Role of hippocampal volumetry in drug resistant epilepsy

Background: Hippocampus is a brain structure located deep in the temporal lobe. The structure is crucial for learning and memory and is a natural inhibitor of seizure activity in brain. In drug resistant epilepsy (DRE), there is shrinkage of the hippocampus leading to poor seizure control.Methods: Patients meeting the diagnostic criteria for drug resistant epilepsy between the age group of 10-60 years were enrolled in the study. Epileptic non drug resistant controls and normal healthy individuals were taken from same cohort. Selected patients underwent MRI Brain and their hippocampal volumes were estimated manually. Coronal oblique sections, perpendicular to the long axis of hippocampus were taken and hippocampal volume (HV) were calculated using region of interest approach with manual delineation . Results: There was increment in detecting hippocampal atrophy from 30% to 46.6% in DRE patients when manual hippocampal atrophy was used in addition to visual assessment. The mean right and left hippocampal volumes in drug resistant epilepsy cases were found to be 2.17+0.57 cc and 1.52+0.54 cc respectively. Left HV was found to be statistically significantly smaller than right side (p value < 0.05). DRE patients had smaller mean bilateral HV than healthy controls, the difference being 33%. The left HV loss was almost double the right HV loss among DRE cases. The hippocampal volumes were reduced in DRE patients compared to epileptic non-resistant patients; however the difference was found to be less than that of normal healthy controls.Conclusion: Manual hippocampal volumetry detected more patients with hippocampal atrophy in our study compared to visual assessment. Manual hippocampal volumetry should be routinely done in patients with Drug resistant epilepsy.

Global hippocampal atrophy in major depressive disorder: a meta-analysis of magnetic resonance imaging studies / Atrofia global do hipocampo no transtorno depressivo maior: uma metanálise de estudos com ressonância magnética

Abstract Introduction: Major depressive disorder (MDD), an incapacitating mental disorder, is characterized by episodes of at least 2 weeks of apparent changes in mood, cognition, and neurovegetative functions. Many neuroimaging studies using magnetic resonance imaging (MRI) have examined morphometric changes in patients with MDD, but the results are not conclusive. This study aims to review the literature and perform a meta-analysis on hippocampal volume (HcV) in patients with MDD. Methods: Studies on HcV in patients with MDD diagnosis were identified from major databases (MEDLINE, EMBASE, The Cochrane Library, Scopus, PsycINFO, and SciELO) using the search terms depression, major depressive disorder, MDD, unipolar, magnetic resonance imaging, MRI, and hippocampus. Results: A meta-analysis of 29 studies fulfilling specific criteria was performed. The sample included 1327 patients and 1004 healthy participants. The studies were highly heterogeneous with respect to age, sex, age of onset, and average illness duration. However, the pooled effect size of depression was significant in both hippocampi. MDD was associated with right (-0.43; 95% confidence interval [95%CI] −0.66 to −0.21) and left (-0.40; 95%CI −0.66 to −0.15) hippocampal atrophy. Conclusions: MDD seems to be associated with global HcV atrophy. Larger longitudinal follow-up studies designed to analyze the influence of sociodemographic variables on this relationship are required to yield better evidence about this topic.

Resumo Introdução: O transtorno depressivo maior (TDM) é uma doença mental incapacitante caracterizada por episódios de pelo menos 2 semanas de mudanças claras no afeto, cognição e funções neurovegetativas. Vários estudos de neuroimagem, realizados através de imagem de ressonância magnética (IRM), examinaram mudanças morfométricas em pacientes com TDM, com resultados não conclusivos. Este estudo tem como objetivo revisar a literatura e realizar uma metanálise sobre o volume do hipocampo (VHc) em pacientes com TDM. Métodos: Estudos de VHc em pacientes com TDM foram identificados a partir dos principais bancos de dados (MEDLINE, EMBASE, The Cochrane Library, Scopus, PsycINFO e SciELO) usando os seguintes termos: depression, major depressive disorder, MDD, unipolar, magnetic resonance imaging, MRI e hippocampus. Resultados: Foi realizada uma metanálise de 29 estudos que preencheram os critérios específicos. A amostra foi composta por 1327 pacientes e 1004 indivíduos saudáveis. Os estudos foram altamente heterogêneos em relação a idade, gênero, idade do primeiro episódio e duração média da doença, mas o efeito combinado da depressão foi significativo em ambos os hipocampos. O TDM foi associado à atrofia do hipocampo à direita [-0,43; intervalo de confiança de 95% (IC95%) −0,66 a −0,21] e à esquerda (-0,40; IC95% −0,66 a −0,15). Conclusões: O TDM parece estar associado à atrofia global do VHc. Estudos longitudinais com maior tempo de seguimento, projetados para analisar a influência dos fatores sociodemográficos nessa relação, são necessários para obter evidências mais robustas.

