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.

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%.

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.

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.

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

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.

Short-term versus long-term outcomes of microvascular decompression for hemifacial spasm

BACKGROUND

Microvascular decompression (MVD) is a useful treatment for hemifacial spasm (HFS), but the postoperative course is extremely diverse. The purpose of this study was to compare short- and long-term outcomes, find the earliest optimal time for determining the long-term outcomes, and investigate the prognostic factors involved in the outcomes over time.

METHODS

From July 2004 to January 2015, 1341 patients who underwent MVD for HFS were enrolled. Information on clinical features, operative findings, and surgical outcomes over time were collected by performing a review of electronic medical records, and their relationships were analyzed. The outcomes of MVD at 1, 3, 6, and 9 months were individually compared against those at > 12 months after surgery.

RESULTS

The mean follow-up period after surgery was 44.9 months (median, 36.8 months; range, 12.0-156.6 months). The overall improvement rate for the 1341 patients was 89.0%. Individual postoperative outcomes at 6 and 9 months showed no differences with those at > 12 months after surgery. Furthermore, in the uni- and multi-variable analyses, patients in whom the offending vessels were intraoperatively determined to be veins showed bad outcomes at 6, 9, and > 12 months (p = 0.048, p = 0.004, and p = 0.003, respectively). Patients with intraoperative indentation on the facial nerve showed good outcomes at 6, 9, and > 12 months (p = 0.005, p = 0.039, and p = 0.020, respectively). Patients with delayed facial palsy after surgery showed better outcomes at 6, 9, and > 12 months (p = 0.002, p = 0.003, and p = 0.028, respectively).

CONCLUSIONS

Short- and long-term outcomes of MVD in patients with HFS manifested differently, but the outcomes at 6 and 9 months showed similarities with those at > 12 months. In patients in whom the intraoperatively detected offending vessel was not a vein, and in patients with intraoperative indentation on the facial nerve and postoperative delayed facial palsy, good outcomes could be predicted after 6 months of surgery.

Facial motor evoked potential with paired transcranial magnetic stimulation: prognostic value following microvascular decompression for hemifacial spasm

OBJECTIVE

Microvascular decompression (MVD) is widely considered the treatment of choice for hemifacial spasm (HFS), but not all patients immediately benefit from it. Numerous electrophysiological tests have been employed to monitor the integrity of the facial nerve prior to, during, and after MVD treatment. The authors sought to verify if facial motor evoked potential (FMEP) with paired transcranial magnetic stimulation (pTMS) can be utilized as a tool to predict prognosis following MVD for HFS.

METHODS

FMEP using pTMS was performed preoperatively and postoperatively for 527 HFS patients who underwent an MVD treatment. Various interstimuli intervals (ISIs), which included 2, 10, 20, 25, 30, 75, and 100 msec, were applied for each paired stimulation and pTMS(%) was obtained. A graph of pTMS(%) versus each ISI was drawn for every patient and its pattern was analyzed in accordance with patients' clinical outcomes.

RESULTS

With ISIs of 75 and 100 msec, pTMS(%) was physiologically further inhibited, whereas it was relatively facilitated under ISIs of 20, 25, and 30 msec; loss of this specific pattern, that is, further inhibition-relative facilitation, indicated impaired integrity of the facial nerve. Those patients who immediately benefited from an MVD and experienced no relapse tended to show proper restoration of this further inhibition-relative facilitation pattern (p = 0.01). Greater resemblance between the physiological pattern of pTMS(%) and postoperative pTMS(%) was correlated to better outcome (p = 0.019).

CONCLUSIONS

A simple linear graph of pTMS(%) versus each ISI may be a helpful tool to predict prognosis for HFS following an MVD.

Evaluation of the Edrophonium Challenge Test for Cervical Dystonia

Objective To examine whether or not an edrophonium challenge test is useful for diagnosing cervical dystonia. Patients We evaluated 10 patients with cervical dystonia and 10 with hemifacial spasms (disease controls). We administered edrophonium and saline in this double-blinded study. Before and after the injection, we recorded the participants' clinical signs using a video camera to assess the objective symptoms every two minutes. Ten minutes after the saline and edrophonium injections, participants evaluated their subjective clinical signs using a visual analog scale. The objective signs on the video recordings were scored by specialists who were blinded to the treatment. The mean visual analog scale scores were compared using the Wilcoxon rank-sum test for paired continuous variables. Results The clinical signs of participants with cervical dystonia were amplified by edrophonium. In contrast, the clinical signs in participants with hemifacial spasms were not affected by the edrophonium challenge test. Conclusion The edrophonium challenge test may be useful for diagnosing cervical dystonia.

