ABSTRACT
Se realiza una revisión de estudios de resonancia magnética integral y funcional, así como estudios bioquímicos en pacientes con y sin ideas suicidas. Estos estudios en pacientes con alto riesgo de suicidio presentan una disminución de volúmenes corticales en la corteza prefrontal dorso y ventrolateral. Lo importante de estos estudios es que resultan de la comparación con pacientes deprimidos con bajo riesgo de suicidio. Los estudios de resonancia magnética funcional mostraron una hipofuncionalidad del lóbulo prefrontal en los pacientes depresivos con ideas suicidas severas, que se observa como una disminución del flujo sanguíneo cerebral en las áreas lateral y ventral. Se observa una disminución del metabolismo de serotonina, en clara relación con la severidad de las ideas de muerte, también con un foco en la región lateroventral prefrontal. Dado que las funciones de la corteza prefrontal afirman al individuo en su perspectiva vital, disfunciones como las descritas debilitan la coordinación y organización del apego a la vida, quedando, por el contrario, la posibilidad de la búsqueda de la muerte. Se concluye que los pacientes depresivos con ideas suicidas tienen una alta vulnerabilidad para el intento de suicidio por la afectación de las zonas prefrontales.
A review of functional integral magnetic resonance and biochemical data from patients with and without suicidal ideation is presented. Patients with high suicidal risk show a decrease in cortical volume in ventrolateral and dorsal prefrontal cortex. These studies are compared to those of depressed patients with low suicidal risk. Functional magnetic resonance in depressed patients with severe suicidal ideation show an hypo functional prefrontal lobe, seen as a decrease in blood flow in lateral and ventral areas. There is a decrease in serotonin metabolism, clearly related to the severity of suicidal ideation, also in ventrolateral prefrontal cortex. As prefrontal cortex functions enhance vital perspectives, such dysfunctions weaken coordination and organization of attachment to life, making search for death a possibility. Authors conclude that depressed patients with suicidal ideation have a high vulnerability for suicidal intent due to changes in prefrontal areas.
Subject(s)
Humans , Suicide, Attempted , Prefrontal Cortex/physiopathology , Neurotransmitter Agents/metabolism , Depression/physiopathology , Suicidal Ideation , Magnetic Resonance Imaging , Prefrontal Cortex/metabolism , Prefrontal Cortex/diagnostic imaging , Depression/metabolismABSTRACT
Hydrocephalus is often treated with a cerebrospinal fluid shunt (CFS) for excessive amounts of cerebrospinal fluid in the brain. However, it is very difficult to distinguish whether the ventricular enlargement is due to hydrocephalus or other causes, such as brain atrophy after brain damage and surgery. The non-trivial evaluation of the consciousness level, along with a continuous drainage test of the lumbar cistern is thus clinically important before the decision for CFS is made. We studied 32 secondary mild hydrocephalus patients with different consciousness levels, who received T1 and diffusion tensor imaging magnetic resonance scans before and after lumbar cerebrospinal fluid drainage. We applied a novel machine-learning method to find the most discriminative features from the multi-modal neuroimages. Then, we built a regression model to regress the JFK Coma Recovery Scale-Revised (CRS-R) scores to quantify the level of consciousness. The experimental results showed that our method not only approximated the CRS-R scores but also tracked the temporal changes in individual patients. The regression model has high potential for the evaluation of consciousness in clinical practice.
ABSTRACT
Hydrocephalus is often treated with a cerebrospinal fluid shunt (CFS) for excessive amounts of cerebrospinal fluid in the brain. However, it is very difficult to distinguish whether the ventricular enlargement is due to hydrocephalus or other causes, such as brain atrophy after brain damage and surgery. The non-trivial evaluation of the consciousness level, along with a continuous drainage test of the lumbar cistern is thus clinically important before the decision for CFS is made. We studied 32 secondary mild hydrocephalus patients with different consciousness levels, who received T1 and diffusion tensor imaging magnetic resonance scans before and after lumbar cerebrospinal fluid drainage. We applied a novel machine-learning method to find the most discriminative features from the multi-modal neuroimages. Then, we built a regression model to regress the JFK Coma Recovery Scale-Revised (CRS-R) scores to quantify the level of consciousness. The experimental results showed that our method not only approximated the CRS-R scores but also tracked the temporal changes in individual patients. The regression model has high potential for the evaluation of consciousness in clinical practice.
ABSTRACT
As our country steps into the aging society gradually, the number of cognitive impairments and the prevalence rate are increasing yearly. The family and society bear a heavy burden. It is more important to explore the more direct and Objective morphological changes of cognitive impairment through neural structural imaging , which is better for early diagnosis, intervention and delay or even prevent its progress. Here we present a review of this topic focusing on neural structural imaging in the assessment of cognitive impairment.
ABSTRACT
Photoacoustic microscopy (PAM) has become an increasingly popular technology for biomedical applications, providing anatomical, functional, and molecular information. In this concise review, we first introduce the basic principles and typical system designs of PAM, including optical-resolution PAM and acoustic-resolution PAM. The major imaging characteristics of PAM, i.e. spatial resolutions, penetration depth, and scanning approach are discussed in detail. Then, we introduce the major biomedical applications of PAM, including anatomical imaging across scales from cellular level to organismal level, label-free functional imaging using endogenous biomolecules, and molecular imaging using exogenous contrast agents. Lastly, we discuss the technical and engineering challenges of PAM in the translation to potential clinical impacts.
Subject(s)
Contrast Media , Microscopy , Molecular Imaging , Weights and MeasuresABSTRACT
The brain structural imaging changes in patients with post-traumatic stress disorders (PTSD) and the related research progress are reviewed. It is elucidated that the volume decrease and the density reductions of gray and white matters in PTSD patients are mainly manifested as the imaging changes of the hippocampus, callus, and anterior cingulate cortex (ACC). The imaging change of callus is characteristic in PTSD patients. The image structure analyses of the white matter and gray matter are the current frontiers and strategic trends of PTSD-related research. Meanwhile, it is pointed out that the relationship between PTSD and brain structure imaging is a problem needs to be urgently solved.
ABSTRACT
@#: Mild cognitive impairment (MCI) represents a transitional status between the cognition of normal aging and the fully developed clinical features of dementia. It has a high risk to progress to Alzheimer disease. Neuroimaging has become increasingly important in the clinical assessment and early diagnosis of MCI. It can also predict the course of MCI and monitor treatment effects.