Physiological and pathological characterization of capsaicin-induced reversible nerve degeneration and hyperalgesia.

BACKGROUND: The study aimed to investigate the physiology, psychophysics, pathology and their relationship in reversible nociceptive nerve degeneration, and the physiology of acute hyperalgesia. METHODS: We enrolled 15 normal subjects to investigate intraepidermal nerve fibre (IENF) density, contact heat-evoked potential (CHEP) and thermal thresholds during the capsaicin-induced skin nerve degeneration-regeneration; and CHEP and thermal thresholds at capsaicin-induced acute hyperalgesia. RESULTS: After 2-week capsaicin treatment, IENF density of skin was markedly reduced with reduced amplitude and prolonged latency of CHEP, and increased warm and heat pain thresholds. The time courses of skin nerve regeneration and reversal of physiology and psychophysics were different: IENF density was still lower at 10 weeks after capsaicin treatment than that at baseline, whereas CHEP amplitude and warm threshold became normalized within 3 weeks after capsaicin treatment. Although CHEP amplitude and IENF density were best correlated in a multiple linear regression model, a one-phase exponential association model showed better fit than a simple linear one, that is in the regeneration phase, the slope of the regression line between CHEP amplitude and IENF density was steeper in the subgroup with lower IENF densities than in the one with higher IENF densities. During capsaicin-induced hyperalgesia, recordable rate of CHEP to 43 °C heat stimulation was higher with enhanced CHEP amplitude and pain perception compared to baseline. CONCLUSIONS: There were differential restoration of IENF density, CHEP and thermal thresholds, and changed CHEP-IENF relationships during skin reinnervation. CHEP can be a physiological signature of acute hyperalgesia. SIGNIFICANCE: These observations suggested the relationship between nociceptive nerve terminals and brain responses to thermal stimuli changed during different degree of skin denervation, and CHEP to low-intensity heat stimulus can reflect the physiology of hyperalgesia.

Transnasal endoscopic resection of vidian nerve schwannoma accompanied by sphenoid mucopyocele and oculomotor palsy: a case report.

Schwannomas are rare tumours arising from the peripheral nerve sheath. Nearly half of all schwannomas occur in the head and neck region, but the sinonasal tract is rarely involved. We report on an extremely rare case of vidian nerve schwannoma accompanied by mucopyocele with symptoms of oculomotor palsy and CSF leakage. An exclusively endoscopic endonasal approach was performed to excise the tumour and the dural defect was repaired. To our knowledge, this is the first time a vidian nerve schwannoma has been excised in an exclusively endoscopic approach. We first review the literature and then discuss the benefits for patients undergoing this type of operation.

Diagnostic performance of serum cystatin C and serum creatinine in the prediction of chronic kidney disease in renal transplant recipients.

BACKGROUND: Chronic kidney disease (CKD) has adverse impacts on mortality and morbidity of renal transplant recipients. Serum cystatin C (sCysC) is a novel marker in predicting the CKD. We therefore compare sCysC and serum creatinine (sCr) with the aim of improving the detection of CKD in renal transplant recipients. METHODS: We enrolled 106 renal transplant recipients and estimated glomerular filtration rates (GFR) using the Cockcroft-Gault (GFR(CG)) and the abbreviated Modification of Diet in Renal Disease (GFR(aMDRD)) formulae. We defined CKD as the presence of structural or functional kidney damage, irrespective of the diagnosis. Comparisons of sCysC and sCr in detecting CKD were analyzed. RESULTS: sCysC correlates with sCr significantly (r = 0.87; P < .001). The receiver operating characteristic curve demonstrates that sCysC has a better specificity and area under the curve, but less sensitivity than sCr in predicting CKD in renal transplant recipients if GFR is estimated by GFR(CG). Additionally, if GFR was estimated by GFR(aMDRD), the role of sCysC or sCr in prediction of CKD was comparable. CONCLUSION: sCysC may be better than sCr to detect CKD in renal transplant recipients using the GFR(CG).

A Salmonella infection complicated with suppurative thyroiditis and ruptured aortic mycotic aneurysm in a renal transplant recipient.

We report a renal transplant recipient who presented with fever and chills for 2 days. The blood and stool cultures revealed the growth of Salmonella enteriditis. A whole-body gallium scan played an important role in the subsequent diagnosis of suppurative thyroiditis. To our knowledge, this is the first report of acute S. enteriditis thyroiditis in a renal transplant recipient. Despite vigorous antibiotic use and a partial thyroidectomy, he experienced recurrent S. enteriditis infection, resulting in a ruptured thoracic mycotic aneurysm 1 month later. Finally the patient was successfully cured with aneurysm resection, in situ reconstruction of the thoracic aorta, and prolonged antibiotics.

Non-life-threatening leukopenia in a renal transplant recipient with acute overdose of mycophenolate mofetil.

Mycophenolate mofetil (MMF) is increasingly used as an immunosuppressant for organ transplantation and for treatment of autoimmune diseases. As yet, the experience with acute overdose of MMF in humans is limited. Herein we have reported a 40-year-old female kidney recipient with moderate leukopenia and lack of gastrointestinal toxicity following ingestion of 25 g MMF, which was confirmed by serum drug levels. We treated the patient with charcoal decontamination and oral cholestyramine. She recovered completely without sequelae.