Hemifacial spasm in vertebrobasilar dolichoectasia

Vascular compression of the facial nerve is a well recognized cause of hemifacial spasm (HFS). Magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) provide vascular and brain tissue diagnosis in a single non-invasive examination and should be recommended as primary neuroradiological procedure in HFS. We report a rare case of symptomatic HFS caused by a vertebrobasilar dolichoectasia. A 49-year-old women experienced left hemifacial spasm for 10 months. MRI showed an enlarged vertebrobasilar dolichoectasia of the left vertebral artery which compressed the seventh cranial nerve at its exit from the caude pons. MRI is essential in establishing the cause of HFS. Together with MR angiography it shows the correlation among the seventh cranial nerve, blood vessels and the structures of mid-brain. Vertebrobasilar delichoestasia is just one of the blood vessel anomalies which causes HFS and which can be shown by MRI. HFS caused by vertebrobasilar dolichoectasia is quite rare.     

Hemifacial spasm due to a tentorial paramedian meningioma: a case report

Abstract Hemifacial spasm (HFS) is a movement disorder characterised by involuntary paroxysmal facial movements that usually involve the orbicularis oculi and then spread to the other facial muscles. A microvascular compression and demyelination of the seventh nerve at its exit from the brain stem is considered to be the main aetiology of HFS. In addition to rare idiopathic (cryptogenetic) cases, others causes of HFS exist: tumours or vascular malformations have been described, of both the ipsilateral and contralateral cerebellopontine angle (CPA). However, space-occupying lesions in locations other than CPA are usually not thought to be responsible for HFS. Here we describe the case of a 45-year-old woman suffering from HFS, who dramatically improved after surgical removal of a tentorial paramedian meningioma.     

Hemifacial spasm as clinical presentation of intracranial meningiomas. Report of three cases and review of the literature

Hemifacial spasm (HFS) is a clinical entity consisting of brief clonic jerking movements of the facial musculature, beginning in the orbicularis oculi with downward spreading to other facial muscles. Apart from vascular loop compression at the root exit zone of the facial nerve, other causes of HFS are rare. It is exceptional as a form of presentation of intracranial meningiomas We report three cases of patients with meningiomas who presented with HFS, either as an isolated sign or associated with symptoms of rise intracranial pressure or focal deficit. We review the literature and discuss the possible physiopathological mechanisms responsible for this association.     

Unusual causes of hemifacial spasm

Hemifacial spasm (HFS) has been defined as consisting of brief clonic jerking movements of the facial musculature, beginning in the orbicularis oculi with downward spreading to other facial muscles. HFS, perhaps the most common of the abnormal involuntary facial movements, has been classically ascribed to vascular loop compression at the root exit zone of the facial nerve. Causes other than such vascular loops are rare in the medical literature. Here we present three case studies in which the phenomenology of the HFS was atypical in onset and evolution. Using these three patients as introduction to the topic, we reviewed the literature of all cases of HFS with causes other than the vascular loop. In these three cases, HFS was caused by (1) a parotid gland tumor, (2) a cerebellopontine angle meningioma, and (3) an acoustic schwannoma. We also discuss the radiological findings as well as possible differences in the genesis of HFS and phenomenology in such cases and present recommendations on how to evaluate these patients.     

Young onset Hemifacial Spasm in patients with Chiari type I malformation

Hemifacial spasm (HFS) resulting from Chiari type I malformation (CIM) is rare. We retrospectively evaluated five patients with CIM and HFS among a series of 103 subjects. The frequency of HFS associated to CIM was of 4.85%. The clinical profile did not differ from the classical primary cases except for young-onset development of facial spasms in patients with CIM. Three patients were treated with BTX-A injections with favorable outcome. Although rare HFS may be associated with CIM especially in young subjects with peculiar phenotypic characteristics (short neck). Moreover, BTX may be an alternative to posterior fossa decompression in selected cases.     

Bilateral hemifacial spasm: a series of 10 patients with literature review

Bilateral hemifacial spasm (HFS) is a rare movement disorder posing diagnostic doubt with other facial dyskinesias. In this report, we describe clinical, radiological and therapeutic features of 10 patients with bilateral HFS. The prevalence of bilateral HFS in our sample was of 2.6%. Clinical characteristics of our patients did not differ from the classic features of unilateral cases. The mean latency for contralateral facial nerve involvement was of 33.3 months. In only one case a vascular abnormality was seen. We conclude that bilateral HFS is rare and that clinical differentiation with other facial dyskinesias should be promptly made to introduce appropriate therapy.     

