Unilateral periocular spasm.

ABSTRACT: Hemifacial spasm is an uncontrollable, recurrent facial muscular contraction that typically occurs on one side of the face, cannot be suppressed, and can last the entire day and during sleep. The most common underlying cause of facial nerve compression is an enlarged or abnormal tracking blood vessel at the brainstem level. Clinical diagnoses are frequently based on a patient's medical history and physical examination. Before deciding on a course of action, however, an electromyogram and MRI are performed to determine the underlying cause. Due to its high effectiveness (success rates of 85% to 95%) and low frequency of adverse reactions, botulinum toxin is the preferred therapy for hemifacial spasm and can provide transient symptomatic alleviation. Surgical microvascular decompression is a therapeutic approach that targets the underlying cause of this condition and has an average success rate of 85%.

How to face the hemifacial spasm: challenges and misconceptions.

Hemifacial spasm (HFS) is characterised by intermittent, brief or sustained, repetitive contractions of the muscles innervated by one facial nerve. It is one of the most frequent movement disorders affecting the face. However common and allegedly straightforward to diagnose, it might reveal as a challenge for clinicians in various situations. Indeed, it often needs prior exclusion of many other movement disorders affecting the face, with frequent phenomenological overlaps with blepharospasm, post-facial palsy, facial motor tics, etc. The clinical diagnosis shall be supported by modern brain imaging techniques, and sometimes electromyography, as some particular aetiologies may require specific treatment. Primary forms are associated with vascular compression of the ipsilateral seventh cranial nerve, whereas secondary forms can be caused by any injury occurring on the facial nerve course. This article proposes a global and organised approach to the diagnosis, and the ensuing therapeutic options, as many practitioners still use some inefficient medications when they encounter a case of facial spasm.

Interrater reliability of motor severity scales for hemifacial spasm.

To compare the inter-rater reliability (IRR) of five clinical rating scales for video-based assessment of hemifacial spasm (HFS) motor severity. We evaluated the video recordings of 45 HFS participants recruited through the Dystonia Coalition. In Round 1, six clinicians with expertise in HFS assessed the participants' motor severity with five scales used to measure motor severity of HFS: the Jankovic rating scale (JRS), Hemifacial Spasm Grading Scale (HSGS), Samsung Medical Center (SMC) grading system for severity of HFS spasms (Lee's scale), clinical grading of spasm intensity (Chen's scale), and a modified version of the Abnormal Involuntary Movement Scale (Tunc's scale). In Round 2, clinicians rated the same cohort with simplified scale wording after consensus training. For each round, we evaluated the IRR using the intraclass correlation coefficient [ICC (2,1) single-rater, absolute-agreement, 2-way random model]. The scales exhibited IRR that ranged from "poor" to "moderate"; the mean ICCs were 0.41, 0.43, 0.47, 0.43, and 0.65 for the JRS, HSGS, Lee's, Chen's, and Tunc's scales, respectively, for Round 1. In Round 2, the corresponding IRRs increased to 0.63, 0.60, 0.59, 0.53, and 0.71. In both rounds, Tunc's scale exhibited the highest IRR. For clinical assessments of HFS motor severity based on video observations, we recommend using Tunc's scale because of its comparative reliability and because clinicians interpret the scale easily without modifications or the need for consensus training.

Incidence and prevalence of Hemifacial Spasm in Finland's largest hospital district.

