Brain blood flow in anxiety disorders. OCD, panic disorder with agoraphobia, and post-traumatic stress disorder on 99mTcHMPAO single photon emission tomography (SPET)

A magnetic resonance spectroscopy investigation of obsessive-compulsive disorder and anxiety

The aim of the current study was to use proton magnetic resonance spectroscopy (MRS) to investigate potential irregularities in neurochemical compounds in obsessive-compulsive disorder (OCD) and the extent to which these irregularities are related to state anxiety. Single voxel MRS was used to image the head of the caudate nucleus (HOC) and orbitofrontal white matter (OFWM) bilaterally in adult patients with OCD and a control group. The results indicated that patients with OCD had increased levels of a combined measure of glutamate and glutamine (Glx/Cr) and N-acetyl-l-aspartic acid (NAA/Cr) relative to creatine in the right OFWM and reduced levels of myo-inositol relative to creatine (mI/Cr) in the HOC bilaterally. Correlational analyses indicated that Glx/Cr in the OFWM was related to OCD symptoms, while mI/Cr in the HOC was related to trait and/or state anxiety. Reanalysis of the significant group differences controlling for state anxiety symptoms erased three of the four group differences. These results are discussed in context of the methodological difficulties facing this area of research.

Cerebral accumulation of Tc-99m ethyl cysteinate dimer (ECD) in severe, transient hypothyroidism

Thyroid dysfunction is a well-known contributor to psychiatric morbidity. To investigate the mechanism(s) by which thyroid hormone availability affects cerebral activity, a group of thyroidectomized individuals were studied at two points in time: when markedly hypothyroid in preparation for a thyroid cancer metastatic survey and when clinically and/or biochemically euthyroid. The analysis consisted of single photon emission computed tomography (SPECT) using a lipophilic radiopharmaceutical, technetium-99m (Tc-99m) ethyl cysteinate dimer (ECD), and measurement of mood, anxiety, and psychomotor function, at both points in time. Both increases and decreases in regional cerebral radiotracer activity were found in the hypothyroid condition relative to the euthyroid condition, and the neuropsychological assessment demonstrated significantly greater depression, anxiety, and psychomotor slowing during the hypothyroid state. Increased radiotracer activity was seen in frontal and temporal regions, posterior cingulate gyrus, thalamus, and putamen. Decreased activity was seen in the occipital cortex, and the pre- and postcentral gyri. This distribution pattern is partially consistent with findings in persons with depression and anxiety unrelated to thyroid disease, supporting the link between the symptoms observed in our subjects and their marked hypothyroidism. Finally, these results support the need to consider the effect of the thyroid state on cellular mechanisms of uptake and retention of cerebral blood flow radiopharmaceuticals when studying 'noneuthyroid' individuals.

Putaminal gray matter volume decrease in panic disorder: an optimized voxel-based morphometry study

Our study aimed to identify gray matter volume differences between panic disorder patients and healthy volunteers using optimized voxel-based morphometry. Gray matter volume was compared between 18 panic subjects and 18 healthy volunteers. Panic disorder severity scale (PDSS) and Zung self-rating anxiety scale (Z-SAS) were administered. Gray matter volumes of bilateral putamen were decreased in panic subjects relative to healthy comparison subjects (corrected P < 0.05). Decreased gray matter volume was also observed in the right precuneus, right inferior temporal gyrus, right inferior frontal gyrus, left superior temporal gyrus, and left superior frontal gyrus at a less conservative level of significance. PDSS score negatively correlated with gray matter volume in the left putamen, right putamen, right inferior frontal gyrus, and left superior frontal gyrus in panic subjects. The duration of illness negatively correlated with left putaminal gray matter volume. There was also a negative correlation between gray matter volume in right putamen and Z-SAS score in panic subjects. The current study reports a putaminal gray matter volume decrease in panic subjects, which may be related to the clinical severity of panic disorder.

Functional connectivity of dissociative responses in posttraumatic stress disorder: a functional magnetic resonance imaging investigation

BACKGROUND

The purpose of this study was to assess interregional brain activity covariations during traumatic script-driven imagery in subjects with posttraumatic stress disorder (PTSD).

METHODS

Functional magnetic resonance imaging and functional connectivity analyses were used to assess interregional brain activity covariations during script-driven imagery in PTSD subjects with a dissociative response, PTSD subjects with a flashback response, and healthy control subjects.

RESULTS

Significant between-group differences in functional connectivity were found. Comparing dissociated PTSD patients and control subjects' connectivity maps in the left ventrolateral thalamus (VLT) [-14, -16, 4] revealed that control subjects had higher covariations between activations in VLT and in the left superior frontal gyrus (Brodmann's area [BA] 10), right parahippocampal gyrus (BA 30), and right superior occipital gyrus (BA 19, 39), whereas greater covariation with VLT in dissociated PTSD subjects occurred in the right insula (BA 13, 34), left parietal lobe (BA 7), right middle frontal gyrus (BA 8), superior temporal gyrus (BA 38, 34), and right cuneus (BA 19). Comparing dissociated PTSD and flashback PTSD connectivity maps in the right cingulate gyrus [3, 16, 30] revealed that dissociated PTSD subjects had higher covariations between activations in this region and the left inferior frontal gyrus (BA 47).

CONCLUSIONS

Greater activation of neural networks involved in representing bodily states was seen in dissociated PTSD subjects than in non-PTSD control subjects. These findings might illuminate the mechanisms underlying distorted body perceptions often observed clinically during dissociative episodes.

