Clinical Implications of EEG and ERP as Biological Markers for Alzheimer's Disease and Mild Cognitive Impairment

OBJECTIVES: Memory impairment is a very important mental health issue for elderly and adults. Mild cognitive impairment (MCI) is a prodromal stage of Alzheimer's disease (AD). Early detection of the prodromal stage of patients with AD is an important topic of interest for both mental health clinicians and policy makers. METHODS: Electroencephalograpgy (EEG) has been used as a possible biological marker for patients with MCI, and AD. In this review, we will summarize the clinical implications of EEG and ERP as a biological marker for AD and MCI. RESULTS: EEG power density, functional coupling, spectral coherence, synchronization, and connectivity were analyzed and proved their clinical efficacy in patients with the prodromal stage of AD. Serial studies on late event-related potentials (ERPs) were also conducted in MCI patients as well as healthy elders. Even though these EEG and ERP studies have some limitations for their design and method, their clinical implications are increasing rapidly. CONCLUSION: EEG and ERP can be used as biological markers of AD and MCI. Also they can be used as useful tools for early detection of AD and MCI patients. They are useful and sensitive research tools for AD and MCI patients. However, some problems remain to be solved until they can be practical measures in clinical setting.

Optimal combination of 3-component photoinitiation system to increase the degree of conversion of resin monomers / 대한치과보존학회지

OBJECTIVES: This study investigated the optimal combination of 3-component photoinitiation system, consisting of CQ, p-octyloxy-phenyl-phenyl iodonium hexafluoroantimonate (OPPI), and 2-dimethylaminoethyl methacrylate (DMAEMA) to increase the degree of conversion of resin monomers, and analyze the effect of the ratio of the photoinitiator to the co-initiator. MATERIALS AND METHODS: Each photoinitiators (CQ and OPP) and co-initiator (DMAEMA) were mixed in three levels with 0.2 wt.% (low concentration, L), 1.0 wt.% (medium concentration, M), and 2.0 wt.% (high concentration, H). A total of nine groups using the Taguchi method were tested according to the following proportion of components in the photoinitiator system: LLL, LMM, LHH, MLM, MMH, MHL, HLH, HML, HHM. Each monomer was polymerized using a quartz-tungsten-halogen curing unit (Demetron 400, USA) for 5, 20, 40, 60, 300 sec and the degree of conversion (DC) was determined at each exposure time using FTIR. RESULTS: Significant differences were found for DC values in groups. MMH group and HHM group exhibited greater initial DC than the others. No significant difference was found with the ratio of the photoinitiators (CQ, OPPI) to the co-initiator (DMAEMA). The concentrations of CQ didn't affect the DC values, but those of OPPI did strongly. CONCLUSIONS: MMH and HHM groups seem to be best ones to get increased DC. MMH group is indicated for bright, translucent color and HHM group is good for dark, opaque colored-resin.

A Case of Crocodile Tear Syndrome / 대한이비인후과학회지

The syndrome of crocodile tear refers to an abnormal gusto-lacrimal reflex where any gustatory stimulation produces excessive tearing as well as salivation. It is a relatively rare syndrome that has mainly been observed after a recovery from a peripheral facial nerve palsy, surgery of the acoustic neuroma or in a congenital syndrome. The most commonly accepted mechanism for the pathogenesis of the crocodile tear syndrome is that of aberrant regeneration of nerve fibers or that of transaxonal transmission. Crocodile tear syndrome may be effectively treated by intraglandular injections of botulinum toxin. Authors experienced a case of crocodile tear syndrome that occurred after the removal of acoustic neuroma; it was treated successfully by injection of botulinum toxin into the lacrimal gland. We report this case with the related literatures.

A Clinical Analysis of Psychogenic Hearing Loss Presenting as Sudden Deafness / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Sudden deafness results from, in most cases, lack an apparent cause. However viral infection, vascular occlusion, cochlear membrane rupture, and others are known to be associated with this disease. In this study, we observed incidence, etiology, audiologic, psychiatric, and clinical aspect of psychogenic sudden deafness through retrospective chart review and analysis of patients who are thought to have had sudden deafness from psychogenic causes and stressor. SUBJECTS AND METHOD: We reviewed the records of 277 patients who had been admitted to the Department of Otolaryngology, Kangbuk Samsung hospital, from January 1997 to July 2003, under the initial diagnosis of idiopathic sudden hearing loss. RESULTS: In patients' medical history, there were 9 patients who had association between sudden onset of hearing loss and psychogenic causes and stressor. And there were 4 patients who had preexisting psycho-pathologic condition. Among these patients, a joint study with psychiatrist classified 7 psychogenic sudden deafness patients (2.5%) who has been ruled out organic causes and showed discrepancy between pure tone audiometry and ABR. In distribution ratio, there were 2 males and 5 females, 4 patients were in their 10's, 1 in 20's, and 2 in 40's (24 years old in average), 3 bilaterals, and 4 unilaterals. In hearing test, there were 4 patients with severe to profound hearing loss at 71 dB or higher, 2 patients with moderately severe hearing loss ranged from 56 to 70 dB, and 1 patient with moderate hearing loss from 41 to 56 dB. Hearing ability of all these patients were partially or completely recovered by treatment including steroid injection and joint psychotherapy with psychiatrist. CONCLUSION: About 2.5% of sudden deafness patients were psychogenic sudden deafness patients, and the results showed distinctive features for each of audiologic, psychiatric, and clinical characteristics. The recovery rate and prognosis were better in patients who had cure and diagnosis under consult with department of psychiatry and accurate audiometry.

Outcomes of Transnasal Endoscopic Sinus Surgery in 86 Cases of Non-invasive Fungal Sinusitis

This study was conducted to review the clinical features of fungal sinusitis and to evaluate the effectiveness of transnasal endoscopic sinus surgery as a primary surgical method for treating fungal sinusitis. Eighty five patients (86 cases) who were treated for fungal sinusitis with transnasal endoscopic sinus surgery between 1993 and 2004 were retrospectively analyzed by reviewing their profile, which included clinical feature, surgical techniques, operative findings postoperative results and complications. All patients were adults consisting of 30 males and 55 females. All cases were treated successfully by transnasal endoscopic sinus surgery. No recurrence and postoperative complication were observed. However, in 18 cases, fungal debries were observed when sinus irrigation was done at primary follow-up. In these cases, fungal debris disappeared at postoperative 1.7weeks (average) and no recurrence was observed. Transnasal endoscopic sinus surgery is successful method in the treatment of non-invasive fungal sinusitis.

Endoscopic Dacryocystorhinostomy for the Treatment of Lacrimal Sac Abscess

In the past, the treatments for acute dacryocystitis with abscess formation were warm compression, systemic and topical antibiotics, and drainage of the abscess, if fluctuation occurs. Acute dacryocystitis with abscess formation is rarely primary, but often secondary to distal obstruction or extension of contiguous inflammation. After resolution of acute infection, evaluation and treatment of the underlying cause should be initiated. Recent reports have demonstrated that endoscopic dacryocystorhinostomy is an effective treatment for acute dacryocystitis associated with nasolacrimal duct obstruction. We experienced a case of acute dacryocystitis with lacrimal sac abscess formation. Drainage of lacrimal sac abscess was safely accomplished with endoscopic dacryocystorhinostomy. The patient had an excellent postoperative course without recurrence.