肌电图监测在面肌痉挛微血管减压术中的应用

目的 探讨面肌肌电图监测在面肌痉挛微血管减压术（MVD）中的应用价值。方法 回顾性分析MVD治疗的72例面肌痉挛患者的临床资料,术中仔细辨别并处理责任血管,通过实时记录面肌的肌电反应了解减压效果。结果 60例有明确责任血管压迫,6例单纯性蛛网膜粘连或增厚,6例存在隐匿性责任血管。术后异常肌电图波形完全消失54例,基本消失16例,无明显变化2例。术后临床症状完全消失57例,部分消失14例,无改善1例;总有效率为98.6%（71/72）。结论 面肌肌电图监测可实时了解术中减压效果,对面肌痉挛的MVD,尤其是隐匿性责任血管所致面肌痉挛具有重要的指导作用。     

Application of electrophysiological methods and magnetic resonance tomographic angiography in the differentiation between hemifacial spasm and Meige syndrome

Bilateral hemifacial spasm and Meige syndrome can be easily confused due to their similar clinical manifestation. Here, we aimed to investigate the application of electrophysiological methods and magnetic resonance tomographic angiography (MRTA) in the differentiation between hemifacial spasm and Meige syndrome. 10 patients with bilateral hemifacial spasm and 9 patients with Meige syndrome received electrophysiological monitoring of nerves. There were two males and eight females with bilateral hemifacial spasm, aged 16–58 years with a course of 5–54 months. For the patients with Meige syndrome, there were three males and six females, aged 51–68 years with a course of 12–36 months. All patients received conventional MRTA of the brain blood vessels before decompression. We found that all patients with Meige syndrome showed synchronous contraction of bilateral orbicularis oculi muscles and (or) burst discharge from orbicularis oris muscles in surface electromyography (sEMG). However, those with hemifacial spasm presented with bilaterally asynchronous burst discharge. Electromyography for patients with Meige syndrome did not record abnormal muscle response (AMR), but recorded AMR for those with bilateral hemifacial spasm. The offending vessels were compressed in patients with hemifacial spasm in MRTA, while MRTA results were generally negative for those with Meige syndrome. Combining sEMG and AMR detection in EMG and MRTA, bilateral hemifacial spasm can be differentiated from Meige syndrome with a reduction of misdiagnosis rate.     

No clinical or neurophysiological evidence of botulinum toxin diffusion to non-injected muscles in patients with hemifacial spasm

Botulinum toxin injected into a muscle may diffuse to nearby muscles thus producing unwanted effects. In patients with hemifacial spasm, we evaluated clinically and neurophysiologically, whether botulinum toxin type A (BoNT-A) diffuses from the injection site (orbicularis oculi) to untreated muscles (orbicularis oris from the affected side and orbicularis oculi and oris from the unaffected side). We studied 38 patients with idiopathic hemifacial spasm. Botulinum toxin was injected into the affected orbicularis oculi muscle alone (at 3 standardized sites) at a clinically effective dose. Patients were studied before (T0) and 3-4 weeks after treatment (T1). We evaluated the clinical effects of botulinum toxin and muscle strength in the affected and unaffected muscles. We also assessed the peak-to-peak amplitude compound muscle action potential (CMAP) recorded from the orbicularis oculi and orbicularis oris muscles on both sides after supramaximal electrical stimulation of the facial nerve at the stylomastoid foramen. In all patients, botulinum toxin treatment reduced muscle spasms in the injected orbicularis oculi muscle and induced no muscle weakness in the other facial muscles. The CMAP amplitude significantly decreased in the injected orbicularis oculi muscle, but remained unchanged in the other facial muscles (orbicularis oris muscle on the affected side and contra-lateral unaffected muscles). In conclusion, in patients with hemifacial spasm, botulinum toxin, at a clinically effective dose, induces no clinical signs of diffusion and does not reduce the CMAP size in the nearby untreated orbicularis oris or contralateral facial muscles.     

Stretch reflex blepharospasm

We studied a patient with blepharospasm provoked by stretching the orbicularis oculi muscles. With the eyes closed, EMG of the orbicularis oculi at rest revealed spontaneous rhythmic muscle activity that was not visible. When she tried to open her eyes, repetitive jerking blepharoclonus and tonic blepharospasm rendered her functionally blind. Passive stretching of the orbicularis oculi evoked a burst of EMG activity with two components. Touch or pinprick did not elicit such reflex activity. Anesthesia of the supraorbital nerves abolished muscle responses to stretch and improved the blepharospasm.     