[The contribution of brain imaging to the study of panic disorder]

AIMS

The present review is aimed to evaluate the recent contribution of brain imaging techniques to the definition of neuroanatomofunctional models of panic disorder (PD).

METHODS

Structural and functional brain imaging studies of PD, conducted from January 1993 to October 2003 and selected through a comprehensive Medline search (key-words: panic disorder, emotions, brain imaging, EEG, Event-Related Potentials, MRI, fMRI, PET, SPECT, TC) were included in the review. The Medline search has been complemented by bibliographic cross-referencing.

RESULTS

The majority of the reviewed studies suggests that a dysfunction of a neural circuit encompassing prefrontal and temporo-limbic cortices is present in PD. A right hemisphere preferential involvement in PD has been shown by several studies.

CONCLUSIONS

Reviewed neuroimaging studies suggest a dysfunction of frontal and temporo-limbic circuitries in PD. However, those studies cannot be considered conclusive because of several methodological limitations. Longitudinal and multi-modal studies involving larger patient samples, possibly integrated with population-based and genetic studies, would provide more insight into pathophysiological mechanisms of PD.

DECLARATION OF INTEREST

Authors declare that none of them had any known real, potential, or apparent conflict of interest and that there was no business or personal interest that might be relevant to the topic of this article.

Cerebral blood flow changes during script-driven imagery in police officers with posttraumatic stress disorder

BACKGROUND

Functional brain imaging studies in posttraumatic stress disorder (PTSD) have focused mostly on war or sexual abuse victims, many of whom also had comorbid disorders. The aim of this study was to examine the neuronal circuitry underlying responses to script-driven imagery in traumatized police officers with and without PTSD and with low comorbidity rates.

METHODS

In a case-matched control study, 30 traumatized police officers with and without PTSD underwent clinical assessment and (99m)technetium-hexa-methyl-propylene-amine-oxime single photon emission computed tomography scanning with neutral and trauma scripts. Statistical parametric mapping was applied to analyze changes in regional cerebral blood flow.

RESULTS

The main findings were significantly less activation in the medial frontal gyrus and more activation in the right cuneus in the PTSD group relative to the trauma-exposed control group in reaction to trauma versus neutral scripts. Within the PTSD group, subjects showed less activation in the superior temporal gyrus, left lentiform nucleus, left middle frontal gyrus, and left inferior frontal gyrus in reaction to trauma scripts.

CONCLUSIONS

We confirmed previous findings of dysfunction of the medial frontal gyrus in PTSD in a new population with low comorbidity rates. Other alterations were found in certain brain structures involved in emotional, memory, linguistic, visuospatial, and motor processing.

A meta-analysis of functional neuroimaging in obsessive-compulsive disorder

Recent neurobiological models of obsessive-compulsive disorder (OCD) posit that a dysfunction in orbitofrontal-subcortical circuitry underlies the etiology of this disorder. Much of the empirical support for these theories comes from studies using neuroimaging techniques to compare brain activity in OCD patients with that in non-OCD controls. Qualitative reviews of this literature implicate the orbitofrontal cortex, caudate nuclei, and thalamus. In this study, a meta-analysis was conducted to summarize the results of studies using positron emission tomography (PET) and single photon emission computed tomography (SPECT) to investigate brain activity in OCD. Results suggest that differences in radiotracer uptake between patients with OCD and healthy controls have been found consistently in the orbital gyrus and the head of the caudate nucleus. No other significant differences were found. The implications of these results for theories regarding the etiology of OCD are discussed.

Dimensional complexity of the EEG in patients with posttraumatic stress disorder

Recent electrophysiological studies have reported evidence of information processing abnormalities in patients with posttraumatic stress disorder (PTSD). The aim of this study is to examine dynamical complexity of the EEG in PTSD patients, which is thought to reflect information processing of the brain. Resting EEG recordings (32,800 data points acquired continuously from 82 s of an EEG record) were obtained in 16 channels of 27 patients with PTSD from a mixed civilian trauma population and 14 healthy subjects. The correlation dimension (D2) of the EEG was used to quantify the complexity of the cortical dynamics underlying the EEG signal. The PTSD patients were found to have lower D2 values than those of the healthy subjects in most channels (Fp1, F8, C4, P4, T3, T4, T5, T6, and O1), indicating that PTSD patients have globally reduced complexity in their EEG waveforms. This study supports the hypotheses that PTSD patients exhibit disturbed cortical information processing, and that non-linear dynamical analysis of the EEG can be a tool for detecting changes in neurodynamics of the brain in PTSD.

Low level of dopaminergic D2 receptor binding in obsessive-compulsive disorder

BACKGROUND

Despite growing evidence for involvement of the dopaminergic system in obsessive-compulsive disorder (OCD), the functional anatomy of the dopaminergic system in the basal ganglia has been investigated sparsely.

METHODS

Dopamine D(2) receptor binding was assessed in 10 medication-free OCD patients and 10 healthy control subjects, matched for age, gender, and handedness. The binding potential was measured with single photon emission computerized tomography (SPECT) and infusion of the D(2) receptor radiotracer [(123)I] iodobenzamide. With magnetic resonance imaging as reference, regions of interest (caudate and putamen) were delineated for each hemisphere and coregistered with the corresponding SPECT scans.

