Somatosensory evoked blink response in hemifacial spasm and peripheral facial palsy

Somatosensory blink response (SBR) is produced by electrical stimulation of peripheral nerves or skin areas remote from the face. We investigated the presence of SBR in cases with hemifacial spasm (HFS) and peripheral facial palsy (PFP). Fifty-seven cases of HFS, 54 cases of PFP and 39 normal subjects were included in the study. A routine blink reflex study was performed in all subjects. Supramaximal stimulation of the median nerve was given ipsilateral to the either spasm or paralytic side for SBR. Recordings were made at the orbicularis oculi (o.oc) bilaterally and ipsilaterally at the orbicularis oris (o.or) muscles. SBR was elicited in 12 of 39 control subject. Twenty four of 48 HFS cases were SBR positive. Twelve of them had o.or response. An SBR was elicited at the ipsilateral o.oc in 35 of 46 patients with PFP with synkinesia. Twenty-six patients had an SBR at the ipsilateral o.or. In the 13 patients with PFP without synkinesia only 3 people had an SBR. SBR positivity was seen more often in PFP with synkinesia than in cases with HFS. SBR if positive spreads to the lower part of the face in most of cases with HFS and PFP with synkinesia.     

Electrophysiological findings of acute peripheral facial palsy in diabetic and non-diabetic patients

The aim of this study is to investigate the role of diabetes mellitus on the clinical and electrophysiological findings of peripheral facial palsy (PFP), the effect of the diabetes duration and polyneuropathy on the electrophysiological parameters. A total of 32 diabetic and 40 non-diabetic patients with peripheral facial palsy were included. All patients were divided into two subgroups based on the time of electrophysiological examinations: within the first 15 days versus within 16–30 days. Neuropathy symptoms and the results of neurological examinations and electrophysiological findings were recorded. The findings of electroneurography (EnoG), blink reflex (BR) evaluation, and needle electromyography (EMG) indicated statistically significant blink reflex abnormalities in diabetic patients compared to non-diabetics. Delay in the latency was more remarkable in the R2 component than in the R1 (p < 0.001). The delay in the R1 latency was also observed in the non-affected side for diabetic patients. The longer duration of the diabetes caused significant delay on the blink reflex latency on both the affected and non-affected sides for R1 component (p = 0.019, p = 0.041, respectively). In contrary, neither the diabetes duration nor the age of the patients correlated with the clinical severity of facial palsy, fiber loss, fibular nerve compound muscle action potential amplitudes, and the nerve conduction velocities.     

面瘫患者面神经电图和瞬目反射的应用比较

目的:比较面瘫患者瞬目反射和面神经电图的应用价值。方法:这些面瘫患者经过四周基础治疗和(或)针灸治疗后,进行健、患侧瞬目反射(207例)和面神经电图(205例)检查比较。结果:瞬目反射治疗前健、患侧R1值的差异有极显著意义(P<0．01);治疗后健、患侧R1值的差异无显著意义 (P>0．05)。面神经电图患侧潜伏期延长者于治疗后均有所好转(P<0．05),波幅降低者治疗后无明显改善(P>0．05)。结论:面瘫患者治疗后瞬目反射改善非常明显,而面神经电图恢复存在明显的滞后现象,早期诊断(发病第一周)瞬目反射检查优于面神经电图,中后期面神经电图检查优于瞬目反射。     

面神经炎病人神经电生理检查和面肌运动评分的相关性

目的：探讨神经电生理检查和面肌运动功能评分在面神经炎诊断和面肌功能评估中的相关性。方法：选取符合入选标准的面神经炎病人37例,在发病第7、28天分别予以神经电生理检查和面肌运动功能评分。神经电生理检查选用瞬目反射和面神经电图;面肌运动功能评分采用House Brackmann分级量表（HB）评分和Nottingham面神经分级量表评分（选用VMG指数）,比较不同评分标准对面神经炎评估的异同,并应用Pearson相关分析法探讨不同评分标准之间的相关性。结果：与神经电图评分法相比较,瞬目反射评分法和HB评分法更为一致。Pearson相关性分析结果显示VMG指数与HB评分法相关性最强（r=-0．925）,神经电图评分法和HB评分法相关性相对较差。结论：针对面神经炎病人的评估应将面神经运动功能评估和神经电生理学评估结合起来,才能达到最好的客观性和准确性。HB评分、VMG指数联合以瞬目反射为最优指标的神经电生理检测是较为理想、科学的面神经炎的诊断和评估方法,可以较为可信地应用到临床诊治和科学研究工作中。     

