Microvascular decompression to treat hemifacial spasm: long-term results for a consecutive series of 143 patients

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.

An investigation into quality of life improvement in patients undergoing microvascular decompression for hemifacial spasm

OBJECTIVE Hemifacial spasm (HFS) is a movement disorder characterized by involuntary spasms of the facial muscles, and it can negatively impact quality of life (QOL). This retrospective study and systematic review with meta-analysis was conducted to investigate the QOL in patients with HFS following intervention with microvascular decompression (MVD) and botulinum toxin (BT). METHODS In the retrospective analysis, a QOL questionnaire was administered to all patients undergoing MVD performed by a single surgeon. The QOL questionnaire included unique questions developed based on the authors' experience with HFS patients in addition to the health-related QOL HFS-8 questionnaire. The authors also report on a systematic review of the English literature providing outcomes and complications in patients with HFS undergoing treatment with either MVD or BT. RESULTS Regarding the retrospective analysis, 242 of 331 patients completed the questionnaire. The mean score of the 10 QOL questions improved from 22.78 (SD 9.83) to 2.17 (SD 5.75) following MVD (p < 0.001). There was significant improvement across all subscales of the questionnaire between pre- and postoperative responses (p < 0.001). Regarding the systematic review, it is reported that approximately 90% of patients undergoing MVD for HFS experience a complete recovery from symptoms, whereas the mean peak improvement of symptoms following treatment with BT is 77%. Furthermore, patients undergoing MVD reported a greater improvement in the mean supplemental index of QOL as compared with patients receiving BT therapy. CONCLUSIONS Microvascular decompression offers a significant improvement in QOL in well-selected patients suffering from HFS, and may offer an increased benefit for QOL over BT injections.

The Current Status of Microvascular Decompression for the Treatment of Hemifacial Spasm in Japan: An Analysis of 2907 Patients Using the Japanese Diagnosis Procedure Combination Database

Microvascular decompression (MVD) is widely used as a safe and effective treatment for hemifacial spasm (HFS). However, the extent of application of this therapeutic method and its outcomes in Japan are currently unclear. To address these questions, we analyzed the utilization of MVD for the treatment of HFS during the 33- month period from July 2010 to March 2013. We conducted an analysis on data contained in the Diagnosis Procedure Combination database in Japan. This analysis showed that MVD was used for the treatment of HFS in 2907 cases (men, 916; women, 1991) with 2.2 times more women treated than men. MVD for HFS was most frequently performed in women aged 50 to 69 years; however, most men were aged between 40 and 59 years at the time of the procedure. The numbers of procedures performed per 100,000 population/year were 0.83 overall in Japan, with the numbers larger in prefectures with larger populations. Regarding discharge outcomes, the mortality rate was 0.1%. The mean length of hospital stay in patients undergoing MVD for HFS was 14.7 days. This analysis provides preliminary information regarding the trends in the performance of MVD for the treatment of HFS in Japan. Further studies on other registries that contain data obtained by standardized assessment methods and that include long-term outcomes and postoperative complications are required.

Bioglue-Coated Teflon Sling Technique in Microvascular Decompression for Hemifacial Spasm Involving the Vertebral Artery

Objective

Microvascular decompression (MVD) for hemifacial spasm (HFS) involving the vertebral artery (VA) can be technically challenging. We investigated the therapeutic effects of a bioglue-coated Teflon sling technique on the VA during MVD in 42 cases.

Methods

A bioglue-coated Teflon sling was crafted by the surgeon and applied to patients in whom neurovascular compression was caused by the VA. The radiologic data, intra-operative findings with detailed introduction of the procedure, and the clinical outcomes of each patient were reviewed and analyzed.

Results

The 42 patients included in the analysis consisted of 22 females and 20 males, with an average follow-up duration of 76 months (range 24–132 months). Intraoperative investigation revealed that an artery other than the VA was responsible for the neurovascular compression in all cases : posterior inferior cerebellar artery (PICA) in 23 patients (54.7%) and anterior inferior cerebellar artery (AICA) in 11 patients (26.2%). All patients became symptom-free after MVD. Neither recurrence nor postoperative neurological deficit was noted during the 2-year follow-up, except in one patient who developed permanent deafness. Cerebrospinal fluid (CSF) leak occurred in three patients, and one required dural repair.

Conclusion

Transposition of the VA using a bioglue-coated Teflon sling is a safe and effective surgical technique for HFS involving the VA. A future prospective study to compare clinical outcomes between groups with and without use of this novel technique is required.

Microvascular Decompression Surgery for Hemifacial Spasm

OBJECTIVE

This study aims to investigate the operative efficacy, surgical complication rate, and surgical strategy of microvascular decompression (MVD) for hemifacial spasm (HFS).

METHODS

Clinical data of 46 patients with HFS who underwent MVD were retrospectively analyzed.

RESULTS

During surgery, it was found that the facial nerve root exit zone was compressed by the following arterial vessels: anterior inferior cerebellar artery in 24 patients (52.17%); posterior inferior cerebellar artery in 14 patients (30.43%); vertebral artery and a small artery in 7 patients (15.22%); and vertebral artery in 1 patient (2.18%). Symptoms of 38 patients were immediately remitted completely after surgery and symptoms of 8 patients were significantly reduced. Main complications included dizziness and tinnitus in 9 patients, hearing loss in 5 patients, cerebrospinal fluid leakage in 1 patient, and infection in 2 patients. No patient died during surgery.

CONCLUSIONS

MVD is the preferred choice for treating idiopathic hemifacial spasm, and hearing impairment is the main complication. Skilled microsurgical techniques, as well as identifying and completely decompressing offending vessels, are the key to ensuring a successful microvascular decompression.

Standardized reporting of adverse events after microvascular decompression of cranial nerves; a population-based single-institution consecutive series

OBJECTIVE

To investigate frequencies of adverse events occurring within 30 days after microvascular decompression (MVD) surgery using a standardized report form of adverse events.

METHODS

We conducted a retrospective review of 98 adult patients (≥16 years) treated with MVD between 1 January 1994 and 1 June 2013. Adverse events occurring within 30 days were classified according to the Landriel Ibanez classification for neurosurgical complications: grade I represents any non-life threatening complication treated without invasive procedures; grade II is complications requiring invasive management; grade III is life-threatening adverse events requiring treatment in an intensive care unit (ICU); grade IV is death as a result of complications. We sought to compare our results with reports from the literature.

