Abnormal white matter integrity in the corpus callosum among smokers: tract-based spatial statistics.

In the present study, we aimed to investigate the difference in white matter between smokers and nonsmokers. In addition, we examined relationships between white matter integrity and nicotine dependence parameters in smoking subjects. Nineteen male smokers were enrolled in this study. Eighteen age-matched non-smokers with no current or past psychiatric history were included as controls. Diffusion tensor imaging scans were performed, and the analysis was conducted using a tract-based special statistics approach. Compared with nonsmokers, smokers exhibited a significant decrease in fractional anisotropy (FA) throughout the whole corpus callosum. There were no significant differences in radial diffusivity or axial diffusivity between the two groups. There was a significant negative correlation between FA in the whole corpus callosum and the amount of tobacco use (cigarettes/day; R = - 0.580, p = 0.023). These results suggest that the corpus callosum may be one of the key areas influenced by chronic smoking.

Diagnosis of intracranial hemorrhagic lesions: comparison between 3D-SWAN (3D T2*-weighted imaging with multi-echo acquisition) and 2D-T2*-weighted imaging.

BACKGROUND: 3D-susceptibility-weighted angiography (SWAN) can produce high-resolution images that yield excellent susceptibility-weighted contrast at a relatively short acquisition time. PURPOSE: To compare SWAN- and 2D-T2*-weighted gradient-echo images (T2*-WI) for their sensitivity in the depiction of cerebral hemorrhagic lesions. MATERIAL AND METHODS: We subjected 75 patients with suspected cerebral hemorrhagic lesions to SWAN and T2*-WI at 3T. We first measured the contrast-to-noise ratio (CNR) using an agar phantom that contained different concentrations of superparamagnetic iron oxide (SPIO). The acquisition time for SWAN and T2*-WI was similar (182 vs. 196 s). Neuroradiologists compared the two imaging methods for lesion detectability and conspicuity. RESULTS: The CNR of the phantom was higher on SWAN images. Of the 75 patients, 50 were found to have a total of 278 cerebral hemorrhagic lesions (microbleeds, n = 229 [82.4%]; intracerebral hemorrhage, n = 18 [6.5%]; superficial siderosis, n = 13 [4.7%]; axonal injuries, n = 8 [2.9%]; subarachnoid hemorrhage [SAH] or brain contusion, n = 3 each [1.0%]; subdural hematoma, n = 2 [0.7%]; cavernous hemangioma or dural arterteriovenous fistula, n = 1 each [0.4%]). In none of the lesions was the SWAN sequence inferior to T2*-WI with respect to lesion detectability and conspicuity. In fact, SWAN yielded better lesion conspicuity in patients with superficial siderosis and SAH: it detected significantly more lesions than T2*-WI (P < 0.01) and it was particularly useful for the detection of microbleeds and lesions near the skull base. CONCLUSION: SWAN is equal or superior to standard T2*-WI for the diagnosis of various cerebral hemorrhagic lesions. Because its acquisition time is reasonable it may replace T2*-WI.

Plasma levels of 3-methoxy-4-hydroxyphenylglycol are associated with microstructural changes within the cerebellum in the early stage of first-episode schizophrenia: a longitudinal VBM study.

The aims of this study are to determine how the interval changes of the brain structures in the early stage of first-episode schizophrenia relate to the interval changes in the clinical data, including the clinical symptoms of schizophrenia and catecholaminergic measures (plasma homovanillic acid [HVA] and 3-methoxy-4-hydroxyphenylglycol [MHPG]). Regional brain volumes and fractional anisotropy (FA)/mean diffusivity (MD) with diffusion tensor imaging (DTI) were measured at baseline and 6-month follow-up in a 3T magnetic resonance imaging (MRI) system in a cohort of 16 schizophrenic patients, who were in their first episode at the time of baseline MRI. At the time of baseline and follow-up MRI, all 16 patients underwent evaluations that included a psychopathological assessment (Positive and Negative Syndrome Scale [PANSS]) and peripheral catecholaminergic measures (plasma MHPG or HVA). For interval changes between baseline and follow-up MRI data (morphological change, MD, and FA), the correlation/regression analysis was performed as a series of single regression correlations in Statistical Parametric Mapping 5, with the interval changes in PANSS or plasma HVA and MHPG as the covariates of interest. Positive and inverse correlations contrasts were created, and in this preliminary analysis, a family-wise error-corrected threshold of P<0.05 was considered significant. In the correlation/regression analysis, a positive correlation between the FA in the right cerebellar vermis and the MHPG was observed. No significant correlations between the brain volume or MD and any laboratory data (plasma HVA and MHPG) were found. During the 6-month follow-up in the early stage of first-episode schizophrenia, the MHPG changes were correlated with the microstructural FA changes in the cerebellum, which may reflect the functional connections of the noradrenergic system in the cerebellum.

Delineation of optic nerves and chiasm in close proximity to large suprasellar tumors with contrast-enhanced FIESTA MR imaging.

PURPOSE: To evaluate whether contrast material-enhanced (CE) fast imaging employing steady-state