Publications by authors named "Leadbetter R"

Article Synopsis
  • The study analyzed lower limb nerve ultrasound measurements to differentiate between inherited neuronopathy, inherited axonopathy, and acquired axonopathy in patients.
  • Researchers compared nerve sizes in 34 healthy controls with three patient groups, finding significant size variations particularly in the tibial and sural nerves.
  • Results indicated that inherited conditions (CANVAS and CMT2) had smaller nerve sizes compared to the acquired condition, suggesting ultrasound can help in diagnosing these neurological diseases more effectively.
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Article Synopsis
  • A study on New Zealand's multiple sclerosis (MS) cohort revealed that, 15 years after recruitment, individuals with MS have a median survival age of 79.4 years, significantly lower than the general population's 86.6 years.
  • Among the 2909 participants, 29% had died by the end of the study, with a standardized mortality ratio (SMR) of 1.9, indicating a nearly double mortality rate compared to the general population.
  • Higher mortality risks were observed for those with progressive-onset MS and those whose symptoms began at a younger age, with the greatest survival gap being 9.8 years for those who started showing symptoms between ages 21 and 30.
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Introduction/Aims Recent studies have shown that ultrasound of peripheral nerves can distinguish inherited sensory neuronopathy from acquired axonopathy with a high degree of accuracy. In this study we aimed to determine whether ultrasound can also distinguish inherited sensory neuronopathy from inherited axonopathy. Methods We compared the ultrasound cross-sectional areas (CSAs) of the median, ulnar, sural, and tibial nerves of retrospectively recruited patients with cerebellar ataxia with neuropathy and vestibular areflexia syndrome (CANVAS), in whom sensory neuronopathy is a cardinal feature, with Charcot-Marie-Tooth type 2 (CMT2) disease patients, who have an inherited axonopathy, using the Kruskal-Wallis test and receiver-operating characteristic curves.

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Introduction/aims: Sensory impairment secondary to dorsal root ganglion neuronopathy is common, although often subclinical, in X-linked spinal and bulbar muscular atrophy (SBMA). We investigated the hypothesis that nerves of SBMA patients show the same morphological changes on ultrasound as other inherited sensory neuronopathies and that these changes are distinct from those in axonal neuropathy.

Methods: We compared the ultrasound cross-sectional areas (CSAs) of median, ulnar, sural, and tibial nerves of prospectively recruited SBMA patients with those of patients with acquired axonal neuropathy and healthy controls.

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Positive and Negative Syndrome Scale (PANSS) data from a pivotal phase 3 study in participants with schizophrenia of RBP-7000, a recently marketed long-acting subcutaneous injectable risperidone formulation, were examined to determine if dose-response relationships existed for different items of the PANSS. Changes in the 30 PANSS items were analyzed individually and using the 5 factor-analysis-derived dimensions defined by Marder and colleagues. Subgroups of patients who could benefit from the RBP-7000 120 mg dose were investigated.

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Introduction: In everyday clinical neurophysiology practice, mononeuropathies are evaluated primarily by traditional electrodiagnostic testing. We sought to assess the additional benefit of neuromuscular ultrasound (US) in this scenario.

Methods: All consecutive mononeuropathies undergoing combined US and electrodiagnostic evaluation over a 23-mo period at a single neurophysiology practice were reviewed.

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Cerebellar ataxia with neuropathy and bilateral vestibular areflexia syndrome (CANVAS) is a recently recognized neurodegenerative disease with onset in mid- to late adulthood. The genetic basis for a large proportion of Caucasian patients was recently shown to be the biallelic expansion of a pentanucleotide (AAGGG)n repeat in RFC1. Here, we describe the first instance of CANVAS genetic testing in New Zealand Māori and Cook Island Māori individuals.

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This study aimed to develop a wearable sensor system, using machine-learning models, capable of accurately estimating peak ground reaction force (GRF) during ballet jumps in the field. Female dancers (n = 30) performed a series of bilateral and unilateral ballet jumps. Dancers wore six ActiGraph Link wearable sensors (100 Hz).

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To determine the incidence of gentamicin vestibulotoxicity with current dosing regimens, and to evaluate the feasibility of routine video-oculography on all patients given gentamicin. In this prospective incidence study serial horizontal vestibulo-ocular reflex (HVOR) gain measurements were recorded using video-oculography on adult inpatients receiving intravenous gentamicin. The primary outcome was the proportion of patients developing impairment of their HVOR gain.

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Objective: The objective was to assess if nerve ultrasound has a role in diagnosing sensory neuronopathy in spinocerebellar ataxia syndrome (SCA) by examining if proposed diagnostic cut-off criteria of ultrasound in sensory neuronopathy caused by cerebellar ataxia neuropathy vestibular areflexia syndrome (CANVAS) were also discriminatory for SCA-related sensory neuronopathy.

Methods: Optimal diagnostic cut-off criteria for nerve size measured by diagnostic ultrasound were developed in 14 patients with CANVAS and 42 healthy controls using six peripheral nerve sites; and logistic regression and receiver operating characteristic (ROC) curves. These proposed cut-off values were tested in seven patients with spinocerebellar ataxia type 2 (SCA2) patients with sensory neuronopathy.