RESULTS

Patients' median age was 61 years (range 26-83), and 64 (65 %) were females. Indications for MVD were trigeminal neuralgia (n = 77, 79 %), glossopharyngeal neuralgia (n = 4, 4 %), hemifacial spasm (n = 16, 16 %) and combined trigeminal neuralgia and hemifacial spasm (n = 1, 1 %). The overall 30-day complication rate was 20 %, with 14 % grade I complications, 5 % grade II complications and 1 % grade III complications. The comparison with the literature was hampered by the diverse and unsystematic way of reporting complications.

CONCLUSION

We provide a standardized report of postoperative complications in a consecutive patient series undergoing MVD. Due to the heterogeneous and non-standardized reporting of complications in the literature, it is difficult to know if our 20 % complication rate is low or high. Standardized reporting is a necessity for meaningful and more valid comparisons across studies. The safety of MVD, a fairly standardized neurosurgical procedure, is well suited for comparisons across centers provided that complications are reported in a standardized manner.

Prognosis research of delayed facial palsy after microvascular decompression for hemifacial spasm

BACKGROUND

Although microvascular decompression (MVD) surgery has been widely accepted as an effective treatment for hemifacial spasm (HFS), delayed facial palsy (DFP) is not an unusual complication, but it has only been sporadically described in the literature. The purpose of this study was to examine the probability of occurrence, the risk/predisposing factors, and the prognosis and timing of DFP.

METHODS

A prospective cohort study was conducted that included patients diagnosed with HFS and treated by MVD at our institution. All patients were followed up at the outpatient department or by telephone from December 2009 to December 2014. Categorical variables were analyzed using the Pearson's Chi-square test or Fisher's exact test. Continuous variables were compared using the independent Student's t test. The Spearman rank test was used to determine the correlation between the time of onset and the duration of DFP. The risk/predisposing factors were analyzed by the logistic regression method.

RESULTS

We enrolled 248 patients who were treated by MVD for HFS. During the follow-up period, 16 patients (6.5 %) developed DFP. Fifteen of those patients had a complete recovery, and in one patient the facial palsy did not resolve. The average onset time was 10.2 days (range, 2-30 days) after surgery, and the mean duration of DFP after MVD, with exclusion of the permanent facial palsy patient, was 59.7 days (range, 7-220 days). The time of onset was correlated with the duration of DFP after MVD (p = 0.036). Furthermore, hypertension contributed to DFP (odds ratio [OR] 4.226, 95 % confidence interval [CI] 1.089-16.401, p = 0.037).

CONCLUSIONS

Although the degree of facial palsy was variable, most patients experienced a complete recovery without requiring any special treatment. DFP may be a self-healing disease that resolves spontaneously without any treatment. The time of onset was correlated with the duration of DFP; i.e., an earlier development of DFP corresponded with a shorter duration, whereas a later development of DFP corresponded with a longer duration. Our results also suggest that hypertension contributes to DFP.

Real-time intraoperative monitoring of brainstem auditory evoked potentials during microvascular decompression for hemifacial spasm

OBJECTIVE The aim of this study was to define a new protocol for intraoperative monitoring (IOM) of brainstem auditory evoked potentials (BAEPs) during microvascular decompression (MVD) surgery to treat hemifacial spasm (HFS) and to evaluate the usefulness of this new protocol to prevent hearing impairment. METHODS To define the optimal stimulation rate, estimate the number of trials to be averaged, and identify useful warning criteria in IOM of BAEPs, the authors performed a preliminary study of 13 patients with HFS in 2010. They increased the stimulation rate from 10.1 Hz/sec to 100.1 Hz/sec by 10-Hz increments, and they elevated the average time from 100 times to 1000 times by 100-unit increments at a fixed stimulus rate of 43.9 Hz. After defining the optimal stimulation rate and the number of trials that needed to be averaged for IOM of BAEPs, they also identified the useful warning criteria for this protocol for MVD surgery. From January to December 2013, 254 patients with HFS underwent MVD surgery following the new IOM of BAEPs protocol. Pure-tone audiometry and speech discrimination scoring were performed before surgery and 1 week after surgery. To evaluate the usefulness of the new protocol, the authors compared the incidence of postoperative hearing impairment with the results from the group that underwent MVD surgery prior to the new protocol. RESULTS Through a preliminary study, the authors confirmed that it was possible to obtain a reliable wave when using a stimulation rate of 43.9 Hz/sec and averaging 400 trials. Only a Wave V amplitude loss > 50% was useful as a warning criterion when using the new protocol. A reliable BAEP could be obtained in approximately 9.1 seconds. When the new protocol was used, 2 patients (0.8%) showed no recovery of Wave V amplitude loss > 50%, and only 1 of those 2 patients (0.39%) ultimately had postoperative hearing impairment. When compared with the outcomes in the pre-protocol group, hearing impairment incidence decreased significantly among patients who underwent surgery with the new protocol (0.39% vs 4.02%, p = 0.002). There were no significant differences between the 2 surgery groups regarding other complications, including facial palsy, sixth cranial nerve palsy, and vocal cord palsy. CONCLUSIONS There was a significant decrease in postoperative hearing impairment after MVD for HFS when the new protocol for IOM of BAEPs was used. Real-time IOM of BAEPs, which can obtain a reliable BAEP in less than 10 seconds, is a successful new procedure for preventing hearing impairment during MVD surgery for HFS.

Trigeminal neuralgia and hemifacial spasm associated with vertebrobasilar artery tortuosity

BACKGROUND

The tortuous vertebrobasilar artery (TVBA) often causes neurovascular conflicts in patients with trigeminal neuralgia (TN) and hemifacial spasm (HFS). Implementation of microvascular decompression (MVD) in these circumstances is hindered due to stiffness of the enlarged and dilated arteries and is often accompanied by poor outcomes. The surgical strategy in cases of trigeminal neuralgia and hemifacial spasm associated with the TVBA should be clarified in order to achieve good outcomes.

MATERIAL AND METHODS

MVD was performed in 268 TN patients and 71 HFS patients. The TVBA as a compressing vessel was identified in 30 cases (11 cases of TN, 18 cases of HFS, and 1 patient with painful tic convulsif). All patients underwent MVD and a retrospective analysis of clinical outcomes.