BACKGROUND: Hemifacial spasm (HFS) is a movement disorder of facial muscles innervated by the facial nerve. This condition often demands regular utilization of healthcare resources. However, knowledge of the incidence and prevalence of this condition is based on scarce studies. This research aimed to identify the incidence and prevalence of HFS in Finland's largest hospital district. METHODS: This retrospective study was conducted in the largest hospital district in Finland (Helsinki and Uusimaa). The study included consecutive HFS patients who visited the departments of Neurology and Neurosurgery in the Hospital District of Helsinki and Uusimaa between 2014 and 2019. The demographics included sex, side of the spasm, treatment allocations, duration of symptoms before diagnosis, and age at the time of diagnosis. RESULTS: 279 patients were identified from the medical records. 62% of patients were women and had left-sided spasms. The crude mean incidence among women was almost double that of men (1.86 vs. 0.94). The highest crude mean annual incidence among men was in the age group 60-79 years, while among women, it peaked in the age group 80 years and over. The mean annual age-standardized incidence of HFS was 1.53, 1.94 in women, and 1.05 in men. The mean age-standardized yearly prevalence was 10.62, 11.62 among women, and 9.31 among men. The annual age-standardized prevalence of HFS increased steadily from 2014 to 2019. CONCLUSIONS: The incidence and prevalence of women outnumbered men. HFS is typically left-sided. The HFS incidence peaked after 80 years in women and men aged 60-79 years.

Evaluating the topographical measurements and tear function status in patients with hemifacial spasm: A comparative fellow eye study.

OBJECTIVE: To investigate the effect of eyelid spasm on corneal and tear film characteristics in patients with hemifacial spasm (HFS) and compare these data with those of the contralateral eyes of the same patients. METHODS: This prospective study is comprised of 64 eyes of 32 HFS patients, 32 eyes on the spasm side (Group 1) and 32 contralateral eyes (Group 2). Corneal tomographic analyses were performed; corneal power of flat axis (K1) and steep axis (K2), astigmatism and thinnest pachymetry; anterior, posterior and total corneal aberrometry [spherical aberration (SA), vertical coma (vcoma), horizontal coma (hcoma), total higher order aberration (THOA) and total RMS], and corneal densitometry values were evaluated and compared between groups. Tear meniscus height and depth (TMH, TMD) were measured using anterior segment optic coherence tomography. Tear function tests including TMH and TMD, the Schirmer I test, and tear break-up time (TBUT) were compared between the groups. RESULTS: K1, K2, astigmatism and corneal densitometry values were similar between groups (p > 0.05). Thinnest pachymetry values were significantly thinner on the spasm side (p = 0.040). Anterior and total corneal SA and RMS were significantly higher on the spasm side (p = 0.032, p = 0.005; p = 0.015, p = 0.006, respectively). TMH, TMD and TBUT were significantly lower in Group 1 (p = 0.01, p = 0.02 and p = 0.03, respectively). Schirmer I test values were similar between groups (p > 0.05). CONCLUSION: In HFS patients, there are changes in corneal parameters and tear film in the eye on the spasm side compared to unaffected eye.

Analysis of Risk Factors and Prediction Model for Recurrence of Hemifacial Spasm After Radiofrequency Ablation.

BACKGROUND: Computed tomography (CT)-guided percutaneous stylomastoid foramen puncture radiofrequency ablation for the treatment of hemifacial spasm has a significant clinical effect; however, related risk factors for recurrence have not been studied. OBJECTIVE: To investigate the risk factors for the recurrence of hemifacial spasm after radiofrequency ablation and construct a model for predicting recurrence. STUDY DESIGN: This is a single-center retrospective observational study. SETTING: The study was conducted at the Pain Department of the Affiliated Hospital of Jiaxing College in Jiaxing, China. METHODS: A retrospective analysis was performed on 99 patients diagnosed with primary hemifacial spasm (HFS) admitted to the Affiliated Hospital of Jiaxing University between August 2018 and December 2021. All patients underwent CT-guided percutaneous stylomastoid foramen radiofrequency ablation. Kaplan-Meier survival analysis, log-rank test, and Cox proportional risk regression model were used to analyze the clinical factors that affect the recurrence of patients with HFS after radiofrequency ablation, and a recurrence prediction model was established. RESULTS: Follow-up was 3-12 months; recurrence rates were 20.2%, 36.4%, and 71.9% at 3, 6, and 12 months postoperatively, respectively. Univariate analysis showed that puncture approach, operation time, and facial paralysis level were factors influencing recurrence in patients with HFS after radiofrequency ablation (P < 0.05). The multivariate Cox proportional risk regression model showed that the operative time and facial paralysis grade were independent factors for recurrence after radiofrequency ablation in patients with facial spasms. The recurrence risk function model of patients with facial spasms after radiofrequency ablation was expressed as h(t) = h0exp(-0.619X1-2.589X2), where X1 and X2 represent the operation time and facial paralysis grade, respectively. The likelihood ratio of the model was statistically significant (chi squared = 55.769, P < 0.001). LIMITATIONS: We look forward to increasing the sample size in follow-up studies and exploring relevant conclusions in randomized controlled trials. CONCLUSION: Long operation times and high-grade facial paralysis can reduce the risk of recurrence in patients with facial spasms. The constructed recurrence prediction model could serve as a reference for clinical diagnosis and treatment.