Orbicularis oculi electromyogram in a girl with ocular myasthenia gravis]

A 12-month-old girl with ocular myasthenia gravis was reported. Electromyograms (EMG) of the orbicularis oculi muscle were studied during a period of 16 months. The degree of the waning phenomenon on EMG correlated well with that of her clinical symptoms. The study of post-tetanic exhaustion after repetitive electrical stimulation at 20 Hz for 4 seconds, was the most sensitive technique in the evaluation of the function of neuromuscular junction. EMG showed the waning phenomenon in the initial worsening after a high dose methylprednisolone therapy, and at the symptom-free stage without medication after the steroid therapy. In our patient, orbicularis oculi EMG was useful in the estimation of the severity of ocular myasthenia gravis and the effect of its treatment.     

Electrophysiological study of congenital facial paralysis

The common cause of neonatal facial asymmetry is facial nerve paralysis or "asymmetric crying facies syndrome". In the not uncommon later the lower lip, symmetrical at rest, becomes tilted to the so-called normal side when the patient is smiling or crying, as the congenital hypogenesis of sublabial muscles fail to pull down the lower lip in the opposite side. The electrophysiological differentiation between the two diseases has been performed by orbicularis oculi and oris reflexes with mechanically glabellar and supralabial tapping stimulation, respectively, in addition to needle and/or surface EMG recording. In the facial nerve paralysis of the case 1, R1 and R2 were absent in the orbicularis oculi and oris reflexes. EMG activity was completely lacking over the M. orbicularis oculi and oris innervated by facial nerve. On the contrary, the orbicularis oculi and oris reflexes were normal in the asymmetric crying facial of the case 2. EMG activity was absent only in the sublabial muscles including M. depressor anguli oris and/or M. depressor labii inferioris. Furthermore, needle EMG disclosed no spontaneous activity at rest, which was suggestive of no denervation in the sublabial muscles. It was, however, not possible to determine exactly which muscle the needle was inserted, the M. deprossor anguli oris or the M. depressor labii inferioris. The case 3 might be a variant of asymmetric crying facies with hypogenesis of M. orbicularis oris and/or oculi as well as the sublabial muscle, since the latency was normal but the amplitude was significantly attenuated in the components of orbicularis oculi and oris reflexes.(ABSTRACT TRUNCATED AT 250 WORDS)     

Blink reflexes and lateral spreading in patients with synkinesia after Bell's palsy and in hemifacial spasm

We compared various electrodiagnostical tests in patients with hemifacial spasm and in patients who developed synkinesia after Bell's palsy. We examined the evoked blink reflexes in the orbicularis oculi (o. oculi) and orbicularis oris (o. oris) muscles in 23 patients with hemifacial spasm (HFS), in 10 patients with synkinesia after Bell's palsy (BPS) and in 22 control subjects. In the patient groups, we recorded synkinesia, latency and amplitude of compound muscle action potential (CMAP) in the mental muscle after stimulation of the facial nerve and we examined electromyographic activity of the o. oculi and mental muscles synchronously. Furthermore, we studied the phenomenon of lateral spreading, also known as ephaptic transmission, between the different facial nerve branches. Patients with BPS had a prolonged R1 latency on the affected side in o. oculi and smaller mental CMAP amplitude as an indication of facial nerve damage and nerve fiber loss. This was not found in patients with HFS, who showed an increased amplitude of the R1 and R2 responses in o. oris. Patients with BPS showed only an increased R1 amplitude in o. oris. All patients had signs of synkinesia. Lateral spreading with different patterns was present in all patients with HFS and in half of the patients with BPS. Latencies of early and late responses showed no differences between HFS and BPS. In addition to alterations in facial nucleus excitability in both conditions, ectopic re-excitation of facial nerve axons in HFS may explain the differences in neurophysiological findings between HFS and BPS patients. A loss of control following synaptic stripping may also be a contributing factor.     

Bilateral vs. unilateral electromyographic examination of the external anal sphincter muscle.

