Search PubMed⌕ Search

Biomedical subjects

M Spitzer

Publications and source records attributed to M Spitzer.

At least 55 records · Page 3Linked to original sources
PubMed1998

[Functional magnetic resonance tomography in psychopathological research].

Mental disorders are characterised by psychopathological symptoms which correspond to functional brain states. Functional magnetic resonance imaging (fMRI) is used for the non-invasive study of cerebral activation patterns in man. First of all, the neurobiological principles and presuppositions of the method are outlined. Results from the Heidelberg imaging lab on several simple sensorimotor tasks as well as higher cognitive functions, such as working and semantic memory, are then presented. Thereafter, results from preliminary fMRI studies of psychopathological symptoms are discussed, with emphasis on hallucinations, psychomotoric phenomena, emotions, as well as obsessions and compulsions. Functional MRI is limited by the physics underlying the method, as well as by practical constraints regarding its use in conjunction with mentally ill patients. Within this framework, the problems of signal-to-noise ratio, data analysis strategies, motion correction, and neurovascular coupling are considered. Because of the rapid development of the field of fMRI, maps of higher cognitive functions and their respective pathology seem to be coming within easy reach.

Brain↗
PubMed1998

Lateralised semantic and indirect semantic priming effects in people with schizophrenia.

BACKGROUND: In schizophrenia, disturbances in the development of physiological hemisphere asymmetry are assumed to play a pathogenetic role. The most striking difference between hemispheres is in language processing. The left hemisphere is superior in the use of syntactic or semantic information, whereas the right hemisphere uses contextual information more effectively. METHOD: Using psycholinguistic experimental techniques, semantic associations were examined in 38 control subjects, 24 non-thought-disordered and 16 thought-disordered people with schizophrenia, for both hemispheres separately. RESULTS: Direct semantic priming did not differ between the hemispheres in any of the groups. Only thought-disordered people showed significant indirect semantic priming in the left hemisphere. CONCLUSIONS: The results support: (a) a prominent role of the right hemisphere for remote associations; (b) enhanced spreading of semantic associations in thought-disordered subjects; and (c) disorganisation of the functional asymmetry of semantic processing in thought-disordered subjects.

Analysis of Variance↗
PubMed1998

Maternal CA-125 levels in pregnancy and the puerperium.

OBJECTIVE: To determine the levels of CA-125 throughout pregnancy and the puerperium to establish a baseline, thereby indicating what values may be indicative of the pathologic conditions usually associated with elevated CA-125 levels. STUDY DESIGN: A prospective, longitudinal study was carried out on a consecutive series of pregnant women to determine their CA-125 levels throughout pregnancy and during the puerperium. Blood was drawn at four- to six-week intervals for clinically indicated tests. The residual sera were kept frozen, and subsequently CA-125 measurements were determined by radioimmunoassay. RESULTS: Of 34 women enrolled in the study, 20 completed the evaluations throughout pregnancy and in the puerperium. The remaining 14 had evaluations for varying portions of their pregnancies but not throughout pregnancy or during the puerperium. The results in these two groups were compared and found not to be statistically significantly different. For the group as a whole, the levels of CA-125 were high, with wide fluctuations in the first trimester; the levels in the early first trimester (five to eight weeks) were particularly high, with a mean of 55.8 and median of 36.2 (range, 6.9-251.2) U/mL. The levels then dropped and remained < 35 U/mL through the rest of pregnancy (including immediately prior to delivery). Another peak, with wide fluctuations, occurred soon after delivery, with a mean of 39.8 and median of 41.9 (range, 10.7-296.7) U/mL. In the late postpartum period (2-10 weeks after delivery) there was a return to baseline levels in all subjects. CONCLUSION: This study showed that there is a distinct pattern in CA-125 levels during pregnancy and the puerperium. Due to the wide fluctuations in CA-125 levels in very early pregnancy and the immediate postpartum period, CA-125 values during these periods are not useful for clinical correlation with the pathologic conditions known to be associated with elevated levels of CA-125. However, further study is needed to determine whether extreme values in the first trimester or elevated levels after the first trimester are diagnostic or predictive of any conditions related to pregnancy.

Adult↗
PubMed1998

Myomectomy performed concurrently with tuboplasty.

