OBJECTIVE: The purpose of the study was to compare cortical amyloid deposition using 18F-florbetaben and positron emission tomography (PET) in healthy controls and subjects with amnestic mild cognitive impairment (aMCI) and Alzheimer's disease (AD). METHODS: We investigated 25 patients : 10 age-matched healthy controls, 10 patients with aMCI and 5 with AD. All participants underwent PET after intravenous injection of 300 MBq of 18F-florbetaben. The 90 min post-injection brain PET data were analysed using statistical parametric mapping. RESULTS: When compared to healthy controls, amyloid deposition was significantly higher in frontal lobe medial frontal gyrus, limbic lobe posterior cingulate, parietal lobe precuneus, sub-loba insula, temporal lobe superior temporal gyrus, parietal lobe inferior parietal lobule, temporal lobe middle temporal gyrus, parietal lobe supramarginal gyrus, occipital lobe middle temporal gyrus of patient group (family wise error correction p<0.05). CONCLUSION: These results indicate 18F-florbetaben to be an efficacious β-amyloid-targeted tracer. Subjects with aMCI, AD could be easily differentiated from healthy controls by assessment of the PET data.
Alzheimer Disease* ; Amyloid* ; Brain ; Frontal Lobe ; Gyrus Cinguli ; Humans ; Injections, Intravenous ; Limbic Lobe ; Mild Cognitive Impairment* ; Occipital Lobe ; Parietal Lobe ; Plaque, Amyloid ; Positron-Emission Tomography ; Prefrontal Cortex ; Temporal Lobe

The core concept for pathophysiology in panic disorder (PD) is the fear network model (FNM). The alterations in FNM might be linked with disturbances in the autonomic nervous system (ANS), which is a common phenomenon in PD. The traditional FNM included the frontal and limbic regions, which were dysregulated in the feedback mechanism for cognitive control of frontal lobe over the primitive response of limbic system. The exaggerated responses of limbic system are also associated with dysregulation in the neurotransmitter system. The neuroimaging studies also corresponded to FNM concept. However, more extended areas of FNM have been discovered in recent imaging studies, such as sensory regions of occipital, parietal cortex and temporal cortex and insula. The insula might integrate the filtered sensory information via thalamus from the visuospatial and other sensory modalities related to occipital, parietal and temporal lobes. In this review article, the traditional and advanced FNM would be discussed. I would also focus on the current evidences of insula, temporal, parietal and occipital lobes in the pathophysiology. In addition, the white matter and functional connectome studies would be reviewed to support the concept of advanced FNM. An emerging dysregulation model of fronto-limbic-insula and temporooccipito-parietal areas might be revealed according to the combined results of recent neuroimaging studies. The future delineation of advanced FNM model can be beneficial from more extensive and advanced studies focusing on the additional sensory regions of occipital, parietal and temporal cortex to confirm the role of advanced FNM in the pathophysiology of PD.
Autonomic Nervous System ; Connectome ; Frontal Lobe ; Limbic System ; Neuroimaging ; Neurotransmitter Agents ; Occipital Lobe ; Panic Disorder ; Panic ; Parietal Lobe ; Rabeprazole ; Temporal Lobe ; Thalamus ; White Matter

Limbic encephalitis (LE) is characterized by short-term memory loss, disorientation, agitation, seizures, and histopathological evidence of medial temporal lobe inflammation. Leucine-rich, glioma inactivated 1 (LGI-1) is an auto-antigen associated with LE. We report a 37-year-old male patient with LGI-1-related LE who presented with recurrent episodes of selective amnesia, seizure-like activity, confusion, and personality change. His symptoms were significantly improved with steroid therapy. Thorough differential diagnosis with consideration for autoimmune encephalitis should be in patients with presentation of symptoms, such as memory impairment, personality change and seizure-like activity, especially when other neurological diagnoses are excluded.
Adult ; Amnesia ; Diagnosis ; Diagnosis, Differential ; Dihydroergotamine ; Encephalitis ; Glioma ; Humans ; Inflammation ; Limbic Encephalitis ; Male ; Memory ; Memory, Short-Term ; Seizures ; Temporal Lobe

