Command hallucinations: who obeys and who resists when?

The impact of auditory command hallucinations on the behaviour of schizophrenic patients sometimes appears to be unpredictable. In order to tackle this problem, the psychopathological characteristics of command hallucinations in 31 schizophrenic patients were assessed using a 24-item questionnaire. Using binary data and relative risk analysis methods, predictors were determined for obeying or resisting command hallucinations. Characteristics of voices and the attitude toward the voices appear equally important for prediction. A set of three psychopathological characteristics comprising a voice known to the patient, emotional involvement during the hallucinations, and seeing the voice as real provides significant predictivity of behaviour following command hallucinations. These results are interesting for clinical and forensic psychiatrists.

Factors related to the magnitude of T2* MR signal changes during functional imaging

Our aim was to determine whether age, sex, the degree of weakness, anticonvulsants, the histology of the underlying lesion(s), the presence of oedema or the distance of the lesion from the motor region have an impact on the blood oxygenation level-dependent (BOLD) signal strength and therefore on the validity of functional MRI (fMRI). We studied 98 patients with masses near the central region imaged for surgical planning at 1.5 tesla, employing a BOLD sequence during a motor task. We calculated percentage signal change in the primary motor cortex between rest and activation and carried out multiple linear regression to examine the impact of the above factors on signal strength. Using a stepwise analysis strategy, the distance of the lesion from the motor region had the strongest influence (r=0.653, P<0.001). The factor with largest uncorrelated additional impact on signal change was the presence of oedema. Both predictors together formed a highly significant multiple r=0.739 ( P<0.001). No other predictive factor was identified (all P>0.20). Disturbances of cerebral blood flow and metabolism induced by the tumour were presumed to be the causes of a decrease in signal in the adjacent cortex.

Activation in primary and secondary motor areas in patients with CNS neoplasms and weakness

OBJECTIVE

To demonstrate whether cortical activation within different cortical motor regions in neurosurgical patients varies with the degree of paresis induced by mass lesions near the central region.

METHODS

A total of 110 patients with brain tumors infiltrating the central region and with varying degrees of paresis were investigated employing fMRI during the performance of hand motor tasks. The percent signal change between rest and activation was calculated for four cortical regions: primary motor cortex (M1), supplementary motor area, premotor area, and superior parietal lobule.

RESULTS

Significant decreases in activation with increasing degrees of paresis were found in M1, whereas significant increases in activation were noted in secondary motor areas that were not affected by the tumor.

CONCLUSIONS

The signal loss in areas adjacent to tumor tissue may relate either to tumor-induced changes in cerebral hemodynamics or to a direct loss of cortical neurons resulting in a lesser degree of hemodynamic changes after motor activation. The increase in activation within secondary motor areas with increasing degrees of paresis supports the growing evidence of a practice- and lesion-dependent reorganization of the cortical motor system and the ability of the brain to modulate its excitatory output according to external demands.

Decade breaks in the mental number line? Putting the tens and units back in different bins

Most models of number recognition agree that among other number representations there is a central semantic magnitude representation which may be conceptualized as a logarithmically compressed mental number line. Whether or not this number line is decomposed into different representations for tens and units is, however, controversial. We investigated this issue in German participants in a magnitude comparison (selection) task in which the larger of two visually presented Arabic two-digit numbers had to be selected. Most importantly, we varied unit-decade-compatibility: a number pair was defined as compatible if the decade magnitude comparison and the unit magnitude comparison of the two numbers would lead to the same response (e.g. 52 and 67) and as incompatible if this was not the case (e.g. 47 and 62). While controlling for overall numerical distance, size and other variables, we consistently found compatibility effects. A control experiment showed that this compatibility effect was not due to perceptual presentation characteristics. We conclude that the idea of one single number line representation that does not additionally assume different magnitude representations for tens and units is not sufficient to account for the data. Finally, we discuss why decade effects were not found in other experimental settings.

