Comparison of Fornix and Stria Terminalis Connectivity among First-Episode Schizophrenia, Chronic Schizophrenia and Healthy Controls

OBJECTIVES: Disrupted integrities of the fornix and stria terminalis have been suggested in schizophrenia. However, very few studies have focused on the fornix and stria terminalis comparing first-episode schizophrenia (FESZ), chronic schizophrenia (CS), and healthy controls (HCs) with the application of diffusion-tensor imaging (DTI) technique. The objective of this study is to compare the connectivity of the fornix and stria terminalis among FESZ, CS, and HCs. METHODS: We included the 44 FESZ patients, 39 CS patients and 20 HCs in this study. Voxel-wise statistical analysis of the fractional anisotropy (FA) data was performed using Tract-Based Spatial Statistics to analyze the connectivity of fornix and stria terminalis. In addition, the Scale for the Assessment of Positive Symptoms (SAPS) and the Scale for the Assessment of Negative Symptoms (SANS) were used to evaluate clinical symptom severities. RESULTS: There were no significant differences between the FESZ, CS, and HCs in age, sex, education years. The SAPS and SANS scores of the schizophrenia groups showed no significant differences. FA values of the right fornix cres/stria terminalis in the CS group were significantly lower than those in FESZ and HCs. There were no significant differences of FA values of the right fornix cres/stria terminalis between the FESZ and the HCs. Pearson correlation analyses revealed that significant correlation between FA values of the right fornix cres/stria terminalies of the the FESZ group and positive, negative symptom scales, and FA values of the right fornix cres/stria terminalis of the CS group and negative symptom scales. CONCLUSIONS: This study shows that FA values of the fornix and stria terminalis in the CS were lower than in the FESZ and the HCs. These results suggest that the fornix and stria terminalis can play a role in pathophysiology of schizophrenia. Thus current study can broaden our understanding of the pathophysiology of schizophrenia.

The fornix: from real to virtual dissection / O fornix: da dissecção real para a virtual

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Avaliação anatômica comparativa dos acessos transcorioideo e transforniceal transcorioideo ao terceiro ventrículo / Comparative anatomical assessment of transchoroidal approach and transforniceal transchoroidal approach to the third ventricle

O acesso ao terceiro ventrículo constitui verdadeiro desafio ao neurocirurgião. Nesse contexto, estudos anatômicos e morfométricos são úteis para estabelecer as limitações e as vantagens de determinado acesso cirúrgico. O acesso transcorioideo é versátil e promove exposição adequada da região média e posterior do terceiro ventrículo. Entretanto, a coluna do fórnice limita a exposição da região anterior do terceiro ventrículo. Há evidências de que a secção ipsilateral da coluna do fórnice tenha pouca repercussão na função cognitiva. Esta tese compara a exposição anatômica proporcionada pelo acesso transforniceal transcorioideo com o do acesso transcorioideo e realiza avaliação morfométrica de estruturas relevantes e comuns aos dois acessos. Material e métodos: A exposição anatômica proporcionada pelos acessos transcaloso transcorioideo e transcaloso transforniceal transcorioideo foram comparadas em oito cadáveres não submetidos à conservação, utilizando o sistema de neuronavegação (Artis, Brasília, Brasil), para aferir a área de trabalho, a área de exposição microcirúrgica, a exposição angular no plano longitudinal e transversal de dois alvos anatômicos (túber cinéreo e aqueduto cerebral). Adicionalmente, foram quantificados a espessura do parênquima do lobo frontal direito, a espessura do tronco do corpo caloso, o diâmetro longitudinal do forame interventricular, a distância de trabalho da superfície cortical ao túber cinéreo e a distância de trabalho da superfície cortical até o aqueduto cerebral. Os valores obtidos foram submetidos a análise de estatística utilizando o teste de Wilcoxon. Resultados: Na avaliação quantitativa, o acesso transforniceal transcorioideo proporcionou maior área de trabalho (transforniceal transcorioideo = 150,299 +/- 11,147 mm2; transcorioideo = 121,421 +/- 7,698 mm2; p < 0,05), maior área de exposição microcirúrgica (transforniceal transcorioideo = 100,920 +/- 8,764 mm2; transcorioideo = 79,944 +/- 4,954 mm2; p <...

Approaches to the third ventricle constitute a formidable challenge to the neurosurgeon and, in this context, anatomical and morphometric studies are useful to establish the limitations and advantages of certain surgical approaches. The transchoroidal approach is a versatile one that promotes adequate exposure of the middle and posterior regions of the third ventricle. However, the column of fornix limits the exposure of the anterior third ventricle region. There is evidence that the ipsilateral section of the column of fornix has little effect on the cognitive function. This thesis compares the anatomical exposure using the transchoroidal transforniceal technique with the transchoroidal approach, and performs morphometric assessment of relevant structures common to both approaches. Material and methods: The anatomical exposure achieved through the transchoroidal transcallosal approach and transchoroidal transforniceal transcallosal were compared in 8 fresh cadavers using the neuronavigation system (Artis, Brasilia, Brazil), to assess the working area, microsurgical exposure area, to quantify the angular exposure in the longitudinal and cross-sectional planes to two anatomical targets (tuber cinereum and cerebral aqueduct), to measure the thickness of the right frontal lobe parenchyma, corpus callosum body thickness, longitudinal diameter of the interventricular foramen, working distance from the cortical surface to the tuber cinereum and working distance from the cortical surface to the cerebral aqueduct. The values obtained were submitted to statistical analysis using Wilcoxon's test. Results: In the quantitative assessment, the transchoroidal transforniceal approach provided: larger working area (transchoroidal transforniceal = 150.299 +/- 11.147 mm2; transchoroidal = 121.421 +/- 7.698 mm2; p < 0.05), larger area of microsurgical exposure (transforniceal transchoroidal = 100.920 +/- 8.764 mm2; transchoroidal...

