A resting-state functional connectivity study in patients at high risk for sudden unexpected death in epilepsy.

OBJECTIVE: Seizure-related respiratory and cardiac dysfunctions were once thought to be the direct cause of sudden unexpected death in epilepsy (SUDEP), but both may be secondary to postictal cerebral inhibition. An important issue that has not been explored to date is the neural network basis of cerebral inhibition. Our aim was to investigate the features of neural networks in patients at high risk for SUDEP using a blood oxygen level-dependent (BOLD) resting-state functional connectivity (FC) approach. SUBJECTS AND METHODS: Resting-state functional magnetic resonance imaging (Rs-fMRI) data were recorded from 13 patients at high risk for SUDEP and 12 patients at low risk for SUDEP. Thirteen cerebral regions that are closely related to cardiorespiratory activity were selected as regions of interest (ROIs). The ROI-wise resting-state FC analysis was compared between the two groups. RESULTS: Compared with patients at low risk for SUDEP, patients at high risk exhibited significant reductions in the resting-state FC between the pons and the right thalamus, the midbrain and the right thalamus, the bilateral anterior cingulate cortex (ACC) and the right thalamus, and the left thalamus and the right thalamus. CONCLUSIONS: This investigation is the first to use neuroimaging methods in research on the mechanism of SUDEP and demonstrates the abnormally decreased resting-state FC in the ACC-thalamus-brainstem circuit in patients at high risk for SUDEP. These findings highlight the need to understand the fundamental neural network dysfunction in SUDEP, which may fill the missing link between seizure-related cardiorespiratory dysfunction and SUDEP, and provide a promising neuroimaging biomarker for risk prediction of SUDEP.

[Application of black tea as a negative oral contrast in magnetic resonance cholangiopancreatography (MRCP)].

OBJECTIVE: To investigate the feasibility of using black tea as a gastrointestinal oral negative contrast agent to null the signal from fluid in bowel during MR cholangiopancreatography (MRCP). METHODS: (1) 15 different drinks were scanned with MRCP, T2-map and T1-map in vitro to identify the most suitable drink for MRCP. (2) 10 volunteers were scanned by MRCP prior to and 5, 10, 15 min after tea consumptions to identify the optimal delay time. (3) 20 patients were scanned with MRCP prior to and 5 min after tea consumptions. The signal intensity (SI) and signal-to-noise ratio (SNR) of stomach, duodenum, liver-parenchyma, common bile duct (CBD), pancreatic duct (PD) and gall bladder (GB); the singal loss of stomach and duodenum; and the image quality of ampulla of vater (AV), intrahepatic ducts (IHD), hepatic duct, CBD, PD and GB were analyzed with Siemens Workstation. RESULTS: (1) Lipton black-tea was identified as the optimal drink in vitro. (2) There were no significant differences in MRCP among the 3 delay times in volunteer tests. (3) The SI, SNR and SI loss of stomach and duodenum, and the image quality of CBD, PD, GB and AV showed a significant improvement of MRCP after tea consumptions (P < 0.05). But tea consumptions made no significant differences in the image quality of IHD and hepatic duct, and the SI and SNR of liver, CBD, GB and PD (P > 0.05). CONCLUSION: As a simple, cheap and safe drink, black tea can be widely used to reduce signal intensity of gastrointestinal tract and provide improved image of MRCP.

The thalamic ultrastructural abnormalities in paroxysmal kinesigenic choreoathetosis: a diffusion tensor imaging study.

Paroxysmal kinesigenic choreoathetosis (PKC) is a rare neurologic disorder. There are not apparent morphological changes in patients with idiopathic PKC. The purpose of this study is to determine whether ultrastructural changes are in the brain of patients with idiopathic PKC using diffusion tensor imaging. From May 2007 to August 2008, seven patients with idiopathic PKC were included. The mean age at initial onset was 11.7 +/- 3.1 (range 8-17) years, and the mean disease duration was 6.9 +/- 5.1 (range 1-14) years. Seven subjects of an age- and sex-matched control group were recruited. DTI data were obtained with a 3-T scanner. Fractional anisotropy (FA) and mean diffusivity (MD) were obtained in eight brain regions of interest. Patients with idiopathic PKC had significantly higher FA values than controls in the right thalamus (P < 0.05 Bonferroni corrected). Patients also had lower MD values than controls in the left thalamus (P < 0.05 Bonferroni corrected). FA and MD values were not significantly correlated with age of onset, gender, frequency of attack and duration of the disease. The results showed that in patients with idiopathic PKC, diffusion tensor imaging discloses distinct ultrastructural abnormalities in the thalamus. DTI is a sensitive neuroradiologic technique for detecting cerebral alterations in patients even without visible lesions on conventional MRI.

Neuroanatomical differences between familial and sporadic schizophrenia and their parents: an optimized voxel-based morphometry study.

Symptomatic differences have been reported between patients with familial and sporadic schizophrenia. The present study examined neuroanatomical differences between the two subgroups and their parents using voxel-based morphometry. High-resolution T1-weighted images were obtained using 3 Tesla magnetic resonance imaging from 20 patients with schizophrenia (familial subgroup, n=10; sporadic subgroup, n=10), 20 of their parents (familial subgroup, n=10; sporadic subgroup, n=10) and 20 healthy volunteers. Gray matter density (GMD) was compared between groups on a voxel-by-voxel basis. Compared with the sporadic patients, the familial patients had significantly reduced GMD in the thalamus bilaterally. Reduction of GMD in bilateral thalami was also found in familial parents in comparison with sporadic parents. Compared with controls, both familial and sporadic patients had lower GMD involving bilateral insula, right temporal lobe, right occipital lobe, left lenticular nucleus and right cerebellum. However, only familial patients showed lower GMD than controls in the right thalamus. Compared with controls, only familial parents showed lower GMD in the right insula extending to the right temporal lobe and the right parietal lobule. The present data suggest that familial schizophrenia is associated with more severe structural abnormalities than sporadic schizophrenia, especially in the thalamus.