OBJECTIVE: To determine whether women who require tuboplasty for infertility and have associated uterine leiomyomas that require removal should have the myomectomy done concurrently. STUDY DESIGN: Eighty-nine infertility patients underwent tuboplasty alone for proximal tubal obstruction, 30 others were treated by both myomectomy and tuboplasty during the same operation, and 15 others underwent tuboplasty, leaving the myomas in situ. The tuboplasty in all cases consisted of tubal resection and anastomosis (TRA). The pregnancy rates and outcomes in the three groups were compared. RESULTS: Of the 89 patients who underwent TRA alone, 74.2% (66 patients) became pregnant, and of those 66, 15.2% had a spontaneous miscarriage, 24.2% developed an ectopic pregnancy, and 60.6% achieved a viable birth. By comparison, of 30 patients who had both TRA and myomectomy, 63.6% (19 patients) conceived, and of those 19, 15.8% miscarried, 26.3% developed ectopic pregnancies, and 57.9% achieved viable births. Of 15 patients who underwent TRA leaving the myomas in situ, 73% (11) became pregnant, and of those 11, 45% (5) miscarried, 18% (2) had ectopic pregnancies and 36% (4) gave birth to viable infants. The incidence of pregnancies, ectopic gestations, miscarriages and viable births in the three groups showed no statistical differences. CONCLUSION: When myomectomy is indicated, because of the lack of disadvantages of performing it at the time of tuboplasty, the combined surgical approach should be the procedure of choice rather than leaving the myomas in situ for their removal in a separate operation at a later date.

Abortion, Spontaneous↗
PubMed1997

Left lateralized P300 amplitude deficit in schizophrenic patients depends on pitch disparity.

The general reduction of P300 amplitude in response to auditory oddball stimuli is one of the most consistently replicated biological observations in schizophrenic patients. Several groups have reported a P300 asymmetry in schizophrenic patients, others have not been able to replicate this finding. In order to clarify this issue, we examined the effect of stimulus discriminability on P300 amplitude distribution in schizophrenic patients and in age-matched normal control subjects, using two different auditory oddball paradigms. The detection of the target tone was either simple or difficult, due to manipulation of pitch disparity. The P300 amplitude was comparatively smaller in the schizophrenic patient group compared to the healthy controls and in the difficult task compared to the simple. The schizophrenic patients showed a specific P300 amplitude reduction over left temporal electrode sites when the simple paradigm was used. The difficult paradigm did not elicit asymmetrical P300 amplitudes in schizophrenic patients.

Adult↗
PubMed1997

The value of repeat Pap smear at the time of initial colposcopy.

OBJECTIVE: The objective was to determine if repeating a Pap smear at the time of an initial colposcopy has sufficient clinical benefit to justify its clinical and financial costs. METHODS: The records were reviewed of all patients who had an initial colposcopy at Queens Hospital Center between 1984 and 1995. Data were gathered regarding the referral cytology, the cytology done at the time of colposcopy, and the results of any biopsies which were taken. The terminology for cytology and histology done prior to 1989 was adjusted to the Bethesda classification system. A repeat Pap smear was defined as clinically valuable if it would have changed the patient's management, i.e., if it suggested more advanced disease than the referral Pap and that the disease was not identified on the colposcopically directed biopsy. RESULTS: Two thousand nine hundred sixty-nine records were reviewed. In 139 cases, no Pap smear was repeated at the time of colposcopy. Of the remaining 2830 women, only 1347 (47.6%) showed exact correlation between their referral Pap smear and the Pap done at the time of colposcopy. In another 1016 (35.9%), the Pap at colposcopy was within one grade of the referral Pap. In 312 women, the Pap at the time of colposcopy was a higher grade than the referral Pap. However, in 236, the higher grade of disease was detected by the colposcopically directed biopsy. Of the remaining 76 women, 58 had a normal biopsy, but their Pap at the time of colposcopy showed low-grade squamous intraepithelial lesions (44) or high-grade squamous intraepithelial lesions (HGSIL) (14). Seventeen others had a biopsy showing low-grade dysplasia while the Pap at the time of colposcopy showed HGSIL. In 1 patient, the repeat Pap showed malignant cells while the biopsy showed a high-grade lesion. Based on the triage protocols at our institution, this means that a repeat Pap at the time of colposcopy would have indicated a cone biopsy in 31 patients (1.1%) and more careful follow-up of another 44 patients (1.6%). Skipping the repeat Pap smear would not have resulted in any missed cancers. In our series of 2830 patients, the cost savings of skipping the repeat smear would have been $68,580 or $24.23 per patient. On a national level, skipping the repeat smear would save more than $24,000,000 annually. CONCLUSION: Using current triage protocols at our institution, repeating the Pap smear at the time of an initial colposcopy would have changed the management in 2.7% of patients and indicated a conization in only 1.1% of patients. It is doubtful that this justifies its cost and the potential detrimental effects on the colposcopic examination.

