Evidence of reduced temporolimbic structure volumes in schizophrenia.
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Adult↗
Biomedical subjects
P Falkai
Publications and source records attributed to P Falkai.
Nasopharyngeally and vertex recorded P300's in normal subjects.
The P300 waveform has been associated with cognitive activity during information processing, and the hippocampus has been discussed as a possible generator of this waveform. This being the case some would argue that it should be possible to record the P300 with a shorter latency and greater amplitude from an electrode placed as near the hippocampus as possible. Under local anaesthesia we inserted a specially constructed needle electrode through the left nostril in the recessus pharyngeus close to the hippocampus. The results did not support the hippocampal hypothesis. Nasopharyngeally recorded P300's were found to have significantly decreased amplitudes and extended latencies when compared to vertex recordings.
Adult↗
Distribution of galanin-like immunoreactivity in the human brain.
The distribution of galanin-like immunoreactivity has been studied in complete coronal sections taken from 9 normal human brains (4 male, 5 female mean age 54, range 42-72 years). Galanin-immunoreactive cells were restricted largely to the basal nucleus of Meynert and to the supraoptic, ventromedial and posterior areas of the hypothalamus. Fibre staining was more widespread, seen throughout the hypothalamus and in the diagonal band, septum, amygdala, hippocampus and scattered throughout the cortex. This distribution may indicate a role for galanin in the modulation of hypothalamic and basal forebrain function in man.
Adult↗
Quantitative study of gliosis in schizophrenia and Huntington's chorea.
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Adult↗
Limbic pathology in schizophrenia: the entorhinal region--a morphometric study.
The volume of the entorhinal region is significantly reduced in postmortem brains of schizophrenics compared with controls (p less than 0.017). In addition, a significant reduction of neurons (p less than 0.017), but no significant increase in absolute glial cell numbers, is found. These results are consistent with the hypothesis that structural changes in the medial temporal lobe of schizophrenics may be developmental in origin.
Adult↗
Cell loss in the hippocampus of schizophrenics.
To investigate whether volume reduction of the hippocampal formation of schizophrenics, as described previously, is paralleled by loss of neurons and fibre systems, tissue volumes and cell numbers of all parts of the hippocampal formation in post mortem brains of 13 schizophrenics and 11 age-matched controls belonging to the Vogt collection were determined. Volumes of the whole hippocampal formation (P less than 0.01), the whole pyramidal band (P less than 0.001) and the hippocampal segments CA1/CA2 (P less than 0.01), CA3 (P less than 0.005), CA4 (P less than 0.01) were decreased, whereas no significant volume reduction of the alveus and fimbria hippocampi and prosubiculum/subiculum could be found. The perforant path showed a trend towards volume reduction (P less than 0.1). The absolute number of pyramidal cells (tissue volume X cell density) was diminished in CA1/CA2 (P less than 0.05), CA3 (P less than 0.05) and CA4 (P less than 0.05), but was not significantly changed in the prosubiculum/subiculum, the presubiculum/parasubiculum and the granular cell layer of the dentate fascia. Pyramidal cell loss in CA1/CA2, CA3, CA4 was more distinct in the paranoid patients than in catatonics. The findings are discussed with respect to current hypotheses of limbic dysfunction in schizophrenia.
Adult↗
Post-mortem volume measurements of limbic system and basal ganglia structures in chronic schizophrenics. Initial results from a new brain collection.
Volumes of the hippocampal formation, external and internal pallidum, caudate, putamen, and nucleus accumbens were measured in both hemispheres of recently collected post-mortem brains of 18 chronically ill schizophrenics and 21 control subjects. In the schizophrenic group, the hippocampal formation and the internal pallidum were significantly smaller in the right and left hemisphere, whereas external pallidum, putamen, caudate and accumbens were not significantly changed. Volumes of the hippocampus and of all evaluated parts of the basal ganglia were in the male schizophrenics more reduced than in the female patients. The right and left hemispheres were equally affected in both sexes. Since the mean brain weight was in patients and controls nearly identical, the volume differences can not be explained by a general brain atrophy or hypoplasia but rather indicate a more focal lack of brain tissue, by which some clinical features of the disease might be explained.
Adult↗
Genetic and non-genetic vulnerability factors in schizophrenia: the basis of the "two hit hypothesis".
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Brain↗
Antipsychotic efficacy of the antidepressant trimipramine: a randomized, double-blind comparison with the phenothiazine perazine.
