Elizabeth J. Richardson

Structural and functional neuroimaging correlates of depression in temporal lobe epilepsy.

Depression is commonly experienced among persons with temporal lobe epilepsy (TLE). Although evidence exists implicating dysfunction of distributed neural structure and circuitry among depressed persons without epilepsy, little is known regarding the neural correlates of depression in TLE. We examined the relationship between self-reported depression severity and both structural MRI volumetry and [(18)F]fluorodeoxyglucose positron emission tomography (PET)-measured resting metabolism of the amygdala and hippocampus of 18 patients with TLE. Significant positive relationships were noted between right and left amygdala volumes and depression. No other significant relationships were observed between amygdala PET measures, hippocampal volumes, or hippocampal PET measures and degree of depressive symptomatology. These findings indicate that both right and left amygdala volumes are associated with depression severity among persons with TLE. Future studies examining the potential role of extended neural regions may clarify the observed structural relationship between depressive symptoms and the amygdala.

Depressive symptoms and pain evaluations among persons with chronic pain: catastrophizing, but not pain acceptance, shows significant effects.

ABSTRACT Cognitive factors such as catastrophic thoughts regarding pain, and conversely, one’s acceptance of that pain, may affect emotional functioning among persons with chronic pain conditions. The aims of the present study were to examine the effects of both catastrophizing and acceptance on affective ratings of experimentally induced ischemic pain and also self‐reports of depressive symptoms. Sixty‐seven individuals with chronic back pain completed self‐report measures of catastrophizing, acceptance, and depressive symptoms. In addition, participants underwent an ischemic pain induction procedure and were asked to rate the induced pain. Catastrophizing showed significant effects on sensory and intensity but not affective ratings of the induced pain. Acceptance did not show any significant associations, when catastrophizing was also in the model, with any form of ratings of the induced pain. Catastrophizing, but not acceptance, was also significantly associated with self‐reported depressive symptoms when these two variables were both included in a regression model. Overall, results indicate negative thought patterns such as catastrophizing appear to be more closely related to outcomes of perceived pain severity and affect in persons with chronic pain exposed to an experimental laboratory pain stimulus than does more positive patterns as reflected in measures of acceptance.

Catastrophizing, acceptance, and interference: laboratory findings, subjective report, and pain willingness as a moderator.

OBJECTIVE The present study investigated the effects of both catastrophizing and the pain willingness component of acceptance on interference in daily activities and task performance during experimentally induced ischemic pain. In addition, the potential moderating role of pain willingness on the relationship between catastrophizing and degree of pain interference was also examined. DESIGN Sixty-seven persons with chronic low back pain completed measures of catastrophizing, acceptance, and daily pain interference. Participants underwent an ischemic pain induction procedure during which a Stroop-like task was administered. MAIN OUTCOME MEASURES Self-reported pain interference and observed performance on a Stroop-like task during induced pain. RESULTS The pain willingness component of acceptance and catastrophizing both contributed significantly to self-reports of pain interference. However, levels of pain willingness had an effect much stronger than the negative effects associated with catastrophizing with respect to observed pain interference during induced pain. Results also indicated that pain willingness serves as a moderator in the relationship between catastrophizing and task performance during induced pain. CONCLUSION The pain willingness factor of acceptance and catastrophizing both appear to be strong predictors for self-reported pain interference. During an objective assessment of pain interference, however, pain willingness shows a stronger effect and attenuates the negative impact of catastrophizing on task functioning.

Memory for famous faces and the temporal pole: functional imaging findings in temporal lobe epilepsy.

The ability to recognize, name, and provide information about famous persons is deficient in patients with temporal lobe epilepsy (TLE), although the neural basis for these deficits is not well understood. We examined the relationship of resting metabolism of the temporal poles, as determined by [18F] fluorodeoxyglucose positron emission tomography, to performance on a task of famous face recognition, naming, and generation of semantic information in 12 patients with TLE. Correlations between metabolic measures of the temporal poles and performance on the Famous Faces Task revealed strong relationships between all aspects of the Famous Faces Task and the left temporal pole, whereas Famous Faces Task correlations with the right temporal pole were not significant. These findings indicate that the left temporal pole is associated with lexical and semantic retrieval of knowledge of famous persons in patients with TLE. Further study appears warranted to elucidate the networks involved in semantic knowledge for famous faces.