Clinico-radiologic correlation in unilateral and bilateral hemifacial spasm

INTRODUCTION: Bilateral hemifacial spasm (HFS) is rare. Clinico-radiologic correlates utilizing advanced imaging techniques have not been systematically examined in bilateral HFS. The prevalence of bilateral HFS in an Asian population has not been clarified. OBJECTIVES: We examined the prevalence and clinico-radiologic correlates of bilateral HFS in a clinic-based cohort and compared the clinical characteristics of unilateral HFS patients with and without contralateral neurovascular contact (NVC) in HFS. METHODS: Patients clinically diagnosed with HFS were examined for bilateral symptoms. Imaging analysis involved the utilization of reformatted, multi-planar three-dimensional time-of-flight magnetic resonance angiography (3D-TOF MRA), and constructive interference at steady state (CISS-MR) sequences. The clinical and imaging data was compared between HFS with and without NVC. RESULTS: Amongst 162 consecutive HFS patients, 2 (1.6%) had bilateral symptoms. Both patients had unilateral onset followed by bilateral and asynchronous facial contractions. The contralateral side of the face began to twitch at a mean of 1.5 years later. MRI/A revealed significant NVC of the root exit zone (REZ) of the facial nerve on the ipsilateral side with mild NVC contralaterally. The degree of NVC correlated with the clinical severity of the patients' symptoms. MRI/A analysis of 40 HFS patients with unilateral symptoms demonstrated NVC on the contralateral side in six patients (15%). The mean age and duration of symptoms were not different between HFS patients with and without contralateral NVC. CONCLUSIONS: We demonstrated clinico-radiologic correlation between the clinical severity and the degree of NVC at the REZ of the facial nerve in bilateral HFS. Amongst unilateral HFS, there was no significant difference clinically between those with and without contralateral NVC. The low 1.6% prevalence of bilateral HFS in our Asian cohort was compatible with the rare prevalence in other ethnic populations.     

Direct correlation between the facial nerve nucleus and hemifacial seizures associated with a gangliocytoma of the floor of the fourth ventricle: a case report

A dysplastic neuronal lesion of the floor of the fourth ventricle (DNFFV) causes hemifacial seizures (HFS) from early infancy. However, it is still controversial whether HFS is generated by the facial nerve nucleus or cerebellar cortex. In this study, we confirm a direct correlation between the rhythmic activities in the DNFFV and HFS using intraoperative electroencephalography (EEG) and electromyography (EMG) monitoring. Our results support the theory that a DNFFV provokes ipsilateral HFS via the facial nerve nucleus.     

Microvascular decompression for hemifacial spasm associated with the vertebral artery

The aim of this study was to discuss the baseline characteristics of hemifacial spasm (HFS) associated with the vertebral artery (VA) and evaluate microvascular decompression (MVD) as a surgical treatment of the associated HFS. From February 2010 to February 2015, 118 consecutive patients with HFS underwent MVD. Of these, 29 cases of HFS were associated with VA, this series was compared with the remaining non-VA-associated HFS. Of the 29 cases of VA-associated HFS, the VA was directly compressing the root exit zone (REZ) in eight cases. In the other 21 cases, the VA contacted REZ indirectly via its branches. The symptoms were completely relieved in 26 cases (89.7%) and partially relieved in another two cases (6.9%). Between the VA-associated group and non-VA-associated group, no statistically significant difference existed in the surgical results. VA-associated HFS is not a rare condition. For all cases of VA-associated HFS, indirect compression due to VA was more common. MVD for VA-associated HFS still can achieve good results.     