RESULTS

Dopamine D(2) receptor binding in the left caudate nucleus was significantly lower in the patients with OCD than in healthy control subjects [F(1,18) = 7.0, p =.016]. In addition, an interhemispheric difference was observed in the patient sample. Both the D(2) receptor binding potential (df = 9, p =.012), and the volume (df = 9, p =.029) of the left caudate nucleus were statistically significantly reduced relative to the right caudate nucleus.

CONCLUSIONS

This study provides in vivo evidence for abnormalities in the binding potential of the dopamine D(2) receptor, which suggest the direct involvement of the dopaminergic system in the pathophysiology of OCD.

Single photon emission computed tomography in posttraumatic stress disorder before and after treatment with a selective serotonin reuptake inhibitor

BACKGROUND

Posttraumatic stress disorder (PTSD) is recognized as a disorder mediated by specific neurobiological circuits. Functional imaging studies using script-driven trauma imagery and pharmacological challenges have documented altered cerebral function (activation and deactivation) in several brain regions, including the amygdala, hippocampus, prefrontal cortex and anterior cingulate. However, the neural substrates of PTSD remain poorly understood and the effect of selective serotonin reuptake inhibition on regional cerebral activity is deserving of further investigation.

METHODS

Eleven adult patients (seven men, four women) (mean age+S.D.=33.6+/-9.2 years) with a DSM-IV diagnosis of PTSD, as determined by the Structured Clinical Interview for DSM-IV (SCID-I) and the Clinician-Administered PTSD Scale (CAPS), underwent single photon emission computed tomography (SPECT) with Tc-99m HMPAO pre- and post-8 weeks of treatment with the selective serotonin reuptake inhibitor, citalopram. Symptoms were assessed at baseline and at 2-week intervals with the Clinician-Administered PTSD Scale (CAPS), Montgomery-Asberg Depression Rating Scale (MADRS), and the Clinical Global Impression Scale (CGI). Image analysis of baseline and post-treatment scans was performed using Statistical Parametric Mapping (SPM).

RESULTS

Treatment with citalopram resulted in significant deactivation in the left medial temporal cortex irrespective of clinical response. On covariate analysis, a significant correlation between CAPS score reduction and activation in the left paracingulate region (medial prefrontal cortex) was observed post-treatment. No significant pre-treatment differences were observed between responders and non-responders in anterior cingulate perfusion.

CONCLUSIONS

These preliminary findings are consistent with clinical data indicating temporal and prefrontal cortical dysfunction in PTSD and preclinical data demonstrating serotonergic innervation of these regions. However, further studies, in particular in vivo receptor imaging studies, are needed to confirm whether these regional abnormalities correlate with clinical features and treatment response.

Obsessive-compulsive disorder after epilepsy surgery

It is a well-known fact that after epilepsy surgery (ES) preexisting psychopathology may deteriorate or de novo psychopathological syndromes, mainly of a depressive and psychotic nature, may appear. Previously, recovery of obsessive-compulsive disorder (OCD) after ES has been reported in patients who had comorbid OCD preoperatively; however, there have been no reports on the appearance of de novo OCD interfering with daily living activities post-ES. This is the first report of OCD after ES in patients with mesial temporal lobe epilepsy (MTLE). Five patients with MTLE were identified with obsessive personality traits before surgery. Within the first 2 months after ES, two of these MTLE patients fulfilled OCD diagnostic criteria. These OCD patients were not any different from the other three patients with respect to age, age of onset of epilepsy, seizure types, and seizure frequency. All patients stopped having seizures postoperatively, but the OCD patients had worse quality of life postoperatively than preoperatively. Our findings show that those patients with obsessive traits preoperatively should be carefully monitored after ES.

Cortical neurophysiology of anticipatory anxiety: an investigation utilizing steady state probe topography (SSPT)

The precise role of the cortex in human anxiety is not well characterised. Previous imaging research among healthy controls has reported alterations in regional cerebral blood flow (rCBF) within the prefrontal and temporal cortices during periods of anxious anticipation; however, the temporal dynamics of this activity has yet to be examined in detail. The present study examined cortical Steady State Probe Topography (SSPT) changes associated with anticipatory anxiety (AA), allowing examination of the temporal continuity and the excitatory or inhibitory nature of AA activations. We recorded Steady State Visually Evoked Potentials (SSVEPs) at 64 scalp locations, skin conductance, and self reported anxiety among 26 right-handed males while relaxed and during the anticipation of an electric shock. Relative to the baseline condition, the AA condition was associated with significantly higher levels of self-reported anxiety and increased phasic skin conductance levels. Across the seven second imaging window, AA was associated with increased SSVEP latency within medial anterior frontal, left dorsolateral prefrontal and bilateral temporal regions. In contrast, increased SSVEP amplitude and decreased SSVEP latency were observed within occipital regions. The observed SSVEP latency increases within frontal and temporal cortical regions are suggestive of increased localised inhibitory processes within regions reciprocally connected to subcortical limbic structures. Occipital SSVEP latency decreases are suggestive of increased excitatory activity. SSVEP amplitude increases within occipital regions may be associated with an attentional shift from external to internal environment. The current findings provide further support for the involvement of frontal, anterior temporal, and occipital cortical regions during anticipatory anxiety, and suggest that both excitatory and inhibitory processes are associated with AA alterations.

