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

PURPOSE: To investigate the locations of the cerebral cortex activated by visually stimulated sexual arousal, and to discriminate the gender differences between the cortical activation patterns in response to sexual stimuli. MATERIALS AND METHODS: Thirty-two male and the twenty-one female volunteers from right-handed medical students were enrolled in this study. The electroencephalography (EEGs) included the segments recorded during resting, watching a music-video, intermission and watching a pornographic video. The low-resolution brain electromagnetic tomography (LORETA) images of cross-spectral analysis were obtained from the segments using the LORETA-KEY software. RESULTS: The beta 1, 2 and 3 activities of males showed the point of maximal current densities in both the uncus and parahippocampal gyrus of the left limbic lobe, the anterior cingulate of the right limbic lobe, the superior temporal gyrus of both temporal lobes, the precuneus of the right parietal lobe, the medial frontal gyrus and superior frontal gyrus of the right frontal lobe, the superior parietal lobule of the right parietal lobe, and the middle occipital gyrus of both occipital lobes. The delta, theta, alpha and beta 1 activities of females showed the point of maximal current densities in the postcentral gyrus and inferior parietal lobule of the left parietal lobe, the middle frontal gyrus of the left frontal lobe, the middle occipital gyrus of the left occipital lobe, the left cuneus, the superior temporal gyrus of both temporal lobes and the left parahippocampal gyrus. CONCLUSIONS: There was a difference in the visually stimulated sexual arousal-associated with the cerebral neuroanatomical areas between men and women, as estimated using the LORETA software. These areas; therefore, were thought to play important roles in the sexual arousal of males and females in response to audiovisual sexual stimulation.
Arousal* ; Brain* ; Cerebral Cortex ; Electroencephalography ; Female ; Frontal Lobe ; Humans ; Magnets* ; Male ; Occipital Lobe ; Parahippocampal Gyrus ; Parietal Lobe ; Photic Stimulation ; Rabeprazole ; Students, Medical ; Temporal Lobe ; Volunteers

PURPOSE: Low resolution brain electromagnetic tomography (LORETA) is a kind of functional imaging technique and it is also an up-to-date technique for conducting electroencephalography (EEG) analysis. We tried to investigate the locations on the cerebral cortex that are activated by visually stimulated sexual arousal. MATERIALS AND METHODS: Thirty-three male volunteers (age range: 24.7+/-1.7 years) among all the right-handed medical students at our university were enrolled in this study. The EEGs included the segments recorded during resting, watching a music-video, intermission and watching a porno-video. The LORETA images of the cross-spectral analysis were obtained with using segments of LORETA-KEY (KEY Institute for Brain-Mind Research, Switzerland) software. RESULTS: In the statistical nonparametric maps (SnPM) of each spectrum and the delta, theta and alpha waves did not show the increased current density. The beta 1, 2 and 3 activity showed the point of maximal current densities in the anterior parahippocampal gyrus of the left limbic lobe and the superior temporal gyrus of both temporal lobes, the superior temporal gyrus of the right temporal lobe, the precuneus of the right parietal lobe, the medial frontal gyrus of the left frontal lobe, the middle occipital gyrus of the right occipital lobe, the superior temporal gyrus of both temporal lobes and the superior frontal gyrus of the right frontal lobe. CONCLUSIONS: The sexual arousal by visual stimulation may activate the anterior parahippocampal gyrus of the left limbic lobe, the superior temporal gyrus of both temporal lobes, the precuneus of the right parietal lobe, the medial frontal gyrus of the left frontal gyrus, and the middle occipital gyrus of the right occipital lobe.
Arousal* ; Brain* ; Cerebral Cortex ; Electroencephalography ; Frontal Lobe ; Humans ; Magnets* ; Male ; Occipital Lobe ; Parahippocampal Gyrus ; Parietal Lobe ; Photic Stimulation ; Students, Medical ; Temporal Lobe ; Volunteers

