Emerging Toxic Neuropathies and Myopathies

High-dose hydroxychloroquine induces changes in low-frequency brain oscillations in electrocorticographic records not concurrent with alterations in cardiac, hepatic, and renal function in wistar rats

The toxicity of hydroxychloroquine (HCQ) can impact the function of vital organs, leading to ocular and cardiovascular damage. This study aims to evaluate the toxicity of HCQ through electrocorticographic evaluation and blood biochemical parameters in Wistar rats. The animals received a dose of HCQ of 350 mg/kg via gavage every 12 hours for periods of 24, 48, 72 and 96 hours, with each group consisting of n = 9. After treatment, the animals underwent surgery to implant electrodes in the motor cortex region and subsequently underwent bipolar electrocorticography. The electrodes for acquiring electrocardiographic recordings were fixed in the D II position and blood samples were analyzed for liver and kidney function. The results demonstrated that high doses of HCQ altered electrocorticographic features, decreased cardiac activity throughout treatment, and significantly elevated aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels. However, assessment of renal function, as indicated by serum creatinine levels, revealed no significant changes. These results suggest that exposure to high doses of HCQ in rats may disrupt the structures and functions of vital organs.

Exploring the Potential Role of Phytopharmaceuticals in Alleviating Toxicities of Chemotherapeutic Agents

BACKGROUND

Chemotherapy is the mainstay of cancer treatment, bringing patients optimism about recurrence and survival. However, the clinical effectiveness of chemotherapeutic drugs is frequently jeopardized by their intrinsic toxicity, resulting in side effects affecting the quality of life of cancer patients. This analysis explores the ethnopharmacological impact of phytopharmaceuticals, highlighting their traditional use in many cultures. The present study, which takes its cues from indigenous knowledge, aims to close the knowledge gap between traditional medicine and modern medicine in reducing the toxicities of chemotherapy treatments.

AIM

The present in-depth study aims to highlight the current research and upcoming developments in phytopharmaceuticals for reducing the toxicity of chemotherapeutic drugs. Further, we address the mechanisms through which phytopharmaceuticals may reduce chemotherapy-induced side effects that include nausea, vomiting, myelosuppression, nephropathy, neuropathy, and cardiotoxicity using data from a variety of preclinical and clinical investigations.

MATERIALS AND METHODS

The literature search was carried out by employing search engines such as PubMed and Google Scholar with keywords such as cancer, chemotherapy, CNS toxicity, hematopoietic toxicity, renal toxicity, GI toxicity, CNS toxicity, and phytopharmaceuticals.

RESULTS

Bioactive chemicals found in plants, such as fruits, vegetables, herbs, and spices, are being studied for their capacity to improve the safety and acceptability of chemotherapy regimens. The current review also dives into the investigation of phytopharmaceuticals as adjuvant medicines in cancer treatment, which is a viable path for addressing the pressing need to lessen chemotherapy-induced toxicities.

CONCLUSION

The present review revealed that the potential of phytopharmaceuticals in alleviating chemotherapeutic drug toxicities would pave the way for better cancer treatment and patient outcomes, harmonizing with the larger trend towards personalized and holistic approaches to chemotherapy.

Comparing the Clinical Manifestations of Bell's Palsy between Pre-COVID-19 Pandemic and COVID-19 Pandemic Periods

BACKGROUND

COVID-19 has been shown to affect the onset and severity of various diseases. We examined whether the clinical characteristics of Bell's palsy differed between before and during the COVID-19 pandemic.

METHODS

From January 2005 to December 2021, 1839 patients were diagnosed and treated for Bell's palsy at Kyung Hee University Hospital. These patients were divided into a pre-COVID period group and COVID-19 period group, and the clinical characteristics of the two groups were compared.

RESULTS

There were 1719 patients in the pre-COVID period group and 120 patients in the COVID-19 period group. There were no between-group differences in sex (p = 0.103) or in the presence of underlying hypertension (p = 0.632) or diabetes (p = 0.807). Regarding symptoms, there were no significant between-group differences in otalgia, dizziness, tinnitus, hyperacusis, or hearing loss (p = 0.304, p = 0.59, p = 0.351, p = 0.605, and p = 0.949). There were also no significant between-group differences in electroneurography results (p = 0.398), electromyography results (p = 0.331), House-Brackmann Grade at visit (p = 0.634), or recovery rate after treatment (p = 0.525).

