The Role of the Amygdala and the Ventromedial Prefrontal Cortex in Emotional Regulation: Implications for Post-traumatic Stress Disorder.

The importance of the amygdala as a salience detector and in emotional learning is now well accepted. The mechanisms that regulate and inhibit the amygdala, however, are less well understood. This review provides evidence from imaging and lesion studies to support the role of the ventromedial prefrontal cortex (vmPFC) as a moderator and inhibitor of the amygdala. The dual inhibition model centres on the broadly defined ventromedial prefrontal cortex (vmPFC) and the distinct role of two of its subcomponents, the rostral anterior cingulate cortex and orbitofrontal cortex. The dual inhibition model posits that these two regions, along with their associated inhibitory pathways, must interact for adequate inhibitory control of the amygdala and emotional regulation. Following a description of the model's experimental support, it is then proposed as a neuropsychological mechanism for post-traumatic stress disorder (PTSD). Flashbacks, as a defining feature of PTSD, are described in terms of a subcortical orienting network. Finally, there is a discussion of how a neuropsychological understanding of post-traumatic stress disorder (PTSD) might inform a clinician's approach to treatment and how the dual inhibition model might have a more general application to understanding emotional dysregulation.

Awareness of psychological and relationship problems amongst brain tumour patients and its association with carer distress.

OBJECTIVE: The aim of this research was to investigate if brain tumour patients underestimate the severity of their impairments and the impact of this behaviour on carer distress . This study also aimed to identify the support services that patients and carers experiencing distress would find most beneficial. METHOD: A total of 32 post-surgery brain tumour patients, their carers, and a control group of 29 patients following surgery to extra-cerebral areas and their carers were recruited from outpatient clinics. Patients and carers rated the patient's psychological well-being and the impact of a range of changes since diagnosis/surgery. Patients and carers also rated their own level of distress and the support services they would find most beneficial. RESULTS: When compared with the control group, brain tumour patients were more likely to underestimate their psychological problems (p < 0.005) and the negative impact of changes to their emotional function (p < 0.05), interpersonal relationships (p < 0.05), cognition (p < 0.05) and coping skills (p<0.05). A multiple regression analysis showed that underestimation of psychological and interpersonal problems by brain tumour patients explained 35% of the variance in their carer's anxiety. CONCLUSION: The finding of reduced awareness or denial in brain tumour patients and its contribution to increased carer anxiety highlights the need for therapeutic interventions, which improve patient insight/denial and encourage patient and carer communication.

Emotional reactivity following surgery to the prefrontal cortex.

We aimed to elicit emotion in patients with surgically circumscribed lesions of the prefrontal cortex (PFC) in order to elucidate the precise functional roles in emotion processing of the discrete subregions comprising the ventromedial PFC, including the medial PFC and orbitofrontal cortex (OFC). Three components of emotional reactivity were measured: subjective experience, behaviour, and physiological response. These included measures of self-reported emotion, observer-rated facial expression of emotion and measurements of heart rate and heart rate variability (HRV) during film viewing, and a measure of subjective emotional change since surgery. Patients with lesions to the ventromedial PFC demonstrated significant differences compared with controls in HRV during the film clips, suggesting a shift to greater dominance of sympathetic input. In contrast, patients with lesions restricted to the OFC showed significant differences in HRV suggesting reduced sympathetic input. They also showed less facial expression of emotion during positive film clips, and reported more subjective emotional change since surgery compared with controls. This human lesion study is important for refining theoretical models of emotion processing by the ventromedial PFC, which until now have primarily been based on anatomical connectivity, animal lesion, and human functional neuroimaging research. Such theories have implications for the treatment of a wide variety of emotional disorders.

Lateralization of the startle reflex circuit in humans: an examination with monaural probes following unilateral temporal lobe resection.