RESULTS

Compression caused by the vertebral artery was found in all HFS patients and 4 TN patients, and compression caused by the basilar artery was observed in 7 TN cases. Additional compression of the cranial nerve root entry/exit zone by cerebellar vessels was observed in 21 cases. The TVBA was mobilized by dissection of arachnoid adhesions between the vessel and the brainstem and retracted laterally. Then, the TVBA was retracted from the brainstem to the caudorostral direction. These manipulations resulted is "spontaneous" decompression of the cranial nerves without placing prostheses between the artery and the nerve root entry/exit zone. In all cases (except two), the displaced TVBA was fixed between the enlarged artery and brainstem using pieces of the patient's muscle and adipose tissues, followed by application of fibrin glue. A cylindrical silicone prosthesis was used in 1 case. In another case, the TVBA was retracted using a fascial loop fixed to the dura mater of the petrous pyramid by means of a suture. After application of MVD, TN and HFS symptoms completely regressed. There were several transient complications and 2 cases of permanent hearing loss. No clinical symptom recurrence was observed.

CONCLUSION

MVD is the most effective surgical treatment of TN and HFS caused by the TVBA. The TVBA should be retracted from the brainstem without placing prostheses in the nerve root entry/exit zone.

Failed microvascular decompression surgery for hemifacial spasm due to persistent neurovascular compression: an analysis of reoperations

OBJECT

Microvascular decompression (MVD) surgery for hemifacial spasm (HFS) is potentially curative. The findings at repeat MVD in patients with persistent or recurrent HFS were analyzed with the aim to identify factors that may improve surgical outcomes.

METHODS

Intraoperative findings were determined from review of dictated operative reports and operative diagrams for patients who underwent repeat MVD after prior surgery elsewhere. Clinical follow-up was obtained from the hospital and clinic records, as well as telephone questionnaires.

RESULTS

Among 845 patients who underwent MVD performed by the senior author, 12 had been referred after prior MVD for HFS performed elsewhere. Following repeat MVD, all patients improved and complete spasm resolution was described by 11 of 12 patients after a mean follow-up of 91 ± 55 months (range 28–193). Complications were limited to 1 patient with aggravation of preexisting hearing loss and mild facial weakness and 1 patient with aseptic meningitis without sequelae. Significant factors that may have contributed to the failure of the first surgery included retromastoid craniectomies that did not extend laterally to the sigmoid sinus or inferiorly to the posterior fossa floor in 11 of 12 patients and a prior surgical approach that focused on the cisternal portion of the facial nerve in 9 of 12 patients. In all cases, significant persistent neurovascular compression (NVC) was evident and alleviated more proximally on the facial root exit zone (fREZ).

CONCLUSIONS

Most HFS patients will achieve spasm relief with thorough alleviation of NVC of the fREZ, which extends from the pontomedullary sulcus root exit point to the Obersteiner-Redlich transition zone.

Management of Bilateral Hemifacial Spasm with Microvascular Decompression

BACKGROUND

Bilateral hemifacial spasm (HFS) is very rare. The literature contains only 32 clinical reports. Although microvascular decompression (MVD) is widely accepted as effective therapy for HFS, the etiology and surgical treatment of bilateral HFS are seldom addressed. We report our experience with MVD for patients with bilateral HFS.

METHODS

This retrospective report included 10 patients with bilateral HFS. All patients underwent MVD 1 or 2 times and were followed for 5-92 months. The clinical data were retrospectively analyzed. The etiology and treatment strategies were discussed.

RESULTS

Spasm stopped completely on the operative side in all 10 patients. Symptoms on the other side also resolved in 3 patients, improved in 1 patient, and did not improve at all in 6 patients. Of the 6 patients with no improvement, 5 underwent another MVD on the contralateral side within 1 year and experienced relief of symptoms, and 1 patient refused the surgery. The neurovascular conflict was found in all the operations. During the follow-up period, no complications of hearing loss or facial palsy and no recurrence were observed.

CONCLUSIONS

Vascular compression was the cause of bilateral HFS in our patients, and MVD relieved the symptoms. Thus, we recommend MVD for patients with bilateral HFS. A crowded cerebellopontine angle space and easy attrition of the neurovascular interfaces may play important roles in the occurrence of bilateral HFS. For some patients, 1 MVD can resolve bilateral symptoms.

Effects of microvascular decompression surgery on posture control: A case report in an elderly patient

AIMS OF THE STUDY

We report the case of an 84-year-old woman with neurovascular conflict of the left cochleovestibular nerve. Prior to surgery, the patient complained of positional vertigo and dizziness for the past two years, and marked instability. Hearing loss and tinnitus were reported on the left side. The aim of this study was to investigate the effects of microvascular decompression of the cochleovestibular nerve on posture control.

MATERIALS AND METHODS

Evaluation of cochleovestibular function and posture control was performed before and after surgery. Postural performance was analyzed in static and dynamic conditions, with and without vision, and with optokinetic stimulation. Perception of the static visual vertical (SVV) was recorded in darkness.

RESULTS

Positional vertigo and tinnitus disappeared immediately after the decompression. The SVV remained unchanged one week after the surgery. Speech intelligibility of the left ear was improved (30 dB), and the vestibular deficit on this side was also significantly reduced (54% versus 18%). However, the more spectacular result was the effect on postural control. This elderly patient improved her postural balance in both static and dynamic conditions, and became able to maintain her equilibrium in the more challenging dynamic conditions, with and without vision, as early as one week after the surgery, a postural performance that she had been unable to do preoperatively.

CONCLUSION

This work is the first to show that the postural deficits resulting from neurovascular conflict of the cochleovestibular nerve are strongly improved after microvascular decompression.

Reduced CSF leak in complete calvarial reconstructions of microvascular decompression craniectomies using calcium phosphate cement

OBJECT

Calcium phosphate cement provides a biomaterial that can be used for calvarial reconstruction in a retrosigmoid craniectomy for microvascular decompression (MVD). This study evaluates the outcomes of postoperative CSF leak and wound infection for patients undergoing a complete cranioplasty using calcium phosphate cement versus incomplete cranioplasty using polyethylene titanium mesh following a retrosigmoid craniectomy for MVD.

METHODS

The authors evaluated 211 cases involving patients who underwent first-time retrosigmoid craniectomies performed by a single attending surgeon fortrigeminal neuralgia from October 2008 to June 2014. From this patient population, 111 patients underwent calvarial reconstruction after retrosigmoid craniectomy using polyethylene titanium mesh, and 100 patients had reconstructions using calcium phosphate cement. A Pearson's chi-square test was used to compare postoperative complications of CSF leak and wound infection in these 2 types of cranioplasties.

