39 results match your criteria: "Imperial College London at St Mary's[Affiliation]"

Background And Purpose: Twenty-four-hour ambulatory blood pressure and heart rate monitoring (24-h ABPM) can provide vital information on circadian blood pressure (BP) profiles, which are commonly abnormal in Parkinson's disease with and without autonomic failure (PD + AF and PD) and multiple system atrophy (MSA). Twenty-four-hour ABPM has not been directly compared between these disorders regarding cardiovascular autonomic function. Our aim was to determine the usefulness of 24-h ABPM with diary compared to head-up tilting (HUT) in diagnosing orthostatic hypotension (OH) in these patients.

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Structural brain abnormalities in postural tachycardia syndrome: A VBM-DARTEL study.

Front Neurosci

April 2015

Department of Psychiatry, Brighton and Sussex Medical School, University of Sussex Brighton, UK ; Sussex Partnership NHS Foundation Trust Brighton, UK ; Sackler Centre for Consciousness Science, University of Sussex Brighton, UK.

Postural tachycardia syndrome (PoTS), a form of dysautonomia, is characterized by orthostatic intolerance, and is frequently accompanied by a range of symptoms including palpitations, lightheadedness, clouding of thought, blurred vision, fatigue, anxiety, and depression. Although the estimated prevalence of PoTS is approximately 5-10 times as common as the better-known condition orthostatic hypotension, the neural substrates of the syndrome are poorly characterized. In the present study, we used magnetic resonance imaging (MRI) with voxel-based morphometry (VBM) applying the diffeomorphic anatomical registration through exponentiated lie algebra (DARTEL) procedure to examine variation in regional brain structure associated with PoTS.

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Exercise hemodynamics in Parkinson's disease and autonomic dysfunction.

Parkinsonism Relat Disord

May 2014

Autonomic and Neurovascular Medicine Unit, Faculty of Medicine, Imperial College London at St Mary's Hospital, London, UK; Autonomic Unit, National Hospital for Neurology and Neurosurgery, Queen Square/Division of Clinical Neurology, Institute of Neurology, University College London, UK.

Aim: To clarify the characteristics of hemodynamic responses to exercise and orthostasis in Parkinson's disease patients, especially those with autonomic failure.

Methods: Clinical audit of supine cycling exercise test data (with active standing tests pre- and post-exercise) of Parkinson's patients with autonomic dysfunction. 23 patients (71 ± 7 yr, 7 females) with a confirmed diagnosis of Parkinson's were identified.

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Neurodegenerative disease and obesity: what is the role of weight loss and bariatric interventions?

Metab Brain Dis

September 2013

The Department of Surgery and Cancer, Imperial College London, Imperial College London at St Mary's Hospital Campus, 10th Floor, Queen Elizabeth the Queen Mother (QEQM) Building, Praed Street, London, W2 1NY, UK.

Neurodegenerative diseases are amongst the leading causes of worldwide disability, morbidity and decreased quality of life. They are increasingly associated with the concomitant worldwide epidemic of obesity. Although the prevalence of both AD and PD continue to rise, the available treatment strategies to combat these conditions remain ineffective against an increase in global neurodegenerative risk factors.

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Exercise-induced hypotension in autonomic disorders.

Auton Neurosci

November 2012

Autonomic and Neurovascular Medicine Unit, Department of Medicine, Division of Brain Sciences, Faculty of Medicine, Imperial College London at St Mary's Hospital, UK.

The autonomic nervous system closely integrates a range of vital processes, including, cardiovascular function. Physical activity, or exercise, requires a range of integrated autonomic and cardiovascular adjustments in order to maintain homeostasis. Pathological conditions that result in dysfunction of the autonomic nervous system, such as autonomic failure, can therefore jeopardize the control of blood pressure resulting in hypotension and have serious implications for health.

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The pharaohs of Egypt's famous eighteenth dynasty all died early of unknown causes. This paper comprehensively reviews and analyses the medical literature and current evidence available for the New Kingdom rulers - Tuthmosis IV, Amenhotep III, Akhenaten, Smenkhkare and Tutankhamun. The integration of these sources reveals that the eighteenth dynasty rulers may have suffered from an inherited condition that may explain their untimely deaths.

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In Parkinsons disease and multiple system atrophy (MSA), cardiovascular dysfunction may occur for a variety of reasons and may manifest itself through inappropriate changes and/or levels in blood pressure, heart rate and/or regional vascular perfusion in a range of situations. The early occurrence of orthostatic hypotension often leads to consideration of MSA, especially in the presence of other features of autonomic failure. Orthostatic hypotension, however, is increasingly recognised in PD, and especially with increasing age, severity of disease and as a result of drug therapy, sometimes for associated disorders.

