Effective Control of Postoperative Cerebrospinal Fluid Leakage by Modified Microvascular Decompression in Patients with Hemifacial Spasm.

Objective: This study aimed to compare the clinical outcomes of a modified microvascular decompression (MVD) with a traditional MVD in hemifacial spasm. Methods: A tota1 of 120 patients with hemifacial spasm who received a modified MVD (modified MVD group) and 115 patients who received a traditional MVD (traditional MVD group) from January 2013 to March 2021 were retrospectively reviewed. The surgery efficiency rate, surgery time and postoperative complications in both groups were recorded and analyzed. Results: There was no significant difference between the 2 groups regarding surgery: efficiency rate (modified MVD group VS traditional MVD group: 92.50% vs 92.17%, respectively; P = .925). The intracranial surgery time and postoperative complications rate in the modified MVD group were significantly lower than in the traditional MVD group (31.00 ± 1.78 min vs 48.00 ± 1.74 min, respectively; P < .05; 8.33% vs 20.87%; P = .006, respectively). There was no statistical difference between open skull time and close skull time between the 2 groups (modified MVD group vs traditional MVD group: 38.50 ± 1.76 min vs 40.00 ± 1.78 min, respectively; P = .055; 38.50 ± 1.76 min vs 36.00 ± 1.78 min, respectively; P = .086). Conclusion: The modified MVD for hemifacial spasm can achieve satisfactory clinical outcomes and reduce intracranial surgery time and postoperative complications.

Facial Nerve Massage for the Treatment of Hemifacial Spasm Refractory to Microvascular Decompression: Outcomes and Complications.

BACKGROUND: After microvascular decompression (MVD) for hemifacial spasm (HFS), a minority of patients realize little to no relief of spasms. In some patients, the absence of relief of spasms results from incomplete or inadequate decompression of vascular compression of the facial nerve, and these patients represent excellent candidates for repeat MVD. However, in other patients, repeat MVD is not appropriate because adequate decompression and resolution of neurovascular compression, as determined by postoperative high-resolution MRI, was achieved with the initial operation. OBJECTIVE: To present a cohort of patients with a history of HFS refractory to MVD, with no evidence of neurovascular compression on postoperative MRI, who underwent facial nerve massage (FNM) in the posterior fossa in an attempt to relieve spasms. METHODS: Thirteen patients with a history of incomplete relief of spasms after technically adequate MVD surgery for hemifacial spasm underwent FNM. Immediate and long-term degree of spasm relief and complications after FNM were documented through in-person or telemedicine interview. RESULTS: At follow-up after FNM, 7 of 12 patients (58.3%) reported complete spasm relief (grade I), 2 of 12 patients (16.7%) reported >75% spasm relief (grade II), 0 patient (0%) reported >50% spasm relief (grade III), 3 of 12 (25.0%) patients reported <50% spasm relief (grade IV), and 1 patient was lost to follow-up. One patient experienced a delayed facial paresis, and another patient experienced high-frequency hearing loss. CONCLUSION: After FNM, durable and, at least, partial relief of spasms with a relatively low complication rate was observed in most patients with HFS with incomplete relief of spasms after technically adequate prior MVD.

Surgical effect and electrophysiological study of patients with hemifacial spasm treated with botulinum toxin or acupuncture before microvascular decompression.

OBJECTIVE: We investigated patients with hemifacial spasm (HFS) who received a botulinum toxin (BT) injection or acupuncture before receiving microvascular decompression (MVD) to determine whether it affects the success rate of surgery. Abnormal Muscle Response (AMR) and Compound Motor Action Potential (CMAP) are commonly used as electrophysiological monitoring methods in surgery, and we will compare the differences between these patients in this regard. PATIENTS AND METHODS: A total of 539 patients with HFS underwent MVD treatment in our department between January 2014 and June 2017. Among them, 83 patients had received BT injection before surgery and were recorded as BT group. Eighty-three patients underwent acupuncture before surgery and were recorded as acupuncture group. Five patients received both BT injection and acupuncture before surgery and were recorded as mixed group. A total of 368 patients who had not received any treatment before surgery were recorded as simple MVD group. We calculated the immediate and long-term remission rates after surgery. AMR and CMAP monitoring were routinely performed during surgery. RESULTS: Immediate remission rate after surgery was 96.4% (80/83) in BT group, 100% (83/83) in acupuncture group, 100% (5/5) in mixed group, and 95.1% (350/368) in simple MVD group, and the immediate remission rate of BT group is significantly higher than that of simple MVD group (p = 0.04). Long-term remission rate: the remission rates of the four groups were 94.0% (78/83), 97.6% (81/83), 100.0% (5/5) and 92.7%(341/368), respectively, and there is no statistical difference between them (p > 0.05). The amplitude of one branch or several branches of CMAP on the affected side was lower than the healthy side in BT or acupuncture treatment patients. CONCLUSIONS: A preoperative BT injection or acupuncture treatment do not reduce the postoperative remission rate of HFS patients treated with MVD, and the amplitude of CMAP on the affected side was lower than the healthy side.

Correlation Between Cerebellar Retraction and Hearing Loss After Microvascular Decompression for Hemifacial Spasm: A Prospective Study.