RESULTS

The polyethylene titanium mesh group included 5 patients (4.5%) with postoperative CSF leak or pseudomeningocele and 3 patients (2.7%) with wound infections. In the calcium phosphate cement group, no patients had a CSF leak, and 2 patients (2%) had wound infections. This represented a statistically significant reduction of postoperative CSF leak in patients who underwent calcium phosphate reconstructions of their calvarial defect compared with those who underwent polyethylene titanium mesh reconstructions (p = 0.03). No significant difference was seen between the 2 groups in the number of patients with postoperative wound infections.

CONCLUSIONS

Calcium phosphate cement provides a viable alternative biomaterial for calvarial reconstruction of retrosigmoid craniectomy defects in patients who have an MVD. The application of this material provides a biocompatible barrier that reduces the incidence of postoperative CSF leaks.

Indications and Timings of Re-operation for Residual or Recurrent Hemifacial Spasm after Microvascular Decompression: Personal Experience and Literature Review

We reviewed reports about the postoperative course of hemifacial spasm (HFS) after microvascular decompression (MVD), including in our own patients, and investigated treatment for delayed resolution or recurrence of HFS. Symptoms of HFS disappear after surgery in many patients, but spasm persists postoperatively in about 10-40%. Residual spasm also gradually decreases, with rates of 1-13% at 1 year postoperatively. However, because delayed resolution is uncommon after 1 year postoperatively, the following is advised: (1) In patients with residual spasms after 1 year postoperatively (incomplete cure) or who again experience spasm ≥ 1 year postoperatively (recurrence), re-operation is recommended if the spasms are worse than before MVD. (2) When re-operation is considered, preoperative magnetic resonance imaging (MRI) findings and intraoperative videos should be reviewed to ensure that no compression due to a small artery or vein was missed, and to confirm that adhesions with the prosthesis are not causing compression. If any suspicious findings are identified, the cause must be eliminated. Moreover, because of the risk of nerve injury, decompression of the distal portion of the facial nerve should be performed only in patients in whom distal compression is strongly suspected to be the cause of symptoms. (3) Cure rates after re-operation are high, but complications such as hearing impairment and facial weakness have been reported in 10-20% of cases, so surgery must be performed with great care.

Reduction in high-frequency hearing loss following technical modifications to microvascular decompression for hemifacial spasm

OBJECT

Microvascular decompression is a safe and effective procedure to treat hemifacial spasm, but the operation poses some risk to the patient's hearing. While severe sensorineural hearing loss across all frequencies occurs at a low rate in experienced hands, a recent study suggests that as many as one-half of patients who undergo this procedure may experience ipsilateral high-frequency hearing loss (HFHL), and as many as one-quarter may experience contralateral HFHL. While it has been suggested that drill-related noise may account for this finding, this study was designed to examine the effect of a number of techniques designed to protect the vestibulocochlear nerve from operative manipulation on the incidence of HFHL.

METHODS

Pure-tone audiometry was performed both preoperatively and postoperatively on 67 patients who underwent microvascular decompression for hemifacial spasm during the study period. A change of greater than 10 dB at either 4 kHz or 8 kHz was considered to be HFHL. Additionally, the authors analyzed intraoperative brainstem auditory evoked potentials from this patient cohort.

RESULTS

The incidence of ipsilateral HFHL in this cohort was 7.4%, while the incidence of contralateral HFHL was 4.5%. One patient (1.5%; also included in the HFHL group) experienced an ipsilateral nonserviceable hearing loss.

CONCLUSIONS

The reduced incidence of HFHL in this study suggests that technical modifications including performing the procedure without the use of fixed retraction may greatly reduce, but not eliminate, the occurrence of HFHL following microvascular decompression for hemifacial spasm.

Hemifacial spasm: 20-year surgical experience, lesson learned

BACKGROUND

Hemifacial spasm is characterized by unilateral, paroxysmal, and involuntary contractions. It is more common in women on the left side. Its evolution is progressive, and it rarely improves without treatment.

METHODS

Microvascular decompressions (N = 226) were performed in 194 Hispanic patients (May 1992-May 2011). Outcomes were evaluated on a 4-point scale: Excellent (complete remission); good (1-2 spasms/day); bad (>2 spasms/day); and recurrence (relapse after initial excellent/good response).

RESULTS

Most patients were female (n = 123); 71 were male. Mean (±SD) age was 49.4 (±11.7) years; age at onset, 43.9 (±11.9) years; time to surgery, 5.7 (±4.7) years. The left side was affected in 114 patients. Typical syndrome occurred in 177 (91.2%); atypical in 17 (8.8%). Findings were primarily vascular compression (n = 185 patients): Anterior inferior cerebellar artery (n = 147), posterior inferior cerebellar artery (n = 12), basilar artery (n = 10), superior cerebellar artery (n = 8), and 2 vessels (n = 8); 9 had no compression. Postsurgical results were primarily excellent (79.9% [n = 155]; good, 4.6% [n = 9]; bad, 15.5% [n = 30]), with recurrence in 21 (10.8%) at mean 51-month (range, 1-133 months) follow-up. Complications included transient hearing loss and facial palsy.

CONCLUSIONS

The anterior inferior cerebellar artery is involved in most cases of hemifacial spasm. Failure to improve postsurgically after 1 week warrants reoperation. Sex, side, and onset are unrelated to treatment response. Microvascular decompression is the preferred treatment. It is minimally invasive, nondestructive, and achieves the best long-term results, with minor morbidity. To our knowledge, this series is the largest to date on a Hispanic population.

Cerebellar retraction and hearing loss after microvascular decompression for hemifacial spasm

BACKGROUND

This retrospective study evaluated the length of cerebellar retraction and the changes of intraoperative brainstem auditory evoked potential (BAEP) during microvascular decompression (MVD), and assessed the predictive value of the hearing loss as a prognostic indicator for the treatment outcome of hemifacial spasm (HFS).

METHODS

This series included 1,518 consecutive patients affected with HFS who underwent MVD, during which BAEP was monitored. Patients were divided into two groups based on whether hearing loss occurred following decompression or not. Each patient underwent a similar procedure performed by one neurosurgeon. The two patients groups were matched with regard to sex, age, and degree of spasm.