Behind the facial twitch: depressive symptoms in hemifacial spasm

BACKGROUND: Depression impairs psychosocial and occupational functioning and contributes to significant morbidity and mortality. Hemifacial spasm (HFS) causes social embarrassment and visual and verbal disability. OBJECTIVE: We examined; (1) the prevalence and predictive factors of depressive symptoms (Becks Depression Inventory (BDI) and clinical assessment) in HFS and (2) the sensitivity and specificity of BDI as a screening and diagnostic tool in HFS. METHODS: A large cohort of HFS patients in a movement disorders clinic was clinically evaluated and the BDI self-administered by patients. Univariate analysis and multivariate logistic regression were undertaken to investigate the effect of age, gender, body-mass index, duration and severity of HFS on the outcome of BDI score. ROC (receiver operating characteristics) analysis was utilized to evaluate the sensitivity and specificity and discriminative property of the scale. RESULTS: There were 90 HFS patients with a mean age of 54.4+11.1 (35-79) years, comprising of 58.9% women and with a mean severity HFS score of 2.9+0.8 (range 1-4). The mean BDI score was higher in depressed HFS than in non-depressed HFS (19.7+6.7 vs 4.2+4.9, p<0.0001). Female gender and a younger age were risk factors (p=0.07). In the multivariate analysis, the severity of HFS was an independent predictor of BDI scores (p<0.0001). The AUC was 97.1% suggesting excellent discriminative property of BDI. For cut-off score of 12/13, the sensitivity was 93.3%, specificity 94.7%, Positive Predictive Value 77.8% and Negative Predictive Value 98.6%. CONCLUSIONS: The prevalence of depressive disorder in HFS was 16.7%, with younger women at greater risk. The severity of HFS was positively correlated with the severity of depressive symptoms. The BDI can be a complimentary screening and/or diagnostic instrument for depressive disorder in HFS. Early diagnosis of at-risk patients will prevent unnecessary morbidity and mortality.     

Long-term depression and associativity in rat primary motor cortex following thalamic stimulation

Associativity is an attractive property of LTP in terms of its possible mechanism as a model for memory storage. In this study, we compare the effects of homosynaptic vs. associative stimulation on the induction of LTP and LTD in the neocortex of freely behaving rats. Using a callosal input to the motor cortex as a 'strong' input (one that potentiates reliably following homosynaptic stimulation), we paired activity of this pathway with a 'weak' thalamocortical pathway (one that does not potentiate when stimulated homosynaptically). Surprisingly, homosynaptic HFS caused a lasting depression of the field EPSP in the thalamocortical pathway. Analysis of this effect revealed that it was largely polysynaptic. Associative HFS (HFS applied to both pathways) not only failed to induce an LTP effect in the thalamocortical pathway, it increased the magnitude of the depression. Associative HFS did, however, facilitate LTP induction in the 'strong' callosal pathway. When comparing the effects of homosynaptic and associative LTD induction (HFS on one pathway anticorrelated with LFS on the other), we found that both protocols induced a similar magnitude of depression. These results show that HFS applied to the thalamocortical pathway causes a depression and this depression is enhanced, not reversed, by associative pairing with a strong input.     

双侧椎动脉相关面肌痉挛的手术疗效分析

目的 探讨双侧椎动脉（BVAs）相关面肌痉挛（HFS）的临床特征及显微血管减压术（MVD）的疗效。方法 回顾性分析2018年1~12月收治的首次行MVD治疗的362例HFS的临床资料。结果 362例中,BVAs相关HFS有16例。责任血管的分布:BVAs合并小脑前下动脉（AICA）有14例,BVAs合并小脑后下动脉（PICA）有1例,BVA合并AICA与PICA有1例。10例（62.5%）BVAs在后组颅神经水平向腹侧无移位空间,8例（50%）对侧椎动脉直径比同侧粗大。术后即刻治愈率为93.6%（15/16）,随访2年治愈率为87.5%（14/16）。结论 BVAs相关HFS临床较少见,往往联合AICA或PICA压迫面神经出脑干区,多表现为对侧椎动脉冗长扩张,且在后组颅神经处无移位空间。因血管类型复杂,可采用联合减压方法,疗效较好。术前影像学评估及熟练掌握神经血管解剖特点是手术成功的关键。     

Hemifacial Spasm: A Neurosurgical Perspective

Hemifacial spasm (HFS) is characterized by tonic clonic contractions of the muscles innervated by the ipsilateral facial nerve. Compression of the facial nerve by an ectatic vessel is widely recognized as the most common underlying etiology. HFS needs to be differentiated from other causes of facial spasms, such as facial tic, ocular myokymia, and blepharospasm. To understand the overall craniofacial abnormalities and to perform the optimal surgical procedures for HFS, we are to review the prevalence, pathophysiology, differential diagnosis, details of each treatment modality, usefulness of brainstem auditory evoked potentials monitoring, debates on the facial EMG, clinical course, and complications from the literature published from 1995 to the present time.     