Significant Correlation between Delayed Relief after Microvascular Decompression and Morphology of the Abnormal Muscle Response in Patients with Hemifacial Spasm.

Although microvascular decompression (MVD) is a reliable treatment for hemifacial spasm (HFS), postoperative delayed relief of persistent HFS is one of the main issues. In patients with hemifacial spasm, stimulation of a branch of the affected facial nerve elicits an abnormal response in the muscles innervated by another branch. Several specific types of waves were found in the abnormal muscle response (AMR). This study aimed to confirm the relationship between the initial morphology of the AMR wave and delayed relief of persistent HFS after MVD. We retrospectively analyzed and compared the data from 47 of 155 consecutive patients who underwent MVD for HFS at our hospital between January 2015 and March 2020. Based on the pattern of the initial AMR morphology on orbicularis oculi and mentalis muscle stimulation, patients were divided into two groups, namely, the monophasic and polyphasic groups. The results of MVD surgery for HFS were evaluated 1 week, 1 month, and 1 year postoperatively, by evaluating whether or not the symptoms of HFS persisted at the time of each follow-up. There were significantly higher rates of persistent postoperative HFS in patients with the polyphasic type of initial AMR at 1 week and 1 month after the surgery (p < 0.05, respectively), as assessed using Yates chi-squared test and Fisher's exact test. A significant correlation was observed between delayed relief after MVD and polyphasic morphology of the AMR in electromyographic analysis in patients with hemifacial spasm.

Neurovascular compression syndrome:Trigeminal neuralgia, hemifacial spasm, vestibular paroxysmia, glossopharyngeal neuralgia, four case reports and review of literature.

Neurovascular compression syndrome is caused by vessels touching a cranial nerve, resulting in clinical manifestations of abnormal sensory or motor symptoms. The most common manifestations are trigeminal neuralgia and hemifacial spasm. However, neurovascular compression of the vestibular nerve or glossopharyngeal nerve are rare. In this article, we describe four typical cases of neurovascular compression syndrome. In addition, we analyze the main features of the etiology, neuroimaging, and treatment of this disease.

Facial involvement in multiple sclerosis.

BACKGROUND: Multiple sclerosis (MS) can present with facial symptoms and signs, such as facial palsy, myokymia, and hemifacial spasm. Considering the importance of early diagnosis, treatment, and exclusion of causes other than MS, we aimed to assess the prevalence of these disorders in patients with MS. METHODS: MS patients who were referred to the Isfahan MS clinic from March 2021 to March 2022 were observed for facial presentations of the disease. A checklist of patients' baseline characteristics and disease features were then completed through patient interview and medical files. RESULTS: Of the total of 2260 MS patients who were assessed, 3.27% had facial palsy, 1.28% had myokymia, and 0.84% presented with hemifacial spasm. The mean age of facial symptom onset was 30.74, 29.07, and 31.37 years, respectively. No relationship was found between the type of facial presentation and factors such as age, gender, subtype of MS, affected side of face, and time of presentation. CONCLUSION: On the grounds that facial disorders can be the first presentation of MS, patients with atypical features of other common facial diseases such as Bell's palsy should therefore be carefully assessed and followed for any clues pertaining to the diagnosis of MS.

Can hemifacial spasm lead to glaucomatous changes?

