Clonic Contractions Research Articles

Microvascular decompression for hemifacial spasm: results from 23 years at a single institution

Objective: Hemifacial spasm (HFS) is characterized by unilateral tonic and/or clonic contractions of the facial muscles. The most frequent cause of HFS is neurovascular focal compression of the root exit zone of the facial nerve. Microvascular decompression (MVD) works well, with effects that last almost permanently. We analyzed the surgical outcomes and complications from the last 23 years at our institution. Methods: This study analyzed 244 patients who underwent MVD between June 1998 and July 2021. All patients were followed up for more than 24 months. The preoperative image workups were brain magnetic resonance imaging, magnetic resonance angiography, and constructive interference in steady state (from 2009 onwards). Starting in July 2012, intraoperative monitoring was performed. Surgery was performed through the retrosigmoid approach by a single neurosurgeon. Results: Out of 244 patients, 160 were female and 84 were male. The average age was 53.8 years (range, 19–78 years). In total, 226 patients (92.6%) completely recovered from HFS, two patients (0.8%) underwent reoperation, and complications occurred in 16 patients (6.6%). In 61 patients with preoperative facial palsy on the affected side, palsy improved in 56 patients (91.8%) and 12 patients (19.7%) had thick arachnoid membranes.Conclusion: MVD has a durable effect on the improvement of HFS and may also improve HFS and concomitant palsy if preoperative facial palsy is present. Therefore, it is thought to be a treatment method that can be actively recommended to patients.

Ilae classification of seizures and antiepileptic medications apothegmatic: hereafter advancement and clinical practice

Introduction: The Antiepileptic medications are frequently categorized into divisions such as ‘first-generation’ (i.e., carbamazepine, phenobarbital, phenytoin, primidone, and valproate) and ‘second-generation’ (lamotrigine, levetiracetam, felbamate, gabapentin, topiramate, tiagabine, oxycarbazepine, zonisamide, and pregabalin). Chronic phenytoin ingestion leads to its impact in the cerebral cortex, resulting in atrophy of cerebellum, cause ataxia and nystagmus. Objective: To recapitulate the International league against epilepsy classifications, first treatment for epilepsy based on their classifications, antiepileptic medications adverse drug reaction, Methodology: The author used 74 distinctive published articles for the accomplishment of this review article. Google search engine was used for accessing published articles from databases like Google Scholar, Research Gate, PubMed, NCBI, NDSS, PMID, PMCID, Cochrane Database and CLINMED international library. Findings: Tonic-clonic is characterized by stiffness for loss of consciousness occurred by tonic extension and rhythmic clonic contractions of all considerable muscle groups. Antiepileptic drugs are implicitly an effective treatment for patient with epilepsy. Carbamazepine cause serious and sometimes fatal dermatologic reactions, including toxic epidermal necrolysis and stevens-johnson syndrome, aplastic anemia and agranulocytosis, Suicidal Behavior and Ideation, Stevens johnson syndrome, cholestatic jaundice, ataxia, xerostomia, speech disturbances, feeling sleepy Conclusion: Commonly happening side-effects of AEDs are memory troubles, exhaustion, tremors, gastrointestinal symptoms, osteoporosis, depression, drowsiness, dizziness, weight change, nausea. In generalized seizures, on the other hand, the seizure is generalized from the endeavor (i.e., primary generalized seizures), launching in both hemispheres of the brain contemporaneously

Evaluation of the effect of botulinum toxin A on the physical and mental health of patients with hemifacial spasm