Resting regional cerebral perfusion in recent posttraumatic stress disorder

BACKGROUND

Brain imaging research in posttraumatic stress disorder has been largely performed on patients with chronic disease, often heavily medicated, with current or past alcohol and substance abuse. Additionally, virtually only activation brain imaging paradigms have been done in posttraumatic stress disorder, whereas in other mental disorders both resting and activation studies have been performed.

METHODS

Twenty-eight (11 posttraumatic stress disorder) trauma survivors underwent resting state hexamethylpropyleneamineoxime single photon emission computed tomography and magnetic resonance imaging 6 months after trauma. Eleven nontraumatized subjects served as healthy controls.

RESULTS

Regional cerebral blood flow in the cerebellum was higher in posttraumatic stress disorder than in both control groups. Regional cerebral blood flow in right precentral, superior temporal, and fusiform gyri in posttraumatic stress disorder was higher than in healthy controls. Cerebellar and extrastriate regional cerebral blood flow were positively correlated with continuous measures of depression and posttraumatic stress disorder. Cortisol level in posttraumatic stress disorder was negatively correlated with medial temporal lobe perfusion. Anterior cingulate perfusion and cortisol level were positively correlated in posttraumatic stress disorder and negatively correlated in trauma survivors without posttraumatic stress disorder.

CONCLUSIONS

Recent posttraumatic stress disorder is accompanied by elevated regional cerebral blood flow, particularly in the cerebellum. This warrants attention because the cerebellum is often used as a reference region in regional cerebral blood flow studies. The inverse correlation between plasma cortisol and medial temporal lobe perfusion may herald hippocampal damage.

Hypoactivation of the prefrontal cortex during verbal fluency test in PTSD: a near-infrared spectroscopy study

Several studies have suggested that there is frontal dysfunction in subjects with posttraumatic stress disorder (PTSD). We investigated the relationship between alterations of the hemodynamic response of the prefrontal cortex during a cognitive task (verbal fluency task; VFT) and memory function measured using the Wechsler Memory Scale-Revised (WMS-R). The subjects were victims of the Tokyo Subway Sarin attack with (n = 8) or without (n = 26) PTSD. Hemodynamic response in the prefrontal cortex was measured using a 24-channel near-infrared spectroscopy (NIRS) system. Subjects with PTSD had a significantly smaller response of oxygenated hemoglobin and total hemoglobin during the VFT compared with those without PTSD, although there was no significant difference in performance on the VFT. Subjects with PTSD had significantly lower scores on attention and concentration in the WMS-R, which was positively correlated with the increase of total hemoglobin during the VFT. The 'frontal dysfunction' observed in subjects with PTSD may be a secondary phenomenon to reduced attentional capacity.

Neuroimaging communality between schizophrenia and obsessive compulsive disorder: a putative basis for schizo-obsessive disorder?

Four major brain regions have been repeatedly implicated in the pathophysiology of obsessive compulsive disorder (OCD) in in vivo neuroimaging studies: the caudate nucleus, the orbitofrontal cortex, the anterior cingulate gyrus and the mediodorsal thalamic nucleus. The present review describes the neuroimaging studies on schizophrenia, pertaining to these brain regions. Our working hypothesis is that such common brain regions, if dysfunctional in schizophrenic patients, would be candidates for a neural network subserving the newly emerging syndrome of schizo-obsessive disorder. Findings, though, are controversial. We conclude that further studies, aimed at specific monitoring of these brain regions, in patients suffering from the schizo-obsessive syndrome are warranted.

Elevated thalamic and prefrontal regional cerebral blood flow in obsessive-compulsive disorder: a SPECT study

Functional neuroimaging studies have pointed to a possible role of cerebral circuits involving the prefrontal and anterior cingulate cortices, the striatum, and thalamus in the pathophysiology of obsessive-compulsive disorder (OCD). Regional cerebral blood flow (rCBF) of 16 drug-free Brazilian patients with OCD and 17 healthy subjects matched for age, gender, handedness and level of education was measured with [99m-Tc] HMPAO single photon emission computed tomography. Analysis of covariance identified four regions of interest with significantly higher rCBF: the right superior and inferior frontal cortex and the right and left thalamus. Positive correlations between symptom severity measured by Clinical Global Impression scores and rCBF were found in the right and left inferior frontal lobes and in the right basal ganglia. Compulsive behavior was inversely correlated with rCBF in the right thalamus, and duration of illness correlated positively with rCBF in the right and left superior frontal lobes and with the right thalamus. The findings of this SPECT study conducted in Brazil are in agreement with prior studies and provide additional support for the involvement of prefrontal-subcortical circuits in the pathophysiology of OCD. Furthermore, the study suggests that similar brain mechanisms appear to be involved cross-culturally.

Cerebral blood flow and anxiety in older men: an analysis of resting anterior asymmetry and prefrontal regions

Asymmetric resting blood flow in prefrontal and hemispheric regions, assessed by single photon emission computed tomography (SPECT), was examined as a potential biological marker for enhanced trait and state anxiety in 30 older men (ages 55-81). Average and asymmetric perfusion in dorsolateral, medial, and orbital regions of the prefrontal lobes was also assessed. Results indicated a significant association between lower levels of resting dorsolateral blood flow and greater state anxiety responses to a series of stressful provocations (measured on a separate occasion). A significant curvilinear (U-shaped) relation between asymmetric dorsolateral perfusion and state anxiety was also identified; increased asymmetric blood flow favoring either the right or the left dorsolateral region related to higher levels of state anxiety. However, this association was attenuated by age and systolic blood pressure. Resting perfusion in the dorsolateral region may represent a more reliable biological marker for state anxiety than trait anxiety in older men.

