Caudate regional cerebral blood flow in obsessive-compulsive disorder, panic disorder and healthy controls on single photon emission computerised tomography

Deep brain stimulation affects conditioned and unconditioned anxiety in different brain areas

Deep brain stimulation (DBS) of the nucleus accumbens (NAc) has proven to be an effective treatment for therapy refractory obsessive-compulsive disorder. Clinical observations show that anxiety symptoms decrease rapidly following DBS. As in clinical studies different regions are targeted, it is of principal interest to understand which brain area is responsible for the anxiolytic effect and whether high-frequency stimulation of different areas differentially affect unconditioned (innate) and conditioned (learned) anxiety. In this study, we examined the effect of stimulation in five brain areas in rats (NAc core and shell, bed nucleus of the stria terminalis (BNST), internal capsule (IC) and the ventral medial caudate nucleus (CAU)). The elevated plus maze was used to test the effect of stimulation on unconditioned anxiety, the Vogel conflict test for conditioned anxiety, and an activity test for general locomotor behaviour. We found different anxiolytic effects of stimulation in the five target areas. Stimulation of the CAU decreased both conditioned and unconditioned anxiety, while stimulation of the IC uniquely reduced conditioned anxiety. Remarkably, neither the accumbens nor the BNST stimulation affected conditioned or unconditioned anxiety. Locomotor activity increased with NAc core stimulation but decreased with the BNST. These findings suggest that (1) DBS may have a differential effect on unconditioned and conditioned anxiety depending on the stimulation area, and that (2) stimulation of the IC exclusively reduces conditioned anxiety. This suggests that the anxiolytic effects of DBS seen in OCD patients may not be induced by stimulation of the NAc, but rather by the IC.

Poor performance on the Iowa gambling task in children with obsessive-compulsive disorder

BACKGROUND

Several lines of evidence implicate orbitofrontal cortex dysfunction in the pathophysiology of obsessive-compulsive disorder (OCD). The purpose of this study was to investigate neuropsychological dysfunction of the orbitofrontal cortex in children with OCD.

METHODS

The Iowa Gambling Task (IGT), which reflects orbitofrontal cortex function, and the Wisconsin Card Sorting Test (WCST), which is associated with functioning of the dorsolateral prefrontal cortex, were administered to 22 children with OCD and 22 healthy controls matched for gender, age, and intelligence.

RESULTS

OCD patients displayed poor performance on the IGT. In contrast, performance on the WCST was not impaired in OCD patients compared to controls.

CONCLUSIONS

These findings are in line with previous studies demonstrating that OCD in childhood is associated with a dysfunction of orbitofrontal-striatal-thalamic circuitry.

Revise the revised? New dimensions of the neuroanatomical hypothesis of panic disorder

In 2000, Gorman et al. published a widely acknowledged revised version of their 1989 neuroanatomical hypothesis of panic disorder (PD). Herein, a 'fear network' was suggested to mediate fear- and anxiety-related responses: panic attacks result from a dysfunctional coordination of 'upstream' (cortical) and 'downstream' (brainstem) sensory information leading to heightened amygdala activity with subsequent behavioral, autonomic and neuroendocrine activation. Given the emergence of novel imaging methods such as fMRI and the publication of numerous neuroimaging studies regarding PD since 2000, a comprehensive literature search was performed regarding structural (CT, MRI), metabolic (PET, SPECT, MRS) and functional (fMRI, NIRS, EEG) studies on PD, which will be reviewed and critically discussed in relation to the neuroanatomical hypothesis of PD. Recent findings support structural and functional alterations in limbic and cortical structures in PD. Novel insights regarding structural volume increase or reduction, hyper- or hypoactivity, laterality and task-specificity of neural activation patterns emerged. The assumption of a generally hyperactive amygdala in PD seems to apply more to state than trait characteristics of PD, and involvement of further areas in the fear circuit, such as anterior cingulate and insula, is suggested. Furthermore, genetic risk variants have been proposed to partly drive fear network activity. Thus, the present state of knowledge generally supports limbic and cortical prefrontal involvement as originally proposed in the neuroanatomical hypothesis. Some modifications might be suggested regarding a potential extension of the fear circuit, genetic factors shaping neural network activity and neuroanatomically informed clinical subtypes of PD potentially guiding future treatment decisions.