Attentional processes facilitate cognitive and behavioral performance in several ways. Attention serves to reduce the amount of information to receive. Attention enables humans to direct themselves to appropriate aspects of external environmental events and internal operations. Attention facilitates the selection of salient information and the allocation of cognitive processing appropriate to that information. Attention is not a unitary process that can be localized to a single neuroanatomical region. Before the cortical registration of sensory information, activation of important subcortical structures occurs, which is called as an orienting response. Once sensory information reaches the sensory cortex, a large number of perceptual processes occur, which provide various levels of perceptual resolution of the critical(heteromodal) systems inferior parietal and temporal lobes. At this stage, the processing characteristics can be modified, and the biases of the system have a direct impact on attentional selection. Information flow has been traced through sensory analysis to a processing stage that enables the new. Information to be focused and modified in relation to preexisting biases. The limbic and paralimbic system play significant roles on modulating attentional response. It is labeled with affective salience and is integrated according to ongoing pressures from the motivational drive system of the hypothalamus. The salience of information greatly influences the allocation of attention. The frontal lobe operate resporse selection system with a reciprocal interaction with both the attention system of the parietal lobe and the limbic system. In this attentional process, the search with the spatial field is organized and a sequence of attentional responses is generated. Affective, motivational and appectitive impulses from limbic system and hypothalamus trigger response intention, preparation, planning, initiation and control of frontal lobe on this process. The reticular system, which produces ascending activation, catalyzes the overall system and increases attentional capacity. Also additional energetic pressures are created by the hypothalamus. As psychophysiological measurement, skin conductance, pupil diameter, muscle tension, heart rate, alpha wave of EEG can be used. Event related potentials also provide physiological evidence of attention during information process. N1 component appears to be an electrophysiological index of selective attention. P3 response is developed during the attention related to stimulus discrimination, evaluation and response.
Automatic Data Processing ; Bias (Epidemiology) ; Discrimination (Psychology) ; Electroencephalography ; Evoked Potentials ; Frontal Lobe ; Heart Rate ; Humans ; Hypothalamus ; Intention ; Limbic System ; Muscle Tonus ; Neuroanatomy* ; Parietal Lobe ; Psychophysiology* ; Pupil ; Rabeprazole ; Skin ; Temporal Lobe

Limbic encephalitis (LE) is characterized by short-term memory loss, disorientation, agitation, seizures, and histological evidence of mesial temporal lobe inflammation. Leucine-rich, glioma inactivated 1 (LGI1) is the autoantigen associated with limbic encephalitis that was previously attributed to voltage-gated potassium channels. We report herein a 54-year-old female with LGI1-related limbic encephalitis who presented with recurrent episodes of episodic memory impairment, depressive mood, and phantosmia. Her symptoms dramatically improved with steroid therapy.
Antibodies* ; Dihydroergotamine ; Female ; Glioma ; Humans ; Inflammation ; Limbic Encephalitis* ; Memory, Episodic ; Memory, Short-Term ; Middle Aged ; Potassium Channels, Voltage-Gated ; Seizures ; Temporal Lobe

BACKGROUND: Various neuronal and glial factors which participate in neural differentiation, including neural cell adhesion molecule (NCAM), are upregulated in pathogenesis of temporal lobe epilesy (TLE).This study aimed to investigate hte effect of (R-)-N6-phenylisopropyladenosine (RPIA), an adenosine A1 receptor agonist, on the morphological alteration of NCAM immunoreactivity (IR) in limbic system of Kainic acid (KA)-induced epileptic rats. METHODS: Experiment animals were divided into control group, KA treatment only (10 mg/kg. i.p.)group, and RPIA pretreatment (100 microgram/kg. i,p, 10 min prior to injection of KA) group. Animals were sacrificed at 24 hours and 1 week after KA treatment. Luxol fast blue-cresyl violet stain for histopathological observation, and NCAM immunohistochemistry to study alteration of NCAM IR in limbic system were performed. RESULTS: Neuronal loss in CA1 and CA3areas of hippocampus, piridorm cortex, basolateral amygdala nucleus and lateral dorsal thalamic nucleus were induced by KA unjection, and thoes were reduced by RPIA pretreatment. Inrease of NCAM-IR was observed in interneurons of all hippocampal areas. except CA2 area, pirform cortex and basolateral amygdala nucleus at 24 hours after KA injection. and increased NCAM-IR was observed in cell membrane and processes of neuroglia, dentate granule cells and pyramidal cells in CA1 area of hippocampus. and neurons in piriform cortex, amygdala and lateral dorsal thalamic nucleus 1 week after KA injection, but those changes were milder than those at 24 hours after KA injection. RPIA pretreatment significantly reduced KA-induced NCAM-IR in hippocampal CA3, CA1 area, piriform cortex, amtgdala and lateral dorsal thalamic nucleus. CONCLUSION: We suggest that decrease of NCAM immunoreactivity is associated with neuprotective effects of RPIA on limbic system against KA neurotoxiciy.
Amygdala ; Animals ; Cell Membrane ; Epilepsy, Temporal Lobe ; Hippocampus ; Immunohistochemistry ; Interneurons ; Kainic Acid ; Lateral Thalamic Nuclei ; Limbic System ; Neural Cell Adhesion Molecules ; Neuroglia ; Neurons ; Pyramidal Cells ; Rats ; Receptor, Adenosine A1 ; Temporal Lobe ; Viola

