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To review the clinical signs of vocal fold paresis on laryngeal videostroboscopy, to quantify its impact on patients’ quality of life and to confirm the benefit of laryngeal electromyography in its diagnosis.
Twenty-nine vocal fold paresis patients were referred for laryngeal electromyography. Voice Handicap Index 10 results were compared to 43 patients diagnosed with vocal fold paralysis. Laryngeal videostroboscopy analysis was conducted to determine side of paresis.
Blinded laryngeal electromyography confirmed vocal fold paresis in 92.6 per cent of cases, with vocal fold lag being the most common diagnostic sign. The laryngology team accurately predicted side of paresis in 76 per cent of cases. Total Voice Handicap Index 10 responses were not significantly different between vocal fold paralysis and vocal fold paresis groups (26.08 ± 0.21 and 22.93 ± 0.17, respectively).
Vocal fold paresis has a significant impact on quality of life. This study shows that laryngeal electromyography is an important diagnostic tool. Patients with persisting dysphonia and apparently normal vocal fold movement, who fail to respond to appropriate speech therapy, should be investigated for a diagnosis of vocal fold paresis.
The pathogenesis of otitis media is related to Eustachian tube dysfunction. The tensor veli palatini muscle actively opens the Eustachian tube and promotes middle-ear ventilation. This study describes a technique for paratubal electromyography that uses a surface, non-invasive electrode able to record tensor veli palatini muscle activity during swallowing.
Twenty otitis media patients and 10 healthy patients underwent tensor veli palatini electromyography. Activity of this muscle before and after Eustachian tube rehabilitation was also assessed.
In 78.5 per cent of patients, the electromyography duration phase and/or amplitude were reduced in the affected side. The muscle action potential was impaired in all patients who underwent Eustachian tube rehabilitation.
This study confirmed that Eustachian tube muscle dysfunction has a role in otitis media pathogenesis and showed that muscle activity increases after Eustachian tube rehabilitation therapy.
Objectives: 1) Assess which electrodiagnostic studies Canadian clinicians use to aid in the diagnosis of carpal tunnel syndrome (CTS). 2) Assess whether Canadian clinicians follow the American Association of Neuromuscular & Electrodiagnostic Medicine/American Academy of Neurology/American Academy of Physical Medicine and Rehabilitation Practice Parameter for Electrodiagnostic Studies in CTS. 3) Assess how Canadian clinicians manage CTS once a diagnosis has been established. Methods: In this prospective observational study, an electronic survey was sent to all members of the Canadian Neuromuscular Group (CNMG) and the Canadian Association of Physical Medicine and Rehabilitation (CAPM&R) Neuromuscular Special Interest Group. Questions addressed which electrodiagnostic tests were being routinely used for the diagnosis of carpal tunnel syndrome. Management recommendations for CTS was also explored. Results: Of the 70 individuals who completed the survey, fourteen different nerve conduction study techniques were reported. Overall, 36/70 (51%) of participants followed the AANEM/AAN/AAPM&R Practice Parameter. The standard followed by the fewest of our respondents with 64% compliance (45/70) was the use of a standard distance of 13 to 14 cm with respect to the median sensory nerve conduction study. Regarding management, 99% would recommend splinting in the case of mild CTS. In moderate CTS, splinting was recommended by 91% of clinicians and 68% would also consider referral for surgery. In severe CTS, most recommended surgery (93%). Conclusions: There is considerable variability in terms of which electrodiagnostic tests Canadian clinicians perform for CTS. Canadian clinicians are encouraged to adhere to the AANEM/AAN/AAPM&R Practice Parameter for Electrodiagnostic Studies in CTS.
In this paper, we propose a biomechatronic design of an anthropomorphic artificial hand that is able to mimic the natural motion of human fingers. The prosthetic hand has 5 fingers and 15 joints, which are actuated by 5 embedded motors. Each finger has three phalanges that can fulfill flexion-extension movements independently. The thumb is specially designed to move along a cone surface when grasping, and the other four fingers are well developed based on the four-bar link mechanism to imitate the motion of the human finger. To accomplish the sophisticated control schemes, the fingers are equipped with numerous torque and position sensors. The mechanical parts, sensors, and motion control systems are integrated in the hand structure, and the motion of the hand can be controlled through electromyography (EMG) signals in real-time. A new concept for the sensory feedback system based on an electrical stimulator is also taken into account. The low-cost prosthetic hand is small in size (85% of the human hand), of low weight (420 g) and has a large grasp power (10 N on the fingertips), hence it has a dexterous and humanlike appearance. The performance of the prosthetic hand is validated in a clinical evaluation on transradial amputees.