Corneal reflex and blink reflex changes in thalamic hemorrhage

We studied the corneal reflex (CR) with air-puff and direct touch by using a standardized method in patients with thalamic hemorrhage (TH) (n: 15) and in normal control subjects (n: 21). The conventional blink reflex (BR) was also studied. In the TH group: 1--When the cornea on the clinically nonaffected side was stimulated the corneal reflex responses were elicited bilaterally, with normal latency on the clinically normal side and delayed on the affected side. 2--When the cornea on the clinically affected side was stimulated, the corneal responses on both sides were either abnormal or could not be elicited. 3--The ipsilateral R1 and R2 responses recorded by stimulation of the supraorbital nerve on the clinically affected side were abnormal where the contralateral R2 responses were in the normal range. In the normal control and TH groups: 1--No statistical difference could be detected between the responses elicited by air-puff or direct touch to cornea (p > 0.05). 2--CR responses were statistically different from the R2 response of the BR (p < 0.005).     

Auditory-evoked masseter inhibitory reflex

We aimed to investigate auditory-evoked masseter inhibitory reflex and discuss possible auditory-trigeminal pathways in brainstem. Our study population consisted of 21 healthy volunteers (age-matched 7 males and 14 females). Bilateral electrical blink reflex (BR), auditory blink reflexes (ABR) and electrical MIR (MIR) were studied. After obtaining normal potentials, auditory MIR (AMIR) was studied. Electrical blink reflexes had two components as R1 and R2, and ABR had one evoked potential in all volunteers. There was no significant difference between gender, nor between right- and left-sided BR and ABR. The mean latency of ABR responses were shorter than latencies of R2 phase of BR (p = 0.013 for left-sided responses, p = 0.035 for right-sided responses). Electrical stimulation revealed two suppression periods (SP1 and SP2) in MIR responses bilaterally in all volunteers. Auditory stimulation evoked typical two suppression periods only in 11 subjects (5 males, 6 females). The mean latency of SP1 component of AMIR was significantly longer than those of MIR bilaterally in both males and females, while the SP2 component had a shorter onset. The durations of SP1, SP2 and total SP were always shorter than those obtained in MIR with smaller degree of suppressions. None of the MIR or AMIR responses showed significance difference between sexes. We assume that auditory-evoked MIR might share the similar interneurons as with other electrical or nociceptive stimulation, which connects cochlear-trigeminal neurons via pontine reticular system to premotor area for masseter muscle.     

Blink reflex in motor neuron disease

The aim of the study was to analyse the diagnostic value of blink reflex (BR) in motor neuron disease (MND). We studied 25 patients with MND including amyotrophic lateral sclerosis (ALS) in 18 patients, primary muscular atrophy (PMA) in 4 patients, and primary lateral sclerosis (PLS) in 3 patients and 12 healthy volunteers. The blink reflex was obtained in typical way. In ALS group, statistically significant increase in latency and decreased amplitude of R2 responses were found compared to the control group (p < 0.05), whereas BR in patients with PLS and PMA was within normal limits. The presence of low amplitude of R2 responses in patients with ALS may suggest loss of lower brainstem neurons connecting trigeminal and facial system, and probably also decreased facilitator effect of central nervous system on reticular formation in the brainstem.     