RESULTS

Among the 1,518 patients, 106 (6.98 %) displayed functional hearing changes. Hearing loss was permanent in 12 patients (0.79 %). Of the 1,412 patients with stationary hearing compared with preoperative audiometry, 96 patients were selected who were individually matched with respect to sex, age, and degree of spasm. BAEP changed immediately after cerebellar retraction in 7 of 12 hearing-loss patients, suggesting the importance of retraction on hearing outcomes. The distance from the cerebellar surface of the petrous temporal bone to the neurovascular compression point was measured. The median distance of cerebellar retraction in the hearing-loss group was 13.77 mm, which was longer than the median distance in the control group.

CONCLUSIONS

Preoperative measurement of the cerebellar retraction distance can be a valuable clue to predict and prevent postoperative hearing loss in MVD for HFS.

Usefulness of subtraction of 3D T2WI-DRIVE from contrast-enhanced 3D T1WI: preoperative evaluations of the neurovascular anatomy of patients with neurovascular compression syndrome

BACKGROUND AND PURPOSE

High-resolution 3D MR cisternography techniques such as 3D T2WI-driven equilibrium radiofrequency reset pulse (DRIVE) are used preoperatively to assess neurovascular anatomy in patients with neurovascular compression syndrome, but contrast between vessels and cranial nerves at the point of neurovascular contact is limited. The postprocessing technique subtraction of 3D T2WI-driven equilibrium radiofrequency reset pulse from contrast-enhanced 3D T1WI (sDRICE) provides both high spatial resolution and excellent contrast in depicting the neurovascular contact. We evaluated the usefulness of sDRICE compared with 3D T2WI-DRIVE.

MATERIALS AND METHODS

Twelve patients who underwent microvascular decompression for hemifacial spasm or trigeminal neuralgia were examined preoperatively with 3D T2WI-DRIVE and sDRICE. Two neuroradiologists retrospectively analyzed and scored lesion conspicuity, defined as the ease of discrimination between offending vessels and compressed nerves or the brain stem at the neurovascular contact. They also quantitatively analyzed the contrast and contrast-to-noise ratio at the neurovascular contact.

RESULTS

The lesion conspicuity scores of sDRICE images were significantly higher than those of 3D T2WI-DRIVE for all 12 patients (P = .006) and the 6 cases of hemifacial spasm (P = .023) but were not significantly higher in the 6 trigeminal neuralgia cases alone (P = .102). For all 12 patients, the contrast-to-noise ratio between the offending vessels and the brain stem and between the vessels and nerves on sDRICE images was significantly higher than that on 3D T2WI-DRIVE (P = .003 and P = .007, respectively). Among these structures, the contrast values were also significantly higher on the sDRICE than on the 3D T2WI-DRIVE (P < .001) images.

CONCLUSIONS

The postprocessing technique sDRICE is useful to evaluate neurovascular anatomy and to improve contrast and the contrast-to-noise ratio in patients with neurovascular compression syndrome.

Presurgical evaluation of hemifacial spasm and spasmodic torticollis caused by a neurovascular conflict from AICA with 3T MRI integrated by 3D drive and 3D TOF image fusion: A case report and review of the literature

Background:

Hemifacial spasm (HS) and spasmodic torticollis (ST) are well-known disorders that are caused by a neurovascular conflict. HS is characterized by irregular, involuntary muscle contractions on one side of the face due to spasms of orbicularis oris and orbicularis oculi muscles, and is usually caused by vascular compression of the VII cranial nerve. ST is an extremely painful chronic movement disorder causing the neck to involuntary turn to the side, upward and/or downward. HS is usually idiopathic but it is rarely caused by a neurovascular conflict with the XI cranial nerve.

Case Description:

We present a case of a 36-year-old woman with a 2-year history of left hemifacial spasm and spasmodic torticollis. Pre-surgical magnetic resonance imaging MRI examination was performed with 3TMRI integrated by 3Ddrive and 3DTOF image fusion. Surgery was performed through a left suboccipital retrosigmoid craniectomy. The intraoperative findings documented a transfixing artery penetrating the facial nerve and a dominant left anteroinferior cerebellar artery (AICA) in contact with the anterior surface of the pons and lower cranial nerves. Microvascular decompression (MVD) was performed. Postoperative course showed the regression of her symptoms.

Conclusions

Transfixing arteries are rarely reported as a cause of neurovascular conflicts. The authors review the literature concerning multiple neurovascular conflicts.

Surgical results of microvascular decompression procedures and patient's postoperative quality of life: review of 139 cases

Microvascular decompression (MVD) is effective for the relief of symptoms, but little is known about the impact of the MVD procedure on patient's quality of life (QoL) or which QoL factors are important. The surgical results of MVD and the impact of this procedure were evaluated on patient's QoL in 139 patients, 74 with hemifacial spasm (HFS) and 65 with trigeminal neuralgia (TN), who underwent MVD between 2004 and 2011 using the 36-Item Short Form Health Survey questionnaire. Symptoms had resolved in approximately 95% of patients after MVD. The QoL questionnaire was completed by 54 HFS patients and 38 TN patients. Although long-term QoL scores for both groups were comparable to the average national value, scores related to physical role, emotional role, and social function were significantly lower for patients within 12 months of receiving MVD for HFS, compared with the reference scores. Symptomatic improvements and complications were correlated with the QoL scores related to the social function domain for patients with HFS. No other significant relationships were observed between any of the factors or scores in any of the respective domains or periods. Subjective symptoms were the main self-reported causes of delayed recovery of QoL domains. Some QoL domains take a long time to recover and postoperative subjective symptoms might be major causes in addition to delayed relief of symptoms.

Emprical factors associated with Brainstem auditory evoked potential monitoring during microvascular decompression for hemifacial spasm and its correlation to hearing loss

BACKGROUND

Cranial nerve VIII is at risk during microvascular decompression (MVD) for hemifacial spasm (HFS). The primary aim of this study is to evaluate the empirical factors associated with brainstem auditory evoked potential monitoring and its correlation to post operative hearing loss (HL) after MVD for HFS.

METHODS

Pre-operative and post-operative audiogram data and BAEP from ninety-four patients who underwent MVD for HFS were analyzed. Pure tone audiometry (PTA) and Speech Discrimination Score (SDS) were performed on all patients before and after surgery. Intraoperative neurophysiological data were reviewed independently. HL was assessed using the AAO-HNS classification system for non-serviceable hearing loss (Class C/D), defined as PTA >50 dB and/or SDS <50% within the speech range of frequencies.