PURPOSE: To evaluate the association between hemifacial spasm (HFS) patients and glaucoma as a function of the Botox dosage required. METHODS: A retrospective review of clinical documents and procedure records. RESULTS: Information of 76 consecutive patients (58 females) with HFS who received Botox treatment were reviewed. The age at onset of HFS was 66±11 (32-85) years, and all manifested unilaterally. Ten (13%, 95% confidence interval: 6.5-22.9%) patients were diagnosed with glaucoma, including 8 primary open-angle glaucoma (POAG) (4 unilateral and ipsilateral to the HFS), and 2 bilateral chronic angle-closure glaucoma (CACG). Nine of the 10 patients developed glaucoma after the onset of the HFS. The Botox dosage was significantly higher among those diagnosed with glaucoma (31+/8 vs. 26+/7units, P<0.05). There was a positive relationship between the presenting intraocular pressure (IOP) and the Botox dosage required (R=0.31, P=0.0116). However, there was a weak relationship between the Botox dosage required and the vertical cup to disc ratio (R=0.076, P=0.525). The presenting IOP of the HFS-affected eyes in those diagnosed with glaucoma was higher than those without glaucoma (19±3.5 vs. 13±3.2mmHg, P=<0.05). The presenting IOP between the HFS-affected and unaffected eyes was similar (16±4.8 vs. 15+/4.6mmHg, P=0.430). Smoking status, history of diabetes mellitus, hypertension, hyperlipidemia and obstructive sleep apnea were not different between HFS patients with or without glaucoma. CONCLUSIONS: Hemifacial spasm patients with glaucoma were associated with a higher Botox dosage. We found a positive relationship between the Botox dosage required and the presenting IOP. Whether hemifacial spasm can result in fluctuation of IOP, eventually causing glaucomatous damage, remains to be studied further.

Usefulness of intraoperative monitoring in microvascular decompression for hemifacial spasm: a systematic review and meta-analysis.

OBJECTIVE: To review the diagnostic accuracy and possible added value of Brainstem Auditory Evoked Potentials (BAEP) monitoring and Lateral Spread Response (LSR) monitoring in microvascular decompression surgery for hemifacial spasms. METHODS: For this systematic review we followed the PRISMA guidelines. We searched different databases and bibliographies of articles. We included studies on BAEP and LSR monitoring that reported data on hearing outcome or efficacy. Selected studies were assessed for bias using the MINORS tool. RESULTS: 64 articles were selected for qualitative synthesis, 42 met inclusion criteria for meta-analysis. The overall incidence of hearing loss was 3.4%. For BAEP monitoring AUC and pooled OR with 95% confidence interval were 0.911 (0.753-0.933) and 7.99 (3.85-16.60) respectively. Short-term data on LSR monitoring showed an overall spasm relief rate of 89% with pooled OR, sensitivity and specificity with a 95% confidence interval of 8.80 (4.82-16.08), 0.911 (0.863-0.943) and 0.451 (0.342-0.564) respectively. Long-term data on LSR monitoring showed an overall spasm relief rate of 95% with pooled OR, sensitivity and specificity with a 95% confidence interval of 4.06 (2.15-7.64), 0.871 (0.817-0.911) and 0.39 (0.294-0.495) respectively. CONCLUSION: The alarm criteria, a wave V latency prolongation of 1ms or a wave V amplitude decrement of 50%, proposed by the 'American Clinical Neurophysiology Society' are a sensitive predictor for postoperative hearing loss. Other BAEP wave changes, for example, complete loss of wave V, are more specific but correspond to irreversible damage and are therefore not useful as warning criteria. LSR monitoring has high diagnostic accuracy at short-term follow-up. At long-term follow-up, diagnostic accuracy decreases because most patients get spasm relief regardless of their LSR status. LSR persistence after surgery has a good long-term outcome, as long as an extensive exploration of the facial nerve has been performed.

Posterior ocular structural changes and glaucoma susceptibility in patients with hemifacial spasm.

