• Korean Journal of Radiology
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• 제2권2호
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• pp.63-67
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• 2001

Objective: Atrophy and a high T2 signal of the hippocampus are known to be the principal MR imaging findings of hippocampal sclerosis. The purpose of this study was to determine whether or not individual MRI findings correlate with surgical outcome in patients with this condition. Materials and Methods: Preoperative MR imaging findings in 57 consecutive patients with pathologically-proven hippocampal sclerosis who underwent anterior temporal lobectomy and were followed-up for 24 months or more were retrospectively reviewed, and the results were compared with the postsurgical outcome (Engel classification). The MR images included routine sagittal T1-weighted and axial T2-weighted spin-echo images, and oblique coronal T1-weighted 3D gradient-echo and T2-weighted 2D fast spin-echo images obtained on either a 1.5 T or 1.0 T unit. The images were visually evaluated by two neuroradiologists blinded to the outcome; their focus was the presence or absence of atrophy and a high T2 hippocampal signal. Results: Hippocampal atrophy was seen in 96% of cases (55/57) [100% (53/53) of the good outcome group (Engel class I and II), and 50% (2/4) of the poor outcome group (class III and IV)]. A high T2 hippocampal signal was seen in 61% of cases (35/57) [62% (33/53) of the good outcome group and 50% (2/4) of the poor outcome group]. All 35 patients with a high T2 signal had hippocampal atrophy. 'Normal' hippocampus, as revealed by MR imaging, occurred in 4% of patients (2/57), both of whom showed a poor outcome (Engel class III). The presence or absence of hippocampal atrophy correlated well with surgical outcome (p<0.01). High T2 signal intensity did not, however, significantly correlate with surgical outcome (p>0.05). Conclusion: Compared with a high T2 hippocampal signal, hippocampal atrophy is more common and correlates better with surgical outcome. For the prediction of this, it thus appears to be the more useful indicator.

• Investigative Magnetic Resonance Imaging
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• 제6권1호
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• pp.47-54
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• 2002

Purpose : Hippocampal atrophy is one of the characteristic pathologic findings of hippocampal sclerosis, for which MR imaging of the hippocampus is essential in the evaluation of hippocampal sclerosis. The purpose of this study is to present the normal MR volumetric data of the hippocampus in normal adult Korean and to compare those with MR volumetric data of hippocampus in patients with hippocampal s-clerosis, providing the diagnostic volume criteria of the hippocampal atrophy. Materials and methods : MR volumetry was performed in 30 normal adults and 28 patients with temporal lobe epilepsy whose final diagnosis was hippocampal sclerosis. The volumetric data were compared between sexes, right and left sides, and normal and abnormal hippocampus, and the volume criteria for the diagnosis of hippocampal atrophy was determined. Results : The mean $volumes({\pm}standard$ deviation) of normal Korean adult were $2.20{\pm}0.73\textrm{cm}^3$ (right) and $2.17{\pm}0.72\textrm{cm}^3$ (left) in male and $2.27{\pm}0.47{\;}\textrm{cm}^3$ (right) and $2.23{\pm}0.48\textrm{cm}^3$ (left) in female. The mean right-left differences were $0.14{\pm}0.11\textrm{cm}^3$ and $0.19{\pm}0.13\textrm{cm}^3$ in male and female, respectively. The MR volumetry showed no significant statistical differences between sexes and between right and left. The mean volume and standard deviation of the hippocampus in hippocampal sclerosis patients was $1.46{\pm}0.60{\;}\textrm{cm}^3$, and the right-left difference was $0.51{\pm}0.41\textrm{cm}^3$, In comparison of two volume distributions between normal adult group and hippocampal sclerosis patients group, the reasonable diagnostic volume criteria was $0.4{\;}\textrm{cm}^3$ as right-left volume difference, in which the sensitivity and specificity are 0.61 and 0.90. In all patients with right-left volume difference more than $0.4{\;}\textrm{cm}^3$, visual determination of unilateral hippocampal atrophy was possible. Conclusion : The MR-based hippocampal volumetry is a useful add-on of visual MR diagnosis, only when visual diagnosis of hippocampal sclerosis is difficult.

• Korean Journal of Biological Psychiatry
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• 제8권1호
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• pp.131-139
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• 2001

This study was conducted to evaluate the effect of PTSD on memory function and hippocampal volume, and to identify major variables correlated to hippocampal volume and memory function. Thirty four Vietnam veterans were collected for this study, among whom eighteen were PTSD patients and sixteen were combat control subjects. The author used Impact of Event Scale(IES), Combat Exposure Scale(CES), Hamilton Depression Rating Scale(HDRS) and Beck Depression Inventory (BDI). Korea Memory Assessment Scale(K-MAS) was assessed for memory function. Magnetic resonance imaging(MRI) was used to measure hippocampal volume. There were significant differences between PTSD and Non-PTSD veterans in IES, HDRS and BDI. Significant difference was found in verbal memory and total memory of K-MAS between PTSD and Non-PTSD veterans. There was significant difference in hippocampal volume between PTSD and Non-PTSD veterans. Short term memory, verbal memory and total memory were positively correlated to hippocampal volume. Hippocampal volume was negatively correlated to IES, HDRS, and BDI. These results suggest that PTSD severity be associated with hippocampal atrophy and memory dysfunction. Reduced or smaller hippocampal volume may be preexisting risk factor for stress exposure or the development of PTSD on combat exposure.