BackgroundHemifacial spasm (HFS) is a debilitating disease characterized by involuntary tonic and clonic contractions of muscles innervated by the facial nerve. Botulinum toxin A (BTX-A) is the first-line option and the most effective medical treatment for HFS. The objective of this study was to evaluate the effect of BTX-A therapy on the physical and mental health of HFS patients. MethodsParticipants included 65 HFS patients and 65 matched healthy controls in the study. Cornell Medical Index (CMI) self-assessment questionnaire was used to detect the psychological health of all participants. Local injection of BTX-A was applied, and the Cohen hierarchical criteria were employed to stratify the degree of spasticity, further evaluating the efficacy of BTX-A before and two months after treatment in HFS patients. The HFS patients at two months post-treatment were re-evaluated by CMI self-assessment questionnaire, and the evaluated factors of these patients were compared with those of patients before treatment. ResultsThe scores of somatization, depression, anxiety, inadaptation, sensitivity, anger, tension, M-R, and total scores in the HFS group were significantly higher than those in the control group (all P<0.05). Two months post-treatment, among 65 HFS patients who received with BTX-A treatment, 42 (64.6%) were completely relieved, 16 (24.6%) were significantly relieved, 7 (10.8%) were partially relieved, and 0 (0%) cases were invalid, and the total effective rate was 89.2%. Two months after BTX-A treatment, the scores of somatization, tension, anxiety, depression, sensitivity, M-R and total scores of patients with HFS were lower than those before treatment (all P<0.05). ConclusionsPatients with HFS are often accompanied by somatization, anger, inadaptation, sensitivity, anxiety, depression, and tension. BTX-A can not only alleviate the symptoms of HFS, but also improve the somatization, tension, anxiety, depression, and sensitivity.

Hemifacial spasm is not affected by state of consciousness: a case report

Background Hemifacial spasm (HFS) is a movement disorder caused by mechanical compression of the facial nerve after it has left the brainstem and is characterized by brief or sustained twitching of the muscles innervated by that nerve. Often we observe spasm in an awakening situation. Actually contractions persist during sleep. To our knowledge, there were no reports on how HFS manifests under disturbance of consciousness. Here, we report a case of primary HFS in which the patient's symptoms persisted in a coma.Case presentationA 74-year-old female with right-sided primary HFS for 20 years and had received botulinum toxin injections in our hospital. Unfortunately she was carried to emergency department after traumatic right pneumothorax by accident. During the emergency treatment, she lost consciousness due to simultaneous cardiac arrest and respiratory arrest. She was then admitted to the emergency intensive care unit for further treatment. During her hospitalization, she was in a coma with stable vital signs and persisting symptoms of HFS. Thus, a multidisciplinary consultation was requested to identify whether it was focal cortical seizures involving the right-side facial muscles. Physical examination revealed brief involuntary clonic or tonic contractions accompanied with the ‘Babinski-2 sign’. A combination of relevant data, including her past history, clinical presentation and a negative computed tomography scan of the head, led to a diagnosis of right-sided HFS. As the symptoms of HFS are not life-threatening, the use of anticonvulsants is unnecessary.ConclusionsFor the layperson, it is crucial to seek a multidisciplinary consultation to obtain a correct diagnosis.

Evaluation of 40 hemifacial spasm patients with MR angiography of the brain and vertebral artery dominance in the etiology of hemifacial spasm

Objectives: Hemifacial spasm is characterised by involuntary, rhythmic, tonic or clonic contractions originating from the facial nerve and occurring intermittently in unilateral facial muscles. The most commonly reported cause of hemifacial spasm is the compression of the facial nerve at its root exit/ entry zone by an ectatic or aberrant blood vessel, leading to local demyelination. In this study, we compared magnetic resonance angiography (MRA) findings from patients with hemifacial spasm and controls to determine whether vertebral artery dominance is part of the aetiology of this condition. Methods: This retrospective case-control study was conducted with data from 40 patients with hemifacial spasm who received botulinum toxin injections and for whom MRA findings were accessible, and 42 patients of similar age and sex who presented with symptoms of nonspecific headache in the outpatient neurology clinic. Magnetic resonance imaging and unenhanced time-of-flight MRA examinations from the study and control groups were evaluated. Results: A dominant vertebral artery was present in 52.2% of patients in the hemifacial spasm group and 33.3% of those in the control group, but this difference was not significant (p = 0.079). Conclusions: The lack of significant results supporting our hypothesis may be attributable to the small study population. Further studies with larger groups are warranted.