Behavioral effects of deep brain stimulation of the anterior nucleus of thalamus, entorhinal cortex and fornix in a rat model of Alzheimer's disease / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Recent clinical and preclinical studies have suggested that deep brain stimulation (DBS) can be used as a tool to enhance cognitive functions. The aim of the present study was to investigate the impact of DBS at three separate targets in the Papez circuit, including the anterior nucleus of thalamus (ANT), the entorhinal cortex (EC), and the fornix (FX), on cognitive behaviors in an Alzheimer's disease (AD) rat model.</p><p><b>METHODS</b>Forty-eight rats were subjected to an intrahippocampal injection of amyloid peptides 1-42 to induce an AD model. Rats were divided into six groups: DBS and sham DBS groups of ANT, EC, and FX. Spatial learning and memory were assessed by the Morris water maze (MWM). Recognition memory was investigated by the novel object recognition memory test (NORM). Locomotor and anxiety-related behaviors were detected by the open field test (OF). By using two-way analysis of variance (ANOVA), behavior differences between the six groups were analyzed.</p><p><b>RESULTS</b>In the MWM, the ANT, EC, and FX DBS groups performed differently in terms of the time spent in the platform zone (F(2,23) = 6.04, P < 0.01), the frequency of platform crossing (F(2,23) = 11.53, P < 0.001), and the percent time spent within the platform quadrant (F(2,23) = 6.29, P < 0.01). In the NORM, the EC and FX DBS groups spent more time with the novel object, although the ANT DBS group did not (F(2,23) = 10.03, P < 0.001). In the OF, all of the groups showed a similar total distance moved (F (1,42) = 1.14, P = 0.29) and relative time spent in the center (F(2,42) = 0.56, P = 0.58).</p><p><b>CONCLUSIONS</b>Our results demonstrated that DBS of the EC and FX facilitated hippocampus-dependent spatial memory more prominently than ANT DBS. In addition, hippocampus-independent recognition memory was enhanced by EC and FX DBS. None of the targets showed side-effects of anxiety or locomotor behaviors.</p>

Precommissural Fornix in the Human Brain: A Diffusion Tensor Tractography Study

PURPOSE: Other than a single case report, no diffusion tensor tractography (DTT) studies of the precommissural fornix in the human brain have been conducted. In the current study, we attempted to visualize the precommissural fornix in the human brain using DTT. MATERIALS AND METHODS: We recruited 36 healthy volunteers for this study. Diffusion tensor images were scanned using a 1.5-T scanner, and the precommissural fornix was analyzed using Functional Magnetic Resonance Imaging of the Brain (FMRIB) software. Values of fractional anisotropy (FA), mean diffusivity (MD), and tract volume of the precommissural fornix were measured. RESULTS: The precommissural fornix originated from the hippocampal formation on each hemisphere as a crus; both crura were then joined to the body of the fornix. The body of the fornix continued anteriorly to the level just superior to the anterior commissure, where it divided into each column of the precommissural fornix. Each column descended anteriorly to the anterior commissure and terminated in the septal nuclei. Values of FA, MD, and tract volumes of the precommissural fornix did not differ between the right and left hemispheres (p>0.05). CONCLUSION: We believe that the methodology and results of this study would be helpful to future research on the precommissural fornix and in the elucidation of the pathology of diseases involving the precommissural fornix.

Anatomia cirúrgica do nervo acessório espinhal: comoevitar lesões em procedimentos cirúrgicos no trígonocervical posterior / Surgical anatomy of the spinal accessory nerve: how to avoid injuries to the posterior cervical triangle during surgical procedures

Introdução: A síndrome resultante da lesão iatrogênica do nervo acessório espinhal (NAE) secaracteriza por dor, paralisia e escápula alada, estando relacionada a morbidade considerável. Opresente estudo investiga o grau de variação na ramificação e no curso do NAE no trígono cervicalposterior (TCP). Método: A região cervical de oito cadáveres foi dissecada bilateralmente paraexpor o NAE. A ramificação e as variações no curso do NAE no TCP foram registradas. Medidasrelacionadas a estruturas anatômicas do Músculo Esternocleidomastóideo (MEC) e do MúsculoTrapézio (MTZ) foram analisadas. Resultados: As 16 dissecções demonstraram padrão de ramificaçãodo NAE como: nenhum ramo em 25%, um ramo em 37,5% e dois ramos em 37,5%dos casos. Considerável variação foi observada na anatomia regional do NAE no TCP. Medidasrevelaram que o NAE tem relação relativamente constante com o nervo auricular magno (NAM)e esta é uma importante referência anatômica para identificação do NAE no TCP. Conclusões:O NAM é uma referência anatômica útil para a identificação do NAE no TCP. Essa abordagemsugere uma possibilidade para diminuição de lesão iatrogênica do NAE, frequentemente relacionadaà manipulação cervical de estruturas anatômicas adjacentes sem exposição direta do nervo.