BACKGROUND: This study prospectively investigated the relationship between cerebellar retraction factors measured on preoperative magnetic resonance and the development of postoperative hearing loss and evaluated their potential role in predicting the possibility of hearing loss after microvascular decompression (MVD) for hemifacial spasm (HFS). METHODS: The study included 110 patients clinically diagnosed with primary HFS who underwent MVD in our department. The cerebellar retraction factors were quantitatively measured on preoperative magnetic resonance. Associations of cerebellar retraction and other risk factors with postoperative hearing loss were analyzed. RESULTS: Eleven patients (10%) developed nonserviceable hearing loss after MVD. Compared with the group without hearing loss, the cerebellar retraction distance and depth of the group with hearing loss were significantly greater (P < 0.05). Multivariate logistic regression analysis showed that greater cerebellar retraction depth was significantly associated with the higher incidence of postoperative hearing loss (P < 0.05). CONCLUSIONS: The results in this study strongly suggested the correlation between the cerebellar retraction depth and the possibility of hearing loss after MVD for HFS. In addition, cerebellar retraction depth could be considered as a useful tool to predict the risk of post-MVD hearing loss.

Appropriate time to establish baseline responses for brain stem auditory evoked potentials during microvascular decompression for hemifacial spasm.

PURPOSE: To evaluate the appropriate time to establish baseline responses for brain stem auditory evoked potentials (BAEPs) during microvascular decompression for hemifacial spasm and its implications on the alarm criteria and outcomes. METHODS: Overall, 61 patients who had intraoperative monitoring with BAEP during microvascular decompression were retrospectively identified. The latencies and amplitudes of wave V before skin incision and at dura opening (before major manipulation) were compared with the latency and amplitude of wave V at change start (first alarm reported to the surgeon). Also, the results with respect to postoperative outcomes were evaluated. RESULTS: More alarms would have been communicated to the surgeon when baseline values were set at the beginning of the procedure, when compared with baseline values reset at dura opening (before major manipulation). CONCLUSIONS: Significant variations in BAEP latency exist before any major manipulations during microvascular decompression. Despite a false-negative case, baselines can be set before any major manipulations (e.g., just before dura opening), with an understanding of the etiology of changes to BAEPs during microvascular decompression. SIGNIFICANCE: This is the first study to establish that during intraoperative BAEP monitoring, baselines that are reset before any significant manipulations are performed, rather than at the beginning of the procedure, have a higher level of sensitivity with regards to hearing outcomes.

Neurophysiological mechanisms of conduction impairment of the auditory nerve during cerebellopontine angle surgery.

OBJECTIVE: Intraoperative auditory brainstem response (ABR)-monitoring is useful for hearing preservation in patients undergoing cerebellopontine angle surgery. Prolongation of the latency of wave V, for example, is observed under surgical stress such as cerebellar retraction. We analyzed intraoperative ABR findings to study the neurophysiological mechanism(s) underlying latency prolongation. METHODS: The ABR recorded during microvascular decompression surgery was studied in 18 patients with hemifacial spasm. We measured each trace of the ABR records, both the latency of each wave and some interpeak latencies. We also analyzed their waveforms especially in the early component, to assess changes during surgery. RESULTS: The latency of wave V varied with cerebellar retraction. The delayed latency of wave V was correlated with the prolonged interpeak latency of waves I-III. An additional wave (designated wave I') between waves I and II was appeared; it was accompanied by a prolongation in the latency of wave V. Wave I' contributed to prolongation of the interpeak latency of waves I-III, resulting in a delay in the latency of wave V. Chronological analysis revealed that the minimum latency of wave I' was the same as wave IN, suggesting that wave I' arose near the porus acusticus internus (PAI). CONCLUSION: Our study showed that cerebellar retraction may result in conduction impairment of the auditory nerve near the PAI, suggesting that the Obersteiner-Redlich zone is an electrophysiologically vulnerable site and wave I' is derived from the change in the vector of wave IN. SIGNIFICANCE: Our findings may provide neurophysiological evidence to support the theoretical model of ABR generators by Scherg and von Cramon.

[What to do in cases of inadequate effectiveness of botulinum toxin for the treatment of eyelid cramping?]. / Was tun bei unzureichender Wirkung von Botulinumtoxin in der Behandlung von Lidkrämpfen?

In 5-15% of individuals suffering essential blepharospasm, treatment with botulinum toxin is insufficient. In these cases the following measures can be applied: increase the dose, increase or vary the injection sites, change the botulinum toxin medication, use additional oral medication, or perform surgery. Certain measures can also be carried out by the patient. In cases of hemifacial spasm, inadequate results of botulinum toxin injections are even more unusual. But for these cases, additional oral medication or the neurosurgical Janetta operation can be used.

Medial olivocochlear system stabilizes active cochlear micromechanical properties in humans.

To investigate the involvement of the medial olivocochlear system (MOCS) in outer hair cell (OHC) motility stabilization, evoked otoacoustic emissions (EOAEs) were recorded in 20 normal-hearing subjects and in eight vestibular-neurotomized subjects, successively in the presence and absence of low-intensity contralateral acoustic stimulation. Intrasubject EOAE amplitude variability was assessed as the standard deviation computed over several successive recordings. In normal-hearing subjects, a significantly lower EOAE amplitude variability with contralateral acoustic stimulation (CAS) was observed in subjects in whom the CAS induced the greatest EOAE amplitude reduction. This result could not be attributed to the EOAE amplitude reduction itself, since variability was otherwise found to increase when EOAE amplitude decreased. Moreover, statistically significant correlations between EOAE amplitude attenuation and EOAE amplitude variability under CAS were observed. In the eight subjects operated for vestibular neurotomy, no such effect was found. Being sectioned in vestibular-neurotomized subjects, the MOCS can no longer exert its effects. These results strongly support the notion that MOCS activity, as induced by CAS, elicits a reduction in EOAE amplitude variability in normal-hearing subjects. This finding and some of its possible implications for understanding the role of the MOCS in hearing in humans are discussed.