Gathering/Management/Security DBS Deact
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D Daily Persistent Headache DBS New Daily Persistent Headache Deep Brain Stimulation DAMGO Deactivation Definition Definition DAMGO is a μ opioid receptor selective enkephalin Many FMRI experiments show regions of cortex that derivative:[D-Ala2,N-Me-Phe4,Gly5-ol]-enkephalin. seem to respond in antiphase with the primary stimu- Opioids and Inflammatory Pain lus. This negative BOLD (blood oxygenated level de- pendent) response or deactivation is spatially and tem- porally linked to reductions in blood flow, and has been Dapsone shown to be primarily due to neuronal inhibition. Hippocampus and Entorhinal Complex, Functional Imaging Definition Nociceptor, Fatigue Dapsone is an antibacterial, belonging to a group of sulfonamide-like sulfones. It is used especially in the treatment of leprosy; administered orally. Dead Sea Hansen’s Disease Definition Dark Disc Disease This region in Israel is a major spa area for patients with various types of arthritis. Discogenic Back Pain Spa Treatment Data Deafferentation Definition Definition Data can be described in one of two of the following Deafferentation means interruption of afferent sensory ways: input due to nerve injury. This may be associated with i) Pieces of numerical or other information. chronic pain mainly due to mechanisms of peripheral ii) A set of facts from which conclusions can be drawn. and central sensitization. Although the lesion is usu- Postoperative Pain, Data Gathering and Auditing ally peripheral, lesions of ascending somatosensory pathways will lead to deafferentation of their target nuclei. Anesthesia Dolorosa Model, Autotomy Data Auditing/Collection/ Atypical Facial Pain, Etiology, Pathogenesis and Gathering/Management/Security Management Atypical Odontalgia Postoperative Pain, Data Gathering and Auditing Central Nervous System Stimulation for Pain 528 Deafferentation Pain Cordotomy Effects on Humans and Animal Models Dorsal Root Ganglionectomy and Dorsal Rhizotomy Decision Theory Hyperpathia, Assessment Peripheral Neuropathic Pain Statistical Decision Theory Application in Pain As- Plexus Injuries and Deafferentation Pain sessment Thalamic Plasticity and Chronic Pain Thalamus, Dynamics of Nociception Deconditioned Deafferentation Pain Definition Deconditioned refers to a state of poor physical condi- Definition tioning brought on by inactivity. Neuropathic pain generated in the central nervous sys- It is usually used to refer to a deterioration of physical tem, and secondary to interruption of afferent sensory conditioning, secondary to areduction in an individual’s pathways, projecting onto the concerned central struc- level of activity. The deconditioning may involve loss of ture.Theexistenceofhyperactiveneuronsinthedeaffer- strength, loss of flexibiIity, and reduced cardiovascular ented dorsal horn (DH) has been proven by microelec- function. trode recordings of the DH neurons, in humans as well Disability, Effect of Physician Communication as in animal experiments. Deafferentation pain may de- velop after avulsion of the brachial plexus, dorsal root rhizotomy or ganglionectomy, or other types of lesions Deep Brain Stimulation of peripheral nerves, or because of pathology of the cen- tral nervous system. N. WEISS,I.GARONZIK,A.SAMDANI,S.OHARA, Anesthesia Dolorosa Model, Autotomy F. A. LENZ BrachialPlexusAvulsionandDorsalRootEntryZone Johns Hopkins Medical Institutions, Department of Central Pain, Diagnosis Neurosurgery, Baltimore, MD, USA Dietary Variables in Neuropathic Pain fl[email protected] Dorsal Root Ganglionectomy and Dorsal Rhizotomy Synonyms DBS; Brain electrode Deception Definition Credibility, Assessment Electrical stimulation of subcortical structures in the brain including peri-ventricular grey; internal capsule somatic sensory and intralaminar nuclei of thalamus Decerebrated is a therapy for some patients with chronic pain. Definition Characteristics Cerebral brain function (in an animal) and its impact on Introduction lower brain and spinal cord can be eliminated experi- The electrical stimulation of subcortical brain struc- mentally by removing the cerebrum, cutting across the tures for the treatment of chronic pain was first reported brain stem, or severing certain arteries in the brain stem. in the 1950s, when hypothalamic nuclei were stim- Postsynaptic Dorsal Column Projection, Anatomical ulated for pain control (Tulane University School of Organization Medicine, Dept. of Psychiatry and Neurology 1954; Pool et al. 1956). Over the next few decades, the sensory thalamus and periaqueductal gray (PAG) became Decidualization the most frequent targets for deep brain stimulation (DBS). This transition followed the observation of stimulation-evoked analgesia, first in animals and