Vagoglossopharyngeal Neuralgia Occurred Concomitantly with Ipsilateral Hemifacial Spasm and Versive Seizure-Like Movement: A First Case Report

Vagoglossopharyngeal neuralgia (VGPN) is a very rare condition. VGPN with convulsive like attack is even rarer All of the cases had their head turned to the opposite side of facial pain. Hemifacial spasm occurring concurrently with VGPN has never been reported. Herein, we present the first case of VGPN that had ipsilateral hemifacial spasm and versive seizure-like movement to the same side of facial pain. We reported a 71-year-old man presenting with multiple episodes of intermittent sharp shooting pain arising on the right middle neck, followed by hemifacial spasm on right face. Then the patient became syncope while his head and gaze turned to the same side of the painful neck. Electrocardiography showed sinus arrest. Interictal Electroencephalography was normal. This patient initially responded to pregabalin for two weeks, then the symptoms became worse. Microvascular decompression and carbamazepine resulted in the complete remission of all symptoms after six months of follow-up. We could not explain the pathophysiology of unilateral versive seizure like movement.

Efficiency of ultrasound and water capsule-guided local injection of botulinum toxin type A treatment on patients with facial spasm

OBJECTIVE

To study the efficacy of ultrasound and water capsule-guided local injection of botulinum toxin type A (BTX-A) treatment on patients with facial spasm.

PATIENTS AND METHODS

One hundred and fifty-seven cases of facial spasm were randomly divided into oral drug treatment group (group A) (78 cases) and ultrasound and water capsule-guided local injection of botulinum toxin type A treatment group (group B) (79 cases). Cohen, Acbert spasm strength grade scores in each case with facial spasm were recorded. Therapeutic effect, duration, significant efficiency, and muscle spasm strength were compared before and three after treatment.

RESULTS

The muscle spasm strength showed no significant change in group A after the treatment. However, the muscle spasm strength was decreased significantly in group B after treatment (p < 0.01).

CONCLUSIONS

Ultrasound and water capsule-guided local injection of botulinum toxin type A treatment is a safe, effective, and simple treatment for patients with facial spasm.

Clinical features and treatment status of hemifacial spasm in China

BACKGROUND

Hemifacial spasm (HFS) is a facial nerve disorder characterized by episodic involuntary ipsilateral facial muscle contraction. Information on Chinese patients with HFS has not been well-characterized. This study aimed to evaluate the clinical feature and the treatment status of HFS across China.

METHODS

A cross-sectional study including 1003 primary HFS patients had been carried out in 15 movement disorder clinics in China in 2012. The investigated information was acquired from questionnaires and medical records including demographic data, site of onset, aggravating and relieving factors, treatments prior to the investigation, etc.

RESULTS

In this study, the ratio of male to female was 1.0:1.8, the mean age at onset was (46.6 ± 11.5) years. About 1.0% patients were bilaterally affected. The most often site of initial onset was the orbicularis oculi muscle. The most often affected sites were orbicularis oculi, zygomatic, and orbicularis oris muscles. Stress/anxiety and relaxation were most often aggravating and relieving factors, respectively; 2.3% patients had family history, 28.4% cases were combined with hypertension, and 1.4% patients were with trigeminal neuralgia. Botulinum toxin type A (BTX-A) injection was the most commonly used treatment, followed by acupuncture and oral medication. BTX-A maintained the highest repeat treatment ratio (68.7%), while 98.4% patients gave up acupuncture. The mean latency of BTX-A effect was (5.0 ± 4.7) days, the mean total duration of the effect was (19.5 ± 11.7) weeks, and 95.9% patients developed improvements no worse than moderate in both severity and function. The most common side effect was droopy mouth.