Paraneoplastic limbic encephalitis, a remote effect of cancer without nervous system metastasis, is rare, especially in childhood. Here, we report a case of paraneoplastic limbic encephalitis associated with an ovarian mature teratoma in an adolescent girl. The 15-year-old girl developed neuropsychiatric symptoms, memory loss, seizures, and unconsciousness. Cerebrospinal fluid analysis and brain magnetic resonance imaging (MRI) findings were normal, while single photon emission computed tomography imaging showed hypoperfusion in both temporal lobes. Ultrasound and MRI of the abdomen revealed a left ovarian cystic mass. The patient experienced a significant recovery of cognitive function after surgical resection of the tumor, which was pathologically identified as a mature ovarian teratoma, and treatment with intravenous immunoglobulin.
Abdomen ; Adolescent ; Brain ; Female ; Humans ; Immunoglobulins ; Limbic Encephalitis ; Magnetic Resonance Imaging ; Memory Disorders ; Neoplasm Metastasis ; Nervous System ; Ovarian Cysts ; Seizures ; Temporal Lobe ; Teratoma ; Tomography, Emission-Computed, Single-Photon ; Unconsciousness

BACKGROUND: Human Herpes Virus 6 (HHV6) is commonly associated with encephalitis following bone marrow transplantation. However, hippocampal atrophy and global hypometabolism are rare findings in HHV6 encephalitis. CASE REPORT: A 41-year-old right-handed woman with acute lymphoblastic leukemia presented with fever and mental changes 2 weeks after receiving a sibling bone marrow transplant. The patient's cerebrospinal fluid (CSF) was positive for HHV-6 deoxyribonucleic acid (DNA), but was negative for other viral DNA. Brain magnetic resonance imaging revealed atrophic changes in bilateral medial temporal lobes. Following 4 weeks of ganciclovir therapy, a CSF exam was negative for HHV-6 DNA and the patient's neurological symptoms partially improved. However, she was disoriented and had severe retrograde and anterograde amnesia. 18F-fluorodeoxyglucose-positron emission tomography indicated global hypometabolism in the medial temporal lobes and the fronto-parietal cortices. CONCLUSIONS: This is a rare and unusual case of hippocampal atrophy in the acute stage of HHV6 encephalitis. Our imaging findings may reflect the chronic indolent course of HHV6 encephalitis.
Adult ; Amnesia, Anterograde ; Amnesia, Retrograde ; Atrophy ; Bone Marrow Transplantation* ; Bone Marrow* ; Brain ; Cerebrospinal Fluid ; DNA ; DNA, Viral ; Encephalitis* ; Female ; Fever ; Ganciclovir ; Herpesvirus 6, Human ; Humans* ; Limbic Encephalitis ; Magnetic Resonance Imaging* ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; Siblings ; Temporal Lobe