RESULTS

Patients with HL had higher rates of loss in the amplitude of wave V and prolongation in the interpeak latency of peak I-V latency during MVD. Gender, age, side, and MVD duration did not increase the risk of HL. There was no correlation between successive number of BAEP changes (reflective of the number of surgical attempts) and HL. There was no association between the speed of recovery of BAEPs and HL.

CONCLUSIONS

Patients with new post-operative HL have a faster rate of change in the amplitude of wave V and the interpeak I-V latency during intraoperative BAEP monitoring for HFS. Our alarm criteria to inform the surgeon about impending nerve injury might have to be modified and prospectively tested to prevent rapid change in BAEPs.

Preoperative assessment of hemifacial spasm by the coronal heavily T2-weighted MR cisternography

BACKGROUND

Microvascular decompression (MVD) has become a well-established surgical procedure for hemifacial spasm (HFS). Before surgery, it is essential to evaluate any possible deformity of the brainstem and establish the precise location of the offending vessels. In the present study of HFS patients we examined coronal sections taken by heavily T2-weighted MR cisternography in addition to routine axial sections, and assessed the usefulness of these images through comparison with intraoperative findings.

METHODS

Eighty patients with HFS underwent preoperative coronal heavily T2-weighted MR cisternography before microvascular decompression surgery. Three neurosurgeons examined the preoperative axial and coronal MR images and evaluated vessel invagination into the brainstem. The usefulness of coronal sections was assessed statistically by the Mann-Whitney U test.

RESULTS

Invagination of the offending vessel into the brainstem was observed in 24 cases (30.0%). In 19 patients, it was predicted preoperatively that compression of the flocculus and brainstem would be required in order to approach the offending vessels. Coronal MR cisternography was significantly more useful in cases with vessel invagination into the brainstem than in cases without invagination.

CONCLUSIONS

Coronal sections obtained by MR cisternography are able to demonstrate the severity of vessel invagination into the brainstem as well as revealing the presence of the offending vessel. This information is helpful for planning a suitable approach to the root exit zone.

Closed-suction drainage and cerebrospinal fluid leakage following microvascular decompression : a retrospective comparison study

OBJECTIVE

We performed this study to investigate whether the use of closed-suction drainage following microvascular decompression (MVD) causes cerebrospinal fluid (CSF) leakage.

METHODS

Between 2004 and 2011, a total of 157 patients with neurovascular compression were treated with MVD. MVD was performed for hemifacial spasm in 150 (95.5%) cases and for trigeminal neuralgia in 7 (4.5%) cases. The mean age of the patients was 49.8±9.6 years (range, 20-69). Dural substitutes were used in 44 (28.0%) patients. Ninety-two patients (58.6%) were underwent a 4-5 cm craniotomy using drainage (drainage group), and 65 (41.4%) did a small 2-2.5 cm retromastoid craniectomy without closed-suction drainage (no-drainage group).

RESULTS

Eleven (7.0%) patients experienced CSF leakage following MVD based on the criteria of this study; all of these patients were in the drainage group. In the unadjusted analyses, the incidence of CSF leakage was significantly related with the use of closed-suction drainage following MVD (12.0% in the drainage group vs. 0% in the no-drainage group, respectively; p=0.003; Fisher's exact test). Those who received dural substitutes and the elderly (cut-off value=60 years) exhibited a tendency to develop CSF leakage (p=0.075 and p=0.090, respectively; Fisher's exact test). In the multivariate analysis, only the use of closed-suction drainage was significantly and independently associated with the development of CSF leakage following MVD (odds ratio=9.900; 95% confidence interval, 1.418 to infinity; p=0.017).

CONCLUSION

The use of closed-suction drainage following MVD appears to be related to the development of CSF leakage.

A recommendation on the basis of long-term follow-up results of our microvascular decompression operation for hemifacial spasm

BACKGROUND

Microvascular decompression (MVD) for hemifacial spasm (HFS) has been popular, but it may take enough time to master this special operative technique and procedure. This may induce uneven distribution of the number of MVD operations in each institute, possibly resulting in an overall unsatisfactory quality of MVD surgeons. Nakanishi's approach to MVD operations has the feature of using a, "supine, no retractor" technique, which would achieve various benefits for patients and medical professionals. We would like to recommend this approach for MVD surgeons on the basis of our follow-up outcomes.

METHODS

A questionnaire, which was based on the method of evaluation for the long-term results of post-MVD operation as recommended by the Japanese Society of MVD, was sent by mail to the 154 HFS patients who had received Nakanishi's approach at our hospital.

RESULTS

Except for 42 patients who had changed their residences, 89 patients (79.5 % of 112) fully answered. The mean postoperative follow-up term was 13.0 years. The 76.4 % of the patients was estimated as excellent. Postoperative deafness was not present. The average value of satisfaction degree for the results of the MVD operation was 87.9 %.

CONCLUSIONS

This study revealed that Nakanishi's approach produced good results equivalent of other approaches for HFS patients. This approach is considered to have many advantages comparing to the other approaches. Therefore, we would like to recommend that Nakanishi's approach would contribute to overall advancement of the level of MVD surgeons.

Long-term results of microvascular decompression for trigeminal neuralgia and hemifacial spasms according to preoperative symptomatology

BACKGROUND

Microvascular decompression (MVD) is currently used in several centres for the treatment of trigeminal neuralgia (TN) and hemifacial spasms (HFS). How long-term results relate to the preoperative symptoms still needs to be documented. The primary aim of this study was to assess long-term results of MVD for TN and HFS, as related to the types of preoperative symptoms.

METHODS

We performed a retrospective study including all first-time MVDs for TN and HFS done during the 11-year period (1999-2009) in the Department of Neurosurgery, The National Hospital (Rikshospitalet), Oslo. The patients were categorized depending on the pre-operative symptomatology.

RESULTS

The study population includes 303 first-time procedures performed by the senior author (PKE), 243 TN patients (65 % TN without constant pain and 35 % TN with constant pain) and 60 HFS patients (95 % typical HFS and 5 % atypical HFS). The patients were followed for a mean 71 months (range, 14-147). In both the TN and HFS patients, MVD caused lasting symptom relief in a high proportion of patients, including patients with atypical symptoms.

CONCLUSION

After MVD for TN and HFS, regardless of preoperative symptoms, lasting relief is observed in a high proportion of patients, with a favorable complication profile.

The utility of calcium phosphate cement in cranioplasty following retromastoid craniectomy for cranial neuralgias

BACKGROUND

Following retromastoid craniectomy for microvascular decompression of the fifth or seventh cranial nerve, the preferred method and value of cranioplasty remains disputed.