CONCLUSIONS

The onset age of HFS in China is earlier than that in western countries. The most often used two treatments are BTX-A injection and acupuncture, while the latter kept the poor repeat treatment ratio because of dissatisfactory therapeutic effect.

[Facial tics and spasms]

Facial tics and spasms are socially incapacitating, but effective treatment is often available. The clinical picture is sufficient for distinguishing between the different diseases that cause this affliction.We describe three cases of patients with facial tics or spasms: one case of tics, which are familiar to many physicians; one case of blepharospasms; and one case of hemifacial spasms. We discuss the differential diagnosis and the treatment possibilities for facial tics and spasms. Early diagnosis and treatment is important, because of the associated social incapacitation. Botulin toxin should be considered as a treatment option for facial tics and a curative neurosurgical intervention should be considered for hemifacial spasms.

Hemifacial spasm caused by the cross-compression of the vertebral artery loop--a case-centered report of a stitched sling retraction technique

Hemifacial spasm (HFS) is one of the neurovascular compression syndromes caused by the compression of the facial nerve outgoing from the brainstem by an artery, a vein or both. The treatment of choice of this disorder is a microvascular decompression (MVD). As initially described, MVD is a technique based on the application of the small prostheses that are placed between a cranial nerve and an imposing vessel. Neurovascular compression syndromes have relatively high rate of incidence. Therefore, many modifications of surgical technique have been described in order to minimize the risk of complications and increase the effectiveness and permanence of the vascular transposition as the success of the MVD most of all depends on the latter. The authors of this paper describe one of the aforementioned modifications that provides a complete and permanent vascular transposition together with its advantages and limitations in the treatment of the hemifacial spasm. Moreover, many aspects of different technical approaches are widely discussed and a case-centered stitched sling retraction technique is presented.

Hemifacial spasm leading to diagnosis of Moyamoya disease

We present a case of Moyamoya disease presenting as hemifacial spasm due to compression of the facial nerve by a vascular loop related to compensatory enlargement of the posterior circulation vessels.

[Hemifacial spasm caused by a dissecting aneurysm of the vertebral artery, and resulting in acute exacerbation]

The authors report a rare case of a symptomatic hemifacial spasm caused by a dissecting vertebral artery aneurysm and by an anterior inferior cerebellar artery(AICA). A 54-year-old man presented with left hemifacial spasm persisting for 5 years, and the spasm had undergone acute aggravation. Brain magnetic resonance imaging and digital subtraction angiography showed a vertebral artery dissecting aneurysm and an AICA compressing the root exit zone of the left facial nerve. Microvascular decompression of the facial nerve with proximal clipping of the vertebral artery dissecting aneurysm was successfully performed. The hemifacial spasm disappeared immediately after the surgery.

Assessment of non-motor hearing symptoms in hemifacial spasm using magnetoencephalography

BACKGROUND

Hemifacial spasm patients often suffer from non-motor symptoms such as tinnitus. These non-motor symptoms are known to be associated with changes in cortical activity. Magnetoencephalography (MEG) is a technique that can record brain activity noninvasively. To determine the usefulness of MEG in assessing changes in cortical activity associated with non-motor hearing symptoms in hemifacial spasm patients.

METHODS

We used MEG to evaluate the reactivity of the auditory cortex in 26 hemifacial spasm patients. We divided patients into a subjective tinnitus group (n = 10) and a non-tinnitus group (n = 16). The latency and amplitude of the most prominent deflection, N100m, was compared between the two groups.

RESULTS

There was a significant difference in the pure tone audiogram on the spasm side compared with the non-spasm side. After stimulation on the spasm side, the amplitude of the N100m peak in the contralateral hemisphere was lower in the subjective tinnitus group than in the non-tinnitus group.

CONCLUSIONS

Our results indicate that MEG can detect differences in cortical activity between hemifacial spasm patients with and without tinnitus. This suggests that MEG can identify changes in cortical activity associated with non-motor symptoms.