3D-TOF磁共振血管成像诊断偏侧面肌痉挛的病因

目的　研究 3D TOF磁共振血管成像对偏侧面肌痉挛 (HFS)病因诊断的临床价值。方法　 3D TOF磁共振血管成像脑干薄层扫描 3 4例HFS患者和 3 5例对照 ,盲法诊断面神经根部解剖改变 ,两组对照分析。结果　 ( 1)HFS患者症状侧面神经根部受压迫 3 2侧 ( 94 % ) ,其中血管压迫 3 1侧( 91% ) ,肿瘤压迫 1侧 ( 3 % ) ;无症状侧受血管压迫 6侧 ( 18% ) ;对照组双侧受压迫 3侧 ( 4 % ) ,其中血管 2侧 ,肿瘤 1侧。 ( 2 )常见压迫血管分别为小脑前下动脉 11侧 ( 3 8% ) ,椎动脉单独或与小脑后下动脉联合 9侧 ( 2 9% ) ,小脑后下动脉 8侧 ( 2 5 % )。 ( 3 )面神经根部血管压迫发生HFS相对危险度的估计值为 3 7.2 8。 ( 4 )面肌痉挛侧面神经根部受血管压迫或包绕有 14侧 ( 4 5 % )。结论　研究提示 ,3D TOF磁共振血管成像为目前面肌痉挛病因诊断的最佳影像检查方法 ,HFS的主要病因为患侧面神经根部受血管压迫、包绕或与其紧密接触。     

The Effect of Microvascular Decompression for Hemifacial Spasm Caused by Vertebrobasilar Dolichoectasia

Objective

Hemifacial spasm (HFS) caused by vertebrobasilar dolichoectasia (VBD) is very rare, and in theses cases, it is difficult to decompress the nerve from its vascular compression. The objective of this study was to investigate the outcome of microvascular decompression (MVD) for HFS caused by VBD.

Methods

There were 10 patients of HFS caused by VBD at our hospital between September 1978 and September 2008. We evaluated magnetic resonance angiography (MRA) and time of flight magnetic resonance imaginge (TOF MRI) findings using the criteria for VBD. We compared the clinical outcomes of MVD for the 10 patients with VBD with the overall outcomes of the total 2058 MVDs performed for HFS.

Results

The results of MVD for HFS caused by VBD were successful in 90.9% of cases. The postoperative complication rate in VBD was 45.5%. Offending vessels in patients with VBD were identified visually during surgery. Adverse effects after MVD were found in 4 patients. We found that the diameter of VBD was significantly greater in patients with complications than in those with no complications (p=0.028).

Conclusion

Our data shows that MVD may be a good treatment modality for HFS caused by VBD but care must be taken to avoid adverse effects from the procedure. It is important to detach the dolichoectatic artery from its surrounding structures sufficiently to allow it to be easily movable. In addition, attempts should be made to lessen the retraction of the cerebellum during release of the dolichoectatic artery.     

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 onsetor=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.     

High frequency deep brain stimulation in the hippocampus modifies seizure characteristics in kindled rats

PURPOSE: This experimental animal study evaluates the effect of high frequency deep brain stimulation (HFS DBS) on seizures in the Alternate Day Rapid Kindling model for temporal lobe epilepsy (TLE). The target for HFS is the hippocampus, as this structure is often presumed to be the seizure focus in human TLE. METHODS: Rats (n = 12) were fully kindled in the hippocampus according to the Alternate Day Rapid Kindling protocol. Characteristics of the evoked afterdischarges (AD) were determined in the baseline period using AD threshold, AD latency, and AD duration as parameters. Rats were divided into a treated group (n = 7) that received 130 Hz HFS for 1 week, and a control group (n = 5) that did not receive HFS. Rats were retested in the following week. After 1 additional week of rest, the HFS group was continuously stimulated again for 1 week, during which AD evoked by kindling stimuli were characterized again. RESULTS: HFS had a direct effect on evoked AD: during HFS, it increased AD threshold to 203 +/- 13% of controls (p < 0.01) and increased AD latency to 191 +/- 19% (p < 0.05). It decreased AD duration to 71 +/- 9% (p < 0.05) of controls. The effect outlasted the HFS stimulation as in the week following HFS similar differences, but smaller in size, could still be established. CONCLUSION: Continuous HFS (130 Hz) in the hippocampus of epileptic rats modulates the characteristics of evoked AD in a way that reflects a reduction in excitability of the target region.     