Functional neuroimaging in obsessive-compulsive disorder

BACKGROUND AND AIM

Obsessive-compulsive disorder (OCD) is a severe, highly prevalent and chronically disabling psychiatric disorder that usually emerges during childhood or adolescence. This paper aims to review the literature on functional neuroimaging in OCD, analysing the reported dysfunctional connectivity in the corticostriatothalamocortical circuitry.

METHOD

This study included papers published in peer-reviewed journals dealing with functional imaging in OCD.

RESULTS

Striatal dysfunction, mainly of the caudate nucleus, leads to inefficient thalamic gating, resulting in hyperactivity within the orbitofrontal cortex (intrusive thoughts) and the anterior cingulate cortex (non-specific anxiety). Compulsions consist of ritualistic behaviours performed to recruit the inefficient striatum and neutralise unwanted thoughts and anxiety. Functional neuroimaging findings are discussed against the background of specific cognitive impairments, mainly regarding visuospatial processing, executive functioning and motor speed. Cognitive deficits are partial and specific, matching imaging data.

CONCLUSIONS

Several studies have targeted brain regions hypothesised to be involved in the pathogenesis of OCD, showing the existence of dysfunctional connectivity in the corticostriatothalamocortical circuitry. Improvements in spatial resolution of neuroimaging techniques may contribute to a better understanding of the neurocircuitry of OCD and other anxiety disorders.

Post-operative Changes of Cerebral Glucose Metabolism in Patients with Lumbar Spinal Stenosis with Pre-operative Anxiety: Statistical Parametric Mapping Analysis of F-18 FDG Brain PET

Study Design

A prospective study.

Purpose

To assess postoperative changes in cerebral glucose metabolism in anxiety patients with lumbar spinal stenosis (SS).

Overview of Literature

Although an association between preoperative anxiety and abnormal cerebral glucose metabolism may exist, only a limited number of studies using F-18 fluorodeoxyglucose positron emission tomography (FDG PET) have evaluated preoperative to postoperative changes in cerebral glucose metabolism in SS patients in detail.

Methods

The present study was designed to assess preoperative to postoperative changes in cerebral glucose metabolism in anxiety patients with SS. F-18 FDG PET with statistical parametric mapping analyses was used to compare preoperative and postoperative regional brain glucose metabolism in 18 SS patients.

Results

F-18 FDG PET scans showed postoperative activation of several brain clusters in gray matter. These included left parahippocampus, left cerebellar tonsil, left inferior semi-lunar lobule, and right cerebellar tonsil. Areas that were deactivated postoperatively were the right insula, left fusiform gyrus, left orbitofrontal cortex, left inferior frontal gyrus, left middle frontal gyrus, left precuneus, and left inferior frontal gyrus.

Conclusions

SS patients with preoperative anxiety showed altered cerebral glucose metabolism at postoperative follow-up.

Perfusion magnetic resonance imaging in psychiatry

INTRODUCTION

Cerebral perfusion imaging using magnetic resonance imaging (MRI) is widely used in the research and clinical fields to assess the profound changes in blood flow related to ischemic events such as acute stroke, chronic steno-occlusive disease, vasospasm, and abnormal vessel formations from congenital conditions or tumoral neovascularity. With continuing improvements in the precision of MRI-based perfusion techniques, it is increasingly feasible to use this tool in the study of the subtle brain perfusion changes occurring in psychiatric illnesses. This article aims to review the existing literature on applications of perfusion MRI in psychiatric disorder and substance abuse research. The article also provides a brief introductory overview of dynamic susceptibility contrast MRI and arterial spin labeling techniques. An outlook of necessary steps to bring perfusion MRI into the realm of clinical psychiatry as a diagnostic tool is brought forth. Opportunities for research in unexplored disorders and with higher field strengths are briefly examined.