CONCLUSIONS

Contrary to our expectation that Bell's palsy cases during the COVID-19 pandemic would show different clinical features than those occurring before COVID-19, the present study found no differences in clinical features or prognosis.

Peripheral neuropathy in COVID-19 is due to immune-mechanisms, pre-existing risk factors, anti-viral drugs, or bedding in the Intensive Care Unit

BACKGROUND

This mini-review aims to summarize and discuss previous and recent advances in the clinical presentation, pathophysiology, diagnosis, treatment, and outcome of SARS-CoV-2-associated peripheral neuropathies.

METHODS

Literature review.

RESULTS

Altogether, 105 articles about SARS-CoV-2-associated neuropathy describing 261 patients were retrieved. Peripheral neuropathy in patients with COVID-19 is frequent and predominantly due to immune mechanisms or neurotoxic side effects of drugs used to treat the symptoms of COVID-19 and, to a lesser extent, due to the compression of peripheral nerves resulting from prolonged bedding in the Intensive Care Unit (ICU) and pre-existing risk factors such as diabetes. SARS-CoV-2 does not cause viral neuropathy. Neurotoxic drugs such as daptomycin, linezolid, lopinavir, ritonavir, hydro-chloroquine, cisatracurium, clindamycin, and glucocorticoids should be administered with caution and patients should be appropriately bedded in the ICU to prevent SARS-CoV-2-associated neuropathy. Patients with Guillain-Barré syndrome (GBS) benefit from immunoglobulins, plasma exchange, and steroids.

CONCLUSIONS

Neuropathies of peripheral nerves in patients with COVID-19 are frequent and mostly result from immune mechanisms or neurotoxic side effects of drugs used to treat the symptoms of COVID-19 and, to a lesser extent, from the compression of peripheral nerves due to prolonged bedding on the ICU. SARS-CoV-2 does not cause infectious neuropathy.

Asymptomatic hyperCKemia During Infliximab Therapy in Patients With Inflammatory Bowel Disease

BACKGROUND

Both muscle-related complaints and elevated serum creatine kinase (CK) levels have been reported in patients with inflammatory bowel disease (IBD) treated with infliximab (IFX), mainly as case reports. The aim of this study was to investigate the effect of IFX therapy on serum CK levels in a cohort of Greek IBD patients.

METHODS

Demographic, clinical (including muscle complaints), and laboratory data of consecutive IBD patients undergoing IFX treatment and a matched control group of IBD patients without any use of biological treatment were retrospectively analyzed. In both groups, patients having at least 3 CK measurements, with at least 10 days' interval among them, were included.

RESULTS

The IFX-treated IBD patient group included 82 individuals (75.6% Crohn's Disease [CD]; mean age, 44.7 ± 13.3 years; 60.9% men; median [interquartile range {IQR}] duration of IFX treatment, 27 [12-84] months). Eighty-two patients without treatment with any biological agent formed the control group (62.2% CD; mean age, 50.4 ± 16.4 years; 59.8% men). Twenty-five IFX-treated patients (30.5%) had elevated mean serum CK levels (>180 U/L), compared with 9 (11%) in the control group (P = 0.0003). The median CK value in the IFX group (123.5 U/L; IQR, 91-190.75) was significantly higher than that of the control group (81 U/L; IQR, 57-112.75; P < 0.0001). In the logistic regression analysis, the presence of hyperCKemia was independently correlated with the use of IFX (odds ratio, 4.03; IQR, 1.64-9.90; P = 0.002). No patient with hyperCKemia in both groups reported any persistent symptom of myopathy.

CONCLUSIONS

More than 30% of IBD patients on IFX present asymptomatic persistent and treatment-related hyperCKemia. Further relevant prospective investigation is needed. 10.1093/ibd/izy088_video1izy088.video15778459427001.