O-MD004. Therapeutic effect of low dose botulinum toxin type A injection in hemifacial spasm patients: A preliminary study

Introduction . Hemifacial spasm (HFS) is a common movement disorder characterized by involuntary tonic or clonic contractions of muscles innervated by the facial nerve. Botulinum toxin type A (BoNT-A) injection is currently the preferred symptomatic treatment for primary hemifacial spasm. Low dose injection of botulinum toxin in patients with HFS is still controversial. In this study, we evaluated the clinical characteristics and therapeutic effects of HFS patients receiving low dose BoNT-A injection. Methods . A descriptive study was conducted on hemifacial spasm patients in a referral hospital in Tangerang, Indonesia since 2018–2019. Patients with hemifacial spasm that had consented to the procedure were included, and patients who had contraindications were excluded. Demographic data, clinical data, duration of response, and side effects were analyzed. 1–4 units of botulinum toxin injection were intramuscularly injected to muscles that had spasm. Results . A total of 26 patients with HFS were treated with 82 BoNT-A treatments, comprising of 34,6% male and 65,4% female with doses injected 3.68 ± 1.68 U. Orbicularis oculi and zygomatic major muscles were the most injected muscles (92.3% and 38.5% respectively) while the least muscles injected were Frontalis and Risorius muscle (injected only in 3.8%). Lagophthalmos was the most common experienced side effects (reported in 17.6% of cases). Overall, 81.3% of patients reported moderate improvement after injection. Conclusion . This study showed that low dose injection of BoNTA might have a promising outcome. Majority of patients experienced moderate benefit with scanty side effects. Extensive evaluation of response rate, complication rate and resistance effects of BoNTA with abundant amount of samples are needed to further substantiate this study.

The relative effectiveness of two expanding bullet designs in young harp seals (Pagophilus groenlandicus): A randomised controlled field study in the Norwegian harp seal hunt

AbstractThe aim of this study was to investigate the relative effectiveness of a rapidly expanding Bonded hunting bullet and an explosively expanding Varmint bullet in young harp seals (Pagophilus groenlandicus). The study was conducted as an open, controlled and randomised parallel-group designed field trial. The animals were pre-randomised (1:1) into one explosively expanding (Varmint) and one expanding (Bonded) bullet type group, with 75 animals in each. The study sample consisted of young, weaned harp seals, 2-7 weeks of age, of both sexes, from the Greenland Sea harp seal population. The study was conducted during the regular hunt. Instantaneous death rate (IDR) and time to death (TTD) were the main variables. The observed IDR was 84% in both bullet groups. Correcting for Weather Condition Index, the IDR for the Varmint bullet was significantly higher compared to the Bonded. The mean TTD was shortest in the Varmint group, but the difference did not reach significance. Compared to the Bonded, a significantly higher total cranial damage score and bleeding intensity, and significantly lower frequencies of bullet exit wounds were detected in the Varmint group. The post mortem reflex movements caused by the Varmint bullet were significantly more powerful with longer duration and higher frequencies of clonic contractions. In conclusion, the results indicate a higher effectiveness of the Varmint bullet relative to the Bonded. The Varmint bullet may thus improve animal welfare in the hunt of young harp seals.

Endoscopic Microvascular Decompression for Hemifacial Spasm.

