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M F Casanova

Publications and source records attributed to M F Casanova.

At least 19 recordsLinked to original sources
PubMed2000

Quantitative analysis of cell columns in the cerebral cortex.

We present a quantified imaging method that describes the cell column in mammalian cortex. The minicolumn is an ideal template with which to examine cortical organization because it is a basic unit of function, complete in itself, which interacts with adjacent and distance columns to form more complex levels of organization. The subtle details of columnar anatomy should reflect physiological changes that have occurred in evolution as well as those that might be caused by pathologies in the brain. In this semiautomatic method, images of Nissl-stained tissue are digitized or scanned into a computer imaging system. The software detects the presence of cell columns and describes details of their morphology and of the surrounding space. Columns are detected automatically on the basis of cell-poor and cell-rich areas using a Gaussian distribution. A line is fit to the cell centers by least squares analysis. The line becomes the center of the column from which the precise location of every cell can be measured. On this basis several algorithms describe the distribution of cells from the center line and in relation to the available surrounding space. Other algorithms use cluster analyses to determine the spatial orientation of every column.

Algorithms↗
PubMed1997

The temporolimbic system theory of paranoid schizophrenia.

The hippocampus serves as a funnel for heavily processed sensory information that has converged at the entorhinal cortex. Lesions of the hippocampus do not alter incoming sensory or motor information but, rather, alter their integration with our baggage of emotional experiences and social values. According to Bogerts, such a lesion would be ideally situated to result in laboriously processed sensory information that is out of context to our outside environment. In this regard, Bogerts describes the pathological findings of a patient with a gross delusional disorder. The salient finding at autopsy was a developmental lesion in the left posterior parahippocampal gyrus. Although a number of lesions have been described in the brains of patients with schizophrenia, Bogerts believes that those in the limbic system appear critical to the expression of paranoid symptoms.

Adult↗
PubMed1997

Functional and anatomical aspects of prefrontal pathology in schizophrenia.

Neuropathology is a field that correlates autopsy findings to clinical symptomatology. Since the brain has an inordinate number of parceled regions, each having a different function, it makes more sense to work in an inverse fashion and use clinical findings to establish pathological correlations. In this regard, a lesion in the prefrontal lobes can explain some of the salient findings in schizophrenia, for example, scrambled language, disordered thinking, and abnormal behavior. Recent quantitative cytoarchitectural observations by Goldman-Rakic and Selemon sustain such a correlation. By using a computerized image analysis system, these authors have described an abnormally high neuronal density and reduced cortical thickness in many of their patients with schizophrenia. The importance of these findings is discussed in terms of the recent schizophrenia literature.

Brain Mapping↗
PubMed1997

Planum temporale asymmetry reversal in schizophrenia: replication and relationship to gray matter abnormalities.

OBJECTIVE: The planum temporale, the posterior superior surface of the superior temporal gyrus, is a highly lateralized brain structure involved with language. In schizophrenic patients the authors previously found consistent reversal of the normal left-larger-than-right asymmetry of planum temporale surface area. The original subjects plus new patients and comparison subjects participated in this effort to replicate and extend the prior study. METHOD: High-resolution magnetic resonance imaging of 28 schizophrenic patients and 32 group-matched normal subjects was performed. The authors measured planum temporale surface area, gray matter volume underlying the planum temporale, and gray matter thickness. Asymmetry indices for areas and volumes were calculated. RESULTS: Overall gray matter and total brain volume were not significantly smaller in the patients than in the comparison subjects. As previously reported, there was striking reversal of the normal asymmetry for planum temporale surface area in the male and female schizophrenic subjects. Bilaterally, gray matter volume beneath the planum temporale was smaller in the schizophrenic patients, and the gray matter thickness of the right planum temporale was only 50% of the comparison value. Volume of planum temporale gray matter did not show significant asymmetry in either group. CONCLUSIONS: This study extends the finding of reversed planum temporale surface area asymmetry in schizophrenic patients and clarifies its relationship to underlying gray matter volume. Although right planum temporale surface area is larger than normal in schizophrenia, gray matter volume is less than the comparison value; thus, gray matter thickness is substantially less than normal.

Adult↗
PubMed1996

Multiple sclerosis and bipolar disorder: a case report with autopsy findings.