椎基底动脉供血不足和脑干梗死患者的瞬目反射检测

目的：探讨瞬目反射(BR)对椎基底动脉供血不足(VBI)及脑干梗死的临床应用价值。方法：用表面电极刺激三叉神经眶上支，在双侧眼轮匝肌进行记录。对BR异常者治疗1、3、6个月后复查。结果：VBI组80例治疗前BR异常者58例(72．5％)，治疗一个月后复查BR恢复正常者39例，BR正常或治疗后恢复正常者近期都能获得基本痊愈，而BR持续异常者则预后较差。脑干梗死组26例，：BR全部异常且异常程度重于VBI组。结论：在对VBI及脑干梗死诊断、疗效观察及预后评价中，BR是一项极为客观有用的指标。     

瞬目反射与神经电图对Bell麻痹的诊断价值

目的：研究瞬目反射（BR）与面神经的神经电图（electroneurogram,ENG）对Bell麻痹（特发性面神经麻痹）的诊断价值。方法：对246例Bell麻痹患者在发病后10d内行BR和ENG检查。结果：BR检测阳性率为100％,ENG检测阳性率为63．8％（P〈0．01）。结论：BR与ENG均能反映面神经损害的严重程度、部位及预后,其中BR在早期诊断中更为敏感,两者结合的临床价值更大。     

Long-term depression of the human blink reflex

Long-term depression (LTD) of synaptic transmission is reliably induced by low-frequency stimulation (LFS) of presynaptic nerve fibers in vitro. Many experiments suggest that LTD of basal transmission is not readily induced either in awake or anesthetized animals in vivo. In order to fill the gap between the in vitro cell studies and the in vivo situation, the effect of LFS on trigeminal somatosensory processing in healthy volunteers was investigated. Excitability of trigeminal sensory neurons was tested by applying the blink reflex (BR) elicited by electric stimulation of supraorbital nerve afferents. LFS of these afferents induced a significant reduction of the BR integral, a significant increase of the BR onset latency and a significant decrease of the stimulus intensity ratings. This depressive effect on the BR lasted for at least 1 h after the end of LFS. Thus, this study documented for the first time a long-term depression of trigeminal somatosensory processing in healthy volunteers. Electronic Publication     

Acute peripheral facial palsy: Is there a trigeminal nerve involvement?

The aim of this study was to investigate trigeminal nerve involvement in patients with peripheral facial palsy. In total, 25 patients with facial nerve palsy and 19 controls were tested by electrophysiological methods regarding their facial and trigeminal nerve functions within 1 month after disease onset. The presence of an abnormal blink reflex was determined in patients with peripheral facial palsy by comparing paralytic and non-paralytic sides (12.3 ± 1.1 and 10.8 ± 1.3, respectively; p = 0.001). However, the average masseter inhibitory reflex difference between the paretic and non-paralytic sides of patients compared with the corresponding side-to-side comparison for controls was not statistically significant. The masseter inhibitory reflex response was abnormal in some cases. These findings suggest that the masseter inhibitory reflex, a trigemino–trigeminal reflex, was normal in most of our patients with peripheral facial palsy, but may be abnormal in individual cases. Our study showed that subclinical disorders affecting the trigeminal pathways occur in individual patients with idiopathic facial palsy, while the majority of patients have no trigeminal nerve involvement.     

不同年龄抑郁症患者瞬目反射的研究

目的:探讨抑郁症与瞬目反射(BR)的关系。方法:对90例抑郁症(青年和老年各45例)患者及60例正常对照组(青年和老年各30例)进行BR检测。结果:与青年对照组和老年对照组比较,青年抑郁症患者和老年抑郁症患者BR的R2、R2′潜伏期分别显著延长(P<0.001),老年抑郁症患者的波幅与老年对照组、青年抑郁症患者的波幅相比显著升高,差异存在极显著意义(P<0.001)。结论:抑郁症患者存在BR的异常,提示抑郁症患者可能存在脑干功能障碍。     

后循环梗死患者的BAEP、BR、TSEP检测

目的：探讨后循环脑梗死（PCI）患者脑干听觉诱发电位（BAEP）、瞬目反射（BR）、三叉神经诱发电位（TSEP）三种电生理变化。方法：选择60例经头颅MRI检查证实为PCI患者（病例组）,分别于入院一周之内行BAEP、BR、TSEP检查,观察BAEP波形及I、Ⅲ、V波潜伏期（PL）、峰间期（IPL）,计算BR既R1、R2、R2波平均PI。、波幅及TSEP各成分PL,并与40例健康体检者作对照。结果：病例组60例中BAEP异常35例（58％）,异常主要表现为I、V波的PL、I—V波的IPL延长和I／V波幅比〉1。BR异常33例（55％）,异常主要表现为R2波的PL延长,R2、R2’波幅下降。TSEP检查病例组与对照组PL比较未见明显差异。结论：BAEP、BR两种电生理检查方法能够较好地检测出PCI患者神经功能异常,联合应用BAEP及BR能够为PCI患者的神经功能的判断提供重要参考。     