Evidence of abnormal amygdala functioning in borderline personality disorder: a functional MRI study

BACKGROUND

Intense and rapidly changing mood states are a major feature of borderline personality disorder (BPD); however, there have only been a few studies investigating affective processing in BPD, and in particular no neurofunctional correlates of abnormal emotional processing have been identified so far.

METHODS

Six female BPD patients without additional major psychiatric disorder and six age-matched female control subjects underwent functional magnetic resonance imaging (fMRI) to measure regional cerebral hemodynamic changes following brain activity when viewing 12 standardized emotionally aversive slides compared to 12 neutral slides, which were presented in random order.

RESULTS

Our main finding was that BPD subjects but not control subjects were characterized by an elevated blood oxygenation level dependent fMRI signal in the amygdala on both sides. In addition, activation of the medial and inferolateral prefrontal cortex was seen in BPD patients. Both groups showed activation in the temporo-occipital cortex including the fusiform gyrus in BPD subjects but not in control subjects.

CONCLUSIONS

Enhanced amygdala activation in BPD is suggested to reflect the intense and slowly subsiding emotions commonly observed in response to even low-level stressors. Borderline subjects' perceptual cortex may be modulated through the amygdala leading to increased attention to emotionally relevant environmental stimuli.

On the Functional Neuroanatomy of Intrinsic and Phasic Alertness

Intrinsic and phasic alertness are the most basic aspects of attention intensity probably constituting the basis for the more complex and capacity-demanding aspects of attention selectivity. Intrinsic alertness represents the cognitive control of wakefulness and arousal and is typically assessed by simple reaction time tasks without a preceding warning stimulus. Phasic alertness, in contrast, is called for in reaction time tasks in which a warning stimulus precedes the target, and it represents the ability to increase response readiness subsequent to external cueing. We report PET and fMRI data from both the literature and our own experiments to delineate the cortical and subcortical networks subserving alertness, sustained attention (as another aspect of attention intensity), and spatial orienting of attention. Irrespective of stimulus modality, there seems to exist a mostly right-hemispheric frontal, parietal, thalamic, and brain-stem network which is coactivated by alerting and orienting attentional demands. These findings corroborate both the hypothesis of a frontal modulation of brain-stem activation probably via the reticular nucleus of the thalamus and of a coactivation of the posterior attention system involved in spatial orienting by the anterior alerting network. Under conditions of phasic alertness there are additional activations of left-hemisphere frontal and parietal structures which are interpreted as basal aspects of attention selectivity rather than additional features of alerting.

Functional MRI for presurgical planning: problems, artefacts, and solution strategies

OBJECTIVES

Presurgical mapping of motor function is a widely used clinical application of functional (f) MRI, employing the blood oxygenation level dependent contrast. The aim of this study was to report on 3 years experience of 194 fMRI studies on the representation of motor function in 103 patients and to describe the problems and artefacts that were typically present.

METHODS

An evaluation was carried out to determine whether the patients' age, type or location of the tumourous lesion, severity of the paresis, or the tasks used during the investigation have an effect on artefacts of fMRI studies and how these artefacts are best overcome.

RESULTS

Functional MRI identified the motor regions in 85% of all investigated paradigms. In 11% of the investigated patients no information at all on functional localisation was obtained. A draining vein within the central sulcus was present in all patients that showed activation within the parenchyma of the precentral gyrus but also in three patients in whom no parenchymal activation was present. Head movement artefacts were the most frequent cause for fMRI failure, followed by low signal to noise ratio. Motion artefacts were correlated with the degree of paresis and with the functional task. Tasks involving more proximal muscles led to significantly more motion artefacts when compared with tasks that primarily involved distal muscles. Mean MR signal change during task performance was 2.5%.

CONCLUSIONS

Most of the artefacts of functional MRI can be reliably detected and at least in part be reduced or eliminated with the help of mathematical algorithms, appropriate pulse sequences and tasks, and-probably most important-by evaluating the fMRI raw data-that is, the MR signal time courses.