Association of serum ghrelin level with cognition, hippocampal volume, and proton magnetic resonance spectrum in patients with type 2 diabetes mellitus / 中华内分泌代谢杂志

Objective To investigate the association of serum ghrelin level with cognition, hippocampal volume, and proton magnetic resonance spectrum ( [ 1 H ]-MRS ) in patients with type 2 diabetes mellitus ( T2DM) . Methods The T2DM patients cared at the Wuhan Fourth Hospital were recruited. Data on demographic characteristics and clinical parameters were collected. Ghrelin was measured by ELISA assay. Cognitive performance was assessed by the Montreal Cognitive Assessment ( MoCA ) and Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). The changes of metabolites in hippocampus were detected by [1 H]-MRS, including N-acetyl asparate ( NAA) , choline ( Cho) , myo-inositol ( MI) , creatine ( Cr) . All patients were divided into 2 groups[cognitive impairment (CI) and non-cognitive impairment (NCI) groups] by MoCA. Results (1) Compared with patients in NCI group, the serum ghrelin level, bilateral hippocampal volume, and NAA/Cr ratio of [1H]-MRS metabolites in CI group were decreased, but MI/Cr and Cho/Cr ratios were increased(all P<0.05). (2) Serum ghrelin was positively correlated with a variety of RBANS scores ( including immediate memory, attention, delayed memory, and total scores) , bilateral hippocampal volume, and NAA/Cr ratio of [ 1 H]-MRS metabolites in T2DM patients, but it was negatively correlated with MI/Cr ratio and Cho/Cr ratio ( all P<0. 05 ) . ( 3 ) Logistic regression analysis showed that ghrelin was a protective factor of cognition in T2DM patients. Conclusions T2DM patients with cognitive impairment had lower levels of ghrelin, and serum ghrelin was postively correlated with their cognitive performance, hippocampal volume, and [1 H]-MRS metabolites, suggesting that serum ghrelin may be involved in the occurrence and development of cognitive dysfunction in patients with T2DM.

Hippocampal volume measurement with MMSE score in the application value of cognitive impairment / 实用放射学杂志

Objective To investigate the clinical application value of hippocampal volume (HV)measurement with MMSE score in varying different degrees cognitive impairment.Methods 30 Alzheimer’s disease(AD)patients,30 mild cognitive impairment (MCI)patients and 30 normal controls(NC)were recruited,HV was measured by Siemens Tim-avanto 3.0T super conductance magnetic resonance.Standardized HV and MMSE scores of three groups were comprehensive analyzed.Results The left and right sides and the total HV of AD group were lower than the MCI and the NC group,with significant differences by statistical analysis (P <0.05).The HV had no significant differences between the MCI and the NC group.The MMSE scores of AD group were lower than the MCI and the NC group,with significant differences by statistical analysis (P <0.05),the score had no significant differences between the MCI and the NC group.Conclusion HV measurement with MMSE score would be helpful to provide effective basis for the AD diagnosis,the sensitivity in the diagnosis of MCI is not high.

