Suicidal brains: A review of functional and structural brain studies in association with suicidal behaviour

Evidence of an association between a vulnerability to suicidal behaviour and neurobiological abnormalities is accumulating. Post-mortem studies have demonstrated structural and biochemical changes in the brains of suicide victims. More recently, imaging techniques have become available to study changes in the brain in vivo. This systematic review of comparative imaging studies of suicidal brains shows that changes in the structure and functions of the brain in association with suicidal behaviour are mainly found in the orbitofrontal and dorsolateral parts of the prefrontal cortex. Correlational studies suggest that these changes relate to neuropsychological disturbances in decision-making, problem solving and fluency, respectively. As a consequence, the findings from these studies suggest that suicidal behaviour is associated with (1) a particular sensitivity to social disapproval (2) choosing options with high immediate reward and (3) a reduced ability to generate positive future events. Further study is needed to elaborate these findings and to investigate to what extent changes in the structure and function of suicidal brains are amenable to psychological and/or biological interventions.     

Neurophysiological assessment of acute pain in infants: a scoping review of research methods

A systematic scoping search to describe the neurophysiological methods used in infant acute pain assessment research was conducted. Of the 2411 abstracts screened, 19 articles were retained. Nine studies utilised near‐infrared spectroscopy (NIRS), two utilised functional magnetic resonance imaging (fMRI), and eight utilised electroencephalography (EEG). There was methodological variability in studies utilising NIRS, whereas EEG and fMRI studies reported consistent methods. Of the eight EEG studies, six identified a nociceptive‐specific event‐related potential. Conclusion: While more methodologically rigorous studies are needed, ERPs appear to hold some promise as indicators of infant nociception during clinical procedures to supplement existing measures.     

Neural correlates of feeling sympathy

Positron emission tomography (PET) was used to investigate the neural correlates of feeling sympathy for someone else (i.e. the affinity, association, or relationship between persons wherein whatever affects one similarly affects the other). While undergoing PET scans, subjects were presented with a series of video-clips showing individuals (who were semi-professional stage actors) telling sad and neutral stories, as if they had personally experienced them. These stories were told with either congruent or incongruent motor expression of emotion (MEE). At the end of each movie, subjects were asked to rate the mood of the communicator and also how likable they found that person. Watching sad stories versus neutral stories was associated with increased activity in emotion processing-related structures, as well as in a set of cortical areas that belong to a "shared representation" network, including the right inferior parietal cortex. Motor expression of emotion, regardless of the narrative content of the stories, resulted in a specific regional cerebral blood flow (rCBF) increase in the left inferior frontal gyrus. The condition of mismatch between the narrative content of the stories and the motor expression of emotion elicited a significant skin conductance response and strong rCBF increase in the ventromedial prefrontal cortex and superior frontal gyrus which are involved in dealing with social conflict. Taken together, these results are consistent with a model of feeling sympathy that relies on both the shared representation and the affective networks. Interestingly, this network was not activated when subjects watched inappropriate social behavior.     

Abnormalities of brain function during a nonverbal theory of mind task in schizophrenia

Theory of mind (ToM), the specific ability to attribute thoughts and feelings to oneself and others is generally impaired in schizophrenia. Previous studies demonstrated a deficit of the attribution of intentions to others among patients having formal thought disorder. During nonverbal tasks, such a function requires both the visual perception of human figures and the understanding of their intentions. These processes are considered to involve the superior temporal sulcus and the medial prefrontal cortex, respectively. Are the functional patterns of activation associated with those processes abnormal in schizophrenia? Seven schizophrenic patients on medication performed a nonverbal attribution of intentions task as well as two matched physical logic tasks, with and without human figures, while H2O15 PET-scanning was performed. Data from the patients were compared to those of eight healthy controls matched for verbal IQ and sex. The experimental design allowed dissociating the effect of the perception of human figures from that of the attribution of intentions. During attribution of intentions, significant activations in the right prefrontal cortex were detected in the control subjects. Those activations were not found in the schizophrenic group. However, in both groups, the perception of human figure elicited bilateral activation of the occipitotemporal regions and of the posterior part of the superior temporal sulcus. Schizophrenic patients performing a nonverbal attribution of intentions task have an abnormal cerebral activity.     

How Important Are Brain Banks for Alcohol Research?

This article contains the proceedings of a symposium at the 2002 RSA/ISBRA Meeting in San Francisco, organized and chaired by Clive Harper and co-chaired by Izuru Matsumoto. The presentations were (1) Introduction, by Clive Harper; (2) The quality of tissue-a critical issue, by Therese Garrick; (3) The first systematic brain tissue donor program in Japan, by Izuru Matsumoto; (4) Brain scans after death-really! by Adolf Pfefferbaum, Elfar Adalsteinsson, and Edith Sullivan; (5) Capture that (genial) expression, by Joanne Lewohl and Peter Dodd; and (6) Neurochemical/pharmacological studies: experimental design and limitations, by Roger Butterworth.     

