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Objective: To investigate gray matter concentration changes in the brains ofnarcoleptic patients. Materials and Methods: Twenty-nine narcoleptic patient with cataplexy and 29age and sex-matched normal subjects (mean age, 31 years old) underwent volu-metric MRIs. The MRIs were spatially normalized to a standard T1 template andsubdivided into gray matter, white matter, and cerebrospinal fluid (CSF). Thesesegmented images were then smoothed using a 12-mm full width at half maxi-mum (FWHM) isotropic Gaussian kernel. An optimized voxel-based morphome-try protocol was used to analyze brain tissue concentrations using SPM2 (statisti-cal parametric mapping). A one-way analysis of variance was applied to the con-centration analysis of gray matter images. Results: Narcoleptics with cataplexy showed reduced gray matter concentra-tion in bilateral thalami, left gyrus rectus, bilateral frontopolar gyri, bilateral shortinsular gyri, bilateral superior frontal gyri, and right superior temporal and left infe-rior temporal gyri compared to normal subjects (uncorrected p < 0.001).Furthermore, small volume correction revealed gray matter concentration reduc-tion in bilateral nuclei accumbens, hypothalami, and thalami (false discovery ratecorrected p < 0.05). Conclusion: Gray matter concentration reductions were observed in brainregions related to excessive daytime sleepiness, cognition, attention, and memo-ry in narcoleptics with cataplexy.arcolepsy is characterized by excessive daytime sleepiness (EDS), adisruption of sleep-wake behavior, cataplexy (a sudden loss of muscletone provoked by emotional stimuli), and other rapid eye movement(REM) sleep phenomena, such as, sleep paralysis and hypnagogic hallucinations (1).Numerous investigations, including neuroimaging studies, have been performed tocharacterize the pathophysiology of narcolepsy. An abnormality of the pontine reticu-lar formation, where REM sleep is generated, was reported in the brain MRIs of threeidiopathic narcoleptic patients (2), whereas another study found no evidence of apontine lesion (3).Several voxel-based morphometry (VBM) studies of brain MRIs in narcoleptics haveproduced controversial results. One distinct VBM study revealed reduced gray matter(GM) concentrations in the hypothalamus and nucleus accumbens (4). A subsequentstudy failed to find any changes of GM concentrations in the hypothalamus (5).Another study found reductions in bilateral inferior temporal and frontal regions (6).Recently, GM loss in the prefrontal and frontomesial cortices was found, but could notprovide functional significance with respect to the relevance to the pathophysiology ofEun Yeon Joo, MD

Purpose To investigate structural brain changes and their relationship with cognitive function by determining the alterations of white matter integrity and changes in hippocampal volume that occur during chronic obstructive pulmonary disease (COPD). Materials and Methods Diffusion tensor images and 3D-T1 MR images were acquired in 13 male nonhypoxemic COPD patients and 13 age- and gender-matched healthy controls. Global probabilistic tractography was used to assess a total of 18 major tracts. We examined the association between the hippocampal volume and diffusivity parameters of white matter tracts. Results A significant difference in diffusion parameters between groups was identified for 11 white matter bundles (p < 0.05). No association was demonstrated between the normalized hippocampus volume and diffusion parameters among the participants. Significant associations between Korean version of the Mini-Mental State Examination (K-MMSE) scores and diffusivities were found for six tracts (p < 0.05). Of note, the mean diffusivity (MD) and redial diffusivity (RD) of the left superior longitudinal fasciculus parietal segment showed a significant negative correlation with the K-MMSE score (MD: r = −0.623, p = 0.001; RD: r = −0.408, p = 0.048). Conclusion Altered white matter integrity was demonstrated across regional white matter bundles, including the superior longitudinal fasciculus, in COPD patients, and it was related to cognitive function. Changes in the volume of the hippocampus should be investigated in further studies.

Objective: To identify changes in gray and white matter concentrations (GMC, WMC), and their relation to heterotopic neuron numbers in mesial temporal lobe epilepsy (mTLE). Materials and Methods: The gray matter or white matter concentrations of 16 left and 15 right mTLE patients who achieved an excellent surgical outcome were compared with those of 24 healthy volunteers for the left group and with 23 healthy volunteers for the right group, by optimized voxel-based morphometry using unmodulated and modulated images. A histologic count of heterotopic neurons was obtained in the white matter of the anterior temporal lobe originating from the patients’ surgical specimens. In addition, the number of heterotopic neurons were tested to determine if there was a correlation with the GMC or WMC. Results: The GMCs of the left and right mTLE groups were reduced in the ipsilateral hippocampi, bilateral thalami, precentral gyri, and in the cerebellum. The WMCs were reduced in the ipsilateral white matter of the anterior temporal lobe, bilateral parahippocampal gyri, and internal capsules, but increased in the pons and bilateral precentral gyri. The heterotopic neuron counts in the left mTLE group showed a positive correlation (r = 0.819, p < 0.0001) with GMCs and a negative correlation (r = - 0.839, p < 0.0001) with WMCs in the white matter of the anterior temporal lobe. Conclusion: The present study shows the abnormalities of the cortico-thalamo-hippocampal network including a gray matter volume reduction in the anterior frontal lobes and an abnormality of brain tissue concentration in the pontine area. Furthermore, heterotopic neuron numbers were significantly correlated with GMC or WMC in the left white matter of anterior temporal lobe.

Purpose: We wanted to develop a standard protocol for auditory functional magnetic resonance imaging (fMRI) for detecting blood oxygenation level-dependent (BOLD) responses at the cortical and subcortical auditory centers with using a 1.5-T MRI scanner. Materials and Methods: Fourteen normal volunteers were enrolled in the study. The subjects were stimulated by four repetitions of 32 sec each with broadband white noise and silent period blocks as a run (34 echo planar images [EPIs]). Multiple regression analysis for the individual analysis and one-sample t-tests for the group analysis were applied (FDR, p