Monitoring facial EMG responses during microvascular decompression operations for hemifacial spasm

1987 ◽  
Vol 66 (5) ◽  
pp. 681-685 ◽  
Author(s):  
Aage R. Møller ◽  
Peter J. Jannetta

✓ Facial electromyographic (EMG) responses were monitored intraoperatively in 67 patients with hemifacial spasm who were operated on consecutively by microvascular decompression of the facial nerve near its exit from the brain stem. At the beginning of the operation, electrical stimulation of the temporal or the zygomatic branch of the facial nerve gave rise to a burst of EMG activity (autoexcitation) and spontaneous EMG activity (spasm) that could be recorded from the mentalis muscle in all patients. In some patients, the spontaneous activity and the autoexcitation disappeared after the dura was incised or when the arachnoid was opened, but stimulation of the temporal branch of the facial nerve caused electrically recordable activity in the mentalis muscle (lateral spread) with a latency of about 10 msec that lasted until the facial nerve was decompressed in all but one patient, in whom it disappeared when the arachnoidal membrane was opened. When the facial nerve was decompressed, this lateral spread of antidromic activity disappeared totally in 44 cases, in 16 it was much reduced, and in seven it was present at the end of the operation at about the same strength as before craniectomy. In four of these last seven patients there was still very little improvement of the spasm 2 to 6 months after the operation; these four patients underwent reoperation. In two of the remaining three patients, the spasm was absent at the 3- and 7-month follow-up examination, respectively, and one had mild spasm. Of the 16 patients in whom the lateral spread response was decreased as a result of the decompression but was still present at the end of the operation, 14 had no spasm and two underwent reoperation and had mild spasm at the last examination. Of the 44 patients in whom the lateral spread response disappeared totally, 42 were free from spasm and two had occasional mild spasm at 6 and 13 months, respectively, after the operation. Monitoring of facial EMG responses is now used routinely by the authors during operations to relieve hemifacial spasm, and is performed simultaneously with monitoring of auditory function for the purpose of preserving hearing. The usefulness of monitoring both brain-stem auditory evoked potentials recorded from electrodes placed on the scalp and compound action potentials recorded directly from the eighth cranial nerve is evaluated.

1982 ◽  
Vol 57 (6) ◽  
pp. 753-756 ◽  
Author(s):  
Tsutomu Iwakuma ◽  
Akihisa Matsumoto ◽  
Nishio Nakamura

✓ Patients with hemifacial spasm were treated by three different surgical procedures: 1) partial sectioning of the facial nerve just distal to the stylomastoid foramen; 2) selective neurectomy of facial nerve branches; and 3) microvascular decompression. A retromastoid craniectomy with microvascular decompression was most effective in relieving hemifacial spasm and synkinesis. In a postmorten examination on one patient, microscopic examination of the facial nerve, which was compressed by an arterial loop of the posterior inferior cerebellar artery at the cerebellopontine angle, revealed fascicular demyelination in the nerve root. On the basis of surgical treatment, electromyography, and neuropathological findings, the authors conclude that compression of the facial nerve root exit zone by vascular structures is the main cause of hemifacial spasm and synkinesis.


1991 ◽  
Vol 74 (2) ◽  
pp. 254-257 ◽  
Author(s):  
Stephen J. Haines ◽  
Fernando Torres

✓ In 11 consecutive patients, intraoperative electromyographic (EMG) recordings were made from the facial muscles during microvascular decompression for hemifacial spasm. In one patient, recordings could not be obtained for technical reasons, and two patients had no abnormality. In the remaining eight patients, the abnormal response resolved before decompression in two, resolved immediately at the time of decompression in five, and failed to resolve in one. All patients were relieved of their hemifacial spasm. In the five patients whose abnormalities resolved at the time of decompression, there was a precise intraoperative correlation between decompression of the nerve and disappearance of the abnormal EMG response. In three cases, this was a useful guide to the need to decompress more than one vessel. These results confirm the findings of Mailer and Jannetta, support the use of this technique for intraoperative monitoring of facial nerve decompression procedures, and provide strong circumstantial evidence that vascular cross-compression is an important etiological factor in hemifacial spasm.


2004 ◽  
Vol 101 (5) ◽  
pp. 861-863 ◽  
Author(s):  
Hiroatsu Murakami ◽  
Tadashi Kawaguchi ◽  
Masafumi Fukuda ◽  
Yasushi Ito ◽  
Hitoshi Hasegawa ◽  
...  

✓ The lateral spread response (LSR) is used in the electrophysiological diagnosis of a hemifacial spasm or for monitoring during microvascular decompression. The authors used LSRs for intraoperative monitoring during endovascular surgery in a rare case of vertebral artery (VA) aneurysm that caused intractable hemifacial spasm. A 49-year-old woman presented with a right hemifacial spasm that had persisted for 9 months. No other clinical symptom was observed. Vertebral artery angiography revealed a saccular aneurysm of the right VA. Magnetic resonance (MR) imaging demonstrated that the aneurysm was compressing the root exit zone of the right facial nerve. Endovascular treatment of the VA aneurysm was performed while monitoring the patient's LSRs. During occlusion of the VA at sites distal and proximal to the aneurysm, the LSRs temporarily disappeared and then reappeared with a higher amplitude than those measured preceding their disappearance. The hemifacial spasm alleviated gradually and disappeared completely 6 months after treatment. The LSRs changed in parallel with the improvement in the patient's hemifacial spasms and eventually disappeared. No recurrence of symptoms has been noticed as of 18 months postoperatively. This is the first report of the use of LSR monitoring during endovascular surgery for an intracranial aneurysm that causes hemifacial spasm. Intraoperative and postoperative changes in the LSRs provided useful information regarding the pathophysiology of hemifacial spasm.