[Endoscopic assistance in microvascular decompression of cranial nerves]

Microvascular decompression (MVD) is an effective method for treatment of trigeminal neuralgia (TN), hemifacial spasm (HFS), glossopharyngeal neuralgia (GPN). The aim of this study was to assess the role of endoscopic assistance in MVD for the treatment of cranial neuropathies. Since 2009 till 2011 133 patients with cranial neuropathies were treated by MVD in Burdenko Neurosurgical Institute, Moscow. In 22 patients (11 patients with HFS, 10 patients with TN, 1 with GPN) endoscopic assistance was applied during the MVD. We used minimally invasive retrosigmoid approach in a unilateral position. Cerebellopontine angle was explored by 30-degree or 70-degree telescope to visualize the root entry zone of trigeminal, facial or glossopharyngeal nerves and to locate the neurovascular conflict. In 9 patients with HFS and in 1 patient with TN and in another patient with GPN endoscopy discovered offending vessels that were not visible through the microscope. In all cases endoscope was used to exclude another site of compression and to verify decompression and to identify position of teflon and offending vessel after MVD. Immediately after the surgery excellent outcome was observed in 10 patients with HFS (89%), one patient was reoperated 1.5 years after first operation with positive effect. Relief of pain in early postoperative period was observed in patients with TN and GPN. There were no major complications and postoperative mortality in our series. Endoscopic assistance is very effective and helpful technique in MVD of cranial nerves, especially in cases with HFS. In this study the use of the endoscope allowed to identify the site of compression and to confirm the position of teflon after MVD.

Prognostic value of intra-operative abnormal muscle response monitoring during microvascular decompression for long-term outcome of hemifacial spasm

The reliability of intra-operative abnormal muscle response (AMR) monitoring as an indicator of post-operative outcome in patients with hemifacial spasm (HFS) is under debate. The primary aim of this study was to evaluate the correlation between intra-operative AMR changes and long-term post-operative outcome. We monitored intra-operative AMR during microvascular decompression (MVD) in consecutive patients with HFS (n = 104). Patients in this study were divided into two groups based on whether their AMR disappeared or persisted following MVD. Ninety patients were followed-up, and the mean duration from surgery to final follow-up examination was 3.7 years. Fourteen patients were lost to follow-up. AMR disappeared during surgery for 80 patients; of these, 74 achieved complete resolution of HFS, five had persistent HFS, and one patient developed a recurrence of HFS. Of the 10 patients with persistent AMR despite effective MVD, eight patients achieved complete resolution, one patient had persistent HFS, and one developed recurrent HFS. The long-term clinical outcome of HFS after MVD did not significantly correlate with intra-operative AMR changes (p = 0.791). Therefore, we suggest that intra-operative AMR monitoring may not be a reliable indicator of long-term post-operative outcome for HFS.

[Vascular compression syndromes of the cranial nerves]

The blood vessels which are running nearby the cranial nerves and the brainstem can be elongated; curves and loops of the vessels may develop mostly due to the degenerative alterations of ageing and these vessels can compress the surrounding neural elements. The authors report a review of vascular compression syndromes based on the literature and their own experience. The typical clinical symptoms of the syndromes subserving the proper diagnosis, the pathomechanism, the significance of imaging especially the magnetic resonance angiography, the experience with the surgical technique of microvascular decompression which is the only causal treatment of the syndromes are discussed. In cases of non-responsible medical treatment the microvascular decompression should be the eligible treatment in certain syndromes (trigeminal and glossopharyngeal neuralgia, hemifacial spasm) for it is a highly effective and low risk method.

Hemifacial spasm

Hemifacial spasm (HFS) is a peripherally induced movement disorder causing clonic or tonic contractions of the facial muscles. HFS is usually unilateral and sporadic. It may be primary (mainly attributed to vascular compressions of the seventh cranial nerve in the posterior fossa) or secondary to facial nerve or brainstem damage. The two forms share a number of features but may differ in clinical presentation (simultaneous involvement of the upper and lower facial muscles in secondary forms). The spasm-related electromyogram activity is probably generated by ephaptic transmission, due to local demyelination at the entry zone of the facial nerve root (possibly owing to nerve damage caused by a compressing cerebral vessel). These findings suggest the "nerve origin hypothesis" as the main pathophysiological mechanism underlying HFS. Medical treatment (anticonvulsants or GABAergic drugs) is generally ineffective. Microvascular decompression of the facial nerve can achieve marked improvements in the majority of patients, although recurrences and complications are not uncommon. Local (orbicularis oculi or lower facial muscles) injection of Botulinum toxin (BoNT) is therefore considered the preferred symptomatic treatment for primary HFS. The long-term efficacy and safety of BoNT have been documented by clinical studies.