An 81-year-old woman with postmenopausal onset of a bipolar disorder had multiple individual manic and depressive episodes over the span of 31 years. Autopsy disclosed widespread periventricular demyelinated plaques. Although the late age at onset of bipolar symptoms suggested an underlying organic disorder, the multiple affective episodes and lack of additional neurological manifestations make the case atypical. The authors stress the use of modern imaging modalities such as MRI in investigating secondary mood disorders.

Age of Onset↗
PubMed1996

Wernicke's disease and schizophrenia: a case report and review of the literature.

OBJECTIVES: A review of the neuropathology literature in schizophrenia suggests that some patients with this disease exhibit periventricular gliosis at postmortem examination. Several researchers have speculated that this finding is the remnant of either a prior viral infection or a gestational intraventricular hemorrhage. The present article uses a case report to hypothesize and discuss an alternate possibility to the putative gliosis, namely Wernicke's disease. METHOD: Based on the pathological findings of our patient and a review of the literature, the author summarizes several reasons why Wernicke's disease may occur, and still be unnoticed, in some schizophrenic patients. RESULTS: Inefficient self-care and homelessness predisposes some patients with schizophrenia to poor dietary habits and malnutrition. Similarly, the high prevalence of concurrent alcoholism in patients with schizophrenia may propitiate thiamine deficiency. The resulting brain insult may be compounded by disturbances of carbohydrate metabolism which may be peculiar to the schizophrenic process itself, or acquired, as in coincidental diabetes. CONCLUSIONS: Since symptoms accrued to Wernicke's may often be subtle and obscured by other schizophreniform manifestations, clinicians should lower their threshold for suspecting this potentially fatal complication. The diagnostic possibility of Wernicke's should be especially entertained in schizophrenic patients who are alcoholics and/or diabetics.

Adult↗
PubMed1995

Asymmetry of the planum temporale: methodological considerations and clinical associations.

Asymmetry of the planum temporale, a region on the posterosuperior surface of the temporal lobe involved in the production and comprehension of language, is a notable feature of the normal human brain. Several attempts have been made to measure it using both post-mortem and magnetic resonance imaging (MRI) methods, but previous approaches made inadequate allowance for the convoluted nature of the structure. The current study used rigorous criteria to define the planum and examined three separate approaches for its measurement on MRI scans. A method involving triangulation of the surface consistently gave larger values for the surface area of the planum, suggesting that this method takes account of the convoluted nature of the structure.

Adult↗
PubMed1995

Polyamines and their metabolizing enzymes in human frontal cortex and hippocampus: preliminary measurements in affective disorders.

Affective disorders are associated with maladaptive response to stressful life events. Based on the observation that a transient increase in brain polyamine metabolism is a common response to stressful stimuli, our hypothesis is that a maladaptive polyamine stress response may be involved in the pathophysiology of affective disorders. Our current research efforts, therefore, concentrate on the characterization of this PA response, and on its pharmacological regulation. The present preliminary study is the first to measure the polyamines, putrescine, spermidine, and spermine, and their metabolizing enzymes, ornithine decarboxylase, S-adenosylmethionine decarboxylase, and spermidine/spermine N1 acetyltransferase, in brain autopsy samples from people who suffered from depressive disorders or schizophrenia, or from those who committed suicide. The data of affected individuals did not reveal significant differences when compared to those of suicide cases, or to those of people with no known neurologic or psychiatric abnormalities. The following regional differences were observed: spermidine concentrations and ornithine decarboxylase activity were higher, but S-adenosylmethionine decarboxylase activity was lower in the hippocampus as compared to the frontal cortex. Preliminary studies with rat brain indicate that an increase in polyamine metabolizing enzyme activities occurs within several hours after death and persists for at least 48 hours. These observations, in turn, indicate that earlier autopsies are crucial for detection of changes in polyamine metabolism. We conclude that further studies to test the polyamine hypothesis are warranted.

Adenosylmethionine Decarboxylase↗
PubMed1995

Decreased DOPAC in the anterior cingulate cortex of individuals with schizophrenia.

The dopamine metabolite, 3,4-dihydroxyphenylacetic acid (DOPAC), was found to be decreased in the anterior cingulate cortex of individuals with schizophrenia compared with normal controls. The finding does not appear to be solely related to the presence of antipsychotic medications, age, postmortem interval, or freezer time. No changes in norepinephrine and its metabolites were found.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1995

Age-related changes in [3H]GBR 12935 binding site density in the prefrontal cortex of controls and schizophrenics.