Contributions of Volumetrics of the Hippocampus and Thalamus to Verbal Memory in Temporal Lobe Epilepsy Patients.

Recent theories have posited that the hippocampus and thalamus serve distinct, yet related, roles in episodic memory. Whereas the hippocampus has been implicated in long-term memory encoding and storage, the thalamus, as a whole, has been implicated in the selection of items for subsequent encoding and the use of retrieval strategies. However, dissociating the memory impairment that occurs following thalamic injury as distinguished from that following hippocampal injury has proven difficult. This study examined relationships between MRI volumetric measures of the hippocampus and thalamus and their contributions to prose and rote verbal memory functioning in 18 patients with intractable temporal lobe epilepsy (TLE). Results revealed that bilateral hippocampal and thalamic volume independently predicted delayed prose verbal memory functioning. However, bilateral hippocampal, but not thalamic, volume predicted delayed rote verbal memory functioning. Follow-up analyses indicated that bilateral thalamic volume independently predicted immediate prose, but not immediate rote, verbal recall, whereas bilateral hippocampal volume was not associated with any of these immediate memory measures. These findings underscore the cognitive significance of thalamic atrophy in chronic TLE, demonstrating that hippocampal and thalamic volume make quantitatively, and perhaps qualitatively, distinct contributions to episodic memory functioning in TLE patients. They are also consistent with theories proposing that the hippocampus supports long-term memory encoding and storage, whereas the thalamus is implicated in the executive aspects of episodic memory.

Effects of Nicotine on Spinal Cord Injury Pain Vary Among Subtypes of Pain and Smoking Status: Results From a Randomized, Controlled Experiment

UNLABELLED Smoking has been associated with increased pain severity in general chronic pain populations. Less is known about the effects of smoking and nicotine on the multifaceted and often complex subtypes of pain that frequently occur following spinal cord injury (SCI). The purpose of this study was to examine the effects of nicotine on self-reported pain among individuals with SCI and to determine if the effect of nicotine varied by pain subtype. A randomized, placebo-controlled crossover design was used to determine the effect of nicotine exposure on subtypes of SCI-related pain among smokers and nonsmokers. A complex relationship emerged, such that the degree of reported pain with exposure to 2 mg of nicotine compared to placebo varied according to pain type and smoking status of the subject. Pain sites that had characteristics of both neuropathic and musculoskeletal symptoms (deemed complex neuropathic pain sites) exhibited pain reduction after nicotine exposure in nonsmokers. In sharp contrast, smokers with this form of pain exhibited an increase in pain severity. Data were also examined descriptively to determine potentially unique factors associated with complex neuropathic pain that may explain trends associated with clinically relevant changes following nicotine exposure. In sum, smoking or tobacco use history may determine the analgesic (or enhanced pain perception) effect of nicotine on post-SCI pain. PERSPECTIVE Pain characterized by both neuropathic and musculoskeletal symptoms decreased in severity after nicotine exposure in nonsmokers with SCI but increased in severity among smokers with SCI. The analgesic (or enhanced nociceptive) effect of nicotine may depend on tobacco use history.

Psychosocial Measures for Clinical Trials in Spinal Cord Injury: Quality of Life, Depression, and Anxiety

Psychosocial measures including quality of life, depression, and anxiety are critical in assessing overall functioning of individuals with spinal cord injuries (SCIs). Unfortunately, there has been little agreement among researchers regarding which instruments most validly capture these constructs. The current article examines clinical trials focusing on psychosocial measures in SCI that have been conducted in the last several years. Because of the variety of instruments used in assessing psychosocial dimensions, comparisons drawn across clinical trials may be problematic. Strengths and shortcomings of several popular measures are described.