PURPOSE: To identify, using functional MR imaging, distinct cerebral centers and to evaluate the neural mechanism associated with implicit and explicit retrieval of words during conceptual processing. MATERIALS AND METHODS: Seven healthy volunteers aged 21-25 (mean, 22) years underwent BOLD-based fMR imaging using a 1.5T Signa Horizon Echospeed MR system. To activate the cerebral cortices, a series of tasks was performed as follows: the encoding of two-syllable words, and implicit and explicit retrieval of previously learned words during conceptual processing. The activation paradigm consisted of a cycle of alternating periods of 30 seconds of stimulation and 30 seconds of rest. Stimulation was accomplished by encoding eight twosyllable words and the retrieval of previously presented words, while the control condition was a white screen with a small fixed cross. During the tasks we acquired ten slices (6 mm slice thickness, 1 mm gap) parallel to the AC-PC line, and the resulting functional activation maps were reconstructed using a statistical parametric mapping program (SPM 99). RESULTS: A comparison of activation ratios (percentages), based on the number of volunteers, showed that activation of Rhs-35, PoCiG-23 and ICiG-26, 30 was associated with explicit retrieval only; other brain areas were activated during the performance of both implicit and explicit retrieval tasks. Activation ratios were higher for explicit tasks than for implicit; in the cingulate gyrus and temporal lobe they were 30% and 10% greater, respectively. During explicit retrieval, a distinct brain activation index (percentage) was seen in the temporal, parietal, and occipital lobe and cingulate gyrus, and PrCeG-4, Pr/PoCeG-43 in the frontal lobe. During implicit retrieval, on the other hand, activity was greater in the frontal lobe, including the areas of SCA-25, SFG/MFG-10, IFG-44, 45, OrbG-11, 47, SFG-6, 8, and MFG-9, 46. Overall, activation was lateralized mainly in the left hemisphere during both implicit and explicit retrieval tasks. For explicit retrieval, the lateralization index was more than twice as high as for implicit retrieval. CONCLUSION: Our findings indicate that there is neuro-anatomical dissociation between implicit and explicit retrieval of words during conceptual processing, suggesting, on the basis of cognitive neuroscience, that the performance of implicit and explicit memory-related tasks involves different mechanisms.
Brain ; Cerebral Cortex ; Frontal Lobe ; Gyrus Cinguli ; Hand ; Healthy Volunteers ; Magnetic Resonance Imaging* ; Memory* ; Neurosciences ; Occipital Lobe ; Rabeprazole ; Temporal Lobe ; Volunteers

OBJECTIVE: Structural changes of brain areas have been reported in depressive disorder and suicidal behavior (SB), in which TPH1 also has been known as a promising candidate gene. We investigated gray matter volume (GMV) differences, TPH1 rs1800532 and rs1799913 polymorphisms previously found to be associated with depressive disorder and SB, and the relationship between the two markers. METHODS: Thirteen depressive disorder patients with suicidal attempts (SA) and twenty healthy controls were included. We examined GMV differences using a voxel-based morphometry and regions of interest analysis. Direct sequencing was used for genotyping. RESULTS: The patients showed significant GMV reduction in left cerebral region including middle frontal gyrus, inferior frontal gyrus, and anterior cingulate cortex; in right middle temporal gyrus; in left cerebellar tonsil; and in right cerebral region including precentral gyrus and postcentral gyrus (corrected p < 0.005). The right precentral and postcentral gyri GMV values of AA and CA genotypes patients were significantly decreased compared to those of CC genotype subjects (corrected p=0.040). CONCLUSION: These findings show the possibility that both GMV reductions and TPH1 rs1800532/rs1799913 A allele may be involved in the pathogenesis of depressive disorder patients with SA.
Alleles ; Brain ; Depressive Disorder* ; Frontal Lobe ; Genotype ; Gray Matter* ; Gyrus Cinguli ; Humans ; Palatine Tonsil ; Prefrontal Cortex ; Somatosensory Cortex ; Temporal Lobe