METHODS

PubMed, ISI Web of Knowledge & Scopus were used to search the literature and cross reference several neuropsychiatric disorders with a search term construct, including "magnetic resonance imaging," "dynamic susceptibility contrast," "arterial spin labeling," perfusion or "cerebral blood flow" or "cerebral blood volume" or "mean transit time." The list of disorders used in the search included schizophrenia, depression and bipolar disorder, dementia and Alzheimer's disease, Parkinson's disease, posttraumatic stress disorder, autism, Asperger disease, attention deficit, Tourette syndrome, obsessive-compulsive disorder, Huntington's disease, bulimia nervosa, anorexia nervosa, and substance abuse. For each disorder for which perfusion MRI studies were found, a brief overview of the disorder symptoms, treatment, prevalence, and existing models is provided, and previous findings from nuclear medicine-based perfusion imaging are overviewed. Findings of perfusion MRI studies are then summarized, and overlap of findings are discussed. Overarching conclusions are made, or an outlook for future work in the area is offered, where appropriate.

RESULTS

Despite the now fairly broad availability of perfusion MRI, only a limited number of studies were found using this technology. The search produced 13 studies of schizophrenia, 7 studies in major depression, 12 studies in Alzheimer's disease, and 2 studies in Parkinson's disease. Drug abuse and other disorders have mainly been studied with nuclear medicine-based perfusion imaging. The literature concerning the use of perfusion imaging in psychiatry has not been reviewed in the last 5 years or more. The use of MRI for perfusion measurements in psychiatry has not been reviewed in 10 years.

CONCLUSIONS

Although MRI-based perfusion imaging in psychiatry has mainly been used as a research tool, a path is progressively being cleared for its application in clinical diagnostic and treatment monitoring. The precision of perfusion MRI methods now rivals that of nuclear medicine-based perfusion imaging techniques. Because of their noninvasive nature, arterial spin labeling methods have gained popularity in studies of neuropsychiatric disorders such as schizophrenia, depression, Alzheimer's, and Parkinson's diseases. Perfusion imaging measurements have yet to be included within the diagnostic criteria of neuropsychiatric disorders despite having shown to have great discriminant power in specific disorders. As this young methodology continues to improve and research studies demonstrate the correlation of measured perfusion abnormalities to microcirculatory abnormalities and neuropsychiatric symptomatology, the idea of including such a test within diagnostic criteria for certain mental illnesses becomes increasingly plausible.

Cerebral activation in children and adolescents with obsessive-compulsive disorder before and after treatment: a functional MRI study

BACKGROUND

Structural and functional fronto-striatal abnormalities are involved in the pathophysiology of obsessive-compulsive disorder (OCD). The aims of the present study were: (a) to investigate possible regional brain dysfunction in premotor cortico-striatal activity in drug-naïve children and adolescents with OCD; (b) to correlate brain activation with severity of obsessive-compulsive symptomatology; and (c) to detect possible changes in brain activity after pharmacological treatment.

METHOD

Twelve children and adolescents (age range 7-18 years; seven male, five female) with DSM-IV obsessive-compulsive disorder and twelve healthy subjects matched for age, sex and intellectual level were studied. Functional magnetic resonance imaging data were obtained during the performance of simple and complex sequences.

RESULTS

Comparing the complex motor condition with the simple control condition, both patients and controls showed a pattern of cerebral activation involving the fronto-parietal cortex and basal ganglia. Compared with controls, OCD patients presented significantly higher brain activation bilaterally in the middle frontal gyrus. After 6 months of pharmacological treatment and with clear clinical improvement, activation in the left insula and left putamen decreased significantly.

CONCLUSION

In a paediatric OCD sample that was treatment naïve and without another psychiatric disorder we showed hyperactivation of the circuits that mediate symptomatic expression of OCD. The cerebral activation decreases after treatment and clinical improvement.

