Role of Nitric Oxide in a Spinal Ligation Model of Neuropathic Pain / 대한마취과학회지

BACKGROUND: The role of NO in neuropathic pain is controversial. The aim of this study was to compare neuropathic pain behavior after a NOS inhibitor or NO donor treatment and to investigate NOS activity in the dorsal root ganglia (DRG) of young and adult rats after spinal nerve injury. METHODS: The effect of L-nitroarginine methylester (L-NAME) or sodium nitroprusside (SNP) on allodynia was measured in a spinal nerve ligation model of neuropathic pain. A NADPH-diaphorase (NADPH-d) histochemistry was performed on the DRG in a spinal nerve ligation model of neuropathic pain. RESULTS: Mechanical allodynia was increased after spinal nerve injury in both young and adult rats, especially more prominent in young rats. The NOS inhibitor, L-NAME, alleviated allodynia after spinal nerve ligation in young rats but not in adults. The NO donor, SNP, aggravated allodynia in a spinal nerve ligation model of neuropathic pain in young rats but not in adult rats. NOS activity increased prominently in the DRG after spinal nerve ligation in young rats in contrast to adult rats. CONCLUSIONS: Severe neuropathic pain behavior may be a result of an increase of NOS activity in the DRG of young rats after spinal nerve ligation, whereas NO production may not be significantly related to neuropathic pain behaviors in a spinal nerve ligation model of adult rats.

The Study of Bilateral Venign Vocal Fold Lesions / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Benign vocal fold lesions are a common cause of voice dysfunction. Successful treatment of these diseases is primarily accomplished through voice therapy and surgical treatment. But many clinicians are faced with cases where problems persist in spite of treatment. The one cause of treatment failure in benign vocal fold lesions may be the bilateral lesions each vocal fold has different lesion. Authors studied to evaluate the possibility of persisted voice dysfunction in bilateral benign vocal fold lesions. MATERIALS AND METHODS: Strobovideolaryngoscopy findings of 128 patients with bilateral benign vocal fold lesions were reviewed. We evaluate to see if lesions in each vocal fold of one patient were the same or not. The treatment methods for each lesion were classified. We compare the treatment methods for each lesion with those already performed on the patients. RESULTS: In cases with nodule in one vocal fold, we observed 8 edema, 2 epidermoid cyst in the opposite vocal fold. In cases with reinke's edema on both vocal fold, we observed combined lesion, such as 1 epidermoid cyst, 1 hyperkeratosis. In cases with sulcus vocalis on both vocal fold, we observed combined lesion, such as 3 nodules, 4 polyps, 6 edema. We observed 2 cases with epidermoid cyst in one side and edema in opposite vocal fold, 5 cases with bilateral vocal nodule and combined varices in one side, 2 cases with bilateral laryngeal edema and combined hyperkeratosis in one side. CONCLUSION: Bilateral benign vocal fold lesions sometimes have more than 2 laryngeal diseases for which the treatment modality is different. Clinician should know the lesion precisely in each vocal fold, and treatment plan should be also made in according to the lesion in each vocal fold.

Microvascular Lesions of the Vocal Folds in the Patients with Hoarseness / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: The various types of varix which has a dilated, tortous, elongated blood vessel arising from the microcirculation of the vocal folds may cause different types of dysphonia. There have not been many specific studies on the characteristics of microvascular lesions of the vocal folds, so authors tried to evaluate the shapes, traveling pathway, and predilection site of the microvascular lesions. MATERIALS AND METHODS: A retrospective review of 119 patients with dysphonia was undertaken. All findings of videotapes were evaluated according to the shapes, the traveling pathway, the predilection sites and accompanying disorders of the microvascular lesions. RESULTS: The most common shapes of the microvascular lesions were the abrupt developed type and the multiple dilated type. The longitudinal type was the most common traveling type. The superolateral surface of the vocal folds was the predilection site of the microvascular lesions. Functional voice disorders, such as laryngeal nodule, laryngeal polyp, laryngeal edema, were more common as accompanying disorders. CONCLUSION: Authors found that there were a variety of types of microvascular lesions.