Experimental Study on a Treatment Technique for Trigeminal Paralysis

1995 Fiscal Year Final Research Report Summary

• Project/Area Number: 06454574
• Research Category: Grant-in-Aid for General Scientific Research (B)
• Allocation Type: Single-year Grants
• Research Field: Surgical dentistry
• Research Institution: The Nippon Dental University
• Principal Investigator: SUMITOMO Masahito The Nippon Dental University, School of Dentistry, associate professor, 歯学部, 助教授 (60095156)
• Project Period (FY): 1994 – 1995
• Keywords: Trigeminal Paralysis / Rat / Stellate Ganglion Block (SGB) / Sympathetic Ganglion Block / Rat-SGB / Thermography / Blood Flow Volume / Somatosensory Evoked potentials (SEP)

Research Abstract

In this study, I tried to objectively cvalute the effectiveness of the stellate ganglion block (SGB) by comparing the recovery of the damaged nerve of rats divided into 2 groups : one group treated with sympathic ganglion block in the cervical area (the followings, Rat-SGB group), and the second group without such treatment (the followings, Non-Rat-SGB group). Neurophysiological evalution, utilizing somatosensory evoked potential (SEP), and histological evalution, based on optical and electron microscopic observation, were employed to judge the stage of recovery. 108 male rats of Wister atrain, whose left side infraorbital nerve was previously cut, were prepared. 30 times of blocks were performed for Rat-SGB group once a day.
1. According to neurophysiological evalution, the recovery of SEP amplitude, had already obserbed in Rat-SGB group, after 1 month of the experiment, while it had never been seen in Non-Rat-SGB group. Moreover, 8 months had elapsed, the average recovery rate of the Rat-SGB group was almost 100%, whereas it was about only 70% in Non-Rat-SGB group.
2. According to histological evalution, there was no statistical significant difference between two groups in number of myelinated nerve fibers per mm^2. However, the mean diameter and diameteric distribution of the mielinated fibers were greater in the Rat-SGB grup, and many myelinated fibers of large diameter were observed in an early stage of the experiment.
The experiment demonstrated that the Rat-SGB group tended to show a good recovery, from both the neurophysiological and histological points of view. Consequently, this experiment suggests that SGB with its sympatholytic effect, accelerate the recovery and regeneration of damaged nerve.