PURPOSE: To evaluate the changes in the posterior ocular structures and glaucoma susceptibility in patients with hemifacial spasm (HFS). STUDY DESIGN: Prospective observational clinical study. METHODS: This study included 46 long-standing HFS patients with a minimum follow-up of 12 months. The participants' eyes were divided into three groups: (1) 46 affected eyes of patients with clinical HFS; (2) 46 unaffected fellow eyes and, (3) 46 eyes of healthy sex and age-matched controls. All participants were assessed by a detailed clinical examination and optical coherence tomography (OCT) with enhanced depth imaging (EDI). EDI-OCT images were binarized using ImageJ software. Peripapillary retinal nerve fiber layer (RNFL), ganglion cell complex (GCC), choroidal thickness (CT), and choroidal vascularity index (CVI) were used to compare the structural characteristics of the affected eyes with fellow and control eyes. The CT measurements were performed from the subfoveal and locations at 750 µm and 3000 µm intervals from the foveal center, and the average of CT measurements at 5 locations was accepted as mean CT. RESULTS: The demographic and clinical characteristics among the groups were similar (for all, P > 0.05). Mean peripapillary RNFL thickness of the inferior quarter was significantly lower in affected eyes, compared to fellow eyes (P = 0.023) and control eyes (P = 0.040). Mean GCC thickness significantly decreased in affected eyes, compared to fellow eyes (P = 0.019) and healthy controls (P = 0.008). Mean CT thickness significantly decreased in affected eyes, compared to fellow eyes (P = 0.002) and healthy controls (P < 0.001). Mean subfoveal CVI (65.94% ± 1.46) was found to be significantly thinner than the unaffected fellow (68.19% ± 1.84, P = 0.011) eyes and control eyes (67.23% ± 0.84, P = 0.044). CONCLUSIONS: This study's outcomes show that long-standing HFS is associated with glaucoma-associated morphological OCT findings and decreased both CT and subfoveal choroidal vascularity. These findings may be related to the fact that the posterior ocular structures are affected by long-lasting paroxysmal orbicularis contractions.

Roles of preoperative anxiety and depression in the outcomes of microvascular decompression in hemifacial spasm for adolescent patients.

ABSTRACT: Hemifacial spasm (HFS) has been recognized as the frequently occurring disease of cranial nerve. At the same time, several articles indicate that, dystonia results in certain psychological disorders. Consequently, this study aimed to examine the association of preoperative depression and anxiety with HFS severity; meanwhile, the role in microvascular decompression (MVD) outcomes after surgery among adolescent patients was also examined.All cases had been classified as two groups based on MVD outcomes among HFS cases; in addition, the preoperative Hamilton anxiety rating scale (HARS) and the Hamilton depression rating scale (HDRS) scores were compared between patients not and still suffering from spasm. Moreover, the multiple logistic regression model was employed in assessing the relationship between preoperative HARS as well as HDRS scores and outcomes of adolescent cases undergoing MVD.The preoperative HARS and HDRS scores showed positive correlation with Cohen spasm grades in HFS patients. Meanwhile, compared with spasm-free group, patients of persistent spams group had apparently higher preoperative HARS and HDRS scores.Our results suggest that, preoperative anxiety and depression status show close association with HFS severity, and they could also impact the MVD outcomes for adolescent cases.

Lateral spread response of different facial muscles during microvascular decompression in hemifacial spasm.

OBJECTIVE: Interpreting lateral spread response (LSR) during microvascular decompression (MVD) for hemifacial spasm (HFS) is difficult when LSRs observed in different muscles do not match. We aimed to analyze LSR patterns recorded in both the orbicularis oris (oris) and mentalis muscles and their relationships with clinical outcomes. METHODS: The data of 1288 HFS patients who underwent MVD between 2015 and 2018 were retrospectively reviewed. LSR was recorded in the oris and mentalis muscles through centrifugal stimulation of the temporal branch of the facial nerve after preoperative mapping. The disappearance of LSR following surgery, clinical outcomes, and the characteristics of LSR in oris were analyzed. RESULTS: After surgery, LSR remained in 100 (7.7%) and 279 (21.6%) of the mentalis and oris muscles, respectively. The postoperative outcome correlated with LSR disappearance in the mentalis, not with that in the oris. CONCLUSION: LSR patterns differed in each muscle and may not be correlated with clinical outcomes. LSR in the mentalis and oris muscles should be interpreted differently. SIGNIFICANCE: We describe a monitoring protocol characterized by preoperative facial nerve mapping, antidromic stimulation, and recording from multiple muscles. We analyze differences in LSRs in the mentalis and oris muscles and suggest technical points for interpretation.