Adolescent↗
PubMed1997

[Neuronal networks and psychopathology].

Within the past 10 years, computer simulations of neural networks have yielded new insights into the nature of information-processing neural systems. Since 1987, more and more network models relevant to psychiatry have been published, and such models have meanwhile been proposed for almost every psychopathological phenomenon. This paper provides an introduction to the theory of neural networks and gives examples of discoveries made via computer simulations. Network models of psychopathological phenomena are discussed with respect to formal thought disorder and delusions. The relevance of neural network models for psychopathological research and theory formulation is highlighted and it is argued that neural network modeling in psychopathology does not merely introduce a few mathematical gimmicks, but rather represents the beginning of a new basis for psychopathology.

Brain↗
PubMed1997

[Event-related potentials in semantic speech processing by schizophrenic patients].

Event-related potentials (ERPs) can be used for high-resolution mental chronometry. For about 15 years, this method has been applied to the study of linguistic phenomena. Semantic incongruency produces a negative component at about 400 ms after stimulus onset, the N400. We measured the N400 component in 20 schizophrenic patients and 20 normal control subjects performing a lexical decision task in which semantic distance between prime and target was varied. The results provide evidence of dysfunctional semantic information processing in schizophrenic patients, and reaction time data from previous studies can be interpreted within an electrophysiological framework. The N400 amplitude and latency data support recent spreading activation models of schizophrenic language dysfunction.

Adult↗
PubMed1997

[Metachromatic leukodystrophy simulating schizophrenia-like psychosis].

A case of late onset metachromatic leukodystrophy with a clinical picture of paranoid hallucinatory psychosis and severe dyskinesia is described. The problem of diagnostic recognition is discussed. In the case, diagnostic procedures were initiated after atypical clinical course, and established on the basis of MRI and specific biochemical tests.

Adult↗
PubMed1997

Functional MR imaging of the prefrontal cortex: specific activation in a working memory task.

Functional magnetic resonance imaging was used to identify cortical regions activated by a working memory task involving letter detection. Twenty four normal subjects were scanned with a conventional 1.5-T magnet while performing one of two tasks: In the activation task, subjects responded by pressing a button whenever any presented letter was the same as the second last in the sequence. In the control condition, subjects had to respond to a single predefined letter without memory update requirements. The activation task and the control condition were identical with regard to perceptual input and motor output. They were different only regarding the task demand. Movement artifacts were minimized in a two way strategy and eight subjects were excluded from further analysis. Functional MR data from the remaining 16 subjects were analyzed on the basis of anatomical regions-of-interest which were manually defined in each subject. The engagement of working memory produced significant activation in the dorsolateral prefrontal cortex (Brodmann's areas 9, 10, 46, and 47) in both hemispheres. Results demonstrate the applicability of the paradigm within a clinical MRI setup and corroborate previous findings of non-lateralized dorsolateral prefrontal activation during continuous context updating and active maintenance.

Adult↗
PubMed1997

[Frontal-subcortical neuronal circuits].

Recent findings on frontal and subcortical circuitry provide an uniform and integral view of numerous neurological and psychiatric disorders. Frontal cortical areas, the basal ganglia and the thalamus are linked in parallel circuits, which can be related to specific mental and motor functions and pathologies. In particular, five such circuits can be distinguished: (1) motor, (2) oculomotor, (3) dorsolateral-pre-frontal, (4) lateral orbitofrontal, and (5) mediofrontal limbic. The anatomy of these circuits as well as the involved neurotransmitters provide a comprehensive framework for understanding the symptoms of neurological diseases such as frontal lobe infarctions, Parkinson's, Huntington's, and Binswanger's disease, as well as psychiatric diseases such as schizophrenic, affective, and obsessive-compulsive disorder.

Animals↗
PubMed1997

A cognitive neuroscience view of schizophrenic thought disorder.

The experimental association psychology approach to mental associations has been the conceptual background for the concept of schizophrenia. Cognitive neuroscience methods and concepts can be used to study various forms of schizophrenic thought disorder. In particular, the concepts of semantic associative and working memory can be applied fruitfully to schizophrenia research. Semantic associative networks can be simulated with self-organizing feature maps. Dysfunctional lexical access can be modeled in terms of low signal-to-noise ratio in intra- or between-network information processing. Evidence for the crucial role of dopamine in this function is presented, and a general neurocomputational model of schizophrenic thought disorder is developed. This model capitalizes on basic aspects of neural information processing (i.e., neuromodulation and neuroplasticity) and allows a parsimonious explanation of a number of otherwise inexplicable or unrelated clinical phenomena and experimental results.