Introduction and Objective:Hemifacial spasm (HFS) is a condition, characterized by painless, involuntary unilateral tonic or clonic contractions of the facial muscles innervated by the ipsilateral facial nerve. HFS starts with contractions in the orbicularis oculi muscle with subsequent eyelid closure and/or eyebrow elevation, but may spread to involve muscles of the frontalis, platysma, and orbicularis oris muscles. Microvascular decompression (MVD) is reliable and accepted surgical treatment for HFS. MVD is the standard surgical technique now for HFS treatment with long-term success rates.Materials and Methods:We performed fully endoscopic MVD technique for 1 patient with HFS (a 83-year-old female) at our institution. HFS was diagnosed based on the clinical history and presentation, a neurologic examination, and additional imaging findings. Respectively, the durations of HFS were 3 years, respectively. The patient had been previously treated with repeated botulinum toxin injections. Preoperative evaluation was done with magnetic resonance imaging; three-dimensional computed tomography fusion images examinations had identified the anterior inferior cerebellar artery (AICA) as the offending vessel in this patient.Results:The patient with HFS was treated by fully endoscopic MVD technique. The AICA, which had been identified as the offending vessel by preoperative magnetic resonance imaging, was successfully decompressed. No surgery-related complications occurred and had excellent outcomes with the complete resolution of HFS immediately after the operation.Conclusions:Endoscopic surgery can provide a more panoramic surgical view than conventional microscopic surgery. Fully endoscopic MVD is both safe and effective in the treatment of HFS. This method minimizes the risks of brain retraction and extensive dissection often required for microscopic exposure. Endoscopic MVD is safe and has advantage over microscope in terms of visualization of structure, identification of neurovascular conflict, but it has a learning curve and technically challenging.

Ptosis following botulinum toxin injection in hemifacial spasm

Hemifacial spasm (HFS) is characterized by irregular involuntary tonic or clonic contractions of muscles innervated by the seventh cranial nerve. Patients usually need long-term treatment, as spontaneous remission is infrequent. Repeated botulinum toxin injection has been shown as a safe and successful treatment for symptomatic relief in patients with HFS.1 Side effects are usually mild and transient. Ptosis has been reported in about 24% of patients with HFS probably due to diffusion of toxin to levator palpebrae superioris muscle.2 However, the frequency of ptosis in patients with HFS has not been addressed yet, due to causes other than botulinum toxin side effect. Herein, we present a case of HFS who presented to our clinic with complaint of complete ptosis and progressive pain early after botulinum toxin injection. Despite initial negative evaluations, further work up revealed a compressive lesion. A 75-year-old man presented with left severe ptosis since 3 weeks ago (Figure 1). He was known case of left HFS since 4 years ago, and botulinum toxin had been regularly injected for his symptom relief in orbicularis oculi, corrugator, and procerus muscles. Figure 1. Left Blepharoptosis one week after botulinum toxin injection The patient stated that this new ptosis had begun within a week after his last Dysport (Ipsen, Ltd., Slough, Berkshire, UK) injection while he had no ptosis in his previous injections. In past medical history, he had ischemic heart disease, hypertension, cataract extraction of both eyes, and glaucoma surgery on his right eye. He had been admitted to the neurology ward of a general hospital.

Prognosis of benign childhood epilepsy with centrotemporal spikes: clinical utility of objective diagnostic criteria

Studies about childhood epilepsy with centrotemporal spikes (CECTS), most of them retrospective, include patients with highly heterogeneous features. To investigate the prognostic value of objective diagnostic criteria for CECTS applied at six month of evolution of epilepsy. All patients with one or more unprovoked epileptic seizures (n = 827) were prospectively included. We investigated prognosis and clinical features of five groups of patients defined in accordance with the presence of centrotemporal spikes (CTS) and the following signs: speech arrest or dysarthria; hemifacial tonic or clonic contractions; and prominent sialorrhea. Group A (two or three signs and CTS), group B (one sign and CTS), group C (no sign and CTS), group D (two or three signs without CTS), group E (tonic-clonic generalized seizures and CTS). 52, 12, 12, 22 and 8 cases were classified respectively into groups A, B, C, D and E. Patients of the five groups presented a similar semiology but differences in the probability of attaining a 3-years remission without antiepileptic treatment were observed: group A (98%), group B (92%), group C (90%), group D (77%), group E (100%). The difference between groups A and D was statistically significant. Cases of group A could be considered as well-defined cases of CECTS; cases of groups B, C and E, as probable cases of CECTS, and cases of group D must be excluded from the diagnosis.

Fully endoscopic microvascular decompression for hemifacial spasm.

