Faculty Book
EVA WIDERSTRÖM-NOGA, D.D.S., Ph.D.
Research Associate Professor
Neurological Surgery,Department of Rehabilitation Medicine and the Neuroscience Program.
Chronic Pain and Altered Sensation Following SCI
Research
Interests
Chronic pain is one of the most frequently reported reasons for reduced quality of life following spinal cord injury. Recent taxonomy for chronic pain following SCI classifies pain as neuropathic or nociceptive, and according to level of injury. The neuropathic pains are usually associated with evoked pain, such as allodynia or hyperalgesia. The clinical presentation of pain associated with SCI is highly complex in that different pain types are often present simultaneously and these are caused by different mechanisms at the spinal cord, thalamic, and cortical levels. Furthermore, the refractory nature of pain following SCI and the associated psychosocial distress emphasize the need for a greater understanding of not only pathophysiological but also psychosocial mechanisms in the generation and maintenance of SCI-related pain. For effective treatment of the heterogeneous pains associated with SCI, specific pain-generating mechanisms in each individual need to be identified and treatments tailored to these mechanisms.
Current Research
Research topics in my laboratory relate to the evaluation of physiological and psychological mechanisms for the generation and maintenance of persistent pain conditions after SCI. our main areas of interest are:
1. Evaluation of sensory dysfunction
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TSA Neurosensory Analyzer
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Sensory dysfunction following SCI is clinically manifested as both spontaneous and evoked sensations. These abnormalities can, for example, be quantitative, such as threshold changes, i.e., hypo- or hyperesthesia or qualitative, such as allodynia, dysesthesia or paresthesia. However, spontaneous neuropathic pain, evoked pain and motor excitability may share common mechanisms, such as neuronal hyperexcitability due to loss of input to certain populations of neurons or lack of inhibition. In order to better elucidate such mechanisms, we perform quantitative sensory testing (QST) in the evaluation of these pain conditions. We use the TSA Neurosensory Analyzer to measure cold and heat thresholds (hypo/hyperesthesia), cold and heat pain thresholds (hypo/hyperalgesia) and vibratory thresholds (dorsal-column function).
2. Evaluation of psychosocial impact
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Pain History Drawing
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The refractory nature of the painful conditions following SCI suggests that personal characteristics related to adaptation and coping skills are critical determinants for quality of life. Despite seemingly similar pain conditions, clinical observation suggests that there is wide variability in how people respond to treatment interventions and adapt to SCI-related pain. For this purpose, we are developing and psychometrically testing various methods for the evaluation of the psychosocial impact of pain.
3. Determining cortical pain-generating mechanisms
Neuroimaging studies strongly suggest that pain perception is dependent on a network of sensory cortical areas (primary and secondary somatosensory cortices, insular cortex), limbic areas (anterior cingulate), associative cortex (prefrontal cortex) and subcortical structures, such as the thalamus. Dysfunction in these networks may underlie the generation and maintenance of chronic pain and associated conditions. The extent to which these basic mechanisms translate into clinical signs and symptoms in people with chronic neuropathic pain associated with SCI is largely unknown. In my lab, we are conducting imaging studies to assess neuronal function in the thalamus and areas of the cingulate cortex in individuals with neuropathic pain and SCI.
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Precise voxel selection in the thalamus
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Selection of anterior cingulate area for further analysis
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Widerström-Noga EG, Roy Felix E, Cruz-Almeida Y, Turk DC. Psychosocial Subgroups in Persons with Spinal Cord Injuries and Chronic Pain. Arch Phys Med Rehabil (in press).
Roy Felix E, Cruz-Almeida Y, Widerström-Noga, EG. Chronic pain after spinal cord injury: Why are some pains more disturbing than others? J Rehabil Res Dev. 2007;44:703-16.
Widerström-Noga EG, Cardenas DD. The role of brain imaging in SCI-related pain. Topics in Spinal Cord Rehab. 2007;13:81-93.
Widerström-Noga EG, Cruz-Almeida Y, Martinez-Arizala A, Turk DC. Internal consistency, stability, and validity of the spinal cord injury version of the multidimensional pain inventory. Arch Phys Med Rehabil 2006;87:516-23.
Cruz-Almeida Y, Martinez-Arizala A, Widerström-Noga EG. Chronicity of pain after SCI: A longitudinal analysis. JRRD 2005;42:585-94.
Widerström-Noga EG, Duncan RC and Turk DC. Psychosocial Profiles of People with Pain Associated with Spinal Cord Injury: Identification and Comparison with Other Chronic Pain Syndromes. Clin J Pain 2004;20:261-71.
Widerström-Noga EG and Turk DC. Exacerbation of chronic pain following spinal cord injury. J of Neurotrauma 2004;21:1384-95.
Widerström-Noga EG, Cruz Y, Krassioukov A. Is there a relationship between chronic pain and autonomic dysreflexia in persons with cervical spinal cord injury? J Neurotrauma 2004;21:195-204.
Widerström-Noga EG and Turk DC. Outcome measures in chronic pain trials involving people with spinal cord injury. SCI Psychosocial Process 2004;17:258-67.
Widerström-Noga EG and Turk DC. Types and Effectiveness of Treatments Used by People with Chronic Pain Associated with Spinal Cord Injuries: Influence of Pain and Psychosocial Characteristics. Spinal Cord 2003;41:600-9.
Pattany PM, Yezierski RP, Widerström-Noga EG, Bowen BC, Martinez-Arizala A, Garcia BR, Quencer RM. Proton Magnetic Resonance Spectroscopy of the Thalamus in Patients with Chronic Neuropathic Pain after Spinal Cord Injury. Am J Neuroradiol 2002:23;901-5.
Last updated: November, 2007
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