AIM OF THE STUDY: In patients with cauda equina or conus medullaris lesions, bilateral electromyographic (EMG) examination of the subcutaneous external anal sphincter (EAS) muscles has been suggested. In spite of its circular shape, EAS should be considered as two separate semicircular muscles. The aim of the present study was to test the hypothesis that information obtained by bilateral examination of the EAS muscle outweighs inconvenience due to additional needle insertions. PATIENTS AND METHODS: A group of 67 patients with clinical and radiological data supportive of cauda equina or conus medullaris lesion was studied. From the subcutaneous EAS muscles motor unit potentials (MUPs) were sampled by the standard concentric EMG needle electrode, and an advanced EMG system with template operated multi-MUP analysis. Severity of EMG abnormalities was determined, and compared in 48 pairs of the left/right subcutaneous EAS muscles. RESULTS: In 18 patients, bilateral EMG abnormalities were found, in five of them asymmetry of involvement was demonstrated. Unilateral MUP abnormalities were found in 22 patients. The sensitivity of unilateral EMG analysis was 57% and of bilateral examination, 83%. CONCLUSION: In patients with suspected cauda equina lesions, as a rule, bilateral EMG of the subcutaneous EAS muscle is recommended.     

Treatment of hemifacial spasm with type A botulinum toxin (AGN 191622): a dose finding study and the evaluation of clinical effect with electromyography]

Forty-one patients with hemifacial spasm had an injection of type A botulinum toxin (AGN 191622; Allergan Co. Ltd., Irvine, CA). Patients were randomly divided into 3 groups by the injection dose: group L (1 unit; 14 patients), group M (5 units; 14 patients), and group H (10 units; 13 patients). Half of the dose was injected into the orbicularis oculi and the rest into the zygomaticus major muscles on the affected side. The clinical effect and electromyogram were evaluated at 2 weeks after the injection. The clinical benefit was dependent on the injection dose, and group H showed the highest rate of improvement (84.6%). No adverse effect related to the toxin was demonstrated except one patient in group H who showed mild and transient lagophthalmos. For 81.8% of group H patients, the final judgement was "useful" or "very useful", which was 9.1% for group L and 50.0% for group M. On the other hand, electromyography disclosed no consistent dose-finding relationship. We conclude that at least 10 (preferably more) units of botulinum toxin are necessary for effectively treating hemifacial spasm. Electromyography has only limited value for the evaluation of clinical effect.     

Chronic progressive spinobulbar spasticity with disturbance of voluntary eyelid closure. Report of a case with special reference to MRI and electrophysiological findings

We describe a 56-year-old man who had a progressive pseudobulbar palsy, spastic tetraparesis, forced laughing and disturbance of voluntary eyelid closure, and was clinically compatible with chronic progressive spinobulbar spasticity. Magnetic resonance images (MRI) revealed atrophy of the bilateral motor cortices and single photon emission tomography after intravenous injection of N-isopropyl-p-iodoamphetamine iodine-123 (IMP-SPECT) showed hyporadioactivity in the same regions. Electrophysiological studies on supranuclear paralysis of eyelid closure demonstrated that so-called apraxia and motor impersistence coexisted and that in attempts to keep the eyelid closed the inhibition of basal activity of the levator palpebrae superioris muscle and activation of the orbicularis oculi muscle were insufficient, indicating the impaired reciprocity of these ocular muscles. The corresponding lesion of these eyelid symptoms was considered to be the bilateral motor cortices.     

Electromyography and recovery of the blink reflex in involuntary eyelid closure: a comparative study.