Quantitative electroencephalography in OCD patients treated with paroxetine

The effectiveness of drugs that have a specific effect on the activity of the serotonergic neurotransmitter systemhas changed the outlook for patients suffering from obsessive-compulsive disorder (OCD). With a response rate of about 70% to such compounds and the great amount of brain imaging studies conducted over the past decades, an understanding of the biochemical nature and origins of OCD is beginning to unfold. Convergent data including ethological and experimental observations, clinico-pathological findings and different imaging methods have implicated the basal ganglia along with the cortical and related thalamic structures to be involved in the pathophysiology of OCD. In a previous study using the quantitative electroencephalographic (QEEG) method known as neurometrics, in which QEEG data from OCD patients were compared statistically with those from an age-appropriate normative population, two subtypes within a clinically homogeneous patient group were classified. Patients with relative excess theta activity, especially in the frontal regions, were nonresponders to treatment with serotonin reuptake inhibitors (SSRI), while those with increased relative power in alpha activity were responders to pharmacological treatment. These findings suggested at least two subgroups in a patient population with similar symptoms but differential responses to treatment. In the present study we used neurometric QEEG to subtype a group of 20 non-depressed OCD patients, fulfilling DSM-R-III criteria, treated with paroxetine, of whom 18 were responders to treatment. Of the treatment responders, 94.4% were predicted by subtype membership to be SSRI responsers. In these subjects there was a strong relative alpha baseline activity; after successful treatment through at least 3 months this activity decreased, looking more normal. The group average topographic maps showed none of the characteristics seen in the nonresponder cluster (no excess relative power in theta). As in the previous investigation, baseline QEEG profile membership points to a predictive value with regard to therapeutic response.

Is the spatial distribution of brain lesions associated with closed-head injury in children predictive of subsequent development of posttraumatic stress disorder?

PURPOSE

To determine whether there is an association between the spatial distributions of lesions detected at magnetic resonance (MR) imaging of the brain in children, adolescents, and young adults after closed-head injury (CHI) and development of the reexperiencing symptoms of posttraumatic stress disorder (PTSD).

MATERIALS AND METHODS

Data obtained in 94 subjects without a history of PTSD as determined by parental interview were analyzed. MR images were obtained 3 months after CHI. Lesions were manually delineated and registered to the Talairach coordinate system. Mann-Whitney analysis of lesion distribution and PTSD status at 1 year (again, as determined by parental interview) was performed, consisting of an analysis of lesion distribution versus the major symptoms of PTSD: reexperiencing, hyperarousal, and avoidance.

RESULTS

Of the 94 subjects, 41 met the PTSD reexperiencing criterion and nine met all three PTSD criteria. Subjects who met the reexperiencing criterion had fewer lesions in limbic system structures (eg, the cingulum) on the right than did subjects who did not meet this criterion (Mann-Whitney, P =.003).

CONCLUSION

Lesions induced by CHI in the limbic system on the right may inhibit subsequent manifestation of PTSD reexperiencing symptoms in children, adolescents, and young adults.

Differences in resting state regional cerebral blood flow assessed with 99mTc-HMPAO SPECT and brain atlas matching between depressed patients with and without tinnitus

An increased occurrence of major depressive disorder has been reported in tinnitus patients, and of tinnitus in depressive patients. Involvement of several Brodmann areas (BAs) has been reported in tinnitus perception. The aim of this study was to assess the regional cerebral blood flow (rCBF) changes in depressed patients with and without tinnitus. The rCBF distribution at rest was compared among 45 patients with a lifetime prevalence of major depressive disorder, of whom 27 had severe tinnitus, and 26 normal healthy subjects. 99mTc-hexamethylenepropylene amine oxime (99mTc-HMPAO) single photon emission computed tomography (SPECT), using a three-headed gamma camera, was performed and the uptake in 34 functional sub-volumes of the brain bilaterally was assessed by a computerized brain atlas. Decreased rCBF in right frontal lobe BA 45 (P<0.05), the left parietal lobe BA 39 (P<0.00) and the left visual association cortex BA 18 (P<0.05) was found in tinnitus patients compared with non-tinnitus patients. The proportion of tinnitus patients with pronounced rCBF alterations in one or more of the temporal lobe BAs 41+21+22 was increased compared to gender matched controls (P<0.00) and patients without tinnitus (P<0.05). Positive correlations were found between trait anxiety scales from the Karolinska Scales of Personality and rCBF in tinnitus patients only in three limbic BAs (P<0.01), and inverse correlations in non-tinnitus patients only in five BAs subserving auditory perception and processing (P<0.05). rCBF differences between healthy controls and depressed patients with and without tinnitus were found in this study. The rCBF alterations were distributed in the cortex and were particularly specific in the auditory cortex. These findings suggest that taking audiological symptoms into account may yield more consistent results between rCBF studies of depression.