Hemifacial spasm, glossodynia, and dolichoectasia of the basilar artery

The case of a 77-year-old hypertensive man presenting with hemifacial spasm and glossodynia is reported. Imaging studies revealed gross dolichoectasia of the vertebrobasilar arterial system with pontine compression. It is suggested that the neurologic symptoms most likely resulted from pontine compression, rather than from any compression of the cranial nerves.

[Study of neurovascular contact in essential hemifacial spasm: an example of CISS sequence and magnetic resonance angiography]

BACKGROUND AND PURPOSE

The purpose of this article is to assess the validity of the magnetic resonance imaging (MRI) CISS 3D sequence associated with 3D time of flight (TOF) angiographic sequence in order to detect neurovascular contact (NVC) between the facial nerve and neighbouring arteries in patients with essential hemifacial spasm (HFS) and to determine the relationship between HFS symptoms and NVC and NVC image features (type, number and site).

MATERIALS AND METHODS

We prospectively enrolled 120 cerebellopontine angle (CPA) MRI studies, 44 cases with HFS symptoms and 76 which were asymptomatic (controls), using axial T2-weighted (CISS) and axial 3D TOF series with associated Maximal intensity (MIP) reconstructions. Prior TOF angiographic studies were available for 56 cases without associated CISS images and the results obtained from that study were compared with the results of the current study.

RESULTS

The diagnostic values obtained significantly favoured the protocol used in this study, which demonstrated a sensitivity of 77.27% and a specificity of 75%. There was a statistically significant relationship between the presence of NVC and HFS symptoms (p<0.0001). Only one statistically significant relationship was found between facial nerve displacement (in type of NVC) and HFS symptoms (p=0.019).

CONCLUSIONS

The proposed MRI protocol is sensitive and valid for detecting NVC in patients with HFS. The results of our study support a relationship between NVC and HFS symptoms. It is not a simple relationship, however. It may be influenced by other factors, such as displacement of the facial nerve due to NVC.

Hemifacial spasm associated with focal bone hyperostosis

We present a very rare case of hemifacial spasm in a 58-year-old patient who was predisposed by focal temporal bone hyperostosis. The patient presented with a 6-year history of progressive left hemifacial spasm, unresponding to the conservative treatment. She underwent a typical microvasular decompression procedure, during which an unusual local hyperostosis of the interior surface of the left temporal bone was found, distorting the adjacent AICA and causing significant pressure on the facial nerve. The postoperative course was uneventful and in the 24-month follow up, the patient is spasm free.

Retroclival arachnoid cyst with hemifacial spasm

Arachnoid cysts are rare lesions occurring anywhere in the cerebrospinal axis. The sylvian fissure remains the most favoured site for their occurrence, followed by cerebellopontine angle, suprasellar, and quadrigeminal cisterns. Retroclival arachnoid cysts are very rare. We report a retroclival arachnoid cyst with bilateral cerebellopontine angle extensions with hemifacial spasm in a 26-year-old woman. The patient underwent surgery and her hemifacial spasm improved.

[The utility of presurgical simulation of microvascular decompression by MR virtual endoscopy]

OBJECTIVE

We conducted the present study to assess the utility of virtual endoscopy (VE) created by volume rendering of MR images in presurgical simulation for trigeminal neuralgia (TN) and hemifacial spasm (HFS).

METHODS

In 12 patients (six with TN and six with HFS), we presurgically evaluated the anatomy of the cerebellopontine angle (CPA) region and simulated an appropriate surgical approach by VE of heavy T2-weighted imaging and MR angiography.

RESULTS

The three-dimensional (3-D) relations of neurovascular structures in the CPA region were compatible between on-VE and on-the-intraoperative view in all patients. The compression sites and the major offending vessels were correctly depicted, except for two small branches as the offending vessel. The other important structures affecting the surgical procedure were identified as major petrosal veins in all patients with TN, a vertebral artery in three with HFS, and a large cerebellar flocculus in three with HFS. Transposition of the offending vessels was performed as simulated in all patients with TN and in three patients with HFS. All patients had an excellent surgical outcome.