Effects of neonatal repeated inha lation of sevoflurane on ability of learning and memory and hippocampal volume in infantile rats / 医学研究生学报

Obj cetive A large number of recent studies show that sevoflurane anesthesia may cause learning and memory dysfunction.The aim of this study was to explore changes of learning and memory ability and hippocampal volume in infantile rats after neonatal interrupted and repeated inhalation of 2.6% sevoflurane through detecting the learning and memory ability by Morris water maze and the hippocampus volume by MRI.Method s Thirty two neonatal SD rats were randomly devided into two groups (n=16):experimental group and control group.Rats inhalated 2.6%sevoflurane in the experimental group and 1 L/min O2 +1 L/min Air in the control group at the postnatal days of 7, 14 and 21 (P7, P14, P21). The learning and memory ability was determined by the Morris water maze test from P31 to P37;The brains of rats were scanned by mag-netic resonance imaging ( MRI) machine under anesthesia with 1%sodium pentobarbital at P37, and the brain and bilateral hippocampal volumes were measured. Results ①In the place navigation test, the escape latency had no significant difference between the two groups (P>0.05).In the spatial probe test, the dwelling time, movement distance and number of entering times in platform quadrant decreased slightly in experimental group compared with those in the control group, while there was no significant difference (P>0.05).②The brain volume [(1.53 ±0.18) cm3 vs (1.60 ±0.13) cm3] and right hippocampal volume [(16.15 ±1.76)mm3 vs(16.46 ±1.71)mm3] had no significant difference between the two groups (P>0.05).The left hippocampal volume [(16.46 ±1.71)mm3] was decreased in the experimental group compared with the control group [(18.10 ±2.53)mm3](P<0.05). Conclusion The learning and memory ability has no significant changes in in-fantile rats after neonatal interrupted and repeated sevoflurane inhalation and MRI examination of hippocampal volume is not sufficient for the diagnosis of cognitive dysfunction.

Hippocampal Atrophy Identified by Volumetric Measurement in Intractable Epilepsy Cases

BACKGROUND: Recurrent seizures result in brain damage, but it is usually gradual, minimal, and difficult to observe by visual inspection of magnetic resonance images (MRIs). It is well known that hippocampal structure is vulnerable to seizure-associated brain damage. We measured the hippocampal volume in patients with epilepsy to evaluate the degree of damage to the hippocampus. METHODS: We recruited 33 patients with epilepsy and 21 healthy subjects from January 2007 to December 2008. We subclassified the patients into two groups: (1) 14 patients with intractable epilepsy and (2) 19 patients with drug-responsive epilepsy. In each group, the volumes of the left and right hippocampus were measured by manual drawing on brain MRIs. We compared the hippocampal volume in intractable epilepsy, drug-responsive epilepsy, and healthy subjects. The compounding effect of hippocampal sclerosis was ruled out by excluding eight patients with hippocampal sclerosis; we then compared the hippocampal volume in the two groups with epilepsy. RESULTS: The volume of the bilateral hippocampus on brain MRIs was smaller in patients with intractable epilepsy than in those with drug-responsive epilepsy and healthy subjects (left, p<0.004; right, p<0.03). After excluding the patients with hippocampal sclerosis by visual inspection, the hippocampal volumes were also found to be smaller in patients with intractable epilepsy than in those with drug-responsive epilepsy (left, p<0.04; right, p<0.05). CONCLUSIONS: While there is no definitive abnormality of the hippocampus on visual inspection of brain MRIs, we determined the degree of hippocampal atrophy and volume loss in patients with intractable epilepsy. Hippocampal volumetry will be helpful for the assessment of brain damage in patients with intractable epilepsy.

Memoria explícita en el trastorno depresivo mayor / Major depression and explicit memory