Startle reflex (SR) modulation elicited by monaural probes during affective picture viewing was investigated in patients following left temporal lobectomy (LTL; n = 8) and right temporal lobectomy (RTL; n = 10) and in controls (n = 18). All patients had undergone anteromedial temporal lobe (ATL) resection. LTL participants exhibited attenuated overall SR magnitude. Affective SR modulation in controls was significant for left ear probes, at both eyes, but not for right ear probes. RTL but not LTL participants displayed significant startle attenuation during pleasant picture viewing. Results suggest that monaural startle probes primarily activate structures in the ipsilateral ATL and that the ATLs are interconnected, with the left ATL more critical in perceiving arousing properties of affective stimuli, necessary for affective SR modulation.

Emotional and personality changes following brain tumour resection.

Psychological distress has a high prevalence in brain tumour patients, and understanding the emotional and personality changes that may follow neurosurgery is important for clinical management of these patients. We aimed to characterise these emotional and personality changes using subjective, observer-rated and clinical measures. We examined subjective changes in emotional experience and observer-rated changes to personality disturbances following neurosurgery for brain tumours (n=44), compared to a control group that had undergone spinal surgery (n=26). Participants completed the Hospital Anxiety and Depression Scale and a Subjective Emotional Change Questionnaire. Observers who knew the patients well also completed the Iowa Rating Scale of Personality Change. Compared to controls, patients with tumours reported significantly more changes to their subjective experience of emotions following neurosurgery, particularly anger, disgust and sadness. For the observer-ratings, tumour patients were described as having significant changes in the personality disturbances of irritability, impulsivity, moodiness, inflexibility, and being easily overwhelmed. Anxiety and depression were not significantly different between groups. Neurosurgical resection of a brain tumour is a major life event that changes patients' subjective experiences of different emotions, and leads to observer-rated changes in personality. In this study, these changes were not accompanied by increases in anxiety or depression. We conclude with a discussion of biological and psychosocial mechanisms that can impact emotional functioning and personality in patients with brain tumours.

The relationship between mood state, interpersonal attitudes and psychological distress in stroke patients.

This study investigated whether increasing positive mood improved interpersonal attitudes and relieved depression in depressed stroke patients despite levels of cognitive and emotional dysfunction. Depressed stroke (n = 30) and rheumatic/orthopaedic controls (n = 30) were compared on the effect of verbal and nonverbal positive and neutral mood induction on mood state, interpersonal attitudes, psychological distress and related cognitive and emotional processing deficits. Compared with the neutral mood induction condition, the positive mood induction significantly improved mood state, interpersonal attitudes and psychological distress, irrespective of cognitive and emotional processing deficits. The nonverbal material was effective for all patients but was more marked for the left hemisphere stroke group. There was no obvious influence of humour appreciation despite reduced understanding in the right hemisphere stroke group. Although the effect is likely to be short-lived, these results support the trial of positive mood induction within therapy programmes to relieve depression.

Assessing the cognitive regulation of emotion in depressed stroke patients.

This study evaluated the psychometric properties of a simple scale for measuring positive interpersonal attitudes of depressed stroke patients, with regard to their cognitive limitations. Two versions of the Attitudes Towards Relationships Scale were developed and administered to depressed stroke (n = 48) and control rheumatic/orthopaedic (n = 45) patients during a study that investigated the relationship between mood state, interpersonal attitudes and psychological distress. Both versions produced homogeneous results and showed acceptable concurrent validity, test-retest reliability, internal consistency and measurement specificity. A principal component analysis produced a three-factor structure highlighting the importance of attitudes towards future interpersonal relationships. These results suggest that the Attitude Towards Relationships Scale may be a psychometrically sound measure that shows some potential as a therapeutic measure of progress in stroke and other comparable samples.

A controlled, prospective study of neuropsychological outcomes post parathyroidectomy in primary hyperparathyroid patients.