• Journal of Integrative Natural Science
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• 제11권3호
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• pp.139-147
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• 2018

Hippocampal atrophy is a well-established imaging biomarker of Alzheimer disease (AD). However, hippocampus is a non-homogenous structure with cytoarchitecturally and functionally distinct sub-regions or subfield, with each region performing distinct functions. Certain regions of the subfield have shown selective vulnerability to AD. Here, we are interested in studying the effects of normal aging and mild cognitive impairment on these sub-regional volumes. With a reliable automated segmentation technique, we segmented these subregions of the hippocampus in 101 cognitively normal (CN), 135 early mild cognitive impairment (EMCI), 67 late mild cognitive impairment (LMCI) and 48 AD subjects. Thereby, dividing the hippocampus into hippocampal tail (tail), subiculum (SUB), cornu ammonis 1 (CA1), hippocampal fissure (fissure), presubiculum (PSUB), parasubiculum (ParaSUB), molecular layer (ML), granule cells/molecular layer/dentate gyrus (GCMLDG), cornu ammonis 3(CA3), cornu ammonis 4(CA4), fimbria and hippocampal-amygdala transition area (HATA). In this cross sectional study of 351 ADNI subjects, no differences in terms of age, gender, and years of education were observed among the groups. Though, the groups had statistically significant differences (p < 0.05 after the multiple comparison correction) in the Mini-Mental State Examination (MMSE) scores. There was asymmetrical volume loss in the early stages of AD with the left hemisphere showing volume loss in regions that were unaffected in the right hemisphere. Bilateral parasubiculum, right cornu ammonis 1, 3 and 4, right fimbria and right HATA regions did not show any volume loss till the late MCI stages. Our findings suggest that the hippocampal subfield regions are selectively vulnerable to AD and also that these vulnerabilities are asymmetrical especially during the early stages of AD.

• Korean Journal of Biological Psychiatry
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• 제8권1호
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• pp.3-19
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• 2001

Recent basic and clinical studies demonstrate a major role for neural plasticity in the etiology and treatment of depression and stress-related illness. The neural plasticity is reflected both in the birth of new cell in the adult brain(neurogenesis) and the death of genetically healthy cells(apoptosis) in the response to the individual's interaction with the environment. The neural plasticity includes adaptations of intracellular signal transduction pathway and gene expression, as well as alterations in neuronal morphology and cell survival. At the cellular level, repeated stress causes shortening and debranching of dendrite in the CA3 region of hippocampus and suppress neurogenesis of dentate gyrus granule neurons. At the molecular level, both form of structural remodeling appear to be mediated by glucocorticoid hormone working in concert with glutamate and N-methyl-D-aspartate(NMDA) receptor, along with transmitters such as serotonin and GABA-benzodiazepine system. In addition, the decreased expression and reduced level of brain-derived neurotrophic factor(BDNF) could contribute the atrophy and decreased function of stress-vulnerable hippocampal neurons. It is also suggested that atrophy and death of neurons in the hippocampus, as well as prefrontal cortex and possibly other regions, could contribute to the pathophysiology of depression. Antidepressant treatment could oppose these adverse cellular effects, which may be regarded as a loss of neural plasticity, by blocking or reversing the atrophy of hippocampal neurons and by increasing cell survival and function via up-regulation of cyclic adenosine monophosphate response element-binding proteins(CREB) and BDNF. In this article, the molecular and cellular mechanisms that underlie stress, depression, and action of antidepressant are precisely discussed.

• The Korean Journal of Physiology and Pharmacology
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• 제16권4호
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• pp.281-285
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• 2012

A previous animal study has shown the effects of erythropoietin (EPO) and its non-erythropoietic carbamylated derivative (CEPO) on neurogenesis in the dentate gyrus. In the present study, we sought to investigate the effect of EPO on adult hippocampal neurogenesis, and to compare the ability of EPO and CEPO promoting dendrite elongation in cultured hippocampal neural progenitor cells. Two-month-old male BALB/c mice were given daily injections of EPO (5 U/g) for seven days and were sacrificed 12 hours after the final injection. Proliferation assays demonstrated that EPO treatment increased the density of bromodeoxyuridine (BrdU)-labeled cells in the subgranular zone (SGZ) compared to that in vehicle-treated controls. Functional differentiation studies using dissociated hippocampal cultures revealed that EPO treatment also increased the number of double-labeled BrdU/microtubulea-ssociated protein 2 (MAP2) neurons compared to those in vehicle-treated controls. Both EPO and CEPO treatment significantly increased the length of neurites and spine density in MAP2(+) cells. In summary, these results provide evidences that EPO and CEPO promote adult hippocampal neurogenesis and neuronal differentiation. These suggest that EPO and CEPO could be a good candidate for treating neuropsychiatric disorders such as depression and anxiety associated with neuronal atrophy and reduced hippocampal neurogenesis.