Introducción: el trastorno depresivo mayor es una alteración muy frecuente del estado de ánimo con gran impacto personal y social. Puede generar déficit notables en funciones psicológicas importantes como la ejecutiva, la atención o la memoria y evolucionar hasta un cuadro de pseudodemencia susceptible de mejorar con tratamiento antidepresivo. Objetivo: describir el funcionamiento de la memoria explícita en el trastorno depresivo mayor. Materiales y métodos: se hizo una búsqueda en la base de datos PUBMED con las palabras clave “major depression” (depresión mayor), “explicit memory” (memoria explícita) y “recollection memory” (memoria de recolección); se tomaron los artículos publicados después del año 2000; adicionalmente se incluyó bibliografía científica relevante para el cumplimiento del objetivo. Desarrollo: en la neuroanatomía del trastorno depresivo mayor se encuentran implicadas redes fronto-subcorticales (como las áreas prefrontales, tálamo, ganglios basales, hipocampo, entre otras). Estas estructuras pueden presentar atrofias que explicarían la persistencia o cronicidad de algunos de los síntomas cognitivos de la depresión. Las alteraciones en la memoria explícita, declarativa o de recolección, son de particular importancia por ser las más frecuentemente encontradas en sujetos con uno o más episodios depresivos mayores, y la estructura cerebral que se ha correlacionado más directamente con alteraciones en el almacenamiento de la memoria explícita es el hipocampo. Se ha observado actividad continua de neurogénesis en el hipocampo de animales adultos, la cual es especialmente susceptible cuando hay exposición prolongada a situaciones de estrés grave. Esto se evidencia en estudios que han encontrado reducido su volumen en sujetos con trastorno depresivo mayor, en comparación con individuos sanos. De todas maneras, aunque no se encuentre una reducción marcada del volumen, se sugiere que hay una alteración de su funcionamiento...

Introduction: Major depression is a highly prevalent affective disorder with great personal and social impact. It can generate remarkable deficits inimportant psychological functions such as executive function, attention or memory and evolve into a profile of pseudodementia that can be amelioratedwith antidepressive treatment. Objective: To describe explicit memory functioning in major depressive disorder. Materials and methods: Using the key words "major depression", "explicit memory", and"recollection memory", a search in PUBMED was carried out, selecting articles published after 2000. Additonal relevant scientific bibliography was alsoincluded. Results: In the neuroanatomy of the major depressive disorder fronto-subcortical networks are involved, among them prefrontal areas, the thalamus, basal ganglia, and the hippocampus. Atrophy of these structures may explain the persistence or chronicity of some cognitive symptoms of depression. Alterations of explicit, declarative or recollectionmemory are particularly important because of their frequency in subjects with one or more depressive episodes. The hippocampus is the cerebral structure more directly related with alterations of the explicit memory. In the hippocampus of adult animalscontinuous neurogenesis activity has been observed, and it is especially vulnerable to prolonged severestress. Hippocampal volume has been found to be reduced in individuals with major depressive disorder, as compared to healthy ones. Even in the absence of marked volume reduction, there may bealterations in hippocampal function. Conclusion: Explicit memory is a psychological process with a very clear biological basis whose structure andfunction may be altered in the presence of major depression.

Hippocampal Volume in Elderly Patients with Major Depressive Disorder

OBJECTIVES: Many recent studies of relationship between geriatric depression and changes in brain have examined the structural abnormalities in hippocampus. Using MRI, the hippocampal volumes of patients with major depression were measured and compared with control subjects for research of above relationship. METHOD: Fourteen patients (early-onset five, late-onset nine) with major depressive disorder based on DSM-IV and fourteen age-matched normal controls are included. Applying semiautomated computer program to MRI, we measured and compared the hippocampal volumes in two groups. Moreover we identified the laterality and the correlation of the volumes with age of onset, duration of education, numbers of psychiatric admission, duration of illness, MMSE scores at admission, and severity of depression. RESULT: No significant difference was observed between the hippocampal volumes of patients with major depressive disorder and those of control subjects. A significant correlation in patients was observed between duration of illness and left hippocampal volume to cerebral volume ratio. In early-onset depressed patients, left hippocampal volume was larger than in late-onset depressed patients and the positive correlation was observed between MMSE scores at admission and left hippocampal volume to cerebral volume ratio. In late-onset depressed patients, there was the negative correlation between numbers of psychiatric admission and MMSE scores at admission as well as and between cerebral volume and age of onset. CONCLUSION: Our study indicated no change in the volume of hippocampus among geriatric major depressive patients. So we suggest that more extensive and systematic studies for structural abnormality of hippocampus will be required.