A study of neuropsychological deficit in children with obsessive-compulsive disorder

This study was conducted to examine the neuropsychological deficits in children with obsessive compulsive disorder (OCD). Furthermore, the focus of present study was to explore whether OCD children show the same executive dysfunction as adult OCD patients. The participants consisted of 106 children between the ages of 6 and 16 years who visited the department of child-adolescent psychiatry, Seoul National University Children's Hospital (17 OCD, 25 ADHD, 21 tic disorder, 20 depressive disorder, and 23 healthy children). The OCD children showed higher verbal ability compared to other psychiatric groups, but performed the worst on WISC-R subtests assessing perceptual organization ability under time pressure. The OCD children did not show any significant deficits in verbal intellectual function, memory, attention and concentration abilities. However, similar to the ADHD children, the OCD children had significantly more errors and completed fewer categories on the WCST compared to the healthy group. Through neuropsychological tests, the OCD children showed cognitive strength and weakness similar to those of OCD adults that were reported in previous research. Specifically, they had executive function deficits in mental set shifting, supporting the frontal-striatal dysfunction hypothesis of OCD in children as well as in adults.

Improvement in mood and ideation associated with increase in right caudate volume

BACKGROUND

The basal ganglia, particularly caudate, are hypothesized to play a role in affective and obsessive-compulsive disorders. The depressive syndrome is a feature of untreated Cushing's disease. The objective of this study was to test the hypothesis that after treatment of Cushing's disease reduces elevated cortisol, improvement in mood and related ideations are associated with increase in caudate volume.

METHODS

In this longitudinal, interventional study of 23 patients with Cushing's disease, 24-hour urinary free cortisol, structural magnetic resonance imaging and behavioral measures were obtained prior to treatment and approximately one year after pituitary microadenomectomy. Five SCL-90-R subscales measuring change in mood, related ideations and physical symptoms were utilized.

RESULTS

Partial correlations (adjusted for age and time since surgery) showed change in caudate, but not hippocampal, volume was significantly associated with change in behavioral SCL-90-R subscales, indicating selectivity for structure. Right but not left caudate showed associations, suggesting selectivity for lateralization. Right caudate volume increase was significantly associated with decreases in Depression, Anxiety, Obsessive-Compulsive, and Paranoid scores, but not with Somatization (physical symptoms), indicating specificity for behavioral but not physical variables.

LIMITATIONS

A limitation is that relatively low-resolution scans were utilized. Although most likely not diminishing the significant findings, less sensitive methodology could lead to an increased probability of a type 2 error.

CONCLUSIONS

These findings support the concept that caudate, and likely right caudate, participates in human brain circuitry regulating mood.

Psychiatric outcome of surgery for temporal lobe epilepsy and presurgical considerations

In recent years, surgery has become a treatment option for some patients with intractable epilepsy, particularly those with temporal lobe epilepsy. Psychiatric disturbances may complicate the postsurgical outcome in some patients and de novo psychiatric symptoms have been reported. In many but not all epilepsy surgical centres, a psychiatric assessment is included as part of the presurgical evaluation of potential candidates for surgery. This review indicates that affective disorders, namely, depression and anxiety, and psychosis are the most frequently reported postsurgical psychiatric disturbances. Whilst there are no absolute psychiatric contraindications to surgery, certain pre-existing psychiatric conditions may need careful consideration as there may be a risk of postsurgical psychiatric complications. Routine pre- and postsurgical psychiatric evaluations in patients undergoing epilepsy surgery are recommended. Clinicians involved in the care of surgical candidates should be aware of the possible psychiatric complications following surgery and ensure that the psychiatric risks are discussed with the patient and family.