Effects of the antidepressant/antipanic drug phenelzine and its putative metabolite phenylethylidenehydrazine on extracellular gamma-aminobutyric acid levels in the striatum

Phenelzine (PLZ) is a non-selective monoamine oxidase inhibitor (MAOI) commonly used to treat depression and panic disorder. As expected, PLZ increases brain levels of dopamine, norepinephrine, and serotonin. Interestingly, PLZ also elevates brain levels of gamma-aminobutyric acid (GABA), and previous studies have suggested that these increases may also contribute to the anxiolytic effects of PLZ. Using in vivo microdialysis in conscious, freely moving rats, combined with high performance liquid chromatography, the present experiments determined that PLZ (15 or 30 mg/kg, free base weight) increases extracellular levels of GABA in the caudate-putamen and nucleus accumbens. The results also indicated that phenylethylidenehydrazine (PEH; 29.6 mg/kg, free base weight), a putative intermediate metabolite of PLZ that is not an MAOI, also significantly increases extracellular GABA levels in the caudate-putamen. These findings provide further evidence that GABA may play an important role in the actions of PLZ and suggest that PEH should be pursued further as a GABAergic drug in its own right.

Neuropsychiatric assessment of Gilles de la Tourette patients: comparative study with other hyperkinetic and hypokinetic movement disorders

The role of the basal ganglia in conditions with co-occurring movement disorders and neuropsychiatric symptoms is not well known. It has been hypothesized that hyperkinesia -disinhibited behaviors and hypokinesia-inhibited behaviors result from an imbalance between the direct and indirect striatal output pathways, and that differential involvement of these pathways could account for the concurrent abnormalities in movement and behavior observed in these disorders. This study aimed to evaluate whether the pattern and the extent of the neuropsychiatric manifestations of patients with GTS, a hyperkinetic movement disorder of basal ganglia origin, differs from that of patients with other basal ganglia hyperkinetic (e.g., HD) or hypokinetic (e.g., PSP) movement disorders, and to determine whether patients with GTS show a greater frequency of hyperactive behaviors (e.g., agitation, irritability, euphoria, or anxiety) than PSP patients, and are comparable to patients with HD. The Neuropsychiatric Inventory (NPI), a scale with established validity and reliability, was administered to 26 patients with GTS (mean age, 30.2 +/- 2.2 years), and the results were compared with that of 29 patients with HD (mean age, 43.8 +/- 2 years) and 34 with PSP (mean +/- S.D. age, 66.6 +/- 1.2 years). There was no difference between the groups in the total NPI scores. However, there was a double dissociation in behaviors: patients with hyperkinetic disorders (HD and GTS) exhibited significantly more agitation, irritability, anxiety, euphoria, and hyperkinesia, whereas hypokinetic patients (PSP) exhibited more apathy. Patients with GTS showed greater scores than HD patients in all those scores differentiating HD and GTS from PSP patients (e.g., agitation, irritability, anxiety and euphoria), and were differentiated in a logistic regression analysis from both HD and PSP patients in having significantly more anxiety. We found that patients with GTS manifested predominantly hyperactive behaviors similar but more pronounced than those presented by patients with HD, while those with PSP manifested hypoactive behaviors. Based on our findings and the proposed models of basal ganglia dysfunction in these disorders, we suggest that the hyperactive behaviors in GTS are comparable to those observed in HD, being both secondary to an excitatory subcortical output through the medial and orbitofrontal cortical circuits, while in PSP the hypoactive behaviors are secondary to hypostimulation of these circuits. Abnormalities of other brain structures (e.g., amygdala, brainstem nuclei) may account for the significantly higher anxiety scores differentiating GTS from HD patients.

Obsessive compulsive behaviour in autism--towards an autistic-obsessive compulsive syndrome?

A portion of autistic patients exhibit compulsive-like behaviours. In addition it has been suggested that serotonin plays a major role in both obsessive compulsive disorder (OCD) and autistic disorder. Other neurohumors such as endogenous opioids and oxytocin have also been implicated in the two disorders. There is also some pharmacological overlap between the two disorders, as well as some similar neuroimaging studies. These similarities and overlaps have led us to propose a putative OCD-autistic disorder, which should be studied in greater detail.

Regional cerebral blood flow correlated with flashback intensity in patients with posttraumatic stress disorder

BACKGROUND

Nuclear imaging studies have examined cerebral blood flow (rCBF) in subjects with posttraumatic stress disorder (PTSD) using symptom evocation paradigms. To date, no such studies have investigated rCBF as related to subjects' reports of flashback intensity.

METHODS

Subjects with varying traumatic histories and longstanding PTSD were studied using [15O]-H2O positron emission tomography with an auditory script of their traumatic event. Eight subjects had three resting scans followed by their script and additional scans. Heart rate responses as well as the presence of flashbacks and their intensity were recorded. rCBF was correlated with flashback intensity in each subject's scan. Combined analysis of all subjects' data yielded common regions related to the flashback experience.

RESULTS

rCBF correlated directly with flashback intensity in the brainstem, lingula, bilateral insula, right putamen and left hippocampal and perihippocampal, somatosensory and cerebellar regions. Inverse correlations with rCBF were found in bilateral dorsolateral prefrontal, right fusiform and right medial temporal cortices.

CONCLUSIONS

This study correlated flashback intensity and rCBF in a group of patients with chronic PTSD suggesting involvement of brainstem, and areas associated with motor control, complex visual/spatial cues and memory.

The psychobiology of obsessive-compulsive disorder: how important is the role of disgust?

