Seong-Ki Ahn

Clinical characteristics and treatment of benign paroxysmal positional vertigo after traumatic brain injury.

BACKGROUND Traumatic brain injury (TBI) has been reported to be a common cause of benign paroxysmal positional vertigo (BPPV). However, only a few studies have investigated BPPV after TBI. The aim of this study was to identify the clinical characteristics of BPPV after TBI and to determine whether there are clinical differences between BPPV after TBI and idiopathic BPPV. METHODS The authors reviewed the medical records of 192 consecutive patients with positional vertigo after head injury during the period 2003 to 2009 and investigated 112 patients with idiopathic BPPV treated over the same period. The clinical characteristics of BPPV after TBI and the clinical differences between the traumatic BPPV and idiopathic BPPV groups were investigated. RESULTS A total of 32 patients with BPPV after TBI fulfilled the inclusion criteria. Twenty-four patients in the traumatic BPPV group had posterior semicircular canal-BPPV and 11 patients lateral semicircular canal-BPPV. A total of 58 repositioning maneuver sessions were performed in these 32 patients. Members of the traumatic BPPV group required more treatment sessions than members of the idiopathic group (p<0.05), but no tendency to recur was observed in the traumatic group (p>0.05). Recurrence rates in the traumatic and idiopathic BPPV groups were 15.6% and 18.8%, respectively (p>0.05). CONCLUSIONS It is likely that BPPV after TBI is more difficult to treat than idiopathic BPPV, but no tendency to recur was observed in patients who developed BPPV after TBI compared with idiopathic BPPV. Further prospective clinical meta-analytic studies are needed to investigate the outcome of BPPV after TBI.

Distribution of 5-HT1B and 5-HT1D receptors in the inner ear

Migraine and anxiety disorders are frequently co-morbid with balance disorders. This study examined the relative distribution of subtypes of serotonin (5-HT) receptor in the inner ear of monkeys and rats. Most vestibular ganglion cells were immunoreactive for 5-HT(1B) and 5-HT(1D) receptors in macaques and rats. In the inner ear, 5-HT(1B) and 5-HT(1D) receptor immunopositivity was associated with endothelial cells of the vestibular ganglion, spiral ganglion, vestibulocochlear nerve, spiral ligament and stria vascularis. It was noteworthy that 5-HT(1B) and 5-HT(1D) receptors are expressed in parallel sites in peripheral vestibular and trigeminal systems, which may be a factor underlying the efficacy of triptans in treating migraine and migrainous vertigo. Because the vestibular ganglion and trigeminal ganglion are both within the subarachnoid space, an interaction between 5-HT(1B) and TRPV1 receptors on blood vessel and ganglion cells may also contribute to the vasospasm and the comorbid headache, dizziness, nausea and vomiting that accompany subarachnoid hemorrhage.

Hemifacial degloving approach for medial maxillectomy: a modification of midfacial degloving approach.

INTRODUCTION Common surgical approaches for medial maxillectomy include lateral rhinotomy and midfacial degloving. Lateral rhinotomy provides an excellent surgical exposure but leaves a prominent scar on the face. Midfacial degloving has been preferred to lateral rhinotomy because it does not leave any external scars on the face, although midfacial degloving has its own limitations. For example, vestibular stenosis is a significant complication that can occur, and the bilateral exposure of the midface may be unnecessary in medial maxillectomy for most unilateral lesions. Several modifications of midfacial degloving have been reported in an attempt to avoid vestibular stenosis. We have designed another modification of midfacial degloving to avoid unnecessary exposure of the healthy side of the midface, as well as vestibular stenosis. The procedure involves a gingivobuccal incision across the midline, a septal transfixion incision, a pyriform aperture incision, and a lateral osteotomy along the frontal process of the maxilla to the nasion. We termed our modification the hemifacial degloving approach. We have performed 12 cases of medial maxillectomy using this hemifacial degloving approach. We present the procedures and the results.

Endoscope-assisted intraoral resection of external dermoid cyst

Surgical removal of a dermoid cyst is usually accomplished through an external neck incision. However, this procedure inevitably results in a neck scar.

Clinical Significance of the Presence of Autonomic and Vestibular Dysfunction in Diabetic Patients with Peripheral Neuropathy

Background We investigated the prevalence of diabetic autonomic neuropathy (DAN) and vestibular dysfunction (VD) in diabetic patients with peripheral neuropathy. Methods Thirty-five diabetic patients with peripheral neuropathy were enrolled from August 2008 to July 2009. All subjects underwent autonomic function tests. Nineteen of the patients (54.3%) underwent videonystagmography. Results Diabetic autonomic neuropathy was observed in 28 patients (80%). A mild degree of autonomic failure was observed in 18 patients (64.3%), and a moderate degree of autonomic failure was observed in ten patients (35.7%). Factors related to DAN included diabetic nephropathy (P=0.032), degree of chronic kidney disease (P=0.003), and duration of diabetes (P=0.044). Vestibular dysfunction was observed in 11 of 19 patients (57.9%). There was no significant association between DAN and VD. Conclusion Diabetic autonomic neuropathy was observed in 28 diabetic patients (80%) with peripheral neuropathy. Vestibular dysfunction was observed in nearly 60% of diabetic patients with peripheral neuropathy who complained of dizziness but showed no significant association with DAN. Diabetic patients who complained of dizziness need to examine both autonomic function and vestibular function.

