• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.18 no.4
• /
• pp.679-700
• /
• 1996

Inferior alveolar nerve dysfunction may be the result of trauma, disease, or iatrogenic injury. Inferior alveolar nerve injury is inherent risk in endodontic therapy, orthognathic surgery of the mandible, and extraction of mandibular teeth, particularly the third molars. The sensory disturbances of inferior alveolar nerve associated with such injury have been well documented clinical problem that is commonly evaluated by several clinical sensory test including Tinels sign, Von Frey test(static light touch detection), directional discrimination, two-point discrimination, pin pressure nociceptive discrimination, and thermal test. These methods used to detect and assess inferior alveolar nerve injury have been subjective in nature, relying on the cooperation of the patients. In addition, many of these techniques are sensitive to differences in the examiners experience and skill with the particular technique. Data obtained at different times or by different examiners are therefore difficult to compare. Prior experimental studies have used electro diagnostic methods(sensory evoked potential) to objectively evaluate inferior alveolar nerve after nerve injury. This study was designed with inferior alveolar nerve of rabbit. Several types of injury including mind, moderate, severe compression and perforation with 19 gauze, 21 gauze needle and 6mm, 10mm traction were applied for taking the sesory evoked ppterntial. Latency and amplitude of injury rabbit inferior alveolar nerve were investigated with sensory evoked potential using unpaired t-test. The results were as follows : 1. Intensity of threshold (T1) was $128{\pm}16{\mu}A$ : latency, $0.87{\pm}0.07$ microsecond : amplitude, $0.4{\pm}0.1{\mu}V$ : conduction velocity, 23.3 m/s in sensory evoked potential of uninjured rabbit inferior alveolar nerve. 2. Rabbit inferior alveolar nerve consists of type II and III sensory nerve fiber. 3. Latency was increased and amplitude was decreased in compression injury. The more injured, the more changed in latency and amplitude. 4. Findings in perforation injury was similar to compression injury. Waveform for sensory evoked potential improved by increasing postinjured time. 5. Increasing latency was prominent in traction injury rabbit inferior alveolar nerve. 6. In microscopic histopathological findings, significant degeneration and disorganization of the internal architecture were seen in nerve facicle of severe compression and 10mm traction group. From the above findings, electrophysiological assessment(sensory evoked potential) of rabbit injured inferior alveolar nerve is reliable technique in diagnosis and prognosis of nerve injury.

• Archives of Reconstructive Microsurgery
• /
• v.6 no.1
• /
• pp.9-28
• /
• 1997

Adequate vascularization is pivotally essential for a successful nerve graft. Theoretically, the immediate vascularization will inhibit fibroblast infiltration and stimulate nerve cell regeneration. In this study, histomorphological and electrophysiological studies were performed to determine if vascularized grafts are functionally superior. In rat model, a 4cm segment of the sciatic nerve was obtained and placed as a non vascularized graft on one side, and as a vascularized graft connected to the inferior gluteal vessels on the opposite side. To determine the compound action potential of the gastrocnemius muscle, electromyography was done after 2, 3 and 4 months. Histomorphologically, the distribution of myelinated nerve fibers and Schwann cell were evaluated after toluidine blue staining, The following resutls were obtained: 1. The electrophysiological studies showed no difference between the nonvascularized and vascularized grafts. 2. Two and three months after grafting, myelinated nerve fibers were more abundant in the vascularized proximal, middle and distal areas in all nerve fibers of varying diameters. 3. In the post-nonvascularized graft 2-month group, a few myelinated nerve fibers were present in the proximal and middle areas, but none distally. In the post-vascularized graft 2 month group, myelinated nerve fibers ranging $2-8{\mu}m$ were present in all three areas. 4. In the post-nonvascularized graft 3 month group, a few myelinated nerve fibers ranging in $2-6{\mu}m$ were present in all three areas, but in the post-vascularized graft 3 month group, many myelinated nerve fibers ranging in $2-10{\mu}m$ were present in all three areas. 5. In the post-graft 4-month group, more myelinated nerve fibers were present in all three areas of the vascularized grafts. However, nerve fibers of less than $2{\mu}m$ in diameter were more abundant in the non vascularized grafts. 6. Schwann cells were more abundant in the proximal, middle and distal areas of the post-vascularized 2, 3 and 4-month grafts. Based on these findings, the immediate restoration of circulation in vascularized nerve grafts allows for the increased number of surviving Schwann cells, rapid healing of the axon and myelin sheath changes which occur during Wallerian degeneration, and thus is able to stimulate a morphologically optimal regeneration.