Psychobiologic models of obsessive-compulsive disorder (OCD) have focused on cortico-striatal-thalamic-cortical (CTSC) circuits, noting normal function in cognitive and motoric procedural strategies. Such models have relied on the classification of OCD as an anxiety disorder, seldom exploring other relevant emotions. Based on the hypothesis that a central emotion in OCD is disgust, the authors review the literature on its psychobiology and its relevance to current models of OCD. There are important parallels between the psychobiology of OCD and that of disgust. Obsessive- compulsive disorder may be conceptualized in terms of a false contamination alarm in which disgust plays a crucial organizing or embodying role, not only at a basic brain level, but also in terms of the psychosocial aspects of the disorder. Just as psychobiologic models of panic disorder and post- traumatic stress disorder have been strengthened by the inclusion of preclinical work on amygdala-mediated fear conditioning, so findings on disgust and its mediating CSTC circuits may generate useful hypotheses for OCD research.

SPECT scan in somatization disorder patients: an exploratory study of eleven cases

OBJECTIVE

There are no previous studies using single photon emission computed tomography (SPECT) scans in somatization disorder (SD) patients. The aim of this paper is to assess SPECT imaging abnormalities in SD patients and study any relation to laterality.

METHOD

Eleven SD patients from the Somatization Disorder Unit of Miguel Servet University Hospital, Zaragoza, Spain, not fulfilling criteria for any other psychiatric disorder and showing normal computed tomography (CT) and magnetic resonance imaging (MRI) images were studied with SPECT. Patients with DSM-IV axis I comorbidity were ruled out because it has been demonstrated that SPECT scans can show abnormalities in patients with depression and anxiety disorders. The technique used for SPECT was 99mTc-D,1,hexamethylpropyleneamide-oxime (99mTc-HMPAO) in four patients and 99mTc-bicisate in the other seven. The SPECT scans were evaluated without knowledge of clinical data and entirely by visual inspection.

RESULTS

Seven out of 11 (63.6%) SD patients showed hypoperfusion in SPECT imaging. In four cases there was hypoperfusion in the non-dominant hemisphere and the predominance of pain symptoms took place in the contralateral hemibody. In the other three patients hypoperfusion was bilateral. The anatomical regions affected were cerebellum (four cases), frontal and prefrontal areas (three cases), temporoparietal areas (two cases) and the complete hemisphere (one case).

CONCLUSIONS

A proportion of SD patients may present hypoperfusion in SPECT images, uni- or bilaterally, in different brain areas. Possible aetiological explanations for this finding are discussed. Controlled studies are necessary to confirm or refute this hypothesis.

Regional cerebral metabolism associated with anxiety symptoms in affective disorder patients

BACKGROUND

We studied the relationship between regional cerebral metabolism and the severity of anxiety in mood disorder patients, controlling for depression severity.

METHODS

Fifty-two medication-free patients with unipolar or bipolar illness underwent positron emission tomography with [(18)F]-fluorodeoxyglucose. Hamilton Depression Rating Scale and Spielberger Anxiety-State Scale scores were obtained for the week of the scan. Analyses were performed on globally normalized images and were corrected for multiple comparisons.

RESULTS

After covarying for depression scores, age, and gender, Spielberger Anxiety-State Scale scores correlated directly with regional cerebral metabolism in the right parahippocampal and left anterior cingulate regions, and inversely with metabolism in the cerebellum, left fusiform, left superior temporal, left angular gyrus, and left insula. In contrast, covarying for anxiety scores, age, and gender, Hamilton Depression Rating Scale scores correlated directly with regional cerebral metabolism in the bilateral medial frontal, right anterior cingulate, and right dorsolateral prefrontal cortices.

CONCLUSIONS

Comorbid anxiety symptoms are associated with specific cerebral metabolic correlates that partially overlap with those in the primary anxiety disorders and differ from those associated with depression severity.

The postconcussion syndrome after mild head trauma part II: is migraine underdiagnosed?

The evidence for post-traumatic migraine as the cause of the postconcussion syndrome in a proportion of patients is reviewed.

CONCLUSION

patients suffering recurrent post-traumatic headaches or other elements of the postconcussion syndrome should be treated for migraine.

Long-lasting stress sensitisation

Stressful experiences in humans can result in a spectrum of long-term changes in behavioural, autonomic and hormonal responsivity. An extreme form of such alterations is found in patients with post-traumatic stress disorder (PTSD). A number of animal models has been developed in which intense stressful experiences (shocks, social confrontations) result in longterm altered responsivity of behavioural, autonomic and hormonal responses to aversive challenges which mimic many of the changes seen in PTSD. These models of stress-induced sensitisation are beginning to generate a better understanding of the vulnerability factors, time-course and underlying neuronal substrates of the long-term disturbances experienced by humans as a result of stressful life events.

Functional neuroimaging and the neuroanatomy of obsessive-compulsive disorder

Functional neuroimaging studies have advanced the understanding of the brain mediation of OCD by orbitofrontal-subcortical circuitry, but much is still unknown. Phenotypic heterogeneity could account for many of the inconsistencies among previous neuroimaging studies of OCD. Current studies are seeking to find the neurobiological basis of OCD symptom subtypes and predictors of treatment response. Future studies combining genetics and basic neuroanatomic research with neuroimaging may clarify the cause and pathophysiology of OCD. Although many lines of evidence point to dysfunction of orbitofrontal-subcortical circuitry in patients with OCD, many questions remain unanswered. Some have suggested that orbitofrontal-subcortical hyperactivity in OCD may be the result of abnormal neuroanatomic development of these structures or a failure of pruning of neuronal connections between them, as occurs in normal development, but no postmortem neuroanatomic studies of OCD exist to delineate its pathophysiology. Interventions that directly alter the indirect-direct pathway balance within frontal-subcortical circuits will allow for direct testing of the pathophysiologic hypotheses presented here. The roles of various neurochemical systems in OCD are similarly unclear. Although an abundance of indirect evidence suggests serotonergic abnormalities in patients with OCD, no direct evidence demonstrates what those abnormalities are or whether they are primary or secondary phenomena in patients with OCD. Ongoing studies of 5-HT synthesis in the brains of patients with OCD may shed light on this question.