面神经根解剖变异与原发性面肌痉挛

目的探讨桥小脑角面神经根解剖变异与原发性面肌痉挛的关系。方法回顾性分析2000年10月～2006年6月采用显微血管减压术（MVD）治疗的787例面肌痉挛病例的临床资料。其中5例（0．6％）术中探查时发现面神经根存在解剖变异．面神经根出脑干区距离听神经根进脑干区均大于10mm。均成功行MVD治疗。其中2例采用责任动脉悬吊法。结果5例病人术后面肌痉挛均立即消失。分别随访2、7、14、50、63个月，均无复发。术后并发症：中度面瘫1例，随访期间恢复为轻度：展神经麻痹致复视2例．随访期间恢复正常1例，好转1例。结论桥小脑角面神经根出脑干区异位至距离听神经根进脑干区大于10mm者罕见．动脉性血管压迫仍然是此类病人原发性面肌痉挛的主要病因．采用MVD治疗可获良效．     

A comparative study of primary and secondary hemifacial spasm

BACKGROUND: Hemifacial spasm (HFS) is a common movement disorder. OBJECTIVE: To evaluate possible differences in the demographic and clinical features between primary and secondary HFS. DESIGN: In-person interview using a standardized questionnaire to collect demographic and clinical data. SETTING: A multicenter study that included patients with HFS attending 3 Italian academic centers.Patients Two hundred fourteen patients with HFS. MAIN OUTCOME MEASURE: A complete neurological examination assessed the current muscle distribution of spasm and the presence of synkinetic movements between upper and lower facial muscles. RESULTS: The study sample comprised 214 patients with HFS, 81 men and 133 women, having a mean +/- SD age of 65.9 +/- 12.3 years; 164 patients were classified as having primary HFS and 50 patients (48 postparalytic and 2 symptomatic cases) were classified as having secondary HFS. Patients with primary and those with secondary HFS had similar mean +/- SD ages at onset (54.9 +/- 13.5 vs 57.0 +/- 12.8 years), male-female ratios (63:101 vs 18:32), right-sided-left-sided HFS (77:86 [1 bilateral] vs 21:28 [1 bilateral]), and frequencies of familial cases (2.9% vs 2.0%), respectively. Most patients (65.0%) with primary HFS had initial symptoms of periocular muscle contractions alone and had subsequent involvement of the lower facial muscles. Most patients (72.0%) with secondary HFS reported initial involvement of the upper and lower facial muscles simultaneously. Signs of synkinesis were present in primary (43.3%) and secondary (58.0%) HFS. CONCLUSIONS: Patients with primary and those with secondary HFS share common demographic and clinical features, including sex distribution, age at onset, affected side of HFS, synkinesis, and rarity of familial cases. Signs of synkinesis were present in significant proportions of patients with primary or secondary HFS. The 2 forms differed in clinical presentation.     

Suppression of axonal conduction by sinusoidal stimulation in rat hippocampus in vitro

Deep brain stimulation (DBS), also known as high frequency stimulation (HFS), is a well-established therapy for Parkinson's disease and essential tremor, and shows promise for the therapeutic control of epilepsy. However, the direct effect of DBS on neural elements close to the stimulating electrode remains an important unanswered question. Computational studies have suggested that HFS has a dual effect on neural elements inhibiting cell bodies, while exciting axons. Prior experiments have shown that sinusoidal HFS (50 Hz) can suppress synaptic and non-synaptic cellular activity in several in vitro epilepsy models, in all layers of the hippocampus. However, the effects of HFS on axons near the electrode are still unclear. In the present study, we tested the hypothesis that HFS suppresses axonal conduction in vitro. Sinusoidal HFS was applied to the alvear axon field of transverse rat hippocampal slices. The results show that HFS suppresses the alvear compound action potential (CAP) as well as the CA1 antidromic evoked potential (AEP). Complete suppression was observed as a 100% reduction in the amplitude of the evoked field potential for the duration of the stimulus. Evoked potential width and latency were not significantly affected by sinusoidal HFS. Suppression was dependent on HFS amplitude and frequency, but independent of stimulus duration and synaptic transmission. The frequency dependence of sinusoidal HFS is similar to that observed in clinical DBS, with maximal suppression between 50 and 200 Hz. HFS produced not only suppression of axonal conduction but also a correlated rise in extracellular potassium. These data provide new insights into the effects of HFS on neuronal elements, and show that HFS can block axonal activity through non-synaptic mechanisms.