Electrophysiological correlates of behavioral response inhibition in patients with obsessive-compulsive disorder

In this study, we have attempted to determine the electrophysiological correlates of behavioral response inhibition in patients with obsessive-compulsive disorder (OCD). To evaluate response inhibition ability, we have used the Go/NoGo task and measured N2 and P3 event-related potential (ERP) components. Both the OCD and control groups exhibited greater and more frontally distributed N2 and P3 amplitudes in the NoGo condition compared to what we observed in the Go condition. However, the patients with OCD also manifested reduced NoGo-N2 and Go-N2 amplitudes at the frontocentral electrode sites compared to the controls. In addition, the NoGo-N2 amplitudes were more posteriorly distributed in patients with OCD than in controls. The NoGo-N2 amplitudes and latencies measured at the central sites were also negatively correlated with the obsession score on the Yale-Brown Obsessive Compulsive Scale (Y-BOCS). The OCD and control groups were comparable with regard to Go-P3 and NoGo-P3 amplitude and latencies. Our findings suggest dysfunctions in frontal regions mediating response inhibition in OCD, consistent with the involvement of response inhibition in the pathophysiology of this disorder. In addition, NoGo-N2 seems to result in more accurate response inhibition measurements in patients with OCD than does NoGo-P3.

Regional cerebral glucose metabolic abnormalities in bipolar II depression

BACKGROUND

Functional neuroimaging studies of bipolar disorder (BD) performed in conjunction with antidepressant treatment trials generally require that patients remain on mood stabilizers to reduce the risk of inducing mania; yet, it is unknown whether the metabolic abnormalities evident in unmedicated BD depressives remain detectable in patients receiving mood stabilizers. This study investigated whether cerebral metabolic abnormalities previously reported in unmedicated BD subjects are evident in depressed bipolar disorder type II (BD II) subjects receiving lithium or divalproex.

METHODS

Using [18F]-fluorodeoxyglucose-positron-emission tomography, cerebral glucose metabolism was compared between 13 depressed BD II subjects on therapeutic doses of lithium or divalproex and 18 healthy control subjects. Regional metabolism was compared between groups in predefined regions of interest.

RESULTS

Metabolism was increased in the bilateral amygdala, accumbens area, and anteroventral putamen, left orbitofrontal cortex and right pregenual anterior cingulate cortex in depressives versus control subjects. Post hoc exploratory analysis additionally revealed increased metabolism in left parahippocampal, posterior cingulate, and right anterior insular cortices in depressives versus control subjects. Correlational analyses showed multiple limbic-cortical-striatal interactions in the BD sample not evident in the control sample, permitting sensitive and specific classification of subjects by discriminant analysis.

CONCLUSIONS

These results confirm previous reports that bipolar depression is associated with abnormally increased metabolism in the amygdala, ventral striatum, orbitofrontal cortex, anterior cingulate, and anterior insula, and extend these results to bipolar disorder type II depressives on lithium or divalproex. They also implicate an extended functional anatomical network known to modulate visceromotor function in the pathophysiology of BD II depression.

Impaired response inhibition in obsessive compulsive disorder

Objective

The present study investigates different three inhibitory control functions in patients with obsessive-compulsive disorder (OCD). Selective motor response inhibition was tested in a GO/NO-GO paradigm, the inhibition of a triggered motor response in a STOP paradigm and the ability to inhibit cognitive interference in a motor STROOP paradigm.

Methods

27 patients who met DSM-IV criteria for OCD and 25 age, handedness and IQ-matched healthy control subjects were tested in the GO/NO-GO, STOP and motor STROOP tasks.

Results

OCD patients performed significantly worse than controls in the selective inhibition of their motor responses (GO/NO-GO) and in the inhibition of cognitive interference (STROOP), and also showed worse performance in suppressing previously triggered motor responses (STOP).

Conclusion

Patients with OCD are impaired in motor and cognitive inhibitory mechanisms. The findings are consistent with psychobiological and neuropsychological models of OCD suggesting impairment of frontostriatal circuitries that mediate functions of inhibitory control.