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Abnormal cardiovascular responses to carotid sinus massage also occur in vasovagal syncope - implications for diagnosis and treatment.

Eur J Neurol

August 2010

Neurovascular Medicine Unit, Imperial College London at St Mary's Hospital and Institute of Neurology, University College London, London, UK.

Background And Purpose: Carotid sinus massage (CSM) is commonly used to identify carotid sinus hypersensitivity (CSH) as a possible cause for syncope, especially in older patients. However, CSM itself could provoke classical vasovagal syncope (VVS) in pre disposed subjects.

Methods: Retrospective analysis of CSM, cardiovascular autonomic function tests (including tilt table testing) and medical history in 388 patients with recurrent syncope to identify and characterize patients in whom an abnormal response to CSM was more likely to reflect VVS than CSH.

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The concept of bionics was developed 50 years ago and represented the development of engineering and technology based on natural biological systems. Traditional applications of bionics in healthcare include artificial bionic organs that apply engineering principles to replace or augment physiological functions by integrating electronic, mechanical or electromechanical components to inherent body tissues/organs (we term this as 'exobionics'). Recently, there has been a new wave of bio-inspired treatments that act through the reorganization of the existing biological organs in an individual to enhance physiology.

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Background: Treatment strategies in chronic hepatitis B (CHB) are evolving as more potent oral antivirals become available. However, drug resistance remains a major challenge and policy guidelines on management are limited by the evidence base. This study aims to review the implications of the National Institute for Health and Clinical Excellence (NICE) guidelines in a cohort of unselected CHB patients in the United Kingdom and to evolve a management algorithm for their treatment.

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Patient suitability for magnetic resonance guided focused ultrasound surgery of uterine fibroids.

Eur J Obstet Gynecol Reprod Biol

April 2009

Academic Department of Obstetrics and Gynaecology, Department of Radiology, Imperial College London at St. Mary's Hospital, Praed Street, London, W2 1NY, UK.

Objective: To assess selection criteria used to determine eligibility for magnetic resonance-guided focused ultrasound surgery (MRgFUS) for the treatment of symptomatic uterine fibroids; to assess the percentage of patients suitable for MRgFUS.

Study Design: A retrospective analysis of 144 patients seeking minimally invasive treatment options for symptomatic uterine fibroids at a single treatment center. Clinical eligibility for MRgFUS was assessed at a gynecology clinic by a Gynecology research fellow trained in the procedure and suitability was assessed by magnetic resonance imaging.

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Background: Supine hypertension and post-prandial hypotension are associated with chronic autonomic failure, and may prove resistant to treatment. We determined if the hypotensive effects of food could be utilised to reduce supine hypertension in pure autonomic failure (PAF).

Methods: A subject with long-standing PAF, documented supine hypertension and post-prandial hypotension had a gastrostomy tube placed for dysphagia.

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Background: High fidelity simulations within the operating theatre (OT) require physical infrastructure and a full OT team. Such teams place heavy demands on clinical service. Research and training programmes in our surgical department were often compromised by the late cancellation of anaesthetists.

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Objective: Patients with pure autonomic failure (PAF) have an abnormal fall in blood pressure (BP) with supine exercise and exacerbation of orthostatic hypotension (OH) after exercise. This study assessed the pressor effect of water on the cardiovascular responses to supine exercise and on OH after exercise.

Methods: 8 patients with PAF underwent a test protocol consisting of standing for 5 min, supine rest for 10 min, supine exercise by pedalling a cycle ergometer at workloads of 25, 50 and 75 W (each for 3 min), supine rest for 10 min and standing for 5 min.

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L-dihydroxyphenylserine (Droxidopa) in the treatment of orthostatic hypotension: the European experience.

Clin Auton Res

March 2008

Neurovascular Medicine Unit, Faculty of Medicine, Imperial College London at St Mary's Hospital, Praed Street, London, W2 1NY, UK.

Neurogenic orthostatic hypotension is a cardinal feature of generalised autonomic failure and commonly is the presenting sign in patients with primary autonomic failure. Orthostatic hypotension can result in considerable morbidity and even mortality and is a major management problem in disorders such as pure autonomic failure, multiple system atrophy and also in Parkinson's disease. Treatment is ideally two pronged, using non-pharmacological and pharmacological measures.

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Multiple system atrophy and autonomic failure.