• Proceedings of the Korean Society of Medical Physics Conference
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• 한국의학물리학회 2006년도 제33회 추계학술대회 발표논문집
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• pp.146-146
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• 2006

• Smart Media Journal
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• 제9권2호
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• pp.22-32
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• 2020

The hippocampal volume atrophy is known to be linked with neuro-degenerative disorders and it is also one of the most important early biomarkers for Alzheimer's disease detection. The measurements of hippocampal pure volumes from Magnetic Resonance Imaging (MRI) is a crucial task and state-of-the-art methods require a large amount of time. In addition, the structural brain development is investigated using MRI data, where brain morphometry (e.g. cortical thickness, volume, surface area etc.) study is one of the significant parts of the analysis. In this study, we have proposed a patch-based ensemble model of 3-D convolutional neural network (CNN) to measure the hippocampal pure volume from MRI data. The 3-D patches were extracted from the volumetric MRI scans to train the proposed 3-D CNN models. The trained models are used to construct the ensemble 3-D CNN model and the aggregated model predicts the pure volume in one-step in the test phase. Our approach takes only 5 seconds to estimate the volumes from an MRI scan. The average errors for the proposed ensemble 3-D CNN model are 11.7±8.8 (error%±STD) and 12.5±12.8 (error%±STD) for the left and right hippocampi of 65 test MRI scans, respectively. The quantitative study on the predicted volumes over the ground truth volumes shows that the proposed approach can be used as a proxy.

• Korean Journal of Radiology
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• 제1권1호
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• pp.25-32
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• 2000

Objective: The purpose of our study was to determine the ability of H-1 MR spectroscopy (MRS) to lateralize the lesion in patients with hippocampal sclerosis. Materials and Methods: Twenty healthy volunteers and 25 patients with intractable temporal lobe epilepsy whose MR imaging diagnosis was unilateral hippocampal sclerosis were included. This diagnosis was based on the presence of unilateral atrophy and/or high T2 signal intensity of the hippocampus. Single-voxel H-1 MRS was carried out on a 1.5-T unit using PRESS sequence (TE, 136 msec). Spectra were obtained from hippocampal areas bilaterally with volumes of interest (VOIs) of 6.0 cm³ and 2.25 cm³ in healthy volunteers, and of either 6.0 cm³ (n = 14) or 2.25 cm³ (n = 11) in patients. Metabolite ratios of NAA/Cho and NAA/Cr were calculated from relative peak height measurements. The capability of MRS to lateralize the lesion and to detect bilateral abnormalities was compared with MR imaging diagnosis as a standard of reference. Results: In healthy volunteers, NAA/Cho and NAA/Cr ratios were greater than 0.8 and 1.0, respectively. In patients, the mean values of these ratios were significantly lower on the lesion side than on the contralateral side, and lower than those of healthy volunteers (p < .05). The overall correct lateralization rate of MRS was 72% (18/25); this rate was lower with a VOI of 6.0 cm³ than of 2.25 cm³ (64% versus 82%, p < .05). Bilateral abnormalities on MRS were found in 24% (6/25) of cases. Conclusion: Although its rate of correct lateralization is low, single-voxel H-1 MRS is a useful and promising diagnostic tool in the evaluation of hippocampal sclerosis, particularly for the detection of bilateral abnormalities. To improve the diagnostic accuracy of H-1 MRS, further investigation, including the use of a smaller VOI and measurement of the absolute amount of metabolites, are needed.

• Clinical and Experimental Pediatrics
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• 제53권1호
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• pp.106-110
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• 2010

Hippocampal sclerosis (HS) is one of the most common features of intractable temporal lobe epilepsy. Generally it can be identified through brain magnetic resonance imaging (MRI) with high degree of sensitivity and specificity. Typical brain MRI findings of HS are hippocampal atrophy with hyperintense signal confined to the lesion. On the other hand cortical dysplasia exhibits blurring of the gray-white matter junction and abnormal white matter signal intensity. We present a case where preoperative brain MRI strongly suggested the presence of diffuse cortical dysplasia in the left temporal lobe but postoperative pathology revealed the temporal lesion to be unremarkable except for hippocampal sclerosis.