Positron emission tomography imaging of risperidone augmentation in serotonin reuptake inhibitor-refractory patients

We studied 15 nondepressed patients with obsessive-compulsive disorder (OCD) who were nonresponders to serotonin reuptake inhibitors with an additive trial of risperidone. Positron emission tomography with (18)F-deoxyglucose and magnetic resonance imaging was obtained at baseline and following 8 weeks of either risperidone or placebo in a double-blind parallel group design. Risperidone treatment was associated with significant increases in relative metabolic rate in the striatum, cingulate gyrus, the prefrontal cortex, especially in the orbital region, and the thalamus. Four of 9 patients who received risperidone showed clinical improvement (CGI score of 1 or 2 at 8 weeks) while none of the 6 patients who received placebo showed improvement. Patients with low relative metabolic rates in the striatum and high relative metabolic rates in the anterior cingulate gyrus were more likely to show a clinical response. These metabolic predictors of clinical response are consistent with earlier PET studies showing similar prediction when either neuroleptics or serotonin reuptake inhibitor treatments are administered individually. Our results are consistent with a frontostriatal circuit change related to both dopaminergic and serotonergic systems and with the presence of psychopharmacological subtypes within OCD.

The neuropsychology of obsessive compulsive disorder: the importance of failures in cognitive and behavioural inhibition as candidate endophenotypic markers

Obsessive compulsive disorder (OCD) is a highly debilitating neuropsychiatric condition with estimated lifetime prevalence of 2-3%, more than twice that of schizophrenia. However, in contrast to other neuropsychiatric conditions of a comparable or lesser prevalence, relatively little is understood about the aetiology, neural substrates and cognitive profile of OCD. Despite strong evidence for OCD being familial, with risk to first-degree relatives much greater than for the background population, its genetic underpinnings have not yet been adequately delineated. Although cognitive dysfunction is evident in the everyday behaviour of OCD sufferers and is central to contemporary psychological models, theory-based studies of neurocognitive function have yet to reveal a reliable cognitive signature, and interpretation has often been confounded by failures to control for co-morbidities. The neuroimaging findings in OCD are amongst the most robust reported in the psychiatric literature, with structural and functional abnormalities frequently reported in orbitofrontal cortex, anterior cingulate cortex, and caudate nucleus. In spite of this, our relative lack of understanding of OCD neurochemical processes continues to impede progress in the development of novel pharmacological treatment approaches. Integrating the neurobiological, cognitive, and clinical findings, we propose that OCD might usefully be conceptualised in terms of lateral orbitofrontal loop dysfunction, and that failures in cognitive and behavioural inhibitory processes appear to underlie many of the symptoms and neurocognitive findings. We highlight existing limitations in the literature, and the potential utility of endophenotypes in overcoming these limitations. We propose that neurocognitive indices of inhibitory functions may represent a useful heuristic in the search for endophenotypes in OCD. This has direct implications not only for OCD but also for putative obsessive-compulsive spectrum conditions including attention deficit hyperactivity disorder, Tourette's syndrome, and trichotillomania (compulsive hair pulling).

A manual and automated MRI study of anterior cingulate and orbito-frontal cortices, and caudate nucleus in obsessive-compulsive disorder: comparison with healthy controls and patients with schizophrenia

Functional imaging and neuropsychological data suggest that interconnected brain structures including the orbito-frontal cortex (OFC), anterior cingulate cortex (ACC) and caudate nucleus (CN) are involved in the pathophysiology of obsessive-compulsive disorder (OCD), but structural imaging studies investigating these regions have yielded inconclusive results. This may be due to inconsistencies in the identification of anatomical boundaries and methodologies utilised (i.e. automated vs. manual tracing). This magnetic resonance imaging study used manual tracing to measure volumes of selected brain regions (OFC, ACC and CN) in OCD patients and compared them with samples of healthy (HC) and psychiatric (schizophrenia; SCZ) controls (n=18 in each group). Concurrently, automated voxel-based analysis was also used to detect subtle differences in cerebral grey and white matter. For the OCD vs. HC comparison, there were no significant volumetric differences detected using the manual or the automated method (although the latter revealed a deficit in the subcortical white matter of the right temporal region). A direct comparison of the two patient groups showed no significant differences using the manual method. However, a moderate effect size was detected for OFC grey matter (reduced in SCZ), which was supported by findings of reduced OFC volume in the automated analysis. Automated analyses also showed reduced volumes in the dorsal (white matter) and ventral ACC (grey and white matter), as well as the left posterior cingulate (grey and white matter) in SCZ. The findings suggest that in contrast to findings in SCZ, there are very few (if any) gross structural anomalies in OCD.