OBJECTIVE: To investigate the effects of specific brain lesions on prognosis and recovery of post-stroke aphasia, and to assess the characteristic pattern of recovery. METHODS: Total of 15 subjects with first-ever, left hemisphere stroke, who were right handed, and who completed language assessment using the Korean version of the Western Aphasia Battery (K-WAB) at least twice during the subacute and chronic stages of stroke, were included. The brain lesions of the participants were evaluated using MRI-cron, SPM8, and Talairach Daemon software. RESULTS: Subtraction of the lesion overlap map of the participants who showed more than 30% improvement in the aphasia quotient (AQ) by the time of their chronic stage (n=9) from the lesion overlap map of those who did not show more than 30% improvement in the AQ (n=6) revealed a strong relationship with Broca's area, inferior prefrontal gyrus, premotor cortex, and a less strong relationship with Wernicke's area and superior and middle temporal gyri. The culprit lesion related to poor prognosis, after grouping the subjects according to their AQ score in the chronic stage (a cut score of 50), revealed a strong relationship with Broca's area, superior temporal gyrus, and a less strong relationship with Wernicke's area, prefrontal cortex, and inferior frontal gyrus. CONCLUSION: Brain lesions in the Broca's area, inferior prefrontal gyrus, and premotor cortex may be related to slow recovery of aphasia in patients with left hemisphere stroke. Furthermore, involvement of Broca's area and superior temporal gyrus may be associated with poor prognosis of post-stroke aphasia.
Aphasia* ; Brain ; Broca Area ; Hand ; Humans ; Motor Cortex ; Prefrontal Cortex ; Prognosis* ; Stroke* ; Temporal Lobe ; Wernicke Area

PURPOSE: Repetitive transcranial magnetic stimulation (rTMS) has recently been clinically applied in the treatment of drug resistant depressed patients. There are mixed findings about the efficacy of rTMS on depression. Furthermore, the influence of rTMS on the physiology of the brain is not clear. We prospectively evaluated changes of regional cerebral blood flow (rCBF) between pre- and post-rTMS treatment in patients with drug resistant depression. MATERIALS AND METHODS: Twelve patients with drug-resistant depression (7 male, 5 female; age range: 19~52 years; mean age: 29.3+/-9.3 years) were given rTMS on right prefrontal lobe with low frequency (1 Hz) and on left prefrontal lobe with high frequency (20 Hz), with 20-minute-duration each day for 3 weeks. Tc-99m ECD brain perfusion SPECT was obtained before and after rTMS treatment. The changes of cerebral perfusion were analyzed using statistical parametric mapping (SPM; t=3.14, uncorrected p<0.01, voxel=100). RESULTS: Following areas showed significant increase in rCBF after 3 weeks rTMS treatment: the cingulate gyrus, fusiform gyrus of right temporal lobe, precuneus, and left lateral globus pallidus. Significant decrement was noted in: the precental and middle frontal gyrus of right frontal lobe, and fusiform gyrus of left occipital lobe. CONCLUSION: Low-frequency rTMS on the right prefrontal cortex and high-frequency rTMS on the left prefrontal cortex for 3 weeks as an add-on regimen have increased and decreased rCBF in the specific brain regions in drug-resistant depressed patients. Further analyses correlating clinical characteristics and treatment paradigm with functional imaging data may be helpful in clarifying the pathophysiology of drug-resistant depressed patients.
Brain ; Depression ; Female ; Frontal Lobe ; Globus Pallidus ; Gyrus Cinguli ; Humans ; Male ; Occipital Lobe ; Perfusion ; Physiology ; Prefrontal Cortex ; Prospective Studies ; Temporal Lobe ; Tomography, Emission-Computed, Single-Photon ; Transcranial Magnetic Stimulation*

To investigate neuronal injury developed in an experimental model of temporal lobe epilepsy, the expression of c-FOS, c-JUN and HSP72 on the amygdala, hippocampus and temporal neocortex was studied. Epileptic seizure was induced in rats by microinjection of kainic acid(1microgrm/microl) dissolved in phosphate buffer(0.1 M, pH 7.4) into the left amygdala. Selective and delayed neuronal injuries appeared in the CA3 region of the hippocampus after 14 days and were characterized by swelling of cytoplasm and neurites, nuclear pyknosis and loss of neurons. Early induction of c-FOS and c-JUN was noted on the injection-side amygdala at 1-12h, and delayed expression developed at 7 days after the injection. HSP72 expression appeared continuously 3 hrs after the injection. Delayed induction of c-FOS, c-JUN and continuous expression of HSP72 were observed in the hippocampus and entorhinal cortex. In the hippocampus, c-FOS expression was relatively strong in the neurons of CA3 and dentate gyrus at 7~14 days after the injection. Similar findings were also noted in the neurons of the entorhinal cortex. Induction of HSP72 occurred slightly later than on that of c-FOS and c-JUN in the amygdala, with the prominent induction being noted in the neurons of amygdala, CA2, CA3, CA4 and dentate gyrus at 3 to 21 days after the injection. These results suggested that the delayed expressions of c-FOS and c-JUN in the hippocampus correlated well with impending clinical epileptic seizure.
Amygdala ; Animals ; Cytoplasm ; Dentate Gyrus ; Entorhinal Cortex ; Epilepsy ; Epilepsy, Temporal Lobe* ; Hippocampus ; Hydrogen-Ion Concentration ; Kainic Acid ; Microinjections ; Models, Theoretical ; Neocortex ; Neurites ; Neurons ; Rats* ; Temporal Lobe*