BACKGROUND: The tricyclic antidepressant trimipramine exhibits several features (e. g., dopaminergic effect, molecular structure similar to a neuroleptic, receptor-binding profile similar to clozapine) that suggest its potential as an antipsychotic medication. The aim of the study was to investigate the antipsychotic potential of trimipramine in a controlled clinical trial comparing its antipsychotic efficacy with that of a neuroleptic. METHOD: In a German multi-center, randomized, double-blind trial, the antipsychotic efficacy of trimipramine was compared with that of the phenothiazine neuroleptic perazine, using the Brief Psychiatric Rating Scale (BPRS), the Positive and Negative Syndrome Scale (PANSS), and Clinical Global Impressions (CGI). Antidepressant efficacy of both agents was measured by use of the Bech-Rafaelsen Melancholia Scale (BRMES). Ninety-five patients with acute schizophrenia (DSM-III-R) and a BPRS total score > 40 at baseline were treated with either 300-400 mg trimipramine or 450-600 mg perazine for 5 weeks. RESULTS: Therapeutic equivalence of both treatments (in the dosages used) could not be demonstrated (change in BPRS total score, per-protocol [PP] analysis, one-sided equivalence testing). However, intention-to-treat (ITT) as well as PP analysis showed a statistically significant decrease in the BPRS total scores in both treatment groups (PP: trimipramine, 56.5 +/- 9.8 to 44.1 +/- 17.9; perazine, 56.4 +/- 10.8 to 37.9 +/- 12.9). Significant decreases in all BPRS and PANSS subscores as well as CGI results and response rate support the antipsychotic efficacy of trimipramine. The BRMES total scores significantly decreased in both treatment groups without showing a significant difference between the two agents. Trimipramine was better tolerated than perazine and did not elicit extrapyramidal symptoms. CONCLUSION: Trimipramine failed to exhibit therapeutic equivalence to perazine in the dosages used. However, there was evidence of a substantial antipsychotic effect of trimipramine. It may be a useful medication if depressive symptoms in psychotic patients require antidepressant treatment or if other antipsychotics cannot be administered.
Antidepressive Agents↗
SNAP-25 deficit and hippocampal connectivity in schizophrenia.
Regional abnormalities of brain connectivity may be an important substrate for the expression of schizophrenia, a severe form of mental illness. Brain imaging and postmortem morphometric studies indicate hippocampal structure is abnormal in schizophrenia. To study molecular components of hippocampal connectivity the presynaptic proteins SNAP-25 and synaptophysin were assayed in postmortem samples. Immunocytochemical studies indicated reduced SNAP-25 immunoreactivity in schizophrenia compared to controls, particularly in the terminal fields of entorhinal cortex projections. Although there were no overall changes in synaptophysin immunoreactivity, in the granule cell layer of the dentate gyrus synaptophysin immunoreactivity was increased in schizophrenia. These results indicate that disconnection of a subset of hippocampal circuitry from the entorhinal cortex, as well as intrinsic changes in hippocampal connectivity, may contribute to the mechanism of illness in schizophrenia.
Adult↗
Amygdala-hippocampal atrophy and memory performance in dementia of Alzheimer type.
The aim of the present study was to examine the involvement of brain structures, especially the amygdala-hippocampal complex, in dementia of Alzheimer type (DAT), and to assess the relation of amygdala-hippocampal atrophy with memory dysfunction. 14 patients with DAT and 10 healthy age-matched controls were examined with different neuropsychologic tests including the UCLA-Auditory Verbal Learning Test. MRI was performed with a conventional 1.5-tesla scanner. Atrophy was found in many brain structures of demented subjects in comparison with healthy age-matched controls. The volumes of amygdala-hippocampal complexes and of the temporal lobes of demented subjects were more reduced than the total brain volume and other structures. Memory dysfunction was highly correlated with atrophy of the amygdala-hippocampal complexes and of the temporal lobes. Consequently, DAT seems to affect the amygdala-hippocampal complex and their related function (i.e. memory) more than other cerebral structures, but cerebral degeneration in DAT is not restricted to these structures.
Aged↗
[Minimizing the risks associated with QTc prolongation in people with schizophrenia. A consensus statement by the Cardiac Safety in Schizophrenia Group].
