/GSSG ratio. Thus, RESV administration resulted in the upregulation of antioxidant mediators, suppression of pro-inflammatory parameters and prevention of OXA-induced mechanical and thermal allodynia.