To study stimulation-related facial electromyographic (FEMG) activity in intensive care unit (ICU) patients, develop an algorithm for quantifying the FEMG activity, and to optimize the algorithm for monitoring the sedation state of ICU patients.
First, the characteristics of FEMG response patterns related to vocal stimulation of 17 ICU patients were studied. Second, we collected continuous FEMG data from 30 ICU patients. Based on these data, we developed the Responsiveness Index (RI) algorithm that quantifies FEMG responses. Third, we compared the RI values with clinical sedation level assessments and adjusted algorithm parameters for best performance.
In patients who produced a clinically observed response to the vocal stimulus, the poststimulus FEMG power was 0.33 µV higher than the prestimulus power. In nonresponding patients, there was no difference. The sensitivity and specificity of the developed RI for detecting deep sedation in the subgroup with low probability of encephalopathy were 0.90 and 0.79, respectively.
Consistent FEMG patterns were found related to standard stimulation of ICU patients. A simple and robust algorithm was developed and good correlation with clinical sedation scores achieved in the development data.
Over the past 150 years, regional post-traumatic pain has had various appellations, most recently complex regional pain syndrome (CRPS) and post-traumatic neuralgia (PTN). CPRS appears to be a complex endophenotype of PTN that involves neurogenic inflammation as well as pain. There is increasing evidence that peripheral and central inflammatory cascades triggered by nerve injuries contribute to CRPS and perhaps PTN as well. PTN and CRPS often spread beyond classic individual nerve territories, although when patients are asked to outline the epicenter, or most abnormal area, this frequently identifies a specific nerve injury. The most dramatic CRPS and PTN-associated movement abnormality is fixed distal dystonia. Nerve conduction studies and electromyography are useful in documenting and localizing peripheral nerve damage. Currently, four classes of medications are primary options for chronic CRPS/PTN: tricyclics and serotonin-noradrenaline reuptake inhibitors; opioids; gabapentinoids; and topical or systemic local anesthetics.
The way in which orthodontic patients swallow poses a major problem during treatment, especially for long-term stability of the end result. If clinical diagnosis of atypical swallowing performed in an empirical manner by the practitioner, aided or not by rehabilitation devices, has been the subject of numerous studies, surface electromyography seems to bring new insight in diagnosing the way patients swallow and in re-training atypical deglutition. After a short refresher about the anatomy and physiology of the mechanisms of swallowing as well as the basic principles of electromyography, a descriptive and comparative study was carried out with 60 patients in order to understand and to prove the reliability and pertinence of this diagnostic tool. The results of the study are based on a collection of graphic and visual data compared to maxillo-facial kinesiographic studies where patients underwent a parallel double blind diagnosis. The objective was to determine if surface electromyography provides reliable, exact and reproducible data based on daily screening. Finally, it may be possible to create a flowchart for clinical decision making by using the results of our study as well as the findings in the literature.
The recurrent laryngeal nerve can be injured during surgery. This study investigated recurrent laryngeal nerve reinnervation.
To study the short-term effects of primary anastomosis of the recurrent laryngeal nerve, by laryngeal electromyography and histopathological analysis, in a rabbit model.
Twenty Zealand rabbits underwent either right recurrent laryngeal nerve (1) transection with excision of 1 cm or (2) transection and end-to-end primary anastomosis. Vocal fold movements, laryngeal electromyography results and histological changes were recorded.
Vocal fold analysis showed a paramedian vocal fold in both groups, with perceptible vibratory movements in group two. Electromyography revealed total denervation potentials in group one, but denervation and regeneration signs in group two. Histopathologically, hyperkeratosis and parakeratosis of the vocal fold mucosa were seen in group one, and signs of parakeratosis and hyperplasia in group two.
Even under ideal conditions for primary recurrent laryngeal nerve anastomosis, a return to normal muscle function is unlikely. However, such anastomosis prevents muscle atrophy, and should be performed as soon as possible. The degree of nerve recovery is associated with the number, amplitude and myelination level of fibrils returning to the original motor end-plaque.
