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Biomedical subjects

R K Pitman

Publications and source records attributed to R K Pitman.

At least 19 recordsLinked to original sources
PubMed2001

An fMRI study of anterior cingulate function in posttraumatic stress disorder.

BACKGROUND: Several recent neuroimaging studies have provided data consistent with functional abnormalities in anterior cingulate cortex in posttraumatic stress disorder (PTSD). In our study, we implemented a cognitive activation paradigm to test the functional integrity of anterior cingulate cortex in PTSD. METHODS: Eight Vietnam combat veterans with PTSD (PTSD Group) and eight Vietnam combat veterans without PTSD (non-PTSD Group) underwent functional magnetic resonance imaging (fMRI) while performing the Emotional Counting Stroop. In separate conditions, subjects counted the number of combat-related (Combat), generally negative (General Negative), and neutral (Neutral) words presented on a screen and pressed a button indicating their response. RESULTS: In the Combat versus General Negative comparison, the non-PTSD group exhibited significant fMRI blood oxygenation level-dependent signal increases in rostral anterior cingulate cortex, but the PTSD group did not. CONCLUSIONS: These findings suggest a diminished response in rostral anterior cingulate cortex in the presence of emotionally relevant stimuli in PTSD. We speculate that diminished recruitment of this region in PTSD may, in part, mediate symptoms such as distress and arousal upon exposure to reminders of trauma.

Case-Control Studies↗
PubMed2001

Multivariate assessment of explicit memory function in combat veterans with posttraumatic stress disorder.

Declarative memory impairment is a frequent complaint of patients suffering from posttraumatic stress disorder (PTSD). We assessed memory, attention, visual spatial skills, and executive function in Vietnam combat veterans with (n = 19) and without (n = 13) PTSD. Although PTSD subjects demonstrated a "generalized impairment" relative to non-PTSD subjects on a majority of tasks, only attention and memory provided unique and independent prediction of PTSD versus non-PTSD status. Our findings suggest that memory functioning represents a neurocognitive domain of specific relevance to the development of PTSD in trauma-exposed individuals, which can be distinguished from generalized attentional impairment as well as the effects of trauma exposure severity, IQ, comorbid depression, history of alcohol use, and history of developmental learning problems.

Alcoholism↗
PubMed2001

Longitudinal MRI study of hippocampal volume in trauma survivors with PTSD.

OBJECTIVE: The authors prospectively explored whether a reduction in the volume of the hippocampus occurs in recent trauma survivors who develop posttraumatic stress disorder (PTSD). METHOD: Thirty-seven survivors of traumatic events were assessed within a week of the traumatic event and 6 months later. The assessment included magnetic resonance imaging of the brain (including 124 coronal slices of 1.5-mm thickness), psychometric testing, and structured clinical interviews. The Clinician-Administered PTSD Scale conferred PTSD diagnoses at 6 months. RESULTS: Ten subjects (27%) had PTSD at 6 months. The subjects with PTSD did not differ from those without PTSD in hippocampal volume (right or left) at 1 week or 6 months. There was no reduction in hippocampal volume in the PTSD subjects between 1 week and 6 months. CONCLUSIONS: Smaller hippocampal volume is not a necessary risk factor for developing PTSD and does not occur within 6 months of expressing the disorder. This brain abnormality might occur in individuals with chronic or complicated PTSD.

Adult↗
PubMed2001

Investigating the pathogenesis of posttraumatic stress disorder with neuroimaging.

Rapidly evolving brain neuroimaging techniques such as magnetic resonance imaging (MRI) and positron emission tomography (PET) are proving fruitful in exploring the pathogenesis and pathophysiology of posttraumatic stress disorder (PTSD). Structural abnormalities in PTSD found with MRI include nonspecific white matter lesions and decreased hippocampal volume. These abnormalities may reflect pretrauma vulnerability to develop PTSD, or they may be a consequence of traumatic exposure, PTSD, and/or PTSD sequelae. Functional neuroimaging symptom provocation and cognitive activation paradigms using PET measurement of regional cerebral blood flow have revealed greater activation of the amygdala and anterior paralimbic structures (which are known to be involved in processing negative emotions such as fear), greater deactivation of Broca's region (motor speech) and other nonlimbic cortical regions, and failure of activation of the cingulate cortex (which possibly plays an inhibitory role) in response to trauma-related stimuli in individuals with PTSD. Functional MRI research has shown the amygdala to be hyperresponsive to fear-related stimuli in this disorder. Research with PET suggests that cortical, notably hippocampal, metabolism is suppressed to a greater extent by pharmacologic stimulation of the noradrenergic system in persons with PTSD. The growth of knowledge concerning the anatomical and neurochemical basis of this important mental disorder will hopefully eventually lead to rational psychological and pharmacologic treatments.