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Background And Purpose: Sensory neuronopathy is a cardinal feature of cerebellar ataxia neuropathy vestibular areflexia syndrome (CANVAS). Having observed that two patients with CANVAS had small median and ulnar nerves on ultrasound, we set out to examine this finding systematically in a cohort of patients with CANVAS, and compare them with both healthy controls and a cohort of patients with axonal neuropathy. We have previously reported preliminary findings in seven of these patients with CANVAS and seven healthy controls.

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Introduction: Sensory impairment in Friedreich ataxia (FRDA) is generally accepted as being due to a ganglionopathy. The degree of contribution from axonal pathology remains a matter of debate. Nerve ultrasound may be able to differentiate these processes.

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Introduction: We report preliminary findings of nerve ultrasound in patients with cerebellar ataxia neuropathy vestibular areflexia syndrome (CANVAS) who have sensory impairment due to dorsal root ganglionopathy.

Methods: The ultrasound cross-sectional area (CSA) of median and ulnar nerves of 7 CANVAS patients was compared with 7 age- and gender-matched controls and with the mean CSA of our reference population.

Results: The nerve CSA of CANVAS patients was significantly smaller than that of controls at all sites (P < 0.

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The purpose of this study was to investigate the utility of peak outward acceleration (POA) measured from an inertial sensor worn at the wrist as an indicator of the critical end point of the bowling action – ball release, a critical element when assessing illegal actions. Twenty-one finger-spin and fast bowlers from nine countries were recruited from the ICC under-19 Cricket World Cup to take part in this research. Bowlers delivered a cross section of their standard deliveries while wearing an inertial sensor placed on their wrists.

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Purpose: Nonrandomized studies of the relationship of antiepileptic drugs (AEDs) with sudden unexpected death in epilepsy (SUDEP) may be susceptible to confounding by tonic-clonic seizure frequency, polypharmacy, and other potential risk factors for SUDEP. We evaluated the risk of SUDEP with lamotrigine (LTG) compared to active comparators and placebo in randomized controlled clinical trials conducted by GlaxoSmithKline (GSK) between 1984 and 2009.

Methods: Among 7,774 subjects in 42 randomized clinical trials, there were 39 all-cause deaths.

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Objectives: The efficacy of lamotrigine as maintenance treatment for bipolar disorder (BD), particularly for delaying depressive episodes, is well established, but its efficacy in the acute treatment of bipolar depression is less clear. This paper reports the results of five randomized, double-blind, placebo-controlled trials of lamotrigine monotherapy for the acute treatment of bipolar depression.

Methods: Adult subjects with bipolar I or II disorder experiencing a depressive episode were randomized to placebo or lamotrigine monotherapy (after titration, at a fixed dose of 50 mg or 200 mg daily in Study 1; a flexible dose of 100-400 mg daily in Study 2; or a fixed dose of 200 mg daily in Studies 3, 4 and 5) for 7-10 weeks.

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There are several issues that need to be better understood before breast tissue-engineering becomes viable clinically. One of the key issues is the interaction between cells and the microtopography of the implant surface. The aim of this study was to evaluate the efficacy of D1 cells, multipotent mouse bone marrow stromal precursors, in differentiating to fat and to characterize their metabolic activity (lactic acid released and glucose consumed) and lipid production when cultured on patterned poly-L-lactide (PLLA) films.

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Based on a review of the literature, a questionnaire was developed to create a scoring system for pregnancy-related symphysis pubis dysfunction (SPD) and completed by 150 (100 without SPD and 50 with SPD) peri-partum women. The questionnaire was tested for reliability in a sub-set of 21 women. Symptoms that were significantly associated with SPD were identified and used in a scoring system in order to diagnose patients with SPD.

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A review of the literature revealed a multitude of terms used to describe Symphysis Pubis Dysfunction (SPD). No unambiguous definition was found, rather the condition is described in terms of symptoms and signs. These occur due to the physiological pelvic ligament relaxation and increased joint mobility seen in pregnancy.

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Background: Two clinical trials, prospectively designed for combined analysis, compared placebo, lithium, and lamotrigine for treatment of bipolar I disorder in recently depressed or manic patients.

Method: 1315 bipolar I patients (DSM-IV) enrolled in the initial open-label phase, and 638 were stabilized and randomly assigned to 18 months of double-blind monotherapy with lamotrigine (N = 280; 50-400 mg/day fixed dose or 100-400 mg/day flexible dose), lithium (N = 167; serum level of 0.8-1.

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Tolerability and safety are important considerations in optimising pharmacotherapy for bipolar disorder. This paper reviews the tolerability and safety of lamotrigine, an anticonvulsant recommended in the 2002 American Psychiatric Association guidelines as a first-line treatment for acute depression in bipolar disorder and one of several options for maintenance therapy. This paper reviews the tolerability and safety of lamotrigine using data available from a large programme of eight placebo-controlled clinical trials of lamotrigine enrolling a total of nearly 1800 patients with bipolar disorder.

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Objective: Questions have been posed about the competence of persons with serious mental illness to consent to participate in clinical research. This study compared competence-related abilities of hospitalized persons with schizophrenia with those of a comparison sample of persons from the community who had never had a psychiatric hospitalization.

Methods: The study participants were administered the MacArthur Competence Assessment Tool for Clinical Research (MacCAT-CR), a structured instrument designed to aid in the assessment of competence to consent to clinical research.

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