The postconcussion syndrome after mild head trauma: is brain damage overdiagnosed? Part 1

Many investigators attribute the postconcussion syndrome following mild closed head injury to permanent brain damage. The evidence supporting this conclusion is reviewed, including the force necessary to cause permanent brain damage; the basis for determining whether the patient was exposed to sufficient force in the accident to permanently damage the brain; the basis for determining whether the patient actually has permanent brain damage (not just brain dysfunction) traceable to the accident; and whether the location and severity of brain damage is sufficient to account for the postconcussion syndrome.

CONCLUSION

the evidence for permanent traumatic brain damage as the cause of the postconcussion syndrome following mild closed head injury is weak.

[Obsessive-compulsive disorder, frontostriatal system and the effect of the serotonergic system]

OBJECTIVES

Focal issues of recent research on obsessive-compulsive disorders have been the involvement of the frontostriatal system in the patho-physiology, as well as the manner of effect and efficacy of the serotonin reuptake inhibitors that unfold their specific efficacy in the frontostriatal system. The course of treatment among adolescent inpatients with obsessive-compulsive disorder was analyzed with regard to the medications used and their effects upon the course of treatment.

METHODS

The data for all adolescents with obsessive-compulsive disorder admitted as inpatients to the Hospital for Child and Adolescent Psychiatry and Psychotherapy in Mannheim since 01.01.1990 were analyzed with regard to medication and the parameters for course and outcome.

RESULTS

Five patients dropped out of treatment, five patients received no medication, eight received sulpiride, ten were treated with clomipramine, and three with fluvoxamine. The average length of inpatient stay was longer for the groups treated with sulpiride and clomipramine than for the group that received no medication, but equivalent for these two medication groups. The success of treatment for obsessive-compulsive disorder was rated as higher in these two groups than in the group without medication. On sulpiride, patients gained weight and exhibited fatigue and increased levels of prolactin. On clomipramine, half of the patients exhibited cardiac side effects.

CONCLUSIONS

This small, nonrandomized medicated sample analyzed under non-double-blind conditions shows no difference in the efficacy of clomipramine and sulpiride under post hoc analysis. Rather, the side effects that occurred in patients on clomipramine indicate a more frequent use of SSRI to increase compliance as regards medication intake.

Restricted unilateral Sydenham's chorea: reversible contralateral striatal hypermetabolism demonstrated on single photon emission computed tomographic scanning

Sydenham's chorea results from group A streptococcus infection and subsequent generation of antineuronal antibodies directed at the caudate nucleus and putamen. Predominantly bilateral, in up to 30% of cases the chorea can be unilaterally restricted. Imaging studies, both structural (magnetic resonance imaging) and functional (positron emission tomography), in patients with bilateral Sydenham's chorea have suggested reversible striatal abnormalities. Two patients with unilateral Sydenham's chorea are presented. Computed tomographic and magnetic resonance imaging were normal in both. However, hexamethylpropylenamine oxime single photon emission tomographic (HMPAO SPECT) studies demonstrated hypermetabolism in the contralateral basal ganglia. Resolution of symptoms in one of the patients coincided with normalization of the SPECT scan. Thus, unilateral striatal hypermetabolism appears to underlie the contralateral chorea observed. A SPECT scan probably should be included in the work-up of new-onset chorea.

Frontal lobe psychopathology: mania, depression, confabulation, catatonia, perseveration, obsessive compulsions, and schizophrenia

The frontal lobes can be subdivided into major functional neuroanatomical domains, which, when injured, surgically destroyed, or reduced in activity or volume, give rise to signature pathological and psychiatric symptomology. A review of case reports and over 50 years of research, including magnetic resonance imaging, positron emission tomography, and single photon emission computed tomography scans, indicates that apathy, "blunted" schizophrenia, major depression, and aphasic-perseverative disturbance of speech and thought are associated with left lateral as well as bilateral frontal (and striatal) abnormalities. Impulsiveness, confabulatory verbosity, grandiosity, increased sexuality, and mania are associated with right frontal (as well as bilateral) disturbances. Gegenhalten, catatonia, and disturbances of "will" are indicative of medial frontal injuries. Disinhibitory states and obsessive-compulsive perseverative abnormalities are more frequently observed with orbital frontal lobe dysfunction, including frontal-striatal disturbances. These associations, however, are not always clear-cut as patients with the same diagnosis may demonstrate different symptoms that may be due to an additional abnormality in a different region of the brain. Moreover, as the frontal subdivisions are richly interconnected, and as frontal lobe abnormalities are not always discrete or well localized, a wide array of seemingly divergent waxing and waning symptoms may be manifest, sometimes simultaneously, including manic depression and what has been referred to as the "frontal lobe personality."