CONCLUSIONS

Presurgical simulation by VE in patients with TN and HFS is a novel method that provides excellent visualization of the 3-D relations of neurovascular structures in the CPA region and allows us to accomplish successful and safe surgery.

Electrodiagnostic studies of the facial nerve in peripheral facial palsy and hemifacial spasm

Electrodiagnostic (EDX) assessment is one of the most important aspects in the evaluation of the two most common disorders of the facial nerve: facial palsy and hemifacial spasm. Facial palsy is usually an acute disorder that resolves in a few weeks but, in a number of cases, leads to a postparalytic facial syndrome featuring muscle synkinesis, myokymia, and involuntary mass contractions of muscles on the affected side. Hemifacial spasm is usually a chronic disorder characterized by paroxysms of involuntary, clonic, and synchronous twitching of all facial muscles on the affected side. EDX studies provide information on lesion location and severity, pathophysiology underlying the two disorders, and differential diagnosis between syndromes presenting with abnormal facial muscle activity. This monograph is intended to describe the most relevant EDX findings in the two disorders and the most appropriate timing for the examinations in order to provide useful information for prognosis and therapeutic decision-making.

Hemifacial seizures and cerebellar tumor: a rare co-existence

We report a 4-year-old boy with multiple daily episodes of abnormal eye movements, hemifacial spasms. Neuro-imaging revealed a cerebellar tumor. We believe that this association constitutes a rare but important syndrome of epilepsy characterized by seizures of cerebellar origin.

Asynchronous blepharospasm, facial and cervical dystonia, and bilateral asynchronous hemifacial spasm

We present a patient with a facial movement disorder that has characteristics of both blepharospasm and bilateral asynchronous hemifacial spasm. Because of the increased incidence of blepharospasm in patients with hemifacial spasm, our patient's clinical presentation is probably not a chance occurrence, but rather a manifestation of some predisposition for these two movement disorders. This unusual constellation of signs and symptoms challenges the current diagnostic criteria and suggests that some of these facial movement disorders may lie on a spectrum, rather than represent distinct entities.

Fusion imaging of three-dimensional magnetic resonance cisternograms and angiograms for the assessment of microvascular decompression in patients with hemifacial spasms

Object

The precise preoperative assessment of the complex nerve–vessel relationship at the root exit zone (RExZ) of the facial nerve is important when planning microvascular decompression (MVD) in patients with hemifacial spasms. The authors have developed an imaging technique—the fusion of 3D magnetic resonance (MR) cisternography and coregistered 3D MR angiography images—that allows clear visualization of the spatial relationship between the vessels and the rootlet of the facial nerve at the brainstem.

Methods

The authors reconstructed 3D MR cisternograms and 3D MR angiograms by using a perspective volume-rendering algorithm that they applied to the volumetric data sets of the following modalities: MR cisternography (a T2-weighted 3D fast spin echo sequence) and coregistered MR angiography (a 3D time-of-flight sequence). The complex anatomical relationship between the offending vessels and the facial nerve RExZ was inspected preoperatively by examining the fusion images from various perspectives within the cerebellopontine angle cistern, within the affected facial nerve, and through the simulated surgical route. The reconstructed 3D findings of the nerve–vessel relationship were compared with the intraoperative findings. Postoperatively, the fused 3D MR imaging technique was used to confirm that microsurgical dissection and the interposed prosthesis had succeeded in maintaining the causative vessels in a position away from the RExZ.

Conclusions

The fusion of 3D MR cisternograms and 3D MR angiograms may prove useful in the pre- and postoperative assessment of MVD in patients with hemifacial spasm.

[Pathology of the cerebellopontine angle]

The pathology of the cistern of the cerebellopontine angle is primarily that of the nervous and vascular structures that it contains and of the meninges that line it. Knowledge of its anatomy makes it possible to understand and search for a rare pathology, the hemifacial spasm, due to a conflict between the facial nerve and the vertebral artery and the posterior inferior cerbellerar artery. However, the pathology of the cerebellopontine angle remains especially tumoral. Imaging should not only make the diagnosis but also make an exhaustive, pretherapy, and accurate assessment of the three main tumours found in this area: the vestibular schwannoma, the meningioma, and the epidermoid cyst.

