Publications by authors named "Geoffrey Sheean"

Background: Disruption of external anal sphincter muscle (EAS) is an important factor in the multifactorial etiology of fecal incontinence (FI).

Objectives: We categorize FI patients into four groups based on the location of lesion in neuromuscular circuitry of EAS to determine if there are differences with regards to fecal incontinence symptoms severity (FISI) score, age, BMI, obstetrical history, and anal sphincter muscle damage.

Methods: Female patients (151) without any neurological symptoms, who had undergone high-resolution manometry, anal sphincter EMG, and 3D ultrasound imaging of the anal sphincter were assessed.

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Introduction/aims: Electromyography (EMG) can provide valuable insights into the pathophysiology of oropharyngeal muscles in various disease states, but the invasive nature of the conventional needle EMG (nEMG) has its limitations in this setting. We aimed to examine the inter-rater reliability (IRR) of a novel transmembranous EMG (tmEMG) sensor as a non-invasive technique for assessment of oral cavity and oropharyngeal muscles for neuromuscular pathology.

Methods: The study was a prospective, cohort, pilot study with blinded data analysis in healthy participants (n = 6), patients with moderate to severe obstructive sleep apnea (OSA) (n = 5) and bulbar amyotrophic lateral sclerosis (ALS) (n = 5).

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Objectives: Evaluate correlation between donor nerve semi-quantitative electromyography (sqEMG) and strength outcome in nerve transfer surgery.

Methods: Retrospective review of pre-operative donor nerve semi-quantitative neurophysiology and post-operative recipient muscle force after at least one-year follow-up. The semi-quantitative technique is the average motor unit number estimate associated with needle recorded interference patterns in the donor muscle (IP-AMUNE), which was correlated with hand-held manometry, standardized as a percent of the contralateral arm, using multivariable linear regression with backward selection.

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A successful nerve transfer surgery can provide a wealth of benefits to a patient with cervical spinal cord injury. The process of surgical decision making ideally uses all pertinent information to produce the best functional outcome. Reliance on clinical examination and imaging studies alone can miss valuable information on the state of spinal cord health.

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Objectives: The study aims to describe an ultrasound (US)-guided peripheral nerve stimulation implant technique and describe the effect of high-frequency peripheral nerve stimulation on refractory postherpetic neuralgia.

Materials And Methods: Following a cadaver pilot trial using US and confirmatory fluoroscopic guidance, a 52-year-old man with refractory left supraorbital neuralgia underwent combined US and fluoroscopic-guided supraorbital peripheral nerve stimulator trial. The patient was subsequently implanted with a percutaneous lead over the left supraorbital and supratrochlear nerve utilizing a high-frequency stimulation paradigm.

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Unlabelled: The use of transcranial motor evoked potentials (TCMEPs) to detect and hopefully prevent injury to the brain, spinal cord, and peripheral nerves intraoperatively has increased greatly in recent years. It is well established that in addition to certain anesthetic agents, patient factors such as advanced age, obesity, diabetes, hypertension, and a collection of neurological and neuromuscular diseases and disorders can greatly reduce or completely eliminate the ability to monitor TCMEPs effectively. One such disease, poliomyelitis (polio), is a highly contagious viral disease that has been mostly forgotten since its near-eradication through vaccination.

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Surgical interventions to improve function following nervous system injury have been in development since the early 1900s. Only recently these have been assimilated into a coherent approach which can be applied to injuries of the brain, spinal cord and peripheral nerves. In addition to pharmacological and stimulation based interventions, surgical manipulation of the peripheral nerves and muscles of the extremity can offer functional enhancement for a variety of limb impairments.

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Quantitative MUAP analysis is often based on outlier detection, in the case of neurogenic conditions, the finding of MUAPs that are larger than the limit determined from a reference normal population. Such reference data is available from only a few sources and for only a few muscles. It would be desirable if muscles could serve as their own controls.

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Objective: Motor unit action potentials (MUAPs) recorded by needle electrode reflect the functional state of the motor unit and its force-generating capacity, and are usually described morphologically (e.g. amplitude, duration).

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Quantification in clinical, diagnostic electromyography (EMG) currently includes motor unit action potential (MUAP) analysis and interference pattern analysis. Early efforts to examine the frequency/power spectra of the interference pattern showed modest value but the technique was not developed further. This paper re-examines spectral analysis, extending it into the time-varying domain, which has never been studied in diagnostic needle EMG.

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Background: Adequate relief from low-back pain (LBP) is not always possible. Emerging evidence suggests a role for botulinum neurotoxin (BoNT) injections in treating pain disorders. Proponents of BoNT suggest its properties can decrease muscle spasms, ischemia and inflammatory markers, thereby reducing pain.

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A delayed consequence of a lesion affecting the upper motor neuron pathways is the appearance of some forms of motor overactivity, including spasticity. Many of these are caused by hyperexcitability of spinal reflexes, such as stretch reflexes (spasticity, tendon hyperreflexia) or flexor withdrawal reflexes (flexor spasms), and are elicited at rest by sensory stimulation. Spastic co-contraction is probably attributable to failure of reciprocal inhibition; it occurs only during active voluntary movement and constrains such movement.

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Focal task-specific dystonia of the hand is rare in the general population, where it usually manifests as writer's cramp, but seems relatively common among musicians. The disability may be so severe as to prevent writing altogether or to end a professional musician's career. The cause is usually unknown but it is thought to be primarily a basal ganglia disorder with dysfunction of cortical-striatothalamic-cortical circuits.

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Injections of botulinum toxin have revolutionised the treatment of focal spasticity. Before their advent, the medical treatment for focal spasticity involved oral anti-spasticity drugs, which had decidedly non-focal adverse effects, and phenol injections. Phenol injections could be difficult to perform, could cause sensory complications and had effects that were of uncertain duration and magnitude.

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Weakness of neck extension causing a dropped head may result from many neuromuscular disorders. One etiology is isolated neck extensor myopathy. A similar focal myopathy of the lower axial muscles may cause the bent spine syndrome, which manifests as flexion of the trunk and inability to stand upright.

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Botulinum toxin type A (Dysport) has been shown in European studies to be a safe and effective treatment for cervical dystonia. This multicenter, double-blind, randomized, controlled trial assessed the safety and efficacy of Dysport in cervical dystonia patients in the United States. Eighty patients were randomly assigned to receive one treatment with Dysport (500 units) or placebo.

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Spasticity is a common complication of CNS injury and a cause of considerable discomfort and disability for the patient and difficulty for caregivers. It is estimated that over half a million people in the USA are affected by spasticity. In recent years, advances in the treatment of spasticity include the use of intrathecal baclofen, addition of tizanidine to oral medication and the introduction of intramuscular botulinum toxin injections.

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The impressive pain relief experienced by sufferers of dystonia and spasticity from intramuscular injections of botulinum toxin suggested that patients with other chronic, musculoskeletal pain conditions also may benefit. However, there have been relatively few placebo-controlled studies of botulinum toxin in such non-neurologic conditions as myofascial pain syndrome, chronic neck and low back pain, and fibromyalgia; the results of these studies have not been impressive. One explanation for the lack of positive findings may be the lack of clinically evident muscle spasms (overactivity), despite the presence of muscle tenderness, tightness, or trigger points.

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