BACKGROUND: There is an increasing number of primary hyperparathyroidism (PHPT) patients with neuropsychological or psychiatric symptoms. Many of these patients do not have osseous or renal complications to satisfy the criteria for parathyroidectomy according to the NIH guidelines. OBJECTIVE: To assess whether there is any improvement in neuropsychological and mood symptoms following parathyroidectomy. PATIENTS AND DESIGN: Twenty PHPT patients undergoing parathyroidectomy and 20 orthopaedic controls matched for age, gender and estimated intelligence were subjects to pre and postoperative assessment of cognition and mood with a mean surgery-retest interval of 3 months. RESULTS: Using two tests of attentional flexibility [the Stroop test, the Digit symbol test of the Wechsler Adult Intelligence Scale-Revised (WAIS-R)], and two memory tests for prose and nonverbal material, no significant change was found between the groups when comparing scores before and after surgery. There was no improvement between pre and postoperative measures of verbal (dominant hemisphere) as opposed to visuo-spatial (nondominant hemisphere) function when compared to controls. There was no relationship between the reduction in serum calcium and the change in the neuropsychological measures postoperatively. CONCLUSION: This controlled, prospective study demonstrates no significant improvement in neuropsychological indices using objective, validated psychometric tools in an unselected cohort of PHPT patients. No relationship was found between serum calcium level and the degree of neuropsychological deficit. More studies are needed to assess whether the effect of parathyroidectomy is beneficial and sustainable in PHPT patients with neuropsychological symptoms alone.

The ESDQ: a new method of assessing emotional and social dysfunction in patients following brain surgery.

The Emotional and Social Dysfunction Questionnaire (ESDQ) has been designed to overcome some of the difficulties of inappropriately applying psychiatric based questionnaires to brain-damaged populations. Two-hundred and twenty-five patients were assessed following brain surgery (BS) using a self-rating patient version of the ESDQ and 211 of these patients were rated by their partner. A factor analysis using a varimax rotation and principal components analysis found the partner results to show eight factors including, Anger, Helplessness, Emotional Dyscontrol, Indifference, Inappropriateness, Fatigue, Maladaptive behaviour, and Insight. The analysis of the Self-rating questions revealed a similar profile, Anger, Emotional Dyscontrol, Helplessness, Inertia, Fatigue, Indifference, Inappropriate, and Euphoria. The scales based on the factors were subjected to discriminant analysis in which the BS patients were compared with a combination control group of neurosurgical outpatients and terminally-ill cancer patients, all of which were without cerebral complaints. The brain surgery results for the partner-rated and the Self-rated version of the ESDQ were compared with control ratings of 42 partners and 54 self-ratings, respectively. The analysis showed a significant discrimination for the Partner-rated version on each of the eight scales individually with an overall significant overall separation (Wilks Lambda=.903, chi=21.1, df=8, p=<.005). The Self-rated version showed less separation on an individual scale basis the Emotional Dyscontrol scale failing to show a significant separation. The overall difference on the Self-rating version was significant [Wilks Lambda=.908, chi=26.2, df=8, p=<.001). The levels of internal consistency of the questionnaire scales were found to be satisfactory (Alpha,.78 -.94). Also the relationship between ESDQ scales and standardised measures of aggression, anxiety, depression, and vigour (STAXI, HADS, and POMS) gave an indication of acceptable levels of concurrent validity.

Emotional and social dysfunction in patients following surgical treatment for brain tumour.

Patients following brain surgery for tumour were assessed using the Emotional and Social Dysfunction questionnaire on a self-rating and partner version of the questionnaire. Analyses were performed on those patients who had self-ratings following surgery for astrocytoma (n=13), meningioma (n=26), neuroma (n=13) and pituitary adenoma (n=17). Patients with astrocytoma were rated highest when compared to the other tumour groups, although all groups of patients performed more poorly on some of the individual scales compared to a matched control group of extra-cerebral neurosurgery patients and terminally ill cancer patients. A malignant (n=48) and benign (n=33) classification similarly showed a higher partner and self-rating of malignant tumour patients. Both diagnosis and location of lesion determined outcome independently. Some differences in profile and severity between patient self-ratings and partner ratings indicate the need to survey both perspectives. This study shows a broader based emotional dysfunction in these patients which includes such prominent features such as anger, helplessness, fatigue, emotional dyscontrol, indifference, and maladaptive behaviour. These results are discussed in terms of follow-up therapeutic care and the need to further explore the relationship between lesion location and emotional profile.