正常学龄儿童瞬目反射的初步研究

应用电刺激法研究４０例正常学龄儿童的瞬目反射。通常能诱发出刺激侧快反应（Ｒ１）、迟反应（Ｒ２）及对侧迟反应（Ｒ２＇）。分析Ｒ１的形态、各波的潜伏期、时程、波幅，制定出正常值。瞬目反对的检查结果可作为诊断多种脑干障碍和三叉神经、面神经病变的方法。     

偏头痛患者发作期脑干听觉诱发电位和瞬目反射检测

目的：观察偏头痛患者发作期脑干听觉诱发电位(BAEP)和瞬目反射(BR)改变。方法：对45例偏头痛发作期患者进行BAEP、BR检测。结果：BR和BAEP联合检测提示脑干病变者31例，占69％；BAEP、BR检测提示听神经、三叉神经传入通路功能障碍和面神经传出通路功能障碍共26例，占58％，其中三叉神经传入通路障碍21例，占81％。结论：偏头痛发作期存在着以脑干和三叉神经为主的神经功能障碍．与血管舒缩功能障碍很可能互为因果、相互影响。     

Modulation of electrically elicited blink reflex components by visual and acoustic prestimuli in man

The effects of a prestimulus on the electrically elicited blink reflex components were investigated in 20 healthy subjects. In the first group of 10 subjects (warned group), electric shocks were delivered in isolation or preceded, at an interstimulus interval (ISI) of 0.1 s, 1 s, or 10 s, by a visual or acoustic warning stimulus. In the second group of 10 subjects (unwarned group), the electric shocks were delivered either in isolation or preceded, at the same ISI, by visual or acoustic stimuli having no warning value. The modulation of the three blink reflex components was then analysed. Compared to the baseline condition, the R1 oligosynaptic component was enhanced at 0.1 s and 1 s ISI, in the warned group with the visual prestimulus, but only at 0.1 s after a visual and acoustic prestimulus in the unwarned group. On the contrary, the polysynaptic responses showed a different course: R2 was significantly reduced at the 0.1 s interval in the warned group with both the prestimuli, and only with the visual prestimulus in the unwarned group. The R3 was inhibited at all three intervals with the visual prestimulus, and at the 0.1 s and 1 s with the acoustic one in the warned group, and only at 0.1 s in the unwarned group, both after visual and acoustic prestimuli. The decrement in R2 and R3 observed with the shortest interval was probably related to the prepulse inhibition of startle reflex. Furthermore, only R3 was still inhibited at longer intervals, when the sustained processes of attention may have influenced this component. Perhaps this combination of events represents, in the warned group, the best preparation for voluntary reflex reaction.     

Impaired attention modulation of the blink reflex R3 component in Parkinson's disease: a non-task warning paradigm study.

PURPOSE: the aim of this experimental study was to evaluate the attention modulating actions on the polysynaptic component of blink reflex responses and especially of the R3 component in patients suffering from Parkinson's Disease (PD). To this end, a non-task warning paradigm was adopted. METHODS: attention processing was evaluated by means of a non-task paradigm in 55 patients suffering from PD. Subjects were presented with a visual 'warning' prestimulus and the blink reflex (BR) analyzed with special regard for any modulation of its polysynaptic components (R2-R3). RESULTS: The mean amplitude of the post-warning R3 component (PW-R3c) of 'de novo' PD patients was 62% of the corresponding component following unannounced stimuli, a figure which differs significantly from both treated PD patients (18.9%) and control subjects (15.4%). De novo patients subsequently started on L-dopa therapy exhibited a more pronounced inhibition of the R3 component after warning stimulus, as the PW-R3c percentage decreased. Inversely, treated patients whose therapy was withheld showed decreased inhibition of this component. Regarding R2, the mean PW-R2c in the de novo patients differed slightly from that of the treated patients (P<0.05), but not from that of the control subjects. Such a finding may be attributable to a specific effects on the excitability of the polysynaptic responses. CONCLUSIONS: Attention disorders in PD have been well documented by means of this kind of non-task warning paradigm, which appears to probe the modulation of the BR R3 component, even if the interpretation of this R3 changes suggesting a specific alteration of attention processing must be put forward extremely carefully, because something similar, but less evident, appears also for R2.     