BACKGROUND: Paraneoplastic limbic encephalitis (PLE) is a rare syndrome characterized by memory impairment, symptoms of hypothalamic dysfunction, and seizures. It commonly precedes the diagnosis of cancer. Small-cell lung cancer is the neoplasm that is most frequently reported as the etiology underlying PLE. CASE REPORT: This report describes a male patient who presented with neurologic symptoms consistent with anterograde amnesia, apathy, and disorientation. MRI revealed diffuse hyperintensities located predominantly in the medial bitemporal lobes, basal ganglia, frontal lobes, and leptomeninges on fluid attenuated inversion recovery images, suggesting PLE. Study of the primary tumor revealed squamous cell carcinoma of the lung. The patient was treated with neoadjuvant chemotherapy followed by surgery and adjuvant chemoradiotherapy, which resulted in his neurologic symptoms gradually improving. CONCLUSIONS: PLE might be a rare debut of squamous cell carcinoma of the lung. Treatment of the primary tumor may improve the neurologic symptoms.
Amnesia, Anterograde ; Apathy ; Basal Ganglia ; Carcinoma, Squamous Cell* ; Chemoradiotherapy, Adjuvant ; Diagnosis ; Drug Therapy ; Frontal Lobe ; Humans ; Limbic Encephalitis* ; Lung Neoplasms ; Lung* ; Magnetic Resonance Imaging ; Male ; Memory ; Neurologic Manifestations ; Paraneoplastic Syndromes ; Seizures

PURPOSE: The present study utilized 3.0 Tesla functional MR imaging to identify and quantify the activated brain regions associated with visually evoked sexual arousal, and also to discriminate the gender differences between the cortical activation patterns in response to sexual stimuli. MATERIALS AND METHODS: A total of 24 healthy, right-handed volunteers, 14 males (mean age: 24) and 10 females (mean age: 23), with normal heterosexual function underwent functional MRI on a 3.0T MR scanner (Forte, Isole technique, Korea). The sexual stimulation consisted of a 1-minute rest with black screen, followed by a 3-minute stimulation by an erotic video film, and concluded with a 1-minute rest. The fMRI data was obtained from 20 slices (5 mm slice thickness, no gap) parallel to the AC-PC (anterior commissure and posterior commissure) line on the sagittal plane, giving a total of 2,100 images. The brain activation maps and the resulting quantification were analyzed by the statistical parametric mapping program, SPM 99. The mean-activated images were obtained from each individual activation map using one sampled t-test. The FALBA program, which is a new algorithm based on the pixel differentiation method, was used to identify and quantify the brain activation and lateralization indices with respect to the functional and anatomical terms. RESULTS: In both male and female volunteers, significant brain activation showed in the limbic areas of the parahippocampal gyrus, septal area, cingulate gyrus and thalamus. It is interesting to note that the septal areas gave a relatively lower activation ratio with high brain activities. On the contrary, the putamen, insula cortex, and corpus callosum gave a higher activation ratio with low brain activities. In particular, brain activation in the septal area, which was not reported in the previous fMRI studies under 1.5 Tesla, represents a distinct finding of this study using 3.0 T MR scanner. The overall lateralization index of activation shows left predominance (LI=35.3%) in the limbic system during sexual stimulation. The gender differences of brain activation in response to sexual arousal were characterized as follows. The activation area observed in males was the hypothalamus in the limbic system, whereas in females it was the cingulate gyrus, head of caudate nucleus, insula and corpus callosum. These findings reveal dissimilarities between males and females in neuronal responses to sexual arousal. As for the overall lateralization of activation in the limbic system, male volunteers gave a lateralization index that was greater than that of females by 300%. CONCLUSION: Our findings confirmed that neuroanatomical regions are associated with visually evoked sexual arousal and also with gender differences in response to sexual stimulation. Given that data from time-course traces of activation pattern and findings are observed by different stimuli, such as tactile and olfactory sense, it might be helpful to evaluate the neurophysiological mechanism for sexual arousal, and furthermore, to develop new diagnostic tools for sexual dysfunction and disorder.
Arousal* ; Brain* ; Caudate Nucleus ; Corpus Callosum ; Female* ; Gyrus Cinguli ; Head ; Heterosexuality ; Humans ; Hypothalamus ; Limbic System ; Magnetic Resonance Imaging* ; Male* ; Neurons ; Parahippocampal Gyrus ; Putamen ; Septum of Brain ; Thalamus ; Volunteers