Single photon emission computed tomography (SPECT) of anxiety disorders before and after treatment with citalopram

BACKGROUND

Several studies have now examined the effects of selective serotonin reuptake inhibitor (SSRI) treatment on brain function in a variety of anxiety disorders including obsessive-compulsive disorder (OCD), posttraumatic stress disorder (PTSD), and social anxiety disorder (social phobia) (SAD). Regional changes in cerebral perfusion following SSRI treatment have been shown for all three disorders. The orbitofrontal cortex (OFC) (OCD), caudate (OCD), medial pre-frontal/cingulate (OCD, SAD, PTSD), temporal (OCD, SAD, PTSD) and, thalamic regions (OCD, SAD) are some of those implicated. Some data also suggests that higher perfusion pre-treatment in the anterior cingulate (PTSD), OFC, caudate (OCD) and antero-lateral temporal region (SAD) predicts subsequent treatment response. This paper further examines the notion of overlap in the neurocircuitry of treatment and indeed treatment response across anxiety disorders with SSRI treatment.

METHODS

Single photon emission computed tomography (SPECT) using Tc-99 m HMPAO to assess brain perfusion was performed on subjects with OCD, PTSD, and SAD before and after 8 weeks (SAD) and 12 weeks (OCD and PTSD) treatment with the SSRI citalopram. Statistical parametric mapping (SPM) was used to compare scans (pre- vs post-medication, and responders vs non-responders) in the combined group of subjects.

RESULTS

Citalopram treatment resulted in significant deactivation (p = 0.001) for the entire group in the superior (t = 4.78) and anterior (t = 4.04) cingulate, right thalamus (t = 4.66) and left hippocampus (t = 3.96). Deactivation (p = 0.001) within the left precentral (t = 4.26), right mid-frontal (t = 4.03), right inferior frontal (t = 3.99), left prefrontal (3.81) and right precuneus (t= 3.85) was more marked in treatment responders. No pattern of baseline activation distinguished responders from non-responders to subsequent pharmacotherapy.

CONCLUSIONS

Although each of the anxiety disorders may be mediated by different neurocircuits, there is some overlap in the functional neuro-anatomy of their response to SSRI treatment. The current data are consistent with previous work demonstrating the importance of limbic circuits in this spectrum of disorders. These play a crucial role in cognitive-affective processing, are innervated by serotonergic neurons, and changes in their activity during serotonergic pharmacotherapy seem crucial.

Single photon emission computed tomography imaging in obsessive-compulsive disorder and for stereotactic bilateral anterior cingulotomy

In conclusion, the present study suggests that SPECT, using a sophisticated SPM analysis method, may be useful as a potential diagnostic tool for OCD and a possible predictor of treatment outcome for OCD patients undergoing bilateral anterior cingulotomy. The anterior cingulate gyrus seems to be an important structure in the pathogenesis of OCD symptoms. Furthermore, our operative technique of anterior cingulotomy, featuring a larger lesion, seems to be effective in ameliorating the symptoms of OCD without causing any serious complications.

Neurobiology of the obsessive-compulsive spectrum disorders

Advances in obsessive-compulsive disorder (OCD) research have led to increased attention to a range of disorders with possibly overlapping phenomenological and neurobiological features; the so-called OCD spectrum disorders. This article briefly reviews neurobiological data relevant to the construction of an OCD spectrum, including neurochemical, neuroanatomic, genetic, neuroimmunology, and animal studies. OCD and related disorders may be heterogenous conditions, and the neurobiology of many putative OCD spectrum disorders has not been well studied. Nevertheless, a gradual accumulation of neurobiological data has provided a number of exciting, and partially overlapping, approaches to an hypothesized OCD spectrum.