[Preoperative assessment of microvascular decompression for hemifacial spasm with fusion imaging of 3D MR cisternogram/angiogram]

The preoperative assessment of microvascular decompression (MVD) for hemifacial spasm has been performed with MRI, but assessment of the compressive status by 2D imaging has a number of limitations. We used a fusion image of the 3D MR cisternogram and co-registered 3D MR angiogram, reconstructed from MR cisternogram, obtained by 3D fast spin-echo sequence, and MR angiography, 3D time-of-flight and spoiled-gradient recalled sequences, for the preoperative assessment of the offending artery in 10 patients with hemifacial spasm. The anatomical relationship of the nerve-vessel complex was assessed on the simulated images, and compared with the intraoperative findings. The fusion image of the 3D MR cisternogram/angiogram depicted contours of the brain, nerves, and vessels clearly, and that allowed precise assessment of the pathogenic compression of the facial nerve by the offending vessels, comparative to the operative findings. The fusion imaging of the 3D MR cisternogram/angiogram may provide useful information in the surgical planning of MVD for hemifacial spasm.

Young onset hemifacial spasm

INTRODUCTION

Hemifacial spasm (HFS) frequently affects middle aged individuals and the clinical features and etiology have been well reported. However, there is limited data on the exact pathogenesis in young-onset HFS. If age is a major determinant of the etiology or influences the presentation of HFS, there may be clinical differences between the young and elderly HFS patients.

OBJECTIVES

We determined the prevalence, clinical and imaging features of young-onset HFS (age of onset<or=30 years) in a tertiary referral center. These data were compared with old onset (age of onset>or=65 years) HFS patients.

METHODS

We examined consecutive patients clinically diagnosed with HFS in a tertiary referral center. The clinical (demographics, clinical presentation, severity of HFS, associated medical conditions and other variables) and imaging findings of young onset patients and old onset patients were tabulated and compared.

RESULTS

Amongst 230 consecutive HFS patients, 15 (6.5%) were young-onset HFS and 50 (21.7%) were old-onset HFS. In the young-onset HFS, the mean age of onset of symptoms was 26.5+/-6.5 (6-30) years, with 80% women and 75.0% of young onset HFS having neurovascular compression (NVC) of the root exit zone (REZ) of the facial nerve on the ipsilateral side; 86.7% had initial onset of twitching in the upper eyelids that later progressed to the lower facial muscles. While the prevalence of hypertension, diabetes mellitus and other associated vascular disorders in late onset HFS was higher than in young onset groups, the clinical features and frequency of NVC of the facial REZ between the two groups were similar.

CONCLUSIONS

We demonstrated a 6.5% frequency of young-onset HFS in our cohort of HFS and their clinical presentation was similar to the old onset patients. Genetic, anatomic or other unidentified factors may contribute to NVC in young-onset HFS.

Reoperation for Persistent or Recurrent Hemifacial Spasm after Microvascular Decompression

OBJECTIVE:

The objective of this study was to investigate the outcome of reoperation for persistent or recurrent hemifacial spasm (HFS) after microvascular decompression (MVD).

METHODS:

Repeat MVD was performed on 13 patients with an HFS between June 1994 and May 2004. Patients who had compressing offending vessels identified on postoperative (prerevision) three-dimensional short-range magnetic resonance angiography were selected for repeat MVD.

RESULTS:

Six patients were found to have no improvement in HFS with the first MVD. All of these patients exhibited excellent improvement after the second MVD. In one patient who had mild improvement with the first MVD, but with more than 50% of remaining spasm, complete abolition of spasm occurred immediately after the second MVD. Six patients showed initial relief and subsequent aggravation of HFS after the first MVD. Of these patients, four had excellent results with the second MVD, one had a good result, and one had a fair outcome. Adverse effects after the second MVD were found in two patients (one patient with permanent mild facial weakness and one patient with hearing impairment). There was no serious morbidity associated with the second MVD.

CONCLUSION:

Our data suggest that repeat MVD of the facial nerve may be sufficient to resolve symptoms in selected patients with persistent or recurrent HFS. Additionally, three-dimensional short-range magnetic resonance angiography may help to identify the offending vessels and to select the patients with persistent or recurrent HFS.