Hemifacial spasm (HFS) is characterized by involuntary tonic and/or clonic contractions of facial nerve muscles. Fully endoscopic microvascular decompression (E-MVD) for HFS has not been widely adopted. This paper aims to illustrate the safety and efficacy of the fully endoscopic technique for HFS treatment. The authors conducted a single-center retrospective study of 27 patients (28 separate E-MVD cases; 1 patient had bilateral E-MVD) diagnosed with HFS who underwent fully E-MVD from January 2013 to October 2016. Intraoperative brainstem auditory evoked potentials and lateral spread resolution were reviewed. Outcome was based on the clinical status of the patient at the last contact point with the senior author. Complications were categorized as facial weakness, hearing loss, ataxia, dysphagia, or any adverse event able to be attributed to the surgical procedure. HFS was relieved either completely or partially in the majority of cases (24 of 28, 85.7%). Of the 28 separate procedures, 17 (60.7%) resulted in complete resolution of symptoms, 4 (14.3%) resulted in near-complete resolution, 2 (7.1%) resulted in 50% reduction of symptoms, 1 (3.6%) resulted in minimal reduction, and 4 (14.3%) resulted in no relief. Of the 27 patients, 26 (96%) had no permanent postoperative complications. In multivariate logistic regression, the best predictor of greater than 50% resolution of spasm was resolution of intraoperative lateral spread response. A fully E-MVD for HFS provides a safe and comprehensive view of the neurovascular conflict. Exclusive use of the endoscope in MVD is both safe and feasible in the treatment of HFS. Attention to lateral spread response monitoring remains an integral part of comprehensive neurosurgical management.

Treatment of hemifacial spasm with botulinum toxin type a: effective, long lasting and well tolerated.

To evaluate the long-term effect of botulinum toxin type A (BTX-A) in the treatment of HFS. A retrospective analysis of patients treated at the Movement Disorders Outpatient Clinic in the Neurology Service, Hospital de Clínicas, Federal University of Paraná, Curitiba, from 2009 to 2013 was carried out. A total of 550 BTX-A injections were administered to 100 HFS patients. Mean duration of improvement following each injection session was 3.1 months, mean latency to detection of improvement was 7.1 days and mean success rate was 94.7%. Patients were evaluated at an interval of 5.8 months after each application. Adverse effects, which were mostly minor, were observed in 37% of the patients at least once during follow-up. The most frequent was ptosis (35.1%). Treatment of HFS with BTX-A was effective, sustainable and safe and had minimal, well-tolerated side effects.

Efficacy of levetiracetam in primary hemifacial spasm

Hemifacial spasm (HFS) is a peripherally-induced movement disorder characterized by the involuntary, unilateral, intermittent, irregular, tonic or clonic contractions of muscles innervated by the ipsilateral facial nerve. Kindling-like hyperactivity of the facial nucleus induced by constant stimulation of compressing artery is considered as the predominant mechanism underlying the pathogenesis of HFS. As a treatment for HFS, microsurgical decompression and botulinum toxin injection have been shown to be highly successful. Anticonvulsant drugs relieve HFS in some patients; however, the use of such drugs is limited owing to their side effects, predominantly in elderly patients. We experienced two elderly HFS patients who exhibited a marked response to levetiracetam (LEV) without side effects. Although the exact underlying pharmacological mechanism remains unknown, we assume anti-kindling effect as one of the important pharmacological mechanism underlying the effect of LEV against HFS. Moreover, LEV is considered to be suitable for use in elderly patients because of its good tolerability. In addition, the lack of hepatic induction or inhibition makes it an easy and safe drug when used in addition to other anticonvulsants. Although the long-term benefit remains unknown, LEV may represent an alternative treatment for elderly HFS patients who are unable to undergo or decline surgical intervention and/or botulinum toxin injections or are intolerant to other anticonvulsants.