Electromyographic (EMG) activity of orbicularis oculi and levator palpebrae muscles was recorded to study the origin of involuntary eyelid closure in 33 patients. The evoked blink reflex in all patients and in 23 controls was also studied. To examine the excitability of facial motoneurons and bulbar interneurons in individual patients and to compare the results with EMG findings, R1 and R2 recovery indices were calculated in all subjects, as the average of recovery values at 0.5, 0.3, and 0.21 second interstimulus intervals. Based on EMG patterns, the patients were divided into three subclasses: EMG subclass 1, 10 patients with involuntary discharges solely in orbicularis oculi muscle; EMG subclass 2, 20 patients with involuntary discharges in orbicularis oculi and either involuntary levator palpebrae inhibition or a disturbed reciprocal innervation between orbicularis oculi and levator palpebrae; EMG subclass 3, three patients who did not have blepharospasm, but had involuntary levator palpebrae inhibition in association with a basal ganglia disease. The total patient group showed an enhanced recovery of both R1 and R2 components compared with controls. Although 30 out of 33 patients had blepharospasm (EMG subclasses 1 and 2), R1 recovery index was normal in 64% and R2 recovery index was normal in 54%. Patients with an abnormal R2 recovery index had an abnormal R1 recovery index significantly more often. All patients from EMG subclass 1 had an abnormal R2 recovery index, whereas all patients from EMG subclass 3 had normal recovery indices for both R1 and R2 responses. Seventy five per cent of the patients from EMG subclass 2 had normal recovery indices. The results provide further evidence that physiologically blepharospasm is not a homogeneous disease entity, and indicate that different pathophysiological mechanisms at the suprasegmental, or segmental level, or both are involved.     

Congenital multiple cranial neuropathies: Relevance of orofacial electromyography in infants

Introduction: The aim of this study was to assess diagnoses and outcomes of infants with 2 or more cranial neuropathies identified using orofacial electromyography (EMG). Methods: This retrospective study involved 90 patients. Diagnoses took into account clinical, radiological, and genetic data. EMG examined the orbicularis oculi, genioglossus, and levator veli palatini muscles, and blink responses. To evaluate outcome, neurological disability, respiratory complications, and feeding difficulties were recorded. Results: The patients had malformation syndromes (59), encephalopathies (29), or no underlying disorders (2). Neurogenic EMG signs were detected in a mean of 4 muscles, reflecting a mean of 3 affected nerves. EMG identified a higher number of neuropathies than clinical examination alone (82 vs. 31, facial; 56 vs. 2, pharyngeal; 25 vs. 3, hypoglossal). Poor outcome and death were more frequent when EMG identified ≥4 affected nerves (P = 0.02). Conclusion: EMG highlights multiple cranial neuropathies that can be clinically silent in infants with malformation syndromes or encephalopathies. Muscle Nerve 52 : 754–758, 2015     

A case of Meige's syndrome associated with post head trauma]

The pathogenesis of Meige's syndrome (MS) is controversial and has yet to be determined up to today. We studied a case of MS associated with post head trauma. The patient was a 52-year-old female. At the age of 46, she began to suffer from oro-lingual dystonia after head trauma induced by a traffic accident and the brief administration of neuroleptics to the delusion deteriorated the dystonia. She showed a wry appearance after 1 year and 6 months of the trauma and began to exhibit blepharospasms, oro-mandibular dystonia and cervical dystonia after 2 years and 3 months. For these symptoms her daily life became difficult. These symptoms were resistant to various drug therapies, although trihexyphenidyl relieved the symptoms transiently. Laboratory examinations and cranial MRI findings were normal. By surface electromyogram of ocular orbicular muscles, bilateral continuous discharge was observed. This patient was diagnosed as MS by clinical symptoms and surface electromyogram findings. It was inferred that the head trauma was associated with the development of MS. We discussed the pathogenesis of MS in the present case and it was speculated that MS was presented by a minute lesion of the brain stem which was produced at the time of the head trauma.     

Gaze-evoked eyelid closure. Report of two cases

Various types of associated movements of eyeballs with other cranial muscles have been described in the literature. Only a few observations, however, have been reported on the relation of ocular movements and facial muscles innervated by the facial nerve, especially the orbicularis oculi muscles. We report two cases presenting gaze-evoked involuntary contraction of the orbicularis oculi muscle and unilateral eyelid closure. Case 1 was a 38-year-old housewife who was admitted to our hospital because of gait disturbance and sensory deficits below the neck. She had a 5-year history of left facial palsy, disturbed horizontal eye movements, retrobulbar optic neuritis, spastic paraparesis and bladder and rectal disturbances, some of which had relapsed a few times. Neurological abnormalities were summarized as follows: bilateral pale discs, right Horner's sign, horizontal nystagmus, left facial nerve palsy of peripheral type, spastic paraparesis with left-sided predominance, sensory disturbances below the third cervical segment, truncal and limb ataxia, and bladder and rectal disturbances. Gaze-linked synchronized contraction of the left facial muscles was observed and on the left lateral gaze marked spasm of the left orbicularis oculi muscle with occasional lid closure was evoked. Case 2 was a 72-year-old female with cerebellar hemorrhage. Neurological abnormal findings included mild disorientation, meningeal irritation signs, horizontal nystagmus on lateral gaze, reduced response of reflex eye movement to the left, minimal weakness of the left facial muscles, ataxic dysarthria, mild left hemiparesis and hemisensory deficits with face, truncal and limb ataxia. She could move eyeballs to any direction but with effort to the left.(ABSTRACT TRUNCATED AT 250 WORDS)     