The welfare consequences of long-distance transportation of animals remain a controversial topic. Animals that stand for most of the long journey (especially if additional muscular activity is required to deal with postural instability) are at risk of developing fatigue. Previous observational studies of behaviour and physiology suggested either that sheep do not become markedly fatigued by long journeys or that previous methods did not adequately identify fatigue. A range of behavioural and physiological measures were made on eight pairs of sheep during and after treadmill exercise. Within each pair of sheep, a treatment sheep was walked on a treadmill at 0.5 m/s for up to 5 h or until the sheep voluntarily stopped exercising or showed other signs of reduced performance, and a control sheep was exercised for two 10-min periods on either side of the exercise period for the treatment sheep. With the exception of one sheep that only walked for 4.5 h, all treatment sheep walked for 5 h without apparent difficulty. After exercise, the plasma cortisol concentration of treatment sheep was significantly greater than that of control sheep. However, there were no significant treatment effects on plasma creatine kinase activity or blood lactate concentration. After 5 h of exercise, there was a proportionate decrease in the median frequency of the electromyogram recorded over the m. semitendinosus, and this was significantly different from control sheep. There was no evidence that treatment sheep lay down sooner or for longer after treadmill exercise than controls. In sheep tested in a maze to examine whether there was increased motivation to rest after exercise, there was no significant difference between the times taken by treatment and control sheep to obtain a food reward. Qualitative behavioural assessment of the sheep by a panel of observers identified two main dimensions of sheep demeanour, but among descriptors elicited from observers only one person used a term associated with fatigue. No significant difference was found between the scores of treatment and control sheep on these two demeanour dimensions. Thus, there was little evidence that prolonged gentle walking exercise fatigues sheep. Further development of methods to both repeatedly induce and to identify fatigue in sheep is required.
Clinical neurophysiology encompasses a variety of diagnostic tests including EEG, nerve conduction studies, electromyography, evoked potentials and polysomnography. This chapter describes the tests that are most widely used for monitoring during neuroanaesthesia and neurocritical care, specifically, EEG, somatosensory evoked potentials (SSEPs), brainstem auditory evoked potentials, motor evoked potentials (MEPs) and electromyography (EMG). The main indications for EEG are in the diagnosis and management of epilepsy, sleep studies and neuromonitoring. Evoked potentials are the electrical response from the nervous system to an external stimulus. There are two types of EPs: sensory and motor. SSEPs monitor the integrity of sensory pathways, including peripheral nerves, and MEPs the motor pathways. Electromyography is a technique used to evaluate the electrical activity in muscle fibres. Two types of EMG monitoring commonly used include: recording spontaneous electrical activity and recording responses generated by stimulation of motor nerves.
Following the onset of facial palsy, physiotherapists routinely inspect the inside of the patient's mouth and cheek for complications such as ulceration or trauma. In several patients with complete facial nerve palsy, it was noticed that when the cheek was stretched there was subsequent spasm of the muscles of facial expression. This also occurred in patients whose facial nerve had been transected.
We present four patients in whom this response was demonstrated. We consider the mechanism of this response and its relevance in the management of patients with facial paralysis.
Following severe or complete denervation, contraction of the facial muscles following mechanical stretch provides evidence of preservation of activity in the facial muscle's excitation–contraction apparatus. Further research will investigate the clinical significance of this sign and whether it can be used as an early predicator of the development of synkinesis, as well as its relevance to facial nerve grafting and repair.
This chapter talks about a 54-year-old right-handed man who was brought to medical attention by his daughter because of progressive speech difficulty over the last 2 years. The patient was clinically diagnosed with fronto-temporal dementia with non-fluent progressive aphasia as well as behavioral symptoms. Sensory and motor nerve conduction studies were normal. EMG needle electromyography showed mixed denervation pattern in the right FDI and left biceps with 2_ fasciculation potentials, positive sharp waves, and fibrillations. Motor units were polyphasic with increase in sharp waves. External examination of the formalin-fixed brain showed no obvious cerebral atrophy or no focal lesions. The base of the brain was unremarkable apart from mild patchy atherosclerosis. Serial coronal sections through the cerebral hemispheres showed a normal ventricular system and deep gray structures. Sections of the brainstem and cerebellum were also unremarkable apart from mild loss of pigmentation of substantia nigra.
This chapter presents a case study of a 56-year-old male, American Society of Anesthesiologists Class III, scheduled to undergo T9-T12 laminectomy and microsurgical correction of a T10-T12 dural ateriovenous fistula. Central nervous system (CNS) function was monitored using somatosensory evoked potentials (SSEP), electromyography (EMG) and transcranial motor evoked potentials (MEP). The neurophysiologic monitors used in this case were monitors of CNS function, and can be described as follows: sensory evoked potentials (SEPs); motor evoked potentials; electromyography; and intraoperative changes. Sensory evoked potentials (SEPs) are measured electrophysiologic responses to somatosensory, visual, or auditory stimulation. Electromyography consists of monitoring muscle activity in response to either spontaneous or active nerve stimulation. In the immediate postoperative period a brief neurologic exam completed by the anesthetic team should be documented in the anesthetic record. In these ways morbidity and mortality in complex spine surgery using neurophysiologic monitoring can be reduced.
