A Study of Blink Reflex and Direct Facial Nerve Stiimulation in Normal Korean Adult

The blink reflex is an electrically induced glabella response that has long been used in clinical neurology. The blink reflex is now known to be a polysynaptic reflex with an afferent arc through sensory fibers of the trigerminal nerve and with an c,fferent arc through the motor fibers of the facial nerve. This study was performed to determine the relationship of latency and amplitude to ethnic groups sex and age and to obtain the normal data of korean in the blink reflex(BR) and direct facial nerve stimulation test(DFNS). BR and DFNS were recorded in 103 normal korean adults that consisted of 52 men and 51 women and the age ranged 22 to 77 years. The results are as follows: (1) the Rl wave was more stable than R2 and contralateral R2 wave, (2) there seerns to be no significant difference of latency and amphtude between ethnic groups, (3) the latency of Rl wave was shorter and the amplitude of CMAP was larger m men compared with women and (4) the latency of Rl wave was increased by aging.

One case of Medial Medullary Syndrome

Medial medullary syndrome is a clinical disorder charactenzed by ipsilateral paralysis of tongue and contralateral hemiparalysis and contralateral hemisensory disturbance of vibration or position but face sparing. The syndrome is ususlly due to lesion of medial medulla oblongata. Involved structures are pyramid, hypoglossal nucleus, medial lemniscus and/or medial longitudinal fasciculus. We present 1 case of medial medullary syndrome with MRI finding, which showed infarction of left medial medulla oblongata.

The Pathophysiologic Approach and Usefulness of Conventional Blink Reflex Test and Electromyography in Hemifacial Spasm

A series of 61 cases of primary hemifacial spasm have been evaluated by means of blink reflex and needle electromyography and their result compared with unaffected site. The R1 and R2 response and late acti-ity. After activity in blink reflex. And electrical activity in EMG at rest were observed. The results of study were as in the followings: 1) The arnplitude of large R1 and R2 responses were increased in affected side in contrast to unaffected side. 2) late activity(72.2%) and after activity(83.6%) were observed in only affected side at rela-ti-ely Iong duration, as well as regular interval spontaneous repetivive discharges in EMG at rest. This result of large R1 and R2 responses could be compatible with ephaptic ransmission, but late activity, after activity, and spontaneous repetitive MUPs could be explained hyperexcitability of the facial motor nucleus rather than autoexcitation of peripheral facial nerve. Additionally the authors thought that the use of conventional blink reflex as well as specialized blink reflex tests could be very useful for the diagnosis of hemifacial spasm and for the evaluation of it's course.