METHODS

In this study, we report the functional outcome of calcium phosphate cranioplasty following first-time microvascular decompression in 79 consecutive patients who underwent operations over a one-year period.

RESULTS

No patient experienced a deep infection, cerebrospinal fluid leak or undue incisional pain at long-term follow-up. Additionally, all patients stated that they were satisfied with the cosmetic outcome.

DISCUSSION

Although this technique is unlikely to affect the rates of infection and postoperative pain, we believe that the low rate of CSF leak provides a unique advantage over other currently used methods of closing retromastoid craniectomies.

Analysis of interpeak latencies of brainstem auditory evoked potential waveforms during microvascular decompression of cranial nerve VII for hemifacial spasm

Object

Microvascular decompression (MVD) of the facial nerve is an effective treatment for patients with hemifacial spasm. Intraoperative monitoring of brainstem auditory evoked potentials (BAEPs) during MVD can reduce the incidence of hearing loss. In this study the authors' goal was to evaluate changes in interpeak latencies (IPLs) of Waves I–V, Waves III–V, and Waves I–III of BAEP Waveforms I, III, and V during MVD and correlate them with postoperative hearing loss. To date, no such study has been performed. Hearing loss is defined as nonuseful hearing (Class C/D), which is a pure tone average of more than 50 dB and/or speech discrimination score of less than 50%.

Methods

The authors performed a retrospective analysis of IPLs of BAEPs in 93 patients who underwent intraoperative BAEP monitoring during MVD. Patients who did not have hearing loss were in Class A/B and those who had hearing loss were in Class C/D.

Results

Binary logistic regression analysis of independent IPL variables was performed. A maximum change in IPLs of Waves I–III and Waves I–V and on-skin change in IPLs of Waves I–V increases the odds of hearing loss. However, on adjusting the same variables for loss of response, change in IPLs did not increase the odds of hearing loss.

Conclusions

Changes in IPL measurements did not increase the odds of postoperative hearing loss. This information might be helpful in evaluating the value of IPLs as alarm criteria during MVD to prevent hearing loss.

Effect of previous botulinum neurotoxin treatment on microvascular decompression for hemifacial spasm

Object

The objective of this study was to investigate the clinical characteristics, intraoperative findings, complications, and outcomes after the first microvascular decompression (MVD) in patients with and without previous botulinum neurotoxin treatment for hemifacial spasm (HFS).

Methods

The authors analyzed 246 MVDs performed at the University of Pittsburgh Medical Center between January 1, 2000, and December 31, 2007. One hundred and seventy-six patients with HFS underwent botulinum neurotoxin injection treatment prior to first MVD (Group I), and 70 patients underwent their first MVD without previous botulinum neurotoxin treatment (Group II). Clinical outcome data were obtained immediately after the operation, at discharge, and at follow-up. Follow-up data were collected from 177 patients with a minimum follow-up period of 9 months (mean 54.48 ± 27.84 months).

Results

In 246 patients, 89.4% experienced immediate postoperative relief of spasm, 91.1% experienced relief at discharge, and 92.7% experienced relief at follow-up. There was no significant difference in outcomes and complications between Group I and Group II (p > 0.05). Preoperatively, patients in Group I had higher rates of facial weakness, tinnitus, tonus, and platysmal involvement as compared with Group II (p < 0.05). The posterior inferior cerebellar artery and vertebral artery were intraoperatively identified as the offending vessels in cases of vasculature compression in a significantly greater number of patients in Group II compared with Group I (p = 0.008 and p = 0.005, respectively, for each vessel). The lateral spread response (LSR) disappeared in 60.48% of the patients in Group I as compared with 74.19% in Group II (p > 0.05). No significant differences in complications were noted between the 2 groups.

Conclusions

Microvascular decompression is an effective and safe procedure for patients with HFS previously treated using botulinum neurotoxin. Intraoperative monitoring with LSR is an effective tool for evaluating adequate decompression.

A "sling swing transposition" technique with pedicled dural flap for microvascular decompression in hemifacial spasm

BACKGROUND

The key to successful microvascular decompression of the neurovascular compression syndrome is maintaining the separation between the nerve and the offending vessel.

OBJECTIVE

We describe a transposition technique in which a local pedicled dural flap, fashioned from the petrous posterior surface, is used to retract the offending vessel away from the root exit zone of the facial nerve in hemifacial spasm cases.

METHODS

We conducted a retrospective review of microvascular decompression operations in which the offending vessel was transposed and then retained by a local pedicled dural flap made from the dura of the petrous posterior surface.

RESULTS

This technique was used in 7 consecutive cases of the most recently operated series. Postoperatively, complete symptom relief was achieved in 100% of the patients without any significant surgical complications.

CONCLUSION

To our knowledge, this is the first report in which an autologous anatomic structure in the cerebellopontine angle, such as petrous dura mater, is used in the microvascular decompression of the facial nerve. This is a simple yet robust method and can be considered an option for the treatment of hemifacial spasm caused by arterial compression.

Hemifacial spasm: conservative and surgical treatment options

BACKGROUND

Hemifacial spasm is a neuromuscular movement disorder characterized by brief or persistent involuntary contractions of the muscles innervated by the facial nerve. Its prevalence has been estimated at 11 cases per 100 000 individuals. Among the patients who were operated on by our team, the mean interval from diagnosis to surgery was 8.2 years, and more than half of them learned of the possibility of surgical treatment only through a personal search for information on the condition. These facts motivated us to write this article to raise the awareness of hemifacial spasm and its neurosurgical treatment among physicians who will encounter it.

METHODS

This review article is based on a selective literature search and on our own clinical experience.

RESULTS

Hemifacial spasm is usually caused by an artery compressing the facial nerve at the root exit zone of the brainstem. 85-95% of patients obtain moderate or marked relief from local injections of botulinum toxin (BTX), which must be repeated every 3 to 4 months. Alternatively, microvascular decompression has a success rate of about 85%.

CONCLUSION

Local botulinum-toxin injection is a safe and well-tolerated symptomatic treatment for hemifacial spasm. In the long term, however, lasting relief can only be achieved by microvascular decompression, a microsurgical intervention with a relatively low risk and a high success rate.