A particular type of epileptic seizures in infancy with cerebellar ganglioneurocytoma

A 4-month-old female infant presented with paroxysmal clonic or tonic hemifacial contractions. Afterward, she sometimes had clonic hemibody contractions. Nystagmoid eyeball movements were also occasionally seen. These evolved to stereotypic clinical patterns and frequencies, despite administration of antiepileptic drugs. Magnetic resonance imaging revealed a mass in the right cerebellar hemisphere, involving the right middle peduncles and effacing the fourth ventricles. Video-scalp electroencephalogram monitoring revealed a left fronto-temporal irregular spike slow wave that at times propagated to the contralateral hemisphere. The lesion was removed and pathologic diagnosis was ganglioneurocytoma. Postoperatively, the infant did not present any new seizures but she died eight days after surgery due to severe duodenal hemorrhage. We suggest that cerebellar ganglioneurocytoma may cause epileptic hemifacial seizures of subcortical origin as was previously described.

Neonatal hemifacial spasm and fourth ventricle mass

Congential hemifacial spasm is a rare condition that is characterized by the occurrence of paroxysmal hemifacial contractions in neonates. We review the clinical, neurophysiological, neuroimaging, and histopathological findings, as well as the differential diagnosis, therapeutic approach, and outcome of all the described cases. Moreover, we report two new cases including the ictal video-electroencephalography recordings. Hemifacial spasm starts early in life, and is characterized by unilateral, involuntary, irregular tonic or clonic contractions of muscles innervated by the seventh cranial nerve. Hemifacial spasm is associated with eyelid blinking, and sometimes with breathing irregularities, hyperventilation, and/or other neurological manifestations (dystonic movements, nystagmus). Interictal and ictal video-electroencephalography did not reveal epileptiform abnormalities. In all cases, brain magnetic resonance imaging showed a mass involving the cerebellar peduncle, the cerebellar hemisphere, or the floor of the fourth ventricle. The semiology of the paroxysmal attacks is probably due to the activation of cranial nerve nuclei through intralesional hypersynchronous discharges, as shown by the intraoperative recordings and functional brain imaging described in the literature. We point out the importance of identifying such seizures in order to make an early diagnosis of the underlying cerebral lesion.

Botulinum toxin in hemifacial spasm: the challenge to assess the effect of treatment

Hemifacial spasm is characterized by intermittent tonic or clonic contractions of the muscles supplied by the facial nerve. Although vision is less impaired than in patients with blepharospasm, the disease can impose significant psychosocial burden on patient's life. Botulinum toxin (BoNT) is the well-established pharmacotherapy of choice, but evidence from controlled clinical trials is sparse. There is a broad variety of rating scales used in clinical studies with BoNT and obviously no consensus has been reached how to assess treatment outcome in hemifacial spasm. Clinical rating scales focusing on objective function were used in a couple of controlled studies with BoNT and were appropriate to discriminate between BoNTA and placebo. But it has not been shown that they would be sensitive enough to detect minor differences between several BoNT formulations. Although most of the clinical scales consist of a five-point rating, the descriptors for the ordinal numbers are not necessarily the same so that the results of different clinical studies are not comparable to each other. The main disadvantage of clinical scales is that they do not take into account patient's perspective of disability and impact on daily life. For this reason some clinical studies applied health-related quality of life (HRQoL) questionnaires to assess efficacy, and one research group worked on the development of disease-specific tools. Although these HRQoL questionnaires have been validated and a good correlation to disease severity could be demonstrated, they are far from having become an established variable for efficacy assessment in hemifacial spasm trials. The challenge remains to establish tools which are appropriate to rate BoNT treatment effects in hemifacial spasm. Currently, it is virtually impossible to identify one rating scale which can cover all relevant aspects of the disorder. In consequence we recommend the implementation of a combination of different rating scales which address functional impairment as well as those issues which are most important to patients. Further research is needed to standardize and validate rating scales for hemifacial spasm in clinical studies.