[Imperative auditory hallucinations in schizophrenia]

Command hallucinations are a subtype of auditory verbal hallucinations in schizophrenia. More likely than any other schizophrenic symptom, they may have an impact on the individual's behavior. In the forensic literature, aspects of dangerous actions induced by psychotic motivation have been discussed. From the psychiatric point of view, the main problem is the unpredictability of behavioral consequences. The present study examines psychopathological details of command hallucinations in 31 hospitalized schizophrenic patients, 10 females and 21 males, using a questionnaire including 24 items. The predictive accuracy of a distinct set of signs was rated concerning compliance vs. resistance of hallucinated commands. The predictors are: identifying the hallucinated voice, being affected by emotions after hallucinations, and misregarding the voice as being real. In the presence of these conditions, behavioral consequences are predicted by a value which was 6.7 times higher than that without any information about predictors. In the absence of these conditions, resistance of command voices is predicted by a value of 7.

Cognitive neuropsychological models of adult calculation and number processing: the role of the surface format of numbers

Several brain-damaged patients showed a series of performance dissociations related to the surface format of numbers. These findings provide empirical evidence against two crucial assumptions of the calculation and number processing model proposed by McCloskey, Caramazza and Basili (36) and widely accepted within the current literature on developmental dyscalculia. First, the unique syntactical system for verbal numbers can fractionate into two syntactic components, one for spoken verbal and one for written verbal numbers, respectively. Second, access to simple number facts (multiplication tables) seems to rely on format-specific routes and not on the access to supposedly unique abstract representations. The data can also hardly be interpreted within the theoretical framework of the "triple-code" information processing model of Dehaene (16) and of its anatomical implementation by Dehaene and Cohen (19). Taken together, these results favour a cognitive architecture of the numerical system with a variety of format-specific processes and multiple representations proposed by Campbell and Clark (8) which remain to be fully specified.

Effects of blood estrogen level on cortical activation patterns during cognitive activation as measured by functional MRI

Modulation of the blood estrogen level as it occurs during the menstrual cycle has a strong influence on both neuropsychological and neurophysiological parameters. One of currently preferred hypotheses is that the menstrual cycle hormones modulate functional hemispheric lateralization. We examined six male and six female subjects by functional magnetic resonance imaging (fMRI) to image cortical activation patterns associated with cognitive and motor activation to determine whether these changes during the menstrual cycle can be visualized. Female subjects, who did not use oral contraceptives, were scanned twice, once during the menses and once on the 11/12 day of the menstrual cycle. A word-stem-completion task, a mental rotation task and a simple motor task were performed by all subjects. Our data provide evidence that the menstrual cycle hormones influence the overall level of cerebral hemodynamics to a much stronger degree than they influence the activation pattern itself. No differences were seen between male subjects and female subjects during the low estrogen phase. During both neuropsychological tasks blood estrogen level had a profound effect on the size but not on the lateralization or the localization of cortical activation patterns. The female brain under estrogen showed a marked increase in perfusion in cortical areas involved in both cognitive tasks, whereas the hemodynamic effects during the motor tasks were less pronounced. This might be due to differences in neuronal or endothelian receptor concentration, differences in synaptic function, or, most likely, changes in the cerebrovascular anatomy in different cortical regions.

Hemispheric lateralization at different levels of human auditory word processing: a functional magnetic resonance imaging study

We used functional magnetic resonance imaging to disentangle the functional anatomy of brain systems involved in the processing of auditory word form and meaning. Three monitoring tasks on auditory stimuli, aimed at phonetic, lexical and semantic processing, were used. We found no lateralization of temporal lobe activations, when word processing was contrasted versus the complex phonetic task. Bilateral middle temporal activations (Brodmann Area [BA] 21) were attributed to processing of word-form. Areas specific to semantic processing were restricted to the left hemisphere: the posterior middle frontal (BA 9) and posterior parietal (BA 7/40) cortex, as well as an inferior temporal area (BA 20/21). Our data suggest, that left hemispheric dominance for auditory word comprehension occurred at the level of semantic processing.