J Neural Transm Suppl

October 2006

Neurovascular Medicine Unit, Faculty of Medicine, Imperial College London at St. Mary's Hospital, UK.

Multiple system atrophy (MSA) is a sporadic neurodegenerative disorder that affects adults. It is characterised by autonomic failure affecting many systems; cardiovascular, urinary, sexual, gastrointestinal and sudomotor, amongst others. In addition there are motor deficits, resulting in both parkinsonian and/or cerebellar features.

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Increased arterial stiffness in Europeans and African Caribbeans with type 2 diabetes cannot be accounted for by conventional cardiovascular risk factors.

Am J Hypertens

September 2006

International Centre for Circulatory Health, National Heart and Lung Institute, Faculty of Medicine, Imperial College London at St. Mary's, Hammersmith Hospital, London, UK.

Background: The impact of diabetes on vascular target organ damage (TOD) is not wholly explained by conventional risk factors. African Caribbeans have a greater prevalence of diabetes and some aspects of TOD. We hypothesized that arterial stiffness, an independent cardiovascular risk factor, would be more prevalent with diabetes and in African Caribbeans with diabetes than Europeans.

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beta-adrenergic receptor blockers and the treatment of vasovagal syncope: more nails in the coffin!

Clin Sci (Lond)

September 2006

Neurovascular Medicine Unit, Faculty of Medicine, Imperial College London at St Mary's Hospital, Praed Street, London W2 1NY, UK.

beta-Adrenergic receptor blockers are one of a number of therapeutic agents promoted as having beneficial effects in vasovagal syncope. In this issue of Clinical Science, Eldadah and co-workers have investigated the effect of the beta-adrenergic receptor blocker propranolol in preventing syncope in a double-blind cross-over trial in eight subjects with a diagnosis based on tilt table testing and elevated plasma adrenaline levels during syncope. Of these, seven did not respond and the authors therefore suggest that this drug has no role in the management of vasovagal syncope.

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Gonadotrophin-releasing hormone and magnetic-resonance-guided ultrasound surgery for uterine leiomyomata.

Obstet Gynecol

July 2006

Academic Department of Obstetrics and Gynaecology, Department of Radiology, Imperial College London at St. Mary's Hospital, London, United Kingdom.

Objective: Magnetic-resonance-guided focused ultrasound is a novel, noninvasive technique of thermoablation for uterine leiomyomata. The hypothesis of this study was that pretreatment of leiomyomata with gonadotrophin-releasing hormone (GnRH) agonists would allow effective treatment of larger uterine leiomyomata, increasing the number of women who could benefit from this technique.

Methods: We report a prospective study of women with leiomyomata in excess of 10 cm in diameter who received GnRH agonist before magnetic-resonance-guided focused ultrasound treatment.

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Objective: To determine the frequency, age distribution and clinical presentation of carotid sinus hypersensitivity (CSH) among 373 patients (age range 15-92 years) referred to two autonomic referral centres during a 10-year period.

Methods: Carotid sinus massage (CSM) was performed both supine and during 60 degree head-up tilt. Beat-to-beat blood pressure, heart rate and a three-lead electrocardiography were recorded continuously.

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Purpose: Sympathetic sudomotor function in chronic spinal cord injury (SCI) has been evaluated to determine if recording the sympathetic skin response (SSR) provides evidence of integrity of the spinal component of the sympathetic pathways.

Methods: Thirty subjects with chronic SCI and 15 healthy normal subjects were studied. The SSR was elicited using two physiological (auditory and inspiratory gasp) stimuli.

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We assessed the effects of clonidine on blood pressure (BP) and heart rate (HR) in multiple system atrophy (MSA), where the autonomic nervous system lesion site is preganglionic, and in pure autonomic failure (PAF), where it is postganglionic. In normal subjects, intravenous infusion of the selective alpha2-adrenoceptor agonist clonidine reduces BP and plasma noradrenaline (NA) levels by means of central alpha2-adrenoceptor action, as well as inducing growth hormone (GH) release. Clonidine-induced GH release is impaired in MSA but spared in PAF.

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Objective: Spinal cord injury (SCI) results in disruption of descending tonic activation of sympathetic circuits in the spinal cord. The authors determined whether different stimuli that increase sympathetic activity induced cutaneous vasoconstriction (skin vasomotor reflex, SkVR) above and below the level of lesion in subjects with clinically complete SCI.

Methods: Baseline skin blood flow (SkBF) and SkVR reduction rate in the pulp of the finger and great toe was measured by laser Doppler probes in chronic complete SCI and in controls.

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