Restless legs syndrome and periodic limb movement disorder are common neurological entities that may be associated with insomnia and excessive daytime sleepiness. This chapter reviews the clinical features, natural history, laboratory investigations, genetics, pathology, and management of primary restless legs syndrome (RLS) and periodic limb movement disorder (PLMD). Large epidemiological surveys have shown that self-reported symptoms of RLS were correlated with sleepiness. Electrodiagnostic testing with nerve conduction studies and electromyography are useful to detect subtle peripheral neuropathies. Several factors suggest that impaired dopaminergic function and iron homeostasis underlie the pathophysiology of RLS. One study demonstrated that dopaminergic treatment of RLS patients improved both RLS severity and sleepiness as measured by multiple sleep latency test (MSLT) score. Considerable research has been directed towards elucidating the basic mechanisms and optimizing the management of RLS and PLMD.
Emotional facial expressions evoke rapid, involuntary, and covert facial reactions in the perceiver that are consistent with the emotional valence of the observed expression. These responses are believed to be an important low-level mechanism contributing to the experience of empathy, which some have argued rely on a simulation mechanism subserved by the human mirror neuron system (MNS). Because schizophrenia is associated with pervasive social cognitive difficulties which have been linked to structural abnormalities in the MNS network, the aim of the present study was to provide the first assessment of how rapid facial mimicry reactions (within 1000 ms poststimulus onset) are affected in schizophrenia. Activity in the corrugator supercilii and zygomaticus major muscle regions was quantified using electromyography while individuals with schizophrenia (n = 25) and controls (n = 25) viewed images of happy and angry facial expressions. In contrast to controls, individuals with schizophrenia demonstrated atypical facial mimicry reactions which were not associated with any clinical features of the disorder. These data provide evidence for a low-level disruption that may be contributing to empathizing deficits in schizophrenia and are discussed in relation to neuropsychological models of empathy and schizophrenia. (JINS, 2010, 16, 621–629.)
To investigate hedonic reactivity and the influence of unconscious emotional processes on the low sensitivity to positive reinforcement of food in anorexia nervosa (AN).
AN and healthy women were exposed to palatable food pictures just after a subliminal exposure to facial expressions (happy, disgust, fear and neutral faces), either while fasting or after a standardized meal (hunger versus satiety). Both implicit [facial electromyographic (EMG) activity from zygomatic and corrugator muscles, skin conductance, heart rate, and videotaped facial behavior] and explicit (self-reported pleasure and desire) measures of affective processes were recorded.
In contrast to healthy women, the AN patients did not display objective and subjective indices of pleasure to food pictures when they were in the hunger states. Pleasure to food cues (liking) was more affected than the desire to eat (wanting) in AN patients. Subliminal ‘fear faces’ increased corrugator muscle reactivity to food stimuli in fasting AN patients, as compared to controls.
The results suggest that unconscious fear cues increase the negative appraisal of alimentary stimuli in AN patients and thus contribute to decreased energy intake.
There is increasing evidence of gender differences in the pharmacokinetics and pharmacodynamics of aminosteroid neuromuscular blocking agents. Compared to males, females are more susceptible, requiring approximately 30% less rocuronium to achieve the same degree of neuromuscular block. However, little information is available whether this difference is applicable to modern benzylisoquinolines (cisatracurium).
In all, 848 patients (423 males, 425 females) undergoing general surgery under total intravenous anaesthesia with muscle relaxation, tracheal intubation and mechanical ventilation were studied. Patients were randomized to receive a single bolus dose of cisatracurium (0.1 mg kg−1, 221 males and 199 females) or rocuronium (0.6 mg kg−1, 202 males and 226 females). The onset time for 95% depression of T1, clinical duration until 25% recovery and recovery index (T1 from 25% to 75%) were determined with an NMT electromyographic module of the Datex-Ohmeda S/5 Anaesthesia Monitor. The data for male and female groups were compared with appropriate statistical tests (unpaired t-test, Mann–Whitney rank sum test and Fisher’s exact test).
In both groups (cisatracurium and rocuronium), males were significantly taller (P < 0.001) and heavier (P < 0.001) than females, but the body mass index was comparable. For rocuronium, the onset time was shorter 91.7 ± 14.3 s vs. 108.0 ± 14.6 s (P < 0.001) and the clinical duration was increased in females 43.3 ± 7.8 min vs. 31.3 ± 5.5 min (P < 0.001). In the cisatracurium group, both onset times (248.9 ± 60.7 s for males vs. 253.4 ± 70.9 s for females) and clinical duration (42.6 ± 6.9 min for males vs. 43.1 ± 6.9 min for females) were similar. The recovery index was identical for males and females in both groups.
Females were more sensitive than males to a single bolus dose of rocuronium. Under the study conditions described, the onset time was shorter and the clinical duration was increased in female patients. This suggests that the routine dose of rocuronium should be reduced in females compared to males. On the contrary, we could demonstrate no gender differences in the onset time or clinical duration of cisatracurium.