sub- Definition sequentlyinhumans(Hosobuchietal.1977;Richardson Forming of the deciduas, which is the changed en- and Akil 1977). dometrium (the lining of the uterus), after the blasto- Chronic pain is pain that occurs daily over a 6-month cyst (fertilized ovum after 4–9 days of development) is period. Nociceptive refers to pain produced by activa- implanted onto the endometrium. tion of peripheral nociceptors and transmitted to the NSAIDs, Adverse Effects central nervous system through intact somatosensory Deep Brain Stimulation 529 pathways. Examples of nociceptive pain include pain tered during an admission to a pain clinic. Often, they of acute trauma and cancer pain secondary to inva- underwent psychosocial assessment, and were selected sion of bone. This pain responds well to opiates. for stimulation if there is no evidence of psychological Neuropathic pain refers to pain arising from injury to or secondary gain issues. In many published studies, pa- the nervous system either peripherally (deafferentation tients have been subjected to intravenous morphine in- pain, e.g. diabetic neuropathy) or centrally (centralpain, fusion tests, based on the hypothesis that nociceptive but e.g. post-stroke pain) (Portenoy 1989). It has been pro- not neuropathic pain responds to opioids. Reversibility D posed that this type of pain does not respond to opiates of analgesia with naloxone is taken as further evidence (Arner and Meyerson 1988), although this proposal is of a nociceptive pain condition. If the patient’s pain was not universally accepted (Vecht 1989; Dellemijn 1999). likely to be nociceptive in origin, PAG stimulation was performed. If the pain appeared to be neuropathic, the Mechanisms of Action patient underwent thalamic stimulation. The mechanisms of action of deep brain stimulation of the PAG and sensory thalamus are not completely un- Intraoperative Targets derstood. Evidence supports the role of endogenous Localization of the surgical target for PAG has been opioid release in PAG stimulation: focal stimulation determined using different means by different authors. of the PAG attenuates nociceptive responses to painful All targets were determined relative to the anterior stimuli (Reynolds 1969), an effect that is reversed by commissure-posterior commissure (AC-PC) line, a opioid antagonists (Hosobuchi et al. 1977), and which third ventricular radiologic landmark with a relatively is associated with increased endogenous opioid levels fixed anatomic relationship to subcortical structures. in the third ventricle (Akil et al. 1978; Hosobuchi et al. Levy and co-workers targeted a point 1 mm below 1979). Several lines of evidence also suggest that the and 1 mm posterior to the posterior commissure, and mechanism of analgesia in PAG stimulation involves 3 mm lateral to the lateral wall of the third ventricle spinal connections (Basbaum and Fields 1984; Ma- (Levy et al. 1987). Young and Rinaldi targeted a point ciewicz and Fields 1986). PAG neurons synapse upon 2 to 3 mm below the AC-PC line, 12 to 14 mm poste- neuronsin themedullary nucleusraphemagnus(NRM), rior to the midpoint (MC) of the AC-PC line and 2 to which, in turn, sends a strong serotonergic projection to 3 mm lateral to the midline (Young and Rinaldi 1997). the dorsal horn. This analgesic effect is also abolished Hosobuchi targeted a site at the level of the opening of by cutting the descending pathways to the spinal cord. the aqueduct into the third ventricle and 3 mm lateral to The PAG, medullary NRM and dorsal horn all contain the midline (Hosobuchi 1986). The correct target was high levels of opiates and opiate receptors. Due to the identified by stimulation-evoked warmth, oscillopsia, important role apparently played by opioids, PAG stim- loss of up-gaze, elevation of both heart rate and blood ulation is usually indicated in chronic nociceptive pain pressure, or pain relief. If the electrode is implanted conditions. more ventrally and posterior – in periaquaductal grey, The mechanism by which sensory thalamic stimula- fear and anxiety are evoked by stimulation (Hosobuchi tion provides pain relief is less clearly understood. 1986). Periventricular gray, which is slightly rostral The target nucleus for this type of stimulation is the to PAG, has been targeted as an alternative site to PAG in principal somatosensory nucleus, known as ventral some studies. The periventriculargray is located 10 mm caudal (Vc) in humans and ventral posterior (VP) in posterior to MC, at the vertical level of the AC-PC line, other species. Stimulation of rat VP inhibits responses and 3 to 4 mm lateral to the midline (Youngand Rinaldi to noxious stimulation through an opioid-independent 1997). pathway (Benabid et al. 1983). The effects of so- Levy and co-workers described sites of thalamic targets matosensory