Therapeutic Effects of Phytochemicals and Medicinal Herbs on Chemotherapy-Induced Peripheral Neuropathy

Chemotherapy-induced peripheral neuropathy (CIPN) is a frequent adverse effect of neurotoxic anticancer medicines. It leads to autonomic and somatic system dysfunction and decreases the patient's quality of life. This side effect eventually causes chemotherapy non-compliance. Patients are prompted to seek alternative treatment options since there is no conventional remedy for CIPN. A range of medicinal herbs have multifarious effects, and they have shown some evidence of efficacy in various neurological and immunological diseases. While CIPN has multiple mechanisms of neurotoxicity, these phytomedicines might offer neuronal protection or regeneration with the multiple targets in CIPN. Thus far, researchers have investigated the therapeutic benefits of several herbs, herbal formulas, and phytochemicals in preventing the onset and progress of CIPN in animals and humans. Here, we summarize current knowledge regarding the role of phytochemicals, herb extracts, and herbal formulas in alleviating CIPN.

Myopathy and eosinophilic pneumonia coincidentally induced by treatment with daptomycin

A 34-year-old man with 22q11.2 deletion syndrome (DiGeorge syndrome) concurrently suffered from myopathy and eosinophilic pneumonia shortly after receiving daptomycin (DAP) for right-sided infective endocarditis. The simultaneous occurrence of these phenomena in relation to DAP therapy has not been previously well described. An allergic reaction was suspected as a possible etiology of these DAP-related complications. This case highlights the need for close observation in order to detect both musculoskeletal and respiratory disorders from the start of DAP therapy. Physicians should pay more attention to this new drug, which is expected to be frequently used in various clinical settings.

Peripheral glia have a pivotal role in the initial response to axon degeneration of peripheral sensory neurons in zebrafish

Axon degeneration is a feature of many peripheral neuropathies. Understanding the organismal response to this degeneration may aid in identifying new therapeutic targets for treatment. Using a transgenic zebrafish line expressing a bacterial nitroreductase (Ntr)/mCherry fusion protein in the peripheral sensory neurons of the V, VII, IX, and X cranial nerves, we were able to induce and visualize the pathology of axon degeneration in vivo. Exposure of 4 days post fertilization Ntr larvae to the prodrug metronidazole (Met), which Ntr metabolizes into cytotoxic metabolites, resulted in dose-dependent cell death and axon degeneration. This was limited to the Ntr-expressing sensory neurons, as neighboring glia and motor axons were unaffected. Cell death was rapid, becoming apparent 3-4 hours after Met treatment, and was followed by phagocytosis of soma and axon debris by cells within the nerves and ganglia beginning at 4-5 hours of exposure. Although neutrophils appear to be activated in response to the degenerating neurons, they did not accumulate at the sites of degeneration. In contrast, macrophages were found to be attracted to the sites of the degenerating axons, where they phagocytosed debris. We demonstrated that peripheral glia are critical for both the phagocytosis and inflammatory response to degenerating neurons: mutants that lack all peripheral glia (foxD3-/-; Ntr) exhibit a much reduced reaction to axonal degeneration, resulting in a dramatic decrease in the clearance of debris, and impaired macrophage recruitment. Overall, these results show that this zebrafish model of peripheral sensory axon degeneration exhibits many aspects common to peripheral neuropathies and that peripheral glia play an important role in the initial response to this process.

Subsite awareness in neuropathology evaluation of National Toxicology Program (NTP) studies: a review of select neuroanatomical structures with their functional significance in rodents

This review article is designed to serve as an introductory guide in neuroanatomy for toxicologic pathologists evaluating general toxicity studies. The article provides an overview of approximately 50 neuroanatomical subsites and their functional significance across 7 transverse sections of the brain. Also reviewed are 3 sections of the spinal cord, cranial and peripheral nerves (trigeminal and sciatic, respectively), and intestinal autonomic ganglia. The review is limited to the evaluation of hematoxylin and eosin-stained tissue sections, as light microscopic evaluation of these sections is an integral part of the first-tier toxicity screening of environmental chemicals, drugs, and other agents. Prominent neuroanatomical sites associated with major neurological disorders are noted. This guide, when used in conjunction with detailed neuroanatomic atlases, may aid in an understanding of the significance of functional neuroanatomy, thereby improving the characterization of neurotoxicity in general toxicity and safety evaluation studies.