Schizophrenia is one of the most debilitating mental illnesses, complicated by an increased incidence of suicide amongst patients compared with the general population. A recent report has also demonstrated a 33% increase in -relative risk of death associated with circulatory disease, indicating that the latter may be a more critical factor than either suicide or accidental death in this population. Indeed, the average life expectancy of a person with schizophrenia is currently approximately a decade less than that of the general population. Additionally, it has been shown that in over 50% of people with schizophrenia, there is a reduction in their chance of reaching psychosocial goals. Since the arrival of the first antipsychotic drugs in the middle of the last century, the outlook for patients with schizophrenia has improved markedly. In particular, the introduction of the new generation (atypical) class of antipsychotic agents in the 1980s and 90s has resulted in a significant reduction in the incidence of violent and aggressive episodes in treated patients. A better side-effect profile of these drugs, especially reduced extra pyramidal symptoms (EPS), has resulted in improved patient outcomes and the possibility of good long-term control of the disorder. However, while the introduction of antipsychotic agents has undoubtedly revolutionised the prognosis for patients with schizophrenia, these medications are not without their own problems. One of the concerns to emerge over the last fifteen years is unpredictable, sudden and unexplained death in patients taking antipsychotic drugs. The cause of sudden death in this population is controversial and the role of drugs is not clear. People with schizophrenia also appear to be at higher risk of cardiovascular disease compared with the general population. Many factors may play a role in this including a higher prevalence of smoking, poorer diet, more sedentary lifestyle and a greater likelihood of alcoholism and substance abuse. However, it is possible that the impact of adverse effects on the cardiovascular system related to certain antipsychotic drug use may well increase the prevalence of mortality and morbidity due to cardiovascular events and may also play a significant role in the reduced life expectancy of the patient with schizophrenia. The range of mechanisms whereby antipsychotic drugs can influence cardiovascular function is very broad and includes: receptor blockade; conduction disturbance (eg bundle branch block); delayed ventricular repolarisation (prolonged QTc interval); left ventricular dysfunction; sinus node abnormalities; myocarditis; postural hypotension; polydipsia-hyponatremia syndrome; weight gain; glucose intolerance. Of these, QTc interval prolongation, with the risk of progression to the potentially fatal ventricular tachyarrhythmia Torsades de Pointes (TdP), is of particular concern as this arrhythmia is unpredictable and difficult to manage. Coupled with these clinical concerns are regulatory issues regarding several compounds that have received warnings or been withdrawn from the market. Recently, there has been no clear guidance for psychiatrists regarding QTc interval prolongation and TdP. This document seeks: 1) to explore drug-induced ventricular arrhythmias with particular emphasis on QTc interval prolongation as a warning of increased vulnerability, 2) to provide guidelines on the therapeutic management of the patient with schizophrenia to minimize the risk of iatrogenic cardiotoxicity. Several guidance documents have previously been published in this area including the report published by the UK Working Group of the Royal College of Psychiatrists' Psychopharmacology Sub-Group in 1997, and the policy document on the potential for QTc prolongation and proarrhythmia by non-antiarrhythmic drugs published in June 1999 under the auspices of the European Society of Cardiology. This document seeks to supplement currently published guidelines.
Antipsychotic Agents↗
Neural expression profile of Elav-like genes in human brain.
BACKGROUND: Hel-N1 and HuD belong to the elav gene family and have a considerable role in neuronal development. However, there is only limited information available on the expression profile in human brain and neural tumor cell lines. METHOD: Therefore, RT-PCR analysis has been performed on human fetal, normal adult, and psychiatric brains (from patients with schizophrenia, Alzheimer's disease, and alcoholism) as well as 20 glioblastoma and 9 medulloblastoma cell lines. RESULTS: Both, Hel-N1 and HuD were abundantly expressed in all brain samples with no obvious difference. However, the neural tumor cell lines showed a differential expression pattern. The medulloblastoma cell lines expressed at least one of the genes in a frequency of 67% for HuD and 78% for Hel-N1 transcripts, respectively. In contrast to the glioblastoma cell lines, which revealed no evidence for HuD RT-PCR products. Surprisingly, 55% of the glioblastoma cell lines showed Hel-N1 expression. CONCLUSION: These observations indicate that Hel-N1 and HuD participate in molecular processes in human brain, both during development and in the mature adult brain. Hel-N1 and HuD transcriptional activity are stable markers for medulloblastoma cell lines, a tumor, which is thought to be derived from a neuronal precursor cell. The role of Hel-N1 in glioblastomas, the most prominent representative of the glial tumors is presently unclear. This finding is the first indication for a possible involvement of an Elav-like gene product in the glial cell lineage.
Alcoholism↗