Brain↗
PubMed2000

Activation of anterior paralimbic structures during guilt-related script-driven imagery.

BACKGROUND: Several recent neuroimaging studies have examined the neuroanatomical correlates of normal emotional states, such as happiness, sadness, fear, anger, anxiety, and disgust; however, no previous study has examined the emotional state of guilt. METHODS: In the current study, we used positron emission tomography and the script-driven imagery paradigm to study regional cerebral blood flow (rCBF) during the transient emotional experience of guilt in eight healthy male participants. In the Guilt condition, participants recalled and imagined participating in a personal event involving the most guilt they had ever experienced. In the Neutral condition, participants recalled and imagined participating in an emotionally neutral personal event. RESULTS: In the Guilt versus Neutral comparison, rCBF increases occurred in anterior paralimbic regions of the brain: bilateral anterior temporal poles, anterior cingulate gyrus, and left anterior insular cortex/inferior frontal gyrus. CONCLUSIONS: These results, along with those of previous studies, are consistent with the notion that anterior paralimbic regions of the brain mediate negative emotional states in healthy individuals.

Adult↗
PubMed2000

Exaggerated amygdala response to masked facial stimuli in posttraumatic stress disorder: a functional MRI study.

BACKGROUND: Converging lines of evidence have implicated the amygdala in the pathophysiology of posttraumatic stress disorder (PTSD). We previously developed a method for measuring automatic amygdala responses to general threat-related stimuli; in conjunction with functional magnetic resonance imaging, we used a passive viewing task involving masked presentations of human facial stimuli. METHODS: We applied this method to study veterans with PTSD and a comparison cohort of combat-exposed veterans without PTSD. RESULTS: The findings indicate that patients with PTSD exhibit exaggerated amygdala responses to masked-fearful versus masked-happy faces. CONCLUSIONS: Although some previous neuroimaging studies of PTSD have demonstrated amygdala recruitment in response to reminders of traumatic events, this represents the first evidence for exaggerated amygdala responses to general negative stimuli in PTSD. Furthermore, by using a probe that emphasizes automaticity, we provide initial evidence of amygdala hyperresponsivity dissociated from the "top-down" influences of medial frontal cortex.

Amygdala↗
PubMed2000

Neurologic soft signs in chronic posttraumatic stress disorder.

BACKGROUND: Subtle neurologic impairment has been reported in several mental disorders. The goals of the present study were to evaluate neurologic status in patients of both sexes with chronic posttraumatic stress disorder (PTSD) from different traumatic experiences. METHODS: Twenty-one adult women who were sexually abused as children (12 with PTSD, 9 without) and 38 male Vietnam War combat veterans (23 with PTSD, 15 without) underwent examination for 41 neurologic soft signs, which were scored by the examiner as well as a blind rater observing videotapes. Subject history was obtained with special attention to neurodevelopmental problems. Psychometrics included the Wender Utah Rating Scale for symptoms of childhood attention-deficit/hyperactivity disorder and the Michigan Alcoholism Screening Test. Veterans also completed the Combat Exposure Scale and subtests of the Wechsler Adult Intelligence Scale-Revised. RESULTS: Average neurologic soft sign scores (interrater reliability = 0.74) of women with PTSD owing to sexual abuse in childhood (mean [SD], 0.77 [0.32]) and veteran men (0.72 [0.20]) with combat-related PTSD were comparable and significantly (P<.001) higher than those of women sexually abused as children (0.42 [0.10]) and combat veteran men (0.43 [0.17]) without PTSD. This effect could not be explained by a history of alcoholism or head injury. Subjects with PTSD reported more neurodevelopmental problems and more childhood attention-deficit/hyperactivity disorder symptoms and had lower IQs, all of which were significantly correlated with neurologic soft signs. CONCLUSION: Neurologic compromise is evident from subject history and findings from physical examination in both women and men with chronic PTSD who had experienced different kinds of traumatic events in childhood and adulthood.

Adolescent↗
PubMed2000

Personality profiles, dissociation, and absorption in women reporting repressed, recovered, or continuous memories of childhood sexual abuse.

Women reporting either repressed, recovered, or continuous memories of childhood sexual abuse or no abuse history completed questionnaires tapping personality traits, absorption (fantasy proneness), dissociation, depression, and posttraumatic stress. Planned contrasts indicated that recovered memory participants scored higher on absorption and dissociation than did those reporting either continuous memories or no abuse history; repressed memory participants scored nonsignificantly higher than did recovered memory participants. On measures of distress, continuous memory participants were indistinguishable from nonabused participants, repressed memory participants scored highest, and recovered memory participants scored midway between continuous and repressed memory participants.

