Protocatechuic acid (PCA) is a type of phenolic acid found in green tea and has been shown to have potent antioxidant and anti-inflammatory properties. However, the effect of PCA on pilocarpine seizure-induced neuronal death in the hippocampus has not been evaluated. In the present study, we investigated the potential therapeutic effects of PCA on seizure-induced brain injury. Epileptic seizure was induced by intraperitoneal (i.p.) injection of pilocarpine (25 mg/kg) in adult male rats, and PCA (30 mg/kg) was injected into the intraperitoneal space for three consecutive days after the seizure. Neuronal injury and oxidative stress were evaluated three days after a seizure. To confirm whether PCA increases neuronal survival and reduced oxidative injury in the hippocampus, we performed Fluoro-Jade-B (FJB) staining to detect neuronal death and 4-hydroxynonenal (4HNE) staining to detect oxidative stress after the seizure. In the present study, we found that, compared to the seizure vehicle-treated group, PCA administration reduced neuronal death and oxidative stress in the hippocampus. To verify whether a decrease of neuronal death by PCA treatment was due to reduced glutathione (GSH) concentration, we measured glutathione with N-ethylmaleimide (GS-NEM) levels in hippocampal neurons. A seizure-induced reduction in the hippocampal neuronal GSH concentration was preserved by PCA treatment. We also examined whether microglia activation was affected by the PCA treatment after a seizure, using CD11b staining. Here, we found that seizure-induced microglia activation was significantly reduced by the PCA treatment. Therefore, the present study demonstrates that PCA deserves further investigation as a therapeutic agent for reducing hippocampal neuronal death after epileptic seizures.

Background: The purpose of this study was to investigate the degree of sedation and the incidence of adverse effects resulting from various methods of administering the initial dose followed by continuous infusion of dexmedetomidine (DEX) for sedation in elderly patients undergoing spinal anesthesia.Methods: In total, 72 patients aged over 65 years who were to be administered spinal anesthesia were randomly allocated into three groups. The initial doses were injected to the groups as follows: group DD, DEX 0.5 μg/kg for 10 min; group MD, midazolam 0.02 mg/kg; and group D, no initial dose. This was followed immediately by infusing a maintenance dose of DEX 0.5 μg/kg/h to all groups.Results: The Bispectral index (BIS) in the D group was significantly higher than in the other two groups. There were no significant differences in the Ramsay sedation scale (RSS) among the groups. The RSS 3 level was reached in 10 min from the start of sedation in MD and DD groups and in 20 min from the start of sedation in D group. Neither bradycardia nor hypotension was observed in any of the groups.Conclusions: Patients in all three groups reached the RSS 3 sedating-effect level. However, the group that received continuous infusion only without the initial dose showed higher BIS than the other two groups and reached the RSS 3 later. No adverse events were observed in any of the groups.

Post-herpetic neuralgia (PHN) is one of the most painful diseases, which has made it a major concern for pain physicians. We aimed to quantitatively analyze the research outputs of studies on PHN published over the past 30 years using bibliometric analysis. We also aimed to analyze the research outputs of studies on interventional treatments for PHN and evaluate the academic achievements of Korean pain physicians. Bibliometric analysis was performed by searching the Web of Science database for PHN-related articles published between 1991 and 2020. Publication number, year, source, country, institution, and citation-related information were retrieved from the database. We also quantitatively analyzed publications related to interventional treatments for PHN. A total of 3285 publications were extracted from the database; 101 (3.1%) of the articles were published by South Korean authors, making South Korea the 11th in the order of countries that published the most articles. There were 185 articles on the effects of interventional treatments for PHN. South Korean authors published 30 (16.2%) articles out of these, making South Korea the 3rd in the order of countries that published the most articles on the effects of interventional treatment for PHN. Our results showed an increasing trend in the number of PHN-related publications and the academic achievements of Korean pain physicians in this field over the past 3 decades. However, the proportion of studies on interventional treatments is relatively small. Korean pain physicians need to establish academic evidence on interventional treatment to expand their role in this field and improve the outcomes of PHN patients.

No abstract

Postherpetic neuralgia (PHN) is the most common but challenging complication of herpes zoster due to long-lasting intractable neuropathic pain. Routine pharmacologic treatments of PHN include anticonvulsants (e.g., gabapentin, pregabalin), antidepressants (e.g., amitriptyline), opioids (e.g., oxycodone, morphine). However, those medications have limitations due to side effects inclusive of peripheral edema, nausea, vomiting and somnolence, or insufficient analgesic effect. Mirogablin, a novel voltage-gated calcium channel (VGCC) selective α 2 δ ligand, has been recently approved as a drug to treat peripheral neuropathic pain. In this case report, we represent a 77-year-old patient with intractable PHN who achieved successful pain relief with intake of mirogabalin with less side effects.