The Thai version of Aachen aphasia test (THAI-AAT)

The lack of a standardized Thai Language aphasia test raises difficulties not only with the assessment and treatment planning for the clinical but also with the accurate diagnosis and the reliable incidence for research on aphasiology in Thailand. This study aimed to use the Thai version of German Aachen aphasia (THAI-AAT), which is systematically adapted according to well-defined linguistic criteria and psychometric requirement, to assess the language deficit of Thai aphasic patients. The subjects participating in this study were 125 aphasia patients, 60 non-aphasic brain damaged patients and 120 normal subjects. The result revealed that the THAI-AAT is linguistically parallel in test design and fulfills the same psychometric properties as the original. The THAI-AAT obtains the goals: to differential diagnosis of aphasia distinguishing it from non-aphasic disturbance and to identify the type of aphasic syndrome.

Differential effects of pain and spatial attention on digit representation in the human primary somatosensory cortex

Reorganization of primary somatosensory cortex subsequent to either reduced or enhanced peripheral input is well established. Recently, plastic changes following arm amputation in humans were shown to correlate with phantom limb pain. This raised the question whether spatial attention and pain may cause cortical reorganization in the absence of deafferentation. Using non-invasive neuroelectric imaging to study the digit representation in the human primary somatosensory cortex, we report a delayed shift of the representation of digits 2-3 due to pain on the digits 4-5, which outlasted the pain by several minutes. In contrast, reorganization during spatial attention was less pronounced, was seen almost immediately and only during the condition. These data indicate that spatial attention and pain without peripheral deafferentation cause cortical reorganization by different mechanisms. The differential time course of reorganizational effects observed at the cortex may be due to modulation of the lemniscal pathways by nociceptive input from the spinal cord dorsal horn.

Cortical activation patterns during complex motor tasks in piano players and control subjects. A functional magnetic resonance imaging study

We performed functional magnetic resonance imaging (MRI) in professional piano players and control subjects during an overtrained complex finger movement task using a blood oxygenation level dependent echo-planar gradient echo sequence. Activation clusters were seen in primary motor cortex, supplementary motor area, premotor cortex and superior parietal lobule. We found significant differences in the extent of cerebral activation between both groups with piano players having a smaller number of activated voxels. We conclude that, due to long-term motor practice a different cortical activation pattern can be visualized in piano players. For the same movements lesser neurons need to be recruited. The different volume of the activated ortical areas might therefore reflect the different effort necessary for motor performance in both groups.

[Aspects of cerebral connnectivity in schizophrenia. A comparative CBF study on treated schizophrenics before and after medication]

INTRODUCTION

The hypothesis of prefrontal-temporolimbic disconnectivity, considered to be relevant to the pathogenesis of schizophrenia, has been tested in 29 drug-naive schizophrenic patients, comparing the active with the remitted state.

METHOD

A pre-post-treatment design was applied to 29 drug-naive schizophrenic inpatients, 18 male, mean age 32 years, 11 female, mean age 32 years, mean duration of illness 29 months. Psychopathological symptoms were assessed using PANSS, regional cerebral blood (rCBF) was measured by HMPAO-SPECT. RCBF values were calculated for 21 regions of interest after normalization to cerebellum, and plotted by Euklidean diagrams using the ordinal, nonmetric, multidimensional scaling method. These diagrams represent similarity correlations visualized as spatial distances. High correlation levels as indicated by small Euklidean distances have been interpreted as functional connectivity.

RESULTS

In active schizophrenia, functional disconnectivity was observed between prefrontal and temporal cortex. After remission, connectivity was improved between temporolimbic and frontal cortex.

CONCLUSION

Comparing active with remitted schizophrenia, a frontotemporal disconnectivity appears. Temporolimbic as well as frontolimbic connections restitute parallel to psychopathological improvement.