OBJECTIVE: To evaluate the spontaneous brain activity alterations in liver transplantation (LT) recipients using resting-state functional MRI. MATERIALS AND METHODS: Twenty cirrhotic patients as transplant candidates and 25 healthy controls (HCs) were included in this study. All patients repeated the MRI study one month after LT. Amplitude of low-frequency fluctuation (ALFF) values were compared between cirrhotic patients (both pre- and post-LT) and HCs as well as between the pre- and post-LT groups. The relationship between ALFF changes and venous blood ammonia levels and neuropsychological tests were investigated using Pearson's correlation analysis. RESULTS: In the cirrhotic patients, decreased ALFF in the vision-related regions (left lingual gyrus and calcarine), sensorimotor-related regions (left postcentral gyrus and middle cingulate cortex), and the default-mode network (bilateral precuneus and left inferior parietal lobule) were restored, and the increased ALFF in the temporal and frontal lobe improved in the early period after LT. The ALFF decreases persisted in the right supplementary motor area, inferior parietal lobule, and calcarine. The ALFF changes in the right precuneus were negatively correlated with changes in number connection test-A scores (r = 0.507, p < 0.05). CONCLUSION: LT improved spontaneous brain activity and the results for associated cognition tests. However, decreased ALFF in some areas persisted, and new-onset abnormal ALFF were possible, indicating that complete cognitive function recovery may need more time.
Ammonia ; Brain* ; Cognition ; Fibrosis ; Frontal Lobe ; Hepatic Encephalopathy ; Humans ; Liver Transplantation* ; Liver* ; Magnetic Resonance Imaging ; Motor Cortex ; Neuropsychological Tests ; Occipital Lobe ; Parietal Lobe ; Rabeprazole ; Somatosensory Cortex

BACKGROUND AND PURPOSE: Although sleep disturbances are common and considered a major burden for patients with Alzheimer's disease (AD), the fundamental mechanisms underlying the development and maintenance of sleep disturbance in AD patients have yet to be elucidated. The aim of this study was to examine the correlation between regional cerebral blood flow (rCBF) and sleep disturbance in AD patients using technetium-99m hexamethylpropylene amine oxime single-photon emission computed tomography (SPECT). METHODS: A total of 140 AD patients were included in this cross-sectional study. Seventy patients were assigned to the AD with sleep loss (SL) group and the rest were assigned to the AD without SL group. SL was measured using the sleep subscale of the Neuropsychiatric Inventory. A whole-brain voxel-wise analysis of brain SPECT data was conducted to compare the rCBF between the two groups. RESULTS: The two groups did not differ in demographic characteristics, severity of dementia, general cognitive function, and neuropsychiatric symptoms, with the exception of sleep disturbances. The SPECT imaging analysis displayed decreased perfusion in the bilateral inferior frontal gyrus, bilateral temporal pole, and right precentral gyrus in the AD patients with SL group compared with the AD patients without SL group. It also revealed increased perfusion in the right precuneus, right occipital pole, and left middle occipital gyrus in the AD with SL group compared with the AD without SL group. CONCLUSIONS: The AD patients who experienced sleep disturbance had notably decreased perfusion in the frontal and temporal lobes and increased rCBF in the parietal and occipital regions. The findings of this study suggest that functional alterations in these brain areas may be the underlying neural correlates of sleep disturbance in AD patients.
Alzheimer Disease* ; Brain* ; Cerebrovascular Circulation ; Cognition ; Cross-Sectional Studies ; Dementia ; Frontal Lobe ; Humans ; Occipital Lobe ; Parietal Lobe ; Perfusion* ; Prefrontal Cortex ; Rabeprazole ; Temporal Lobe ; Tomography, Emission-Computed ; Tomography, Emission-Computed, Single-Photon