Background: The resulting syndrome from iatrogenic injury to the spinal accessory nerve (SAN)is characterized by pain, paralysis and winging of the scapula are often the source of considerablemorbidity. This study analyses the degree of ramification and variations of the SAN at the posteriortriangle (PT). Method: The necks of 8 adult cadavers were dissected bilaterally to expose the SAN.The ramifications and variations of the SAN at the PT were recorded. Measurements related toanatomical landmarks of the Sternocleidomastoid Muscle (SM) and the Trapezius Muscle (TM)were analyzed. Results: The sixteen dissections performed showed the ramification pattern ofthe SAN as: no ramus in 25%, one ramus in 37.5% and 2 ramus in 37.5% of cases. Considerablevariation was seen in regional anatomy of the SAN at the PT. Measurements revealed that the SANhas a relatively constant relationship with the great auricular nerve (GAN) and this is a importantlandmark for the identification of the SAN at the PT. Conclusions: The GAN is a useful landmarkfor identification of the SAN at the PT. This approach suggests a possibility to decrease theincidence of iatrogenic injury of the SAN, that is frequently related to dissection of surroundinganatomical structures and reduced direct exposure of the nerve.

Strategic Infarct Dementia after Bilateral Anterior Fornix Infarction

Even a single brain infarct can cause dementia when it occurs in functionally critical areas of the brain. A 71- year-old female developed sudden cognitive impairment without any other focal neurologic deficits. A brain MRI revealed a bilateral anterior fornix infarction. Neuropsychological evaluation revealed verbal and visual memory deficits, visuospatial dysfunction, and frontal executive dysfunction. The cognitive impairment did not improve for 3 months and the patient showed impairments in daily activities. We report a patient who demonstrated strategic infarct dementia after a bilateral anterior fornix infarction.

Effects of fimbria/fornix transection on rat's synaptic configuration of hippocampus CA3 area / 中国应用生理学杂志

<p><b>AIM</b>To observe the effect of fimbria-fornix (FF) transection on rat's hippocampal synaptic configuration.</p><p><b>METHODS</b>Animal models were produced by transecting rat's bilateral fimbria-fornix (FF). Y-type maze test were carried out respectively before and after the models were built, and emphasis was laid on the quantitative analyses of the parameters of synapses in the hippocampal CA3 areas.</p><p><b>RESULTS</b>The thickness of postsynaptic density material, the curvature of synaptic interface and the occurrence of perforated synapses decreased, while the width of synaptic cleft increased.</p><p><b>CONCLUSION</b>Fimbria-fornix transection resulted in evident changes of the synaptic configuration in the hippocampal CA3 areas and we presume that the normal Ach level in the hippocampus plays a key role in maintaining the normal synaptic interface ultrastructure of the hippocampus CA3 area.</p>

Analysis of parahippocampal gyrus in 115 patients with hippocampal sclerosis

PURPOSE: Analysis of the parahippocampal gyrus (PHG) involvement in 115 patients with hippocampal sclerosis (HS) by MR imaging. The simultaneous occurrence of ipsilateral fornix (F) and mamillary body (MB) volume loss was checked also. These findings were correlated with the side of hippocampal involvement, the sex, patient s age, and the symptoms onset. METHOD: The MR images of 115 patients with HS were studied retrospectively. All the examinations were performed on 1.5 T units (SIGNA, GE, Milwaukee, WI) and included high resolution coronal T2-weighted images (3 mm thickness, 0.6 mm gap). RESULTS: The patient's age ranged between 3.5 and 80 years (mean 34.1); 62 (53.9 percent) were female and 53 (46.1 percent) were male. There were HS on the left side in 53 (46.0 percent), on the right side in 51 (44.3 percent), and bilateral in 11 (9.7 percent). In 43 (37.3 percent) cases there were ipsilateral PHG volume loss and signal hyper intensity on T2-weighted imaging. In 29 (25.2 percent) cases there were ipsilateral fornix volume loss and in 10 (34.5 percent) of this there were also ipsilateral MB changes. In abnormal PHG, 23 (53.4 percent) were on the left side, 17 (39.5 percent) were on the right side, and 3 (7.1 percent) were bilateral. There were fornix changes in 15 (34.8 percent) cases and MB volume loss in 5 (11.6 percent) cases. Pertinent clinical data were obtained in only 18 (41.8 percent) of the PHG lesion cases and 11 (61.1 percent) of these patients had epileptic attacks for more than 20 years before the examination. CONCLUSION: PHG involvement must be investigated in patients with HS and we suggest that the term mesial temporal sclerosis should be used only if there are also changes at this anatomical site