Active clinical trials for "Neuralgia"

Patients with peripheral neuropathy frequently exhibit treatment-refractory neuropathic pain. Although both peripheral and central determinants are recognized for the pathophysiological basis of neuropathic pain following peripheral injury, the modulating effect on pain processing in brain by peripheral mechanisms remains elusive. Here, we will systematically compare the sensory symptoms and brain activation to painful heat stimulation applied to the foot dorsum between patients with peripheral neuropathy and healthy controls. Functional magnetic resonance imaging will be used to define brain activation to thermal stimulation with noxious heat and innocuous warm thermal stimuli applied by contact heat stimulator. Brain activation during thermal stimulation in patients with neuropathic pain will be clarified, and we will also analyze the potential relationships between the topography, quality and intensity of the different painful symptoms and the magnitude and pattern of brain activation during thermal stimulation. This will add in our understanding in the pathophysiology of brain modulation in pain and provide clinically useful message toward the potential therapeutics in the management of neuropathic pain.

Postherpetic neuralgia(PHN) is a chronic neuropathic pain syndrome which persists more than 3 months after the resolution of the acute shingles episode. PHN is a complicated neuropathic pain that results from the sustained peripheral injury by herpes zoster and its pathological mechanism in skin and spine has been reported. But the cerebral mechanism is still unclear. Based on the previous study that has proved the reorganization of cerebral functional connectivity in pain chronicity, the investigators hypothesize that the process from acute herpetic pain (AHP) to PHN is also accompanied with the reorganization of functional connectivity.In the study, the investigators intend to use 7 Tesla functional magnetic resonance imaging(fMRI) to observe the difference of brain activity and functional connectivity between acute herpetic pain and PHN. Meanwhile, the investigators examine the evolution of functional connectivity longitudinally in patients who is suffering from acute pain, so as to explore the central mechanism of transition to PHN.

Patients with neuropathic pain exhibit hyperalgesia and allodynia. Although both peripheral and central determinants are recognized for the pathophysiological basis of neuropathic pain following peripheral injury, the modulating effect on pain processing in brain by peripheral mechanisms remains elusive. Here, we will systematically compare the sensory symptoms and brain activation to innocuous and noxious thermal stimulation applied to the distal leg, foot dorsum or forearm between patients with peripheral neuropathy and healthy controls. Functional magnetic resonance imaging will be used to define brain activation to somatic stimulation with noxious and innocuous stimuli. The blood-oxygenation-level-dependent signals will be correlated with visual analogue scale scores and sensory and affective components obtained from the Short-Form McGill Pain Questionnaire. Brain activation during thermal stimulation in patients with neuropathic pain will be clarified, and we will also analyze the potential relationships between the topography, quality and intensity of the different painful symptoms (i.e. spontaneous ongoing pain, paroxysmal pain, allodynia, hyperalgesia) and the magnitude and pattern of brain activation during thermal stimulation. This will add in our understanding in the pathophysiology of brain modulation in pain and provide clinically useful message toward the potential therapeutics in the management of neuropathic pain.

Oral burning can have a multitude of reasons. Recent neurophysiologic study results suggest that a primary burning mouth disorder (BMD) may be a peripheral and/or a central neuropathic disorder. The aim of this study is to first identify patients with a primary burning mouth disorder by excluding other possible causes for oral burning. By means of qualitative and quantitative sensory testing and a gustatory examination in the individual patient the investigators want to find out whether neurosensory differences exist between patients with a primary BMD and controls and whether gustatory and neurosensory deficits always coexist in BMD-patients.

In order to clarify the normal components of thermal and painful evoked potentials by heat in normal subjects of both genders and different age group, to clarify the effect of specific anatomy in pain transduction, transmission and modification, and to establish the effect of peripheral nerve and their terminal free ending on the nociceptive transduction, the investigators will use heat stimulation on normal controls and patients with neurological diseases to clarify such issues.

The investigators will observe increased or decreased CBV in patients with thermal injury compared with the CBV in healthy controls.