Functional anatomy of intrinsic alertness: evidence for a fronto-parietal-thalamic-brainstem network in the right hemisphere

Alertness, the most basic intensity aspect of attention, probably is a prerequisite for the more complex and capacity demanding domains of attention selectivity. Behaviorally, intrinsic alertness represents the internal (cognitive) control of wakefulness and arousal; typical tasks to assess optimal levels of intrinsic alertness are simple reaction time measurements without preceding warning stimuli. Up until now only parts of the cerebral network subserving alertness have been revealed in animal, lesion, and functional imaging studies. Here, in a 15O-butanol PET activation study in 15 right-handed young healthy male volunteers for this basic attention function we found an extended right hemisphere network including frontal (anterior cingulate-dorsolateral cortical)-inferior parietal-thalamic (pulvinar and possibly the reticular nucleus) and brainstem (ponto-mesencephalic tegmentum, possibly involving the locus coeruleus) structures, when subjects waited for and rapidly responded to a centrally presented white dot by pressing a response key with the right-hand thumb.

Determination of cognitive hemispheric lateralization by "functional" transcranial Doppler cross-validated by functional MRI

BACKGROUND AND PURPOSE

Changes of blood flow velocity in the right and left middle cerebral artery (MCA) induced by cognitive demands are detectable by means of "functional" transcranial Doppler sonography (fTCD). Functional MRI (fMRI) is an alternative method for mapping brain activity. The purpose of this study was to determine whether fTCD can detect hemispheric lateralization and to cross-validate fTCD with fMRI.

METHODS

Bilateral continuous MCA monitoring of 14 healthy, right-handed subjects with TCD was performed while the subjects underwent a visuospatial task, and the hemispheric blood flow velocity shift was calculated. Identical stimulus and response patterns were used in fMRI. Blood oxygenation level-dependent fMRI was performed with the use of a gradient-echo echo-planar sequence on a 1.5-T scanner. Statistical maps were computed on a voxel-by-voxel basis, hemispheric ratios for activated pixels were computed, and a group study was performed separately for the male and female subgroups.

RESULTS

Statistical analyses (t test) showed a significantly higher mean peak blood flow velocity increase (P<0.05) of the right MCA (111.3+/-7.0%) compared with the left MCA (107.1+/-6.1%). fMRI demonstrated bilateral activation in the superior parietal lobulus (Brodmann area 7) with a right/left ratio of 1.95. Concordant differences between the female and male subgroups could be visualized with both methods.

CONCLUSIONS

Both methods succeeded in discriminating a blood flow shift to the right hemisphere induced by a complex cognitive visuospatial task. fMRI cross-validates the findings of fTCD. Our study suggests that fTCD can investigate the close relationship between brain activity and blood flow and lateralize higher cognitive functions reliably.

Success rate of radioiodine therapy in Graves' disease: the influence of thyrostatic medication

There is controversy whether simultaneous thyrostatic medication influences the outcome of radioiodine (131I) therapy in Graves' disease by reducing the absorbed energy dose of 131I when delivering a standard dose. We therefore sought to ascertain whether the outcome of ablative 131I therapy is in any way affected by simultaneous thyrostasis (carbimazole) by aiming for a constant absorbed dose of 200-250 Gy. We prospectively studied 207 patients with Graves' disease (106 with and 101 without simultaneous carbimazole at the time of 131I therapy). All patients were reexamined 3, 6, and 12 months after 131I therapy. The 101 nonthyrostatic patients showed a highly significantly greater success rate (93%) than the 106 thyrostatic patients (49%). Stepwise logistic regression demonstrated that failure was related to the administration of carbimazole during 131I therapy (P < 0.00005) and the absorbed dose (P < 0.025), but was not related to free T3, free T4, TSH receptor antibodies, or thyroid volume. The success rate was 100% in 93 nonthyrostatic patients with absorbed doses of 200 Gy or more, but was only 12.5% (1 of 8) for absorbed doses less than 200 Gy. Correlation between success and absorbed dose was significantly higher for nonthyrostatic than for thyrostatic patients (r = 0.93 vs. r = 0.24). Sixteen patients who discontinued thyrostasis 1-3 days before 131I therapy showed 94% successes. Simultaneous thyrostasis is the decisive factor against a successful 131I therapy even if the significantly reduced 131I uptake/half-life values under thyrostasis are compensated with a higher delivered dose to ensure a comparable absorbed dose, possibly due to the additionally effective radioprotective properties of carbimazole. Therefore, if clinically feasible, we recommend discontinuing thyrostasis at least 1 day before beginning 131I therapy, because even in hyperthyroid nonthyrostatic patients the success rate was 100%.