瞬目反射、脑干听觉诱发电位、经颅多普勒超声对椎基底动脉供血不足的诊断价值

目的：观察瞬目反射（ＢＲ）、脑干听觉诱发电位（ＢＡＥＰ）、经颅多普勒超声（ＴＣＤ）对椎基底动脉供血不足（ＶＢＩ）的诊断意义。方法：对４１例已经临床确诊的ＶＢＩ病人在间歇期进行ＢＲ、ＢＡＥＰ及ＴＣＤ检查。结果：ＴＣＤ、ＢＲ、ＢＡＥＰ异常率分别为８３％、８０％、６８％。ＢＲ提示脑桥损害１例、延髓损害１５例、广泛性脑干损害１７例；ＢＡＥＰ发现内耳听力减退２０例、脑干病变１３例；ＴＣＤ发现多血管流速异常１４例、一支流速改变１６例，有或伴有血管张力异常１３例。结论：由于ＢＲ、ＢＡＥＰ反射路径不同，检测结果不尽一致。联合检查有助于对病损部位进行定位。ＴＣＤ则有助于定性诊断     

特发性面神经麻痹病变部位与神经电生理检测关系探讨

目的：探讨特发性面神经麻痹病变部位与电生理检测结果的关系。方法：对发病20d内的109例特发性面神经麻痹患者,根据临床表现进行面神经病变定位,分为4个组：膝状神经节病变组、面神经管镫骨神经以上病变组、面神经管镫骨神经以下病变组、茎乳孔以外病变组,并行面神经电生理检查,各组数据进行统计学处理。结果：109例患者中膝状神经节病变组15例,面神经管镫骨神经以上病变组21例,面神经管镫骨神经以下病变组38例,茎乳孔以外病变组35例;患侧瞬目反射、面神经复合肌肉动作电位（CMAP）潜伏期、波幅及患侧波幅下降比、F波消失率各组比较差异有统计学意义。结论：面神经麻痹电生理指标波幅下降比、瞬目反射、F波与其病变部位有关。     

Blink reflexes in patients with atypical odontalgia and matched healthy controls

Atypical odontalgia (AO) is an orofacial pain condition which has been suggested to involve neuropathic pain mechanisms. The aim of this study was to use a brain stem reflex to investigate craniofacial nociceptive mechanisms in AO. In 38 AO patients and 27 matched healthy controls, the R2 component of the blink reflex (BR) was elicited using a “nociceptive-specific” electrode and recorded with surface electromyography electrodes on both orbicularis oculi muscles. The BR was tested by stimulation of both sides of the face of the participants before, during, and after an intraoral pain provocation test with capsaicin. The data were analyzed with three- and four-way mixed-model analyses of variance. The root mean square value of the ipsilateral R2 (R2i) was significantly reduced in patients compared with controls (P=0.046). No differences in R2 between stimulation sides were detected in either group (P>0.757). In all participants, R2 responses and the intensity of the pain evoked by the electrical stimulus were decreased during and after application of capsaicin compared with baseline (P<0.001). In patients, R2i onset latencies were significantly prolonged compared with controls (P=0.031). The present data show disturbances in the central processing of craniofacial information and that endogenous pain inhibitory systems in AO patients and healthy controls were activated to a similar degree by an acute intraoral nociceptive input. Additional clinical research with AO patients will be needed to determine to what extent neuropathic pain mechanisms are involved in this pain condition.This study was supported by The Danish Medical Research Council, The Aarhus University Research Foundation, the Danish Dental Association, the Health Research Council in the South-East of Sweden (FORSS), and the Swedish Research Council.