Predictive value of electroencephalography and computed tomography in childhood non-traumatic coma

Objectives: To study value of electroencephalogram (EEG) and computed tomography (CT Scan) in predicting outcome of non-traumatic coma in children.Methods: 100 consecutive children, between 2 months to 12 years, with nontraumatic coma, (Glasgow Coma Scale score <-8). Demographic and clinical data was recorded at admission. EEG and CT scan were done within 24 hours of admission. Etiologic diagnosis was assigned on basis of clinical data and relevant laboratory investigations. The outcome was recorded as survived and died. Among survivors it was graded as no disability, or mild, moderate, or severe disability. Odds ratio and/or relative risk (RR) with 95% confidence interval (CI) were calculated.Results: EEG could be done in 60 patients (43 survived; 7 were normal, 8 had mild, 17 moderate and 11 severe disability) CT scan in 93 patients (60 survived; 11 were normal, 14 had mild, 21 moderate and 14 severe disability). A normal/borderline EEG was associated with good outcome (P = 0.001); 11 of 12 survived and of survivors 55% had no or mild disability. Electrocerebral silence on EEG was a predictor of death (OR = 44; 95% CI -1.5-7372; P =0.01). An abnormal EEG was associated with significant increase in risk of disability among survivors (RR=2.6, 95% CI= 1.2–5.4, P=0.03). Among CT abnormalities intracranial bleed suggested increased risk of death (RR = 2.1; 95% CI-0.8-5.3; P = 0.058), while, hydrocephalus was associated with better survival (RR = 0.7; 95% CI-0.5 to 0.96; P = 0.029). However, hydrocephalus when compared with other abnormal CT scan findings, was associated with higher risk of moderate and severe disability among survivors (P= 0.046)Conclusion: A normal CT scan and EEG, and some of the specific findings could be helpful in predicting outcome in children with non-traumatic coma. EEG and CT scan should be done at admission in all patients with non-traumatic coma if feasible     

Differences in forebrain activation in two strains of rat at rest and after spinal cord injury

Forebrain activation patterns in normal and spinal-injured Sprague-Dawley (SD) rats were determined by measuring regional cerebral blood flow as an indicator of neuronal activity. Data are compared to our previously published findings from normal and spinal-injured Long-Evans (LE) rats and reveal a striking degree of overlap, as well as differences, between strains in the basal (unstimulated) forebrain activation in normal animals. Specifically, 81% of the structures sampled showed similar activation in both strains, suggesting a consistent and identifiable pattern of basal cerebral activation in the rat. LE controls showed significantly greater basal activation in the remaining structures compared to SD control group, including the anterior dorsal thalamus, basolateral amygdala, SII cortex, and the hypothalamic paraventricular nucleus. In contrast, spinal cord injury (SCI) resulted in strain-specific changes in forebrain activation categorized by structures that showed significant increases in: (1) only LE SCI rats (posterior, ventrolateral, and ventroposterolateral thalamic nuclei); (2) only SD SCI rats (anterior-dorsal and medial thalamus, basolateral amygdala, cingulate and retrosplenial cortex, habenula, interpeduncular nucleus, hypothalamic paraventricular nucleus, periaqueductal gray); or (3) both strains (arcuate nucleus, ventroposteromedial thalamus, SI and SII somatosensory cortex). These results provide information related to the remote, i.e. supraspinal, effects of spinal cord injury and suggest that genetic differences play an important part in the forebrain response to such injury. Brain activation studies therefore provide a useful tool in understanding the full extent of secondary consequences following spinal injury and for identifying potential central mechanism responsible for the development of pain.     

Co-activation of the amygdala, hippocampus and inferior frontal gyrus during autobiographical memory retrieval

Functional MRI was used to investigate the role of medial temporal lobe and inferior frontal lobe regions in autobiographical recall. Prior to scanning, participants generated cue words for 50 autobiographical memories and rated their phenomenological properties using our autobiographical memory questionnaire (AMQ). During scanning, the cue words were presented and participants pressed a button when they retrieved the associated memory. The autobiographical retrieval task was interleaved in an event-related design with a semantic retrieval task (category generation). Region-of-interest analyses showed greater activation of the amygdala, hippocampus, and right inferior frontal gyrus during autobiographical retrieval relative to semantic retrieval. In addition, the left inferior frontal gyrus showed a more prolonged duration of activation in the semantic retrieval condition. A targeted correlational analysis revealed pronounced functional connectivity among the amygdala, hippocampus, and right inferior frontal gyrus during autobiographical retrieval but not during semantic retrieval. These results support theories of autobiographical memory that hypothesize co-activation of frontotemporal areas during recollection of episodes from the personal past.