Effects of Nicotine on Spinal Cord Injury Pain: A Randomized, Double-Blind, Placebo Controlled Crossover Trial

BACKGROUND One factor affecting spinal cord injury (SCI)-related pain may be nicotine. Case reports have described a worsening of neuropathic pain from smoking and relief from abstinence. Neurobiological correlates also implicate the potential effect of nicotine on SCI-related pain. METHOD The current study employed a randomized, placebo-controlled crossover design to examine the effect of nicotine exposure on subtypes of SCI-related pain among smokers and nonsmokers. RESULTS Whereas nonsmokers with SCI showed a reduction in mixed forms of pain following nicotine exposure, smokers with SCI showed a converse increase in pain with regard to both mixed and neuropathic forms of pain. The exacerbation of pain in chronic nicotine or tobacco users may not only elucidate possible pain mechanisms but may also be of use in smoking cessation counseling among those with SCI.

Changes in pain and quality of life in depressed individuals with spinal cord injury: does type of pain matter?

Objective: To examine the association of neuropathic and nociceptive pain severity and interference with quality of life (QoL) in persons with spinal cord injury (SCI) who underwent a randomized controlled 12-week trial of an antidepressant to treat depression. A secondary objective was to assess the effect of changes in pain on mobility and physical independence. Design: Multivariable ANCOVA models controlling for relevant demographic covariates, treatment condition, and baseline pain and QoL were used. Setting: Six rehabilitation centers. Participants: Of the 133 persons who were randomized into the trial, 108 provided pain severity and interference ratings through follow-up. Interventions: Not applicable. Outcome Measures: The Satisfaction with Life Scale and the physical and mental component summary scores of the 12-Item Short-Form Health Survey (SF-12). Secondary outcome measures included the mobility and physical independence subscales of the Craig Handicap Assessment and Reporting Technique (CHART). Results: Broadly, few associations between pain and QoL were evident. Results revealed relationships between lower baseline nociceptive pain interference and higher satisfaction with life and mental health-related QoL at 12 weeks. Similarly, lower neuropathic pain interference was associated with change in physical independence, but unrelated to mobility. Conclusions: Pain interference over time may be differentially related to QoL outcomes based on the type of pain following SCI, but overall, there were no extensive relationships between pain and QoL in this sample of depressed persons with SCI.

Evaluating the Psychometric Properties and Responsiveness to Change of 3 Depression Measures in a Sample of Persons With Traumatic Spinal Cord Injury and Major Depressive Disorder.

OBJECTIVES To compare the measurement properties and responsiveness to change of the Patient Health Questionnaire-9 (PHQ-9), the Hopkins Symptom Checklist-20 (HSCL-20), and the Hamilton Depression Rating Scale (HAM-D) in people with spinal cord injury (SCI) diagnosed with major depressive disorder (MDD). DESIGN Secondary analysis of depression symptoms measured at 6 occasions over 12 weeks as part of a randomized controlled trial of venlafaxine XR for MDD in persons with SCI. SETTING Outpatient and community settings. PARTICIPANTS Individuals (N=133) consented and completed the drug trial. Eligibility criteria were age at least 18 years, traumatic SCI, and diagnosis of MDD. INTERVENTIONS Venlafaxine XR. MAIN OUTCOME MEASURES Patients completed the PHQ-9 and the HSCL-20 depression scales; clinical investigators completed the HAM-D and the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition (DSM-IV) Dissociative Disorders, which was used as a diagnostic criterion measure. RESULTS All 3 instruments were improved with rating scale analysis. The HSCL-20 and the HAM-D contained items that misfit the underlying construct and that correlated weakly with the total scores. Removing these items improved the internal consistency, with floor effects increasing slightly. The HAM-D correlated most strongly with Structured Clinical Interview for DSM-IV Dissociative Disorders diagnoses. Improvement in depression was similar on all outcome measures in both treatment and control groups. CONCLUSIONS The psychometric properties of the revised depression instruments are more than adequate for routine use in adults with SCI and are responsive to clinical improvement. The PHQ-9 is the simplest instrument with measurement properties as good as or better than those of the other instruments and required the fewest modifications.