Colocalization of 5-HT1F receptor and calcitonin gene-related peptide in rat vestibular nuclei

The aim of this study was to determine whether calcitonin gene-related peptide (CGRP) colocalizes with 5-HT(1F) receptor in rat vestibular nuclei using a double immunohistochemical staining procedure. The frequent co-occurrence of migraine and balance disorders suggests a pathophysiologic link between the two. However, the mechanism of migrainous vertigo has not been elucidated, though serotonin (5-HT) and its receptors are believed to involve in the pathogenesis of migrainous vertigo. Furthermore, 5-HT(1F) receptor agonists and CGRP receptor antagonists have recently attracted attention as potential treatments for migraine, and CGRP release from trigeminal neurons has been associated with migraine. This study demonstrates the colocalization of 5-HT(1F) receptor and CGRP in the rat vestibular nuclei, which suggests that 5-HT(1F) receptor regulates the release of CGRP from vestibular nuclei. This finding indicates that 5-HT(1F) receptor agonists may ameliorate migrainous vertigo by attenuating elevated levels of CGRP release from vestibular nuclei.

Wound healing of nasal mucosa in a rat

Background Postoperative wound healing of the nasal mucosa is a highly organized process. However, this process still has not been fully understood. The present study aimed to establish a wound healing model in a rat and describe histomorphological changes of the nasal mucosa after mechanical injury. Methods Unilateral wound in the nasal cavity was induced using the brushing technique in 4-week-old, Sprague-Dawley rats. Experimental rats were divided into five groups (n = 7 for each group). Animals were killed 1 hour and 2, 5, 14, and 28 days after injury. The histological sections were examined for inflammatory cell infiltration, goblet, and ciliated cell formation in hematoxylin and eosin staining. The subepithelial and epithelial thicknesses were measured and expressed as the subepithelial thickness index (STI) and epithelial thickness index (ETI). Fibrosis was evaluated by subepithelial fibrosis index (SFI) in Massons trichrome–stained sections. Results Respiratory epithelial discontinuity and hemorrhage were observed 1 hour after injury. On day 2, edematous subepithelium and infiltration of neutrophils could be found on the injured site. Day 5 was characterized by the infiltration of monocytes and granulation tissue. SFI and ETI values increased significantly at day 14. Goblet cells and ciliated cells began to regenerate from day 14 and restored to near normal at day 28. Conclusion Using mechanical injury, the wound healing model of the nasal mucosa was established in a rat. The regeneration of respiratory mucosa was completed on day 28 after injury.

Surgical management of intraoral ranulas in children: An analysis of 17 pediatric cases

OBJECTIVE The preferred treatment of pediatric intraoral ranulas remains controversial. We present our experience with ranulas at the Gyeongsang National University Hospital and review the literature. METHODS The study involved 17 children under 15 years of age who visited our hospital from 2001 to 2008 and were diagnosed with a ranula exceeding 2 cm in diameter. The age and gender of the patients, the surgical procedures, presurgical observation period, postsurgical follow-up period, and complications of each case were determined. The unruptured specimens were all subjected to detailed pathological analysis. RESULTS The patients were on average 9.3 years and there were 10 girls and 7 boys. Spontaneous resolution was not detected in any of the cases during the presurgical observation period. Indeed, in two cases, the ranula had increased in size. The ranula and sublingual gland (SG) were resected in all cases. The average operation time was 1h. Recurrence and complications were not detected in any of the cases. Pathological analyses revealed that there was no communication of the ranula with the SG in any of the cases. CONCLUSIONS Our experiences suggest that the presurgical observation period need not be longer than 3 months and that the resection of ranulas along with the ipsilateral SG is a safe and effective primary treatment for symptomatic pediatric intraoral ranulas that exceed 2cm in diameter.

Clinical characteristics and natural course of recurrent vestibulopathy: A long-term follow-up study†‡

To investigate the clinical characteristics and the natural course of recurrent vestibulopathy (RV).

Colocalization of 5.HT1F receptor and glutamate in neurons of the vestibular nuclei in rats

Interplay between migraine and balance disorder morbidities has been a topic of interest for many years. Serotonin (5-HT) receptor is closely related with migraine and is associated with vestibular symptoms. The mechanism underlying migrainous vertigo, however, has not been determined. 5-HT1F receptor has recently attracted attention in the treatment of migraine, and the release of glutamate from trigeminal neurons has been implicated in migraine. In this study, the authors observed the colocalization of 5-HT1F receptor and glutamate in the vestibular nuclei of rats using double immunofluorescence, which suggests that 5-HT1F receptor might modulate glutamate release from the vestibular nuclei. The results of this study suggest that 5-HT1F receptor agonists represent a potential therapeutic strategy for migraine and balance disorders by blocking the release of glutamate.