Neurosurgery ◽  
1985 ◽  
Vol 16 (5) ◽  
pp. 612-618 ◽  
Author(s):  
Aage R. Møller ◽  
Peter J. Jannetta

Abstract Facial muscle responses in patients with hemifacial spasm undergoing microvascular decompression operations were recorded. Two peripheral branches of the facial nerve were stimulated and the electrical responses of muscles innervated by these branches were studied to see how the lateral spread of activity that is known to be present in these patients was affected by decompressing the facial nerve. In some of the patients the hemifacial spasm ceased when the dura mater was opened, in some it ceased when the arachnoid was opened, and in others the spasm persisted until the offending vessel was dissected away from the nerve. The lateral spread of activity elicited by antidromic stimulation of a branch of the facial nerve was less affected by opening of the dura mater or arachnoid: it usually persisted until the blood vessel that had been compressing the facial nerve was removed and reappeared when the vessel that had been compressing the facial nerve was allowed to slip back onto the nerve. This seems to indicate that microvascular decompression of the facial nerve is effective in alleviating hemifacial spasm because it removes the actual cause of the disorder rather than simply causing local injury to the nerve as a result of the procedure.


2019 ◽  
Vol 80 (S 03) ◽  
pp. S312-S313
Author(s):  
James K. Liu ◽  
Vincent N. Dodson

In this operative video atlas manuscript, the authors demonstrate the operative nuances and surgical technique for endoscopic-assisted microvascular decompression of a large ectatic vertebral artery causing hemifacial spasm. A retrosigmoid approach was performed and a large ectatic vertebral artery was transposed away from the root exit zone of cranial nerve VII (Fig. 1). The lateral spread response disappeared, signifying adequate decompression of the facial nerve (Fig. 2). The use of endoscopic-assistance during the microsurgical decompression was very useful to confirm the origin and also the resolution of neurovascular conflict. Postoperatively, the patient experienced immediate resolution of hemifacial spasm with normal facial nerve and hearing function. Written consent was obtained from the patient to publish videos, photographs, and images from the surgery.The link to the video can be found at: https://youtu.be/RlMz44uCDCw.


2007 ◽  
Vol 106 (3) ◽  
pp. 384-387 ◽  
Author(s):  
Doo-Sik Kong ◽  
Kwan Park ◽  
Byoung-gook Shin ◽  
Jeong Ah Lee ◽  
Dong-Ok Eum

Object The authors conducted a large retrospective study in which they evaluated the efficacy of intraoperative electromyography (EMG) monitoring of facial musculature during microvascular decompression (MVD) and assessed the predictive value of the lateral spread response (LSR) as a prognostic indicator for the treatment outcome of hemifacial spasm (HFS). Methods The authors undertook intraoperative monitoring during MVD in 300 consecutive patients with HFS. The patients were divided into two groups based on whether the LSR disappeared or persisted following decompression. The mean follow-up period was 35.8 months (range 12–55 months). In 263 (87.7%) of the 300 patients, the LSR was observed during intraoperative facial EMG monitoring. In 230 (87.4%) of these 263 patients, the LSR disappeared following decompression (Group I), and in the remaining 33 patients (12.5%) the LSR persisted despite decompression (Group II). At the postoperative 1-year follow-up visit, there was a significant difference in clinical outcomes between both groups (p < 0.05). Conclusions Facial EMG monitoring of the LSR is an effective tool to use when performing complete decompression, and it may be helpful in predicting outcomes.


1999 ◽  
Vol 90 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Mark R. McLaughlin ◽  
Peter J. Jannetta ◽  
Brent L. Clyde ◽  
Brian R. Subach ◽  
Christopher H. Comey ◽  
...  

Object. Microvascular decompression has become an accepted surgical technique for the treatment of trigeminal neuralgia, hemifacial spasm, glossopharyngeal neuralgia, and other cranial nerve rhizopathies. The senior author (P.J.J.) began performing this procedure in 1969 and has performed more than 4400 operations. The purpose of this article is to review some of the nuances of the technical aspects of this procedure.Methods. A review of 4415 operations shows that numerous modifications to the technique of microvascular decompression have occurred during the last 29 years. Of the 2420 operations performed for trigeminal neuralgia, hemifacial spasm, and glossopharyngeal neuralgia before 1990, cerebellar injury occurred in 21 cases (0.87%), hearing loss in 48 (1.98%), and cerebrospinal fluid (CSF) leakage in 59 cases (2.44%). Of the 1995 operations performed since 1990, cerebellar injuries declined to nine cases (0.45%), hearing loss to 16 (0.8%), and CSF leakage to 37 (1.85% p < 0.01, test for equality of distributions). The authors describe slight variations made to maximize surgical exposure and minimize potential complications in each of the six principal steps of this operation. These modifications have led to decreasing complication rates in recent years.Conclusions. Using the techniques described in this report, microvascular decompression is an extremely safe and effective treatment for many cranial nerve rhizopathies.


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