Contextualization: Neuropathic pain is a complication present in the clinical picture of patients with traumatic Brachial Plexus injury (BPI). It is characterized by high intensity, severity and refractoriness to clinical treatments, resulting in high disability and loss of quality of life. Due to loss of afferent entry, it causes cortical and subcortical alterations and changes in somatotopic representation, from inadequate plastic adaptations in the Central and Peripheral Nervous System, one of the therapies with potential benefit in this population is the Transcranial High Definition Continuous Current Stimulation (HD-tDCS). Thus, by using connectivity-based response prediction and machine learning, it will allow greater assurance of efficiency and optimization of the application of this therapy, being directed to patients with greater potential to benefit from the application of this approach. Objective: Using connectivity-based prediction and machine learning, this study aims to assess whether baseline EEG related characteristics predict the response of patients with neuropathic pain after BPI to the effectiveness of HD-tDCS treatment. Materials and methods: A quantitative, applied, exploratory, open-label response prediction study will be conducted from data acquired from a pilot, triple-blind, cross-over, placebo-controlled, randomized clinical trial investigating the efficacy of applying HD-tDCS to patients with neuropathic brachial plexus trauma pain. Participants will be evaluated for eligibility and then randomly allocated into two groups to receive the active HD-tDCS or simulated HD-tDCS. The primary outcome will be pain intensity as measured by the numerical pain scale. Participants will be invited to participate in an EEG study before starting treatment. Clinical improvement labels used for machine learning classification will be determined based on data obtained from the clinical trial (baseline and post-treatment evaluations). The hypothesis adopted in this study is that the response prediction model constructed from EEG frequency band pattern data collected at baseline will be able to identify responders and non-responders to HD-tDCS treatment.

Spinal cord injury (SCI), induced by damage to the spinal cord, can cause life-altering levels of disability including the development of chronic pain. Central Neuropathic Pain (CNP) typically develops within months after injury in 40-50% of SCI patients, affecting everyday activity, sleep and mood. There is no cure for CNP, it can be very difficult to treat and is often refractory to any pharmacological treatments. In a previous study (study no. 14/WS/1029) the principle investigators showed that the likelihood of CNP developing can be predicted by defining characteristics of brain waves that are related to pain. We will use electroencephalograph (EEG) to measure brain activity in people early after SCI, before they develop pain, knowing that about half will develop pain within a year. We aim to recruit 80 participants, aged 18-80; 40 with subacute spinal injury (level C3-T12) and no symptoms of CNP; 20 with symptoms of CNP and 20 able-bodied participants. Completeness of injury is irrelevant. Patients will be recruited by clinical consultants within national spinal units in Glasgow and Stoke Mandeville. Patients will undergo two EEG recording sessions in which they will imagine movements while we record EEG. Sessions will also involve basic sensory testing and completion of questionnaires. Able-bodied participants will be recruited by the Philosophy Doctor (PhD) candidate at the University of Glasgow and undergo only one EEG session (identical to SCI patients). The primary aim of this study is to use early EEG markers of CNP to optimise and validate an existing computer program based on machine learning to enable more accurate prediction of pain in newly injured patients with the hope of aiding future treatments. Secondary aims include characterising EEG features which might describe different phases in patients' development of CNP and exploring possible differences between pain at/below the level of SCI based on EEG markers.

Arteriovenous fistulae are artificial connections between the artery and vein in the arm which allow needles to be inserted for haemodialysising patients wit kidney failure. Occasionally severe debilitating pain can arise from these fistulae for which no cause can be found. Such pain can be very difficult to treat. Many commonly used used painkillers are known to cause significant side effects in patients with renal failure (drowsiness, confusion etc. Qutenza (topical capsaicin 8%) is a new treatment made from chilli peppers which is applied to the skin as a patch and works directly at the nerve endings in the skin to prevent pain. It therefore should not have the systemic side effects of other drugs. It has been demonstrated to be beneficial in other painful conditions for example post-shingles pain and nerve pain from HIV. It has never been used for critical ischaemia before. We propose to investigate the efficacy of Qutenza in treating patients with end stage renal failure and chronic pain from their fistulae (AVF). We will recruit 20 patients with painful AVF and treat them with Qutenza. We will follow them up for 12 weeks and monitor the change in their pain scores.

Neuropathic (nerve pain) following amputation of a limb is very common, affecting 60-80% of patients (Sherman et al, 1984). It can prolong their recovery making it difficult to fit protheses and mobilise. Current treatment options are limited and existing painkillers have significant side effects. Nevertheless there is some evidence that pre-emptive analgesia (pain relief provided prior to the surgery) has additional benefits after the surgery (Ypsilantis & Tang, 2010) Qutenza (topical capsaicin 8%)is a novel analgesic agent which is applied directly onto the skin. It works by desensitising to pain receptors in the skin (Nolano et al., 1999) and has been shown to be effective in reducing neuropathic pain in other conditions (Backonja et al., 2008) We propose to evaluate the use of Qutenza for pre-emptive analgesia in patients undergoing amputation of a limb. This is a small, pilot, randomised controlled study of 30 patients undergoing lower limb amputation who will have Qutenza or active control applied prior to surgery. They will be followed up for 12 weeks post-operatively with regular assessment of pain scores, quality of life and wound healing.