Botulinum toxin-induced paralysis of frontotemporal muscles improves seizure focus localization.

BACKGROUND: Scalp EEG localization of epileptic foci may be obscured by electromyographic (EMG) artifact produced by ictal contraction of cranial muscles. Injection of botulinum toxin type A (BTX-A) into frontotemporal scalp muscles reduces EMG activity. Initial scalp video-EEG monitoring in three patients suggested partial seizures, but definitive lateralization or localization was precluded by EMG artifact. METHODS: EMG-guided BTX-A injection to bilateral frontotemporal muscles was performed. When artifact persisted, BTX-A administration was selectively repeated. Patients subsequently underwent scalp video-EEG monitoring 1 week later. RESULTS: All patients had reduction of EMG artifact during subsequent scalp video-EEG monitoring. No patient had adverse effects after BTX-A administration. All three patients had localization to either frontal or temporal lobes and definitive lateralization. Two of the three patients were able to proceed to invasive placement of frontotemporal subdural grid electrodes based on the BTX-A scalp video-EEG localization, and the third patient was determined to have a multifocal seizure disorder. CONCLUSIONS: Paralysis of frontotemporal scalp muscle after BTX-A administration reduces EMG artifact and may improve localization and lateralization of a seizure focus, providing a noninvasive technique for advancement toward epilepsy surgery.     

Motor unit number index (MUNIX) in the orbicularis oculi muscle of healthy subjects

Introduction: The motor unit number index (MUNIX) refers to an electrophysiological method that measures the number of motor units in the surface electromyographic interference pattern (SIP) recorded during graded muscle contractions. MUNIX studies of limb muscles have been conducted, but MUNIX studies of bulbo‐facial muscles have not been reported. Methods: We assessed bilateral orbicularis oculi muscles using MUNIX, and the reference values and reproducibility of MUNIX and motor unit size index (MUSIX) were investigated in healthy subjects. Results: In this study, MUNIX was applied successfully to the orbicularis oculi muscles and showed good reproducibility. The correlation coefficients for MUNIX and MUSIX were 0.803 and 0.592, respectively, and the coefficients of variation were 20.9% and 8.5%, respectively. Conclusions: The MUNIX procedure for the orbicularis oculi muscle would be a useful tool for evaluating bulbar symptoms, especially in amyotrophic lateral sclerosis. Muscle Nerve 51 : 197–200, 2015     

A case report of mirror writing with low perfusion of bilateral anterior cerebral arteries]

A 20-year-old female experienced temporary unintentional mirror writing associated with low perfusion of the bilateral anterior cerebral arteries. When she was 17 years old, she had developed multiple idiopathic intracerebral hemorrhages and right hemiparesis. At the age of 20, she had a generalized convulsion for which she was transferred to our department. Computed tomography (CT) and magnetic resonance images of the brain were obtained, but no fresh abnormal lesion could be detected. The following day, after she had recovered from postictal symptoms, she wrote mirror image words, and her mirror writing then gradually improved within one week. Single photon emission CT showed low perfusion of both anterior cerebral arteries. We concluded that bilateral vascular insufficiency to the supplementary motor areas and corpus callosum caused mirror writing in this case.     

Head retraction reflex in stiff-man syndrome and related disorders.