Adolescent↗
PubMed2000

False recognition in women reporting recovered memories of sexual abuse.

False recognition--the mistaken belief that one has previously encountered a novel item--was examined in four groups of subjects: women reporting recovered memories of childhood sexual abuse, women who believe that they were sexually abused as children but who cannot recall this abuse (the "repressed" group), women who were sexually abused as children and always remembered the abuse, and women with no history of childhood sexual abuse. Subjects were administered a Deese/Roediger-McDermott paradigm. The results suggest that the recovered-memory group was more prone to false recognition than the other groups. In addition, women reporting recovered and repressed memories showed greater reduction in false recognition across study trials than did other subjects, perhaps reflecting strategic changes in performance.

Adult↗
PubMed2000

Auditory startle response in trauma survivors with posttraumatic stress disorder: a prospective study.

OBJECTIVE: Previous studies have shown elevated autonomic responses to startling tones in trauma survivors with chronic posttraumatic stress disorder (PTSD). The origin of these abnormal responses is obscure. The present study attempted to clarify this issue by prospectively evaluating responses to sudden, loud tones in individuals who arrived at a hospital emergency room after psychologically traumatic events. METHOD: By using a previously established protocol, autonomic and muscular responses to the tones were evaluated at 1 week, 1 month, and 4 months after the traumatic event. Structured diagnostic interviews performed at 4 months classified subjects into groups with (N=36) and without (N=182) PTSD, which were further subdivided according to the presence or absence of major depressive disorder as follows: neither PTSD nor depression (N=166), depression alone (N=16), PTSD alone (N=21), and both PTSD and depression (N=15). RESULTS: The groups showed comparable physiological responses to the tones at 1 week posttrauma. However, at 1 and 4 months posttrauma, the subjects with PTSD showed a greater heart rate response and required more stimulus trials to reach the criteria of skin conductance and orbicularis oculi electromyogram nonresponse. These findings were not significantly influenced by comorbid depression and were not explained by the severity of the traumatic event or by the intensity of the initial symptoms. CONCLUSIONS: Differences in physiological response to startling tones develop along with PTSD in the months that follow a traumatic event. This pattern supports the theories that associate PTSD with progressive neuronal sensitization.

Accidents, Traffic↗
PubMed2000

De novo conditioning in trauma-exposed individuals with and without posttraumatic stress disorder.

Differential conditioning was assessed in 15 medication-free individuals meeting Diagnostic and Statistical Manual of Mental Disorders (4th ed.; American Psychiatric Association, 1994) criteria for chronic posttraumatic stress disorder (PTSD) and 18 trauma-exposed individuals who never developed PTSD (non-PTSD). Conditioned stimuli (CSs) were colored circles, and the unconditioned stimulus was a "highly annoying" electrical stimulus. Individuals with PTSD had higher resting heart rate (HR) and skin conductance (SC) levels and produced larger SC orienting responses. During conditioning, the PTSD group showed larger differential SC, HR, and electromyogram responses to the reinforced vs. nonreinforced stimuli (CS+ vs. CS-) compared with the non-PTSD group. Only PTSD participants continued to show differential SC responses to CS+ vs. CS- during extinction trials. Results suggest that individuals with PTSD have higher sympathetic nervous system arousal at the time of conditioning and are more conditionable than trauma-exposed individuals without PTSD.

Adult↗
PubMed2000

Cognitive processing of trauma cues in adults reporting repressed, recovered, or continuous memories of childhood sexual abuse.

Psychologically traumatized people exhibit delayed color naming of trauma words in the emotional Stroop task. Four groups of participants were asked to color name positive words, neutral words, and trauma words; these groups included 15 women who believed that they harbored repressed memories of childhood sexual abuse (CSA), 13 women who reported recovered memories of CSA, 15 women who had never forgotten their CSA, and 12 women who had never been abused. Repressed-memory participants exhibited patterns of interference indistinguishable from those of the nonabused control group participants. Irrespective of group membership, the severity of self-reported posttraumatic stress disorder symptoms was the only significant predictor of trauma-related interference, r(48) = .30, p < .05.

Adult↗
PubMed2000

Psychophysiologic assessment of posttraumatic stress disorder in Vietnam nurse veterans who witnessed injury or death.

This study examined whether witnessing death and injury could produce psychophysiologically responsive posttraumatic stress disorder (PTSD). Participants consisted of medication-free female Vietnam nurse veterans with a diagnosis of current PTSD (n = 17) and who never had PTSD (n = 21), related to their military service. Individualized scripts describing personal traumatic military nursing events, a standard military nursing event, and other life events were tape recorded and played back to the participant while heart rate, skin conductance, and facial electromyograms were recorded. Nurses with PTSD showed significantly larger physiologic responses than non-PTSD nurses only during imagery of military-related nursing events. The groups' self-reported emotional responses did not differ during imagery. Psychophysiologic results support the proposition that witnessing death and serious injury to others is sufficiently stressful to cause PTSD.