Hemifacial spasm: clinical characteristics of 321 Indian patients

Hemifacial spasm (HFS) is a common neurological disorder characterized by involuntary tonic and clonic contractions of the muscles innervated by the facial nerve. We aimed to describe clinical features, common antecedents, triggers and relieving factors in patients with hemifacial spasm to study the correlation of hypertension and HFS, and to compare clinical features of primary and secondary cases of HFS. The data for the study were collected prospectively on a predesigned and pre-tested format at the first attendance in all consecutive HFS patients attending the movement disorders clinic of a tertiary teaching hospital in India. The demographic profile, HFS symptoms, antecedent illnesses and neurological examination were recorded and analyzed. Muscle power in individual muscles innervated by the facial nerve was tested carefully before botulinum toxin injection. Hemifacial spasm occurred in 7.14% (n = 582) of 8,151 cases registered at the movement disorders clinic from 1993 to 2010. Data of 321 patients were complete and were included in the study. Females constituted 49.22% (n = 158). The mean age the patients was 46.02 ± 11.82 years; ipsilateral ear clicking was observed in 22.74% cases. The most common aggravating factor was stress (44.86%), while the most common relieving factor was sleep (44.24%). Two hundred fifty-two patients (78.5%) had primary HFS. The severity of spasm correlated significantly with disease duration (p < 0.001) and weakness of facial muscles (p < 0.001). We did not observe any correlation between HFS on the left side and hypertension, as has been reported earlier. This is one of the largest studies of HFS patients and the only one that prospectively assesses patients with HFS clinically on their first visit. Interesting observations of this study are lack of female preponderance, presence of clicking in the ipsilateral ear and facial weakness even prior to botulinum toxin injection.

Accidental Administration of Ionic Contrast Medium through Intrathecal Route

Context: We report a case of generalized clonic contractions that developed after accidental administration of ionic contrast medium through intrathecal route for computed tomography (CT) cisternography. Non-ionic contrast media can be delivered intrathecally, whereas this route is contraindicated for ionic contrast media. Case details: 31 year-old woman, sodium meglumine ioxitalamate was administered through the intrathecal route, developed convulsions. Eventually she was cured with anticonvulsive agents and supportive treatment. Discussion: Ionic contrast medium should never be administered intrathecally, or else it may cause a lifethreatening neurotoxic reactions.

Hemifacial spasm as a manifestation of pilocytic astrocytoma in a pediatric patient

Hemifacial spasm is a disorder of the seventh cranial nerve, which is characterized by irregular, involuntary and recurrent tonic and clonic contractions of the ipsilateral facial expression muscles. This disorder affects mainly adults, and there are few cases reported in childhood. The main etiologies are vascular problems, although tumors are an important cause of hemifacial spasm via a direct or an indirect mass effect. We report a 6-year-old girl who presented with right hemifacial spasm. Magnetic resonance imaging showed a lesion in the cerebellopontine angle, extending from the midbrain to the pons with a slight mass effect on the fourth ventricle. The histological examination revealed a pilocytic astrocytoma.

Design and Medical Safety of Neuromuscular Incapacitation Devices [Emerging Technologies

Neuromuscular incapacitation (NMI) devices deliver electric shocks that disrupt muscle functions in order to immediately stop a truly pain-resistant, aggressive, focused, or combat-trained attacker. Improvements made to shock waveforms secure temporary incapacitation by capturing motor nerves and causing clonic muscular contractions. Suspects can recover immediately after cessation of current delivery. This article discusses NMI topics with a focus on TASER devices. Current models of TASER devices known as electronic control devices (ECD), utilize compressed nitrogen to propel toward the subject two small probes at a speed of about 48 m/s. A special-waveform electrical signal is transmitted through trailing wires to where the probes make contact with the body or clothing. This signal directly stimulates pre-endplate motor nerve tissue resulting in an immediate loss of the person's neuromuscular control, with the initial reaction being a gravitational dysreflexia (i.e., fall to the ground) and loss of ability to perform coordinated action for the duration of the pulse. This provides the law enforcement officers with an opportunity to subdue the resisting suspect. This section address aspects related to the design of ECDs and medical safety concerns raised by their use in the field.