Outcomes of surgical treatment for hemifacial spasm associated with the vertebral artery: severity of compression, indentation, and color change

OBJECT

The object of surgical treatment for hemifacial spasm (HFS) is the exclusion of pulsatile neurovascular compression of the root exit zone (REZ). However, spasm persists transiently or permanently in some cases even after complete decompression. In particular, we mainly experience these results when the vertebral artery (VA) is the offender. Hence, we verified color changes of the nerve and indentations from within the operative field in HFS patients with the VA as the offender. So, we reviewed retrospectively the records of those patients who were treated with microvascular decompression (MVD) in order to assess the relationship between operative findings and clinical results.

METHODS

A total of 232 patients with HFS associated with the VA were treated with MVD between January 1994 and January 2009 at our institution. The patients were classified into one of the following three categories based on compression severity: Group I, mild; Group II, moderate; Group III, severe. The patients were also classified into one of the following four categories based on the existence of indentation and discoloration of nerve VII: Group A (-/-), B (+/-), C (-/+), or D (+/+).

RESULTS

A total of 94.2% and 96.6% of the patients in Groups I and II, respectively, had improved to grades I-II at the last follow-up. The surgical outcomes of Group III were slightly poorer than those of Groups I and II. Group A showed the poorest outcomes with 60% of the patients classified as grades III-IV. In Group B, 98.4% of the patients showed a marked improvement and Groups C and D showed relatively poor outcomes compared with those of Group B.

CONCLUSIONS

Severe deviations and color changes of the facial nerves may be the risk factors for poor surgical outcomes. Future studies with larger sample sizes and investigations of the pathophysiology underlying these findings are needed.

Functional end-plate recovery in long-term botulinum toxin therapy of hemifacial spasm: a nerve conduction study

Botulinum toxin type-A is currently thought to be effective and safe for hemifacial spasm (HFS). The pre-synaptic block of acetylcholine release at the neuromuscular junction induces depression of orbicularis oculi muscle compound motor action potential (CMAP). The aim of our study was to evaluate at what extent end-plate functional recovery is possible even in botulinum toxin treatments lasting up to 15 years. We examined 81 outpatients with primary HFS (mean treatment duration = 7.2 ± 4.2 years) who underwent neurophysiologic study, once clinical effect of the previous treatment had vanished. The mean CMAP amplitude, mean rectified amplitude of response 1 (R1) of the blink reflex and area of response 2 (R2) of treated orbicularis oculi muscle were measured in comparison to the controlateral side. Mean amplitude of the above mentioned parameters was slightly lower (about 20%; p < 0.001) in the treated side at the end of the follow-up period (4.7 ± 1.7 months). The CMAP amplitude reduction weakly correlated with the interval from last treatment, while other neurophysiologic parameters did not change due to treatment duration or total toxin amount. Our study demonstrates that botulinum toxin affects compound motor action potential and blink-reflex responses for at least 4-5 months in HFS patients. The residual block is slight and does not increase with repeated injections after several years of treatment. Our study, beside confirming the long-term efficacy of botulinum toxin treatment for HFS, provides neurophysiologic evidence that therapeutic effect may be obtained without hindering the regenerative potential of the nerve-muscle complex.

Early surgical results of auditory brainstem implantation in nontumor patients

OBJECTIVES/HYPOTHESIS

An auditory brainstem implant (ABI) that stimulates the cochlear nucleus in the brainstem was initially designed for patients with neurofibromatosis type-2. Recently, promising surgical outcomes after ABI have been reported in nontumor patients with sensorineural hearing loss including those with cochlear nerve aplasia or ossified cochlea. We herein describe the surgical results and auditory outcomes of ABI in nontumor patients.

STUDY DESIGN

Retrospective case series at a tertiary hospital.

METHODS

Eleven deaf patients who received ABI from 2008 to 2010 were included in this study. The first group included eight patients with narrow internal auditory canals (IACs) and the second group consisted of three postlingually deaf adults with cochlear ossification. Pulsar CI100 ABI (Med-El Co., Innsbruck, Austria) was implanted via the suboccipital approach.

RESULTS

All eight patients with narrow IACs clearly demonstrated behavioral responses following initial stimulation using an ABI. The category of auditory performance (CAP) scores were progressively improved to reach auditory performances of CAP 4 in three patients, CAP 3 in two patients, CAP 2 in two patients, and CAP 1 in one patient. The three patients with ossified cochlea also reported auditory sensations when the ABI was activated. Two of them showed an auditory performance of CAP 4 or 5, but the third patient could not use the device due to nonauditory stimulation.

CONCLUSIONS

Based on our experience, ideal nontumor candidates for ABI include congenitally deaf children who experienced failure after cochlear implantation owing to cochlear nerve deficiency and postlingually deaf adults with severe cochlear ossification.

Using the new clinical grading scale for quantification of the severity of hemifacial spasm: correlations with a quality of life scale

BACKGROUND

To date, no consensus has been reached regarding validated and practical tools to quantify the severity of hemifacial spasm (HFS) before and after surgery.

OBJECTIVE

The aim of this study has been to establish objective parameters for determining the preoperative severity of HFS and to assess the correlation with quality of life (QoL) in HFS patients.

METHODS

Patients who experienced HFS between April and August 2010 were reviewed. The patients were divided into four groups according to the severity of spasm (SMC grade): grade I - localized spasm around the periocular area; grade II - involuntary movement spreads to other parts of the ipsilateral face and it affects other muscle groups, i.e. the orbicularis oris, zygomaticus, frontalis or platysma muscle; grade III - interference with vision because of frequent tonic spasms, and grade IV - disfiguring asymmetry. We interviewed each patient using an HFS-7 questionnaire containing a short self-rating QoL scale. We estimated the measure of agreement across observers and examined the relationships between SMC grade and other factors, including HFS-7 responses.

RESULTS

Preoperative evaluation using the SMC grading system showed 25 patients with grade I, 48 patients with grade II, 33 patients with grade III, and 12 patients with grade IV HFS. The HFS-7 scores indicating QoL were 9 (range: 0-17) in grade I, 12 (range: 1-25) in grade II, 16 (range: 2-23) in grade III, and 17 (range: 3-24) in grade IV subjects. SMC grade was correlated with symptom duration (p < 0.0001) and HFS-7 score (p = 0.02). In addition, higher SMC grade was closely associated with longer duration of persisting symptoms (p < 0.05).

CONCLUSIONS

An SMC grading system is useful as a means of quantifying spasms to allow for more precise descriptions of a patient's condition including QoL, and to improve the accuracy of communication between medical teams.