• Polymer(Korea)
• /
• v.25 no.6
• /
• pp.893-901
• /
• 2001

We developed the nerve growth factor (NGF) loaded poly (L - lactide) (PLA) scaffolds by means of emulsion freeze drying method to the possibility for the application of the nerve regeneration of spinal cord disease and the degeneration in Alzheimer's disease. The release amount of NGF from NGF loaded PLA scaffold were analyzed over a 4 week period in vitro at phosphate buffered saline (PBS), pH 7.4, at $37^{\circ}C$. It can be observed the open cell pore structure of porous scaffolds and can be easily controlled the pore structure by the controlling of formulation factors resulting in the controlling of the release rate and the release period. The stability of NGF during the preparation of PLA scaffold was evaluated by comparing the released amounts of total NGF, assayed NGF enzyme - linked immunosorbent assay (ELISA). Released NGF has been found to enhance the neurite sprouting and outgrowth from pheochromocytoma (PC-12) cells. These results suggest that the released NGF from NGF loaded PLA scaffold such as conduit type can be very useful for the nerve regeneration in the neural tissue engineering area.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
• /
• v.36 no.2
• /
• pp.26-44
• /
• 2023

Objectives : This study was designed to examine and analyze the recent trend of Korean medicine research on retinal and optic nerve diseases, which is increasing. Methods : This study examines papers related to diseases occurring in the retina and optic nerve that were published in Korean journals of Korean medicine, and analyzes the results of research so far by classifying them by year, journal, disease type and type of paper. Results : 1. Since it was first published in 1995, a total of 17 articles have been published until 2018, with 2 articles(11.1%) each in 1997, 2014 and 2018, and 1 article(5.6%) each in other years. 2. The number of searched journals was 17 paper; 4 review articles, 1 original articles, 12 case reports. 3. Distribution of journals; the percentage of Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology ranked the highest(41.2%). 4. Classification of 12 case reports into three categories; 7 retinal diseases, 3 optic nerve diseases, 2 other diseases. Conclusions : Currently, researches on retinal and optic nerve involvement in the Korean medicine journals have been conducted mainly through case reports. In the future, more clinical research and case reports are necessary to give practical application to patients.

• Journal of radiological science and technology
• /
• v.27 no.3
• /
• pp.13-18
• /
• 2004

In most patients with facial palsy after temporal bone injury, temporal bone High Resolution CT revealed direct or indirect facial nerve canal involvement, and in complete palsy severe degeneration groups, there were direct findings in most cases. Author believe that meticulous analysis and symptom correlation of the fracture patterns seen in facial canal injury in patients with traumatic facial nerve palsy is helpful for treatment planning and prognosis.

• Journal of the Korea Convergence Society
• /
• v.7 no.2
• /
• pp.61-67
• /
• 2016

The olfactory system is an important model for the study of neuronal degeneration and regeneration, including neuronal diseases. When the olfactory sensory neurons are damaged by nerve injury or are exposed to environmental factors, they degenerate and are replaced by regenerating neurons. To monitor neuronal degeneration in living animal, we established an olfactory-specific GFP transgenic zebrafish. The effects of Triton X-100 or sodium acetate on the olfactory system were examined. A significant decrease in the number of GFP-positive olfactory sensory neurons was observed after chemical lesion. We found a recovery of GFP-positive neurons by 2 days posttreatment. From these results, we expect that further studies of olfactory degeneration and regeneration using this transgenic zebrafish will provide important advances for the study of neuronal degeneration and regeneration.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
• /
• v.27 no.2
• /
• pp.130-133
• /
• 2016