Brain Mapping↗
PubMed1997

Psychotic experience and disordered thinking: a reappraisal from new perspectives.

The reports of a person suffering from loose associations and disordered behavior serve as the basis for a phenomenology of some central components of psychotic experience. Especially salient are "the expansion of the horizon of meanings," "the emergence of explicit experiences from implicit ones," and "the reduction of complexity." The phenomenological concepts thus developed supplement recent discoveries in neuroscience and experimental psychopathology. Cognitive neuroscientists have depicted the surface of the brain as a repository of self-organizing cortical maps of mental life. Furthermore, experimental psychopathologists have characterized semantic associative networks in normal experience and in psychosis. The authors conclude by joining the phenomenology of psychotic consciousness with the findings of these neuroscientists and experimental psychopathologists.

Adult↗
PubMed1997

Recidivism and concomitant criminality in pathological firesetters.

The purpose of this study was to explore dangerousness and fire setting recidivism of mentally disordered firesetters in comparison with mentally healthy arsonists. In Germany, all trials are registered centrally by the Federal Central Register. The records of this Register for the three year period from 1983 until 1985 were used in this follow-up study of arsonists to identify three samples of subjects: (1) All persons convicted of arson who have been found not guilty by reasons of insanity (n = 186), (2) all person convicted of arson who have been found guilty of diminished responsibility (n = 97), and (3) a random selection from all persons convicted of arson who have had no psychiatric examination in their trial (n = 187). The follow-up ended in 1994, providing a period of, on average, ten years. Mentally disordered arsonists differed from non-mentally disordered arsonists in the following ways: They were more likely, first, to have a history of arson before 1983, and secondly, to be convicted of arson again (11% relapse compared to 4%). Mentally disordered arsonists had fewer registrations of common offenses, such as theft as well as traffic violations and alcohol-related offenses. Based on the present sample, mentally disordered firesetters have a higher rate of recurrence of firesetting than non-mentally disordered firesetters and commit fewer common offenses other than firesetting.

Adolescent↗
PubMed1996

The Stroop effect in schizophrenic patients.

Schizophrenic patients (n = 44) and normal controls (n = 50) performed a computerized version of the Stroop color-word interference task. Schizophrenic patients generally showed more Stroop interference than normal subjects. The effect was neither related to demographic variables, nor to actual psychopathology. However, the course of the disorder was related to the Stroop effect, in that acute, chronic, and schizoaffective patients displayed a larger interference effect than patients with a recurrent episode. From a methodological perspective, the computerized version of the Stroop task proved to be more sensitive to interference effects in the patient group. The finding of enhanced reverse Stroop interference in patients strongly preoccupied with colors is discussed within the framework of MacLeod and Dunbar's (MacLeod and Dunbar, 1988) theory of Stroop interference involving differential practice effects.

Adult↗
PubMed1996

Dopaminergic modulation of semantic network activation.

In order to examine the effect of dopamine on semantic processing, we performed a double-blind, placebo-controlled study. Healthy volunteers (n = 31) were tested in a lexical decision paradigm after ingestion of either L-dopa 100 mg with benserazide 25 mg or placebo. While direct semantic priming was influenced only marginally by L-dopa, the indirect priming effects was reduced significantly. These data support the hypothesis that dopamine increases the signal-to-noise ratio in semantic networks by reducing the spread of semantic processing, thereby leading to a focussing of activation.

Adult↗
PubMed1996

Monsel's solution-induced artifact in the uterine cervix.

We documented and quantified Monsel's solution-related artifacts after cervical biopsies. All loop electrosurgical cone biopsy specimens over a 3-month period were reviewed for necrosis artifact of the surface epithelium. The degree of change was quantified and correlated with the antecedent use of Monsel's solution. Twenty-four cone biopsy specimens were evaluated. Three of the eight cone biopsy specimens obtained fewer than 10 days after the use of Monsel's solution showed definite changes. Between 10 and 18 days after the use of Monsel's solution, four of eight specimens showed change. After 18 days, none of eight specimens showed change. One specimen at 18 days showed focal changes that seemed to be related to the use of an unusually large amount of Monsel's solution, because the patient had had six biopsies within 2 days. The routine use of Monsel's solution may interfere with the ability to recognize and characterize disease process in cone biopsy specimens when the cone procedure is done within 3 weeks after the use of Monsel's solution.

Artifacts↗