Active and remitted schizophrenia: psychopathological and regional cerebral blood flow findings

Single photon emission computed tomography with technetium-99m-d,l-hexamethylpropyleneamine oxime (99mTc-HMPAO) was used to assess regional cerebral blood flow (rCBF) during both florid and remitted stages of schizophrenia. Forty schizophrenic patients in an active phase of illness (diagnosis by DSM-III-R) were examined in two clinical states (ill vs. improved). At study entry, 24 patients were drug-naive, five were currently drug-free, and 11 were being treated with antipsychotic medication. Twenty medical patients who suffered from non-specific headaches but were free of neurological and psychiatric symptoms served as control subjects. At initial examination during the active phase of illness, cerebral perfusion patterns in the schizophrenic patients were characterized by both hypofrontality and hypotemporality. After remission, hypofrontality was no longer apparent in two of four frontal regions, and hypotemporality disappeared completely. As assessed with the Positive and Negative Syndrome Scale (PANSS), formal thought disorders, hallucinations, and ideas of grandiosity correlated with rCBF in the active phase of illness, but not after remission. In the remitted but not in the florid state, blunted affect, difficulties in abstract thinking, lack of spontaneity, and stereotyped thoughts correlated with rCBF. Correlations of five symptoms with rCBF changed significantly from first to second examination. The present study suggests that correlations between single psychotic symptoms and rCBF differ significantly in florid vs. remitted phases of schizophrenia.

The Thai version of the German Aachen Aphasia Test (AAT): description of the test and performance in normal subjects

The Aachen Aphasia Test (AAT), originally developed as a test for aphasia language disorders in Germany, consists of six spontaneous speech rating scales and five subtests: Token Test, Repetition, Written Language, Confronting Naming and Comprehension. The study aimed to describe the linguistic properties of the AAT Thai version and to investigate the test performances of the normal subjects. In this study some problems of linguistic changes in the construction of the Thai version were discussed. The results revealed that the normal subjects' performances on the test were independent of age, sex and education level. Therefore, the Thai version of AAT is applicable to the differential diagnosis of the communicative abilities of Thai aphasic patients.

Subjective experience in brain-injured patients and their close relatives: a European Brain Injury Questionnaire study

Results are reported from an international project the aim of which has been to develop and validate a wide-ranging questionnaire suitable for administration to brain-injured patients and their relatives. A self-report questionnaire concerning subjective experience of cognitive, emotional and social difficulties (The European Brain Injury Questionnaire, EBIQ) was administered to a group of 905 brain-injured patients, and close relatives to these competed a parallel version of the questionnaire concerning the brain-injured person. The sample was drawn from seven European countries together with Brazil. The same questionnaire was also administered to a group of 203-non-brain-injured controls, similarly in self-report and relative-report versions. Scales relating to eight specific areas of functioning, together with a global scale, are derived from the questionnaire and their internal reliability was estimated in the present data. Analyses of the 63 items of the questionnaire showed consistently greater levels of problems for the brain-injured group, especially as indicated by relatives. This pattern was substantially replicated among the nine scales. The scales discriminated well between stroke patients and those who had suffered a traumatic brain injury. There was also a tendency for reported problems to be greater for patients who were surveyed later post-injury (> or = 19 months) rather than earlier. Comparison of sets of controls derived from two countries (France and Brazil) showed small but important differences. It is concluded that the questionnaire has an acceptable reliability and validity, but that it will be necessary to obtain culturally relevant non-brain-injured control data when employing it in different countries.