Rheumatoid arthritis (RA) is a connective tissue disease involving the larynx in 30 % of the patients. Foreign body sensation, hoarseness, and cough are common symptoms in laryngeal involvement. An urgent tracheostomy is required when acute airway obstruction occurs in case of bilateral vocal fold paralysis. The most common cause of bilateral vocal fold paralysis in RA patients is a cricoarytenoid joint arthritis. Laryngeal nerve degeneration is rare cause of bilateral vocal fold paralysis in RA patients. In this case report, an emergent tracheostomy was performed on a 64-years-old male patient with acute dyspnea, and concurrent involvement of RA on laryngeal nerve and cricoarytenoid joint was revealed by laryngeal electromyography and histopathology. The vocal fold mobility was restored after 3-months medical treatment.

• Healthcare Informatics Research
• /
• v.24 no.4
• /
• pp.335-345
• /
• 2018

Objectives: The retinal nerve fiber layer (RNFL) is a site of glaucomatous optic neuropathy whose early changes need to be detected because glaucoma is one of the most common causes of blindness. This paper proposes an automated RNFL detection method based on the texture feature by forming a co-occurrence matrix and a backpropagation neural network as the classifier. Methods: We propose two texture features, namely, correlation and autocorrelation based on a co-occurrence matrix. Those features are selected by using a correlation feature selection method. Then the backpropagation neural network is applied as the classifier to implement RNFL detection in a retinal fundus image. Results: We used 40 retinal fundus images as testing data and 160 sub-images (80 showing a normal RNFL and 80 showing RNFL loss) as training data to evaluate the performance of our proposed method. Overall, this work achieved an accuracy of 94.52%. Conclusions: Our results demonstrated that the proposed method achieved a high accuracy, which indicates good performance.

• BMB Reports
• /
• v.50 no.2
• /
• pp.60-70
• /
• 2017

Glaucoma is characterized by a slow and progressive degeneration of the optic nerve, including retinal ganglion cell (RGC) axons in the optic nerve head (ONH), leading to visual impairment. Despite its high prevalence, the biological basis of glaucoma pathogenesis still is not yet fully understood, and the factors contributing to its progression are currently not well characterized. Intraocular pressure (IOP) is the only modifiable risk factor, and reduction of IOP is the standard treatment for glaucoma. However, lowering IOP itself is not always effective for preserving visual function in patients with primary open-angle glaucoma. The second messenger cyclic adenosine 3',5'-monophosphate (cAMP) regulates numerous biological processes in the central nervous system including the retina and the optic nerve. Although recent studies revealed that cAMP generated by adenylyl cyclases (ACs) is important in regulating aqueous humor dynamics in ocular tissues, such as the ciliary body and trabecular meshwork, as well as cell death and growth in the retina and optic nerve, the functional role and significance of cAMP in glaucoma remain to be elucidated. In this review, we will discuss the functional role of cAMP in aqueous humor dynamics and IOP regulation, and review the current medications, which are related to the cAMP signaling pathway, for glaucoma treatment. Also, we will further focus on cAMP signaling in RGC growth and regeneration by soluble AC as well as ONH astrocytes by transmembrane ACs to understand its potential role in the pathogenesis of glaucoma neurodegeneration.

• Clinical and Experimental Pediatrics
• /
• v.46 no.9
• /
• pp.934-938
• /
• 2003

Canavan disease, also known as van Bogaert-Bertrand disease, is a rare autosomal recessive disorder characterized by early an onset and a progressive spongyform degeneration of the brain, associated with an edema of the central nerve system, intramyelinic swelling and neurologic symptoms. This disorder is most prevalent in people of Ashkenazi Jewish descent but has been observed in other ethnic groups. Patients have severe mental retardation, poor head control, macrocephaly and seizures. Canavan disease is caused by the accumulation of N-acetylaspartic acid(NAA) in the brain as the result of a deficiency of aspartoacylase(ASPA) activity. Most children are reported to have the infantile form, becoming symptomatic between three and six month of age, after unremarkable prenatal and perinatal course. We experienced a case of Canavan disease in a six day old female newborn baby, associated with seizure, degeneration of brain white matter and markedly elevated urine N-acetylaspartic acid(NAA) level. So, we report the case with a brief review of the related literature.