Culprit vascular patterns and surgical outcomes of hemifacial spasm caused by an AICA segment passing between cranial nerve VII and VIII: A series of 25 cases.

OBJECTIVE: To report the vascular anatomic characteristics and surgical outcomes of hemifacial spasm (HFS) caused by an anterior inferior cerebellar artery (AICA) segment passing between cranial nerve VII (CN VII) and cranial nerve VIII (CN VIII). PATIENTS AND METHODS: This case series study retrospectively reviewed records of 1040 consecutive patients treated with MVD for HFS in our hospital in 10 years. 25 patients had the culprit vessel recorded as an AICA segment passing between CN VII and CN VIII. Vascular anatomic characteristics were reviewed from intraoperative microscopic videos. The clinical outcomes were followed up at 3-month and 1-year time points. RESULTS: The culprit AICA segments feature 3 discrete anatomic patterns. The patterns denoted as pattern A, B, and C were identified in 19(76%), 3(12%), and 3 (12%) of the 25 patients respectively. Postoperative spasm relief were achieved in 19(76%), 22(88%), and 23 (92%) of the patients at immediately after surgery, 3-month, and 1-year follow-up respectively. 3(12%) of them have permanent postoperative cranial nerve deficits, including one patient with hearing loss and 2 patients with vocal cord palsy. CONCLUSIONS: Though an AICA segment passing between CN VII and CN VIII is common, very rarely it was deemed the culprit for HFS in our patients. We used fREZ centered definition and operation. We found the culprit AICA segments feature 3 discrete anatomic patterns. We observed good spasm relief outcome and relatively fewer complications with CN VII and CN VIII. Identifying the 3 anatomic patterns may help with a smooth decision-making when vascular compression by an AICA segment passing between CN VII and CN VIII is suspected.

Microvascular decompression for hemifacial spasm involving the vertebral artery: A modified effective technique using a gelatin sponge with a FuAiLe medical adhesive.

Microvascular Decompression for Hemifacial Spasm Involving the Vertebral Artery (VA): A Modified Effective Technique Using a Gelatin Sponge with a FuAiLe Medical Adhesive. (a)The VA pushes the anterior inferior cerebellar artery (AICA) which compressed the root exit zone (REZ) of the facial nerve. (b) The VA was adhered to the petrous dura, and the AICA was decompressed from the REZ by a Teflon pad.

The Five-Year Prospective Study of Quality of Life in Hemifacial Spasm Treated with Abo-Botulinum Toxin A.

This study aimed to determine the long-term quality of life (QoL) in hemifacial spasm (HFS) patients after treating with Abo-botulinum toxin A (Abo-BTX). The study assessed the disease-specific QoL (hemifacial spasm questionnaire 30 items; HFS 30), the involuntary movements (abnormal involuntary movement scale; AIMS), general health QoL (Medical Outcomes 36-Item Short Form Health Survey; SF-36), and Depression (the Center of Epidemiologic Studies-Depression questionnaire; CES-D). A total of 74 HFS patients were enrolled from 2012 to 2017. The disease-specific QoL; involuntary movements; and the general health domain of SF 36 were significantly improved after injections of Abo-BTX A in the first few years (p < 0.04), but significantly decreased at the fifth year of treatment without significant clinical resistance observed (p < 0.001). Only the general health domain of SF 36 showed persistent improvement over five years (p = 0.02). In summary, Abo-BTX A can improved quality of life in the first few years; however only the general health domain of SF-36 showed significant improvement over five years (p = 0.02). No clinical resistance was observed.