The head retraction reflex (HRR) is a vestigial withdrawal reflex of the face and is suppressed in healthy subjects. We investigated the prevalence and electrophysiological patterns of the HRR in patients suffering from stiff-man syndrome (SMS, n = 28) and related disorders, stiff-limb syndrome (SLS, n = 2), and progressive encephalomyelitis with rigidity and myoclonus (PERM, n = 20). In patients with a positive HRR, the electromyographic (EMG) pattern was analyzed with surface recordings from the orbicularis oculi, sternocleidomastoid, trapezius, and the paraspinal extensor muscles at midthoracic and lumbar levels. On clinical testing, 17 of 28 SMS patients, 10 of 20 PERM patients, and 0 of 2 SLS patients had a positive HRR, ranging from a brief contraction of the neck extensors to violent retropulsion of the upper body. In all muscles, EMG reflex patterns elicited by gentle taps to the face or by electrical stimulation of the trigeminal nerve branches consisted of two components: an early, synchronous, brief burst with the shortest latency in trapezius (12.5-20.0 msec) and a late, asynchronous, longer response with latencies between 44 and 70 msec. We conclude that the HRR is an abnormal cutaneomuscular brainstem reflex that occurs in a considerable proportion of patients with SMS and related disorders. Although neither specific nor particularly sensitive for SMS, presence of the HRR in a setting with otherwise unexplained stiffness and spasms might help to avoid the otherwise frequent misdiagnosis of a psychogenic motor disturbance in patients with SMS.     

Trigemino-facial reflex inhibitory responses in some lower facial muscles

The effects of electrical trigeminal stimulation on activated facial muscles were studied in 20 normal subjects in order to evaluate whether excitatory or inhibitory responses are present and to investigate whether the reflex organization is similar in all the facial muscles. No inhibition was observed in frontalis, orbicularis oculi, orbicularis oris, and mentalis muscles. By contrast, a clear suppression of electromyographic (EMG) activity (late silent period or SP2) was present in the levator labii superioris, depressor anguli oris, and depressor labii inferioris muscles, with a mean latency ranging from 41.8 to 50.2 ms, and a mean duration ranging from 27.5 to 40.9 ms. An early suppression of EMG activity (early silent period or SP1) was observed, with a latency of 16 to 20 ms and a duration of 10 ms, mainly in inferior perioral muscles. Our findings show a selective trigeminal inhibitory influence upon some specific lower facial muscles.     

A case of subacute necrotizing lymphadenitis complicated with brachial plexus neuritis]

A 22-year-old female noted a low grade fever and swelling of the cervical lymph nodes in May 1997, and later developed a dry cough. She was diagnosed to have interstitial pneumonitis, and then administration of corticosteroids alleviated her symptoms. On February 6, 1998, however, a high fever recurred and her swollen cervical lymph node on the right side was biopsied on February 9, 1998. A histological examination revealed an increased number of histiocytes and karyorrhexis of the lymphocytes in the paracortical areas, and she was therefore diagnosed to have histiocytic necrotizing lymphadenitis. She could not fully elevate her arm on February 16, 1998. On admission, her cervical lymph node was swollen on the left side. A neurological examination revealed a marked weakness of the right deltoid muscle, moderate weakness of the right latissimus dorsi, triceps and brachioradialis muscles and also a mild weakness of the serratus anterior, supra- and infra-spinatus, and biceps brachii muscles. The muscle power of the other muscles were normal and no muscle atrophy was evident. Winging of the right scapula was observed. The deep tendon reflexes were normal in all four limbs, and her sensation was also normal. No cerebellar sign was found. The Jackson, Spurling, Allen, Morley and Adson tests were all negative. ESR was mildly elevated to 18 mm/hr, but CRP was negative. RF, ANA and anti-SS-A and SS-B antibodies were positive, whereas LE-test, direct and indirect Coombs tests and other autoantibodies were negative. Needle EMG disclosed fasciculation potentials in the right triceps muscle and polyphasic waves in the right deltoid muscle. MRI showed gadolinium-enhancement of the right brachial plexus. Although an abnormal accumulation of gallium was detected in the right parotid and bilateral submandibular glands, no sicca symptoms were found and the Schirmer test findings were normal. Oral prednisolone (50 mg/day with gradual tapering) alleviated both her symptoms and the gadolinium-enhancement of the right brachial plexus. As a result, her right upper limb paresis was thus considered to have been caused by right brachial plexus neuritis, which was probably associated with histocytic necrotizing lymphadentis. Although acute cerebellar ataxia and meningitis have previously been reported to be complicated with histiocytic necrotizing lymphadenitis, this is the first report to describe the complication of peripheral neuritis with this condition.