Analysis of Variance↗
PubMed1999

Anger in healthy men: a PET study using script-driven imagery.

BACKGROUND: An understanding of the neurobiological basis of normal emotional processing is useful in formulating hypotheses regarding the pathophysiology of psychiatric illnesses. METHODS: This study examined the mediating functional neuroanatomy of anger in eight healthy men. Narrative scripts were developed from autobiographical information to induce anger and neutral states. The subjects imagined the content of the narrative scripts to induce anger during positron emission tomography to measure normalized regional cerebral blood flow (rCBF). Psychophysiologic responses and subjective ratings of emotional state were measured for each condition. Statistical parametric maps were constructed to reflect the Anger versus Neutral state contrast. RESULTS: Anger was associated with activation of the left orbitofrontal cortex, right anterior cingulate cortex affective division, and bilateral anterior temporal poles. CONCLUSIONS: These results suggest that the subjective experience of anger is associated with rCBF increases in anterior paralimbic regions of the brain.

Adult↗
PubMed1999

Neural activation during sexual and competitive arousal in healthy men.

To investigate the mediating neuroanatomy of positively valenced arousal, we used script-driven imagery in conjunction with positron emission tomography to measure relative regional cerebral blood flow (rCBF) during sexual and competitive arousal, as well as neutral comparison states. Subjects were eight healthy right-handed men. Psychophysiologic responses and subjective ratings confirmed that the desired state manipulations were achieved. Statistical parametric mapping revealed similar patterns of rCBF changes for both positively valenced arousal conditions: increases were found within anterior cingulate and anterior temporal cortex as well as the ventral globus pallidus; decreases were found within widespread heteromodal association areas. These results complement findings from studies of other normal and pathological emotional states, and provide new insights regarding the neural substrates of pleasurable arousal in healthy men.

Adult↗
PubMed1999

Physiologic reactivity to startling tones in women with posttraumatic stress disorder.

Autonomic and eyeblink reactivity to startling tones were investigated in women with histories of childhood sexual abuse (CSA). Twenty-one women with current posttraumatic stress disorder (PTSD), 23 with lifetime but not current PTSD, and 13 women who never had PTSD listened to 15 95-dB, 500-ms, 1000-Hz tones with a 0-ms rise time while heart rate (HR), skin conductance (SC), and orbicularis oculi electromyogram (EMG) responses were measured. Participants in the current and lifetime PTSD groups produced larger HR responses across tones and showed slower absolute habituation of SC response magnitude compared with the never PTSD group. EMG response magnitudes did not differ among groups. Women with CSA-related PTSD showed increased autonomic reactivity and slower habituation to high-intensity tones similar to that observed in primarily male, combat PTSD samples. This suggests that heightened autonomic responsivity to startling stimuli in PTSD is not gender or event specific.

Acoustic Stimulation↗
PubMed1999

Regional cerebral blood flow during script-driven imagery in childhood sexual abuse-related PTSD: A PET investigation.

OBJECTIVE: The purpose of this study was to determine whether anterior limbic and paralimbic regions of the brain are differentially activated during the recollection and imagery of traumatic events in trauma-exposed individuals with and without posttraumatic stress disorder (PTSD). METHOD: Positron emission tomography (PET) was used to measure normalized regional cerebral blood flow (CBF) in 16 women with histories of childhood sexual abuse: eight with current PTSD and eight without current PTSD. In separate script-driven imagery conditions, participants recalled and imagined traumatic and neutral autobiographical events. Psychophysiologic responses and subjective ratings of emotional state were measured for each condition. RESULTS: In the traumatic condition versus the neutral control conditions, both groups exhibited regional CBF increases in orbitofrontal cortex and anterior temporal poles; however, these increases were greater in the PTSD group than in the comparison group. The comparison group exhibited regional CBF increases in insular cortex and anterior cingulate gyrus; increases in anterior cingulate gyrus were greater in the comparison group than in the PTSD group. Regional CBF decreases in bilateral anterior frontal regions were greater in the PTSD group than in the comparison group, and only the PTSD group exhibited regional CBF decreases in left inferior frontal gyrus. CONCLUSIONS: The recollection and imagery of traumatic events versus neutral events was accompanied by regional CBF increases in anterior paralimbic regions of the brain in trauma-exposed individuals with and without PTSD. However, the PTSD group had greater increases in orbitofrontal cortex and anterior temporal pole, whereas the comparison group had greater increases in anterior cingulate gyrus.

Adult↗