Hemifacial spasm caused by a tortuous recurrent perforating artery: A case report.

INTRODUCTION: When the culprit vessel in hemifacial spasm (HFS) is hard to determine, this is a challenge in microvascular decompression (MVD) surgery. In such a situation, small arteries such as perforators to the brainstem might be suspected. But small arteries are omnipresent near the facial nerve root exit/entry zone (fREZ). How to decide whether a given small artery is responsible for HFS is unclear. METHOD: We report a case with a previously unreported form of neurovascular impingement, in which the culprit was found to be the recurrent perforating artery (RPA) from the anterior inferior cerebellar artery (AICA). An aberrant anatomic configuration of the RPA was found intraoperatively, which we thought was responsible for generating focal pressure on the facial nerve. CASE REPORT: A 62-year-old woman presented with a 1-year history of paroxysmal but increasingly frequent twitching in her right face. MRI showed tortuosity of the vertebral artery and apparently marked neurovascular impingement on the asymptomatic left side, while only the right AICA could be implicated as the possible culprit. Hemifacial spasm was diagnosed based on the typical clinical manifestation, and MVD was performed. The pre-meatal segment of the AICA was found not to be impinging the facial nerve at any susceptible portion near the fREZ: root exit point, attached segment, or root detachment point. The real culprit was in fact the RPA. This occult culprit vessel was tortuous, forming a coil-shaped twist which was interposed between the facial nerve and the intermediate nerve near the root detachment point. Focal pressure atrophy of the nerve was clearly observed at the compressing site. The patient achieved total spasm relief immediately after surgery, and remained spasm-free at 1-year follow-up, without any postoperative complications. CONCLUSION: MVD is the only curative treatment for hemifacial spasm, but with a failure rate of around 10%. Mistaking the real culprit has been reported to be the most likely reason for surgical failure. Therefore, intraoperative identification of atypical occult forms of vascular compression is of importance to improve surgical outcome. In the present case, the RPA formed a coil-shaped twist, which inflicted focal vascular compression causing hemifacial spasm. We recommend careful inspection of the recurrent perforating artery during MVD for HFS, and decompressing any such neurovascular impingement.

Is the pre-operative lateral spread response on facial electromyography a valid diagnostic tool for hemifacial spasm?

The lateral spread response (LSR) on preoperative facial electromyogram (EMG) is a useful tool in evaluating patients with hemifacial spasm (HFS). There may be some instances where the LSR does not appear on the preoperative EMG, thus disrupting the diagnosis and treatment of HFS. In this study, we evaluated the patients who did not exhibit LSR on preoperative EMG but underwent microvascular decompression (MVD) for hemifacial spasm. We searched for patients who underwent MVD for HFS but had an absence of LSR on preoperative EMG between January 2016 and June 2018. Surgical outcomes were evaluated at 1, 3, and 6 months after surgery. Follow-up facial EMG was performed 3 months after surgery. Results were divided into two categories: (1) spasm relief within 24 h of surgery and (2) spasm was observed immediately post-operation. The following parameters were analyzed when comparing between the two groups: age, sex, affected side, duration of symptoms, and offending vessel(s). A total of 306 patients underwent MVD for HFS during the study period. Among them, 13 (4.2%) patients had no LSR on preoperative EMG. Eight patients (61.5%) were female and five patients were male. The 13 patients had a mean age of 51 years. All patients exhibited probable offending vessels in the root exit zone (REZ) of the facial nerve on preoperative magnetic resonance (MR) imaging that was confirmed during surgery. Seven patients were free of HFS immediately after surgery, though six patients were not. Only one (7.7%) patient had persisted symptom 6 months after surgery. No patients experienced recurrence of spasm, nor exhibited abnormal waves on follow-up facial EMG. LSR on facial EMG is a valuable tool for evaluating hemifacial spasm. However, although LSR did not appear on preoperative EMG, if the patient presents with typical symptoms and the offending vessels are identified on MRI, we expect good results after MVD for HFS.