We investigated dopamine transporter receptor ligand binding in the prefrontal cortex as a function of age in schizophrenic and control postmortem brains. [3H]GBR 12935 binding constants were calculated by Scatchard analysis from the autopsied brains from 29 individuals with schizophrenia, and 28 control subjects. There were wide interindividual variations in Bmax and KD that were not related to gender, age, or postmortem interval (PMI) in controls. While there were no significant associations between gender, PMI, and Bmax, or KD in individuals with schizophrenia, there was a significant negative correlation between age and Bmax (r = -.44, p = .02). The slope of the regression lines between age and Bmax for the two groups was significantly different. The results suggest a differential effect of age, or something associated with age, on [3H]GBR 12935 binding sites in the prefrontal cortex of controls and individuals with schizophrenia.

Adult↗
PubMed1995

Sydenham's chorea and schizophrenia: a case report.

The following is a case report of a patient with Sydenham's chorea who later developed schizophrenia. Autopsy examination of this patient revealed mineral deposits in the basal ganglia. The deposition of minerals, especially iron, within subcortical brain structures has been associated with dopaminergic abnormalities, schizophreniform symptoms, and abnormal movement disorders. The psychosis these patients experience is sometimes resistant to treatment with traditional neuroleptics. A CT or MRI scan may prove useful in screening those patients with Sydenham's chorea that develop psychotic symptoms.

Basal Ganglia↗
PubMed1995

Reversal of asymmetry of the planum temporale in schizophrenia.

OBJECTIVE: The planum temporale is intimately involved in the generation and understanding of language and has been suggested to be a key area affected in schizophrenia. To explore temporal lobe abnormalities in schizophrenia, the authors measured the planum temporale, a normally asymmetric area lying on the superior part of the temporal lobe, in schizophrenic patients. METHOD: High-resolution magnetic resonance imaging (MRI) scans were obtained for 14 right-handed schizophrenic patients and 14 healthy comparison subjects individually matched for age, sex, handedness, race, and parental socioeconomic status. The surface area of the planum temporale was measured by using MRI reconstruction techniques. RESULTS: There was striking reversal of the normal asymmetry (left larger than right) in planum temporale surface area in 13 of the schizophrenic patients but in only two of the comparison subjects. However, Heschl's gyrus (primary sensory cortex), which served as an anatomically contiguous nonheteromodal cortical comparison region, showed no difference between the left and right sides in either group. Severity of thought disorder in the patients was related to asymmetry. CONCLUSIONS: This is a clear demonstration of a reversal of expected symmetry in the brains of right-handed schizophrenic patients, which involves a region of key importance in normal human behavior. The nature of the abnormality strongly suggests that schizophrenia is a neurodevelopmental disorder.

Adult↗
PubMed1994

Alterations in TRH receptors in temporal lobe of schizophrenics: a quantitative autoradiographic study.

We utilized quantitative autoradiography to determine the distribution of receptors for thyrotropin-releasing hormone (TRH) throughout the human temporal lobe and to examine the distribution of these receptors in discrete subregions of the temporal lobe from patients diagnosed premortem with schizophrenia. When compared to non-neurologic controls, schizophrenic patients demonstrated an increase of 51% in the concentration of TRH receptors in the molecular layer of the dentate gyrus. Within nuclei of the schizophrenic amygdala, marked decreases were found in the central (44%), medial (38%), cortical (36%), accessory cortical (52%), lateral (54%), and medial basal (22%) nuclei. We also examined postmortem brain samples from patients with Huntington's disease, amyotrophic lateral sclerosis, and Alzheimer's disease for alterations in the distribution of TRH receptors. No significant differences from non-neuropsychiatric controls were noted within the hippocampus in any of these disease states; however, slight alterations were noted in the central and medial basal amygdala in Huntington's disease and in the cortical amygdala in Alzheimer's disease. These disease-specific findings suggest that TRH may play a role in the neurochemical dysfunction of schizophrenia.

Adult↗
PubMed1994

Fewer dopamine transporter receptors in the prefrontal cortex of cocaine users.

The authors investigated dopamine transporter receptor binding in the post-mortem prefrontal cortex of 13 subjects with histories of cocaine use who had positive blood screens for cocaine at autopsy and 13 comparison subjects with no history of cocaine use and negative blood screens for cocaine at autopsy. Synaptosomes from pulverized prefrontal cortex were assayed with [3H]GBR 12935 for dopamine transporter receptor. There was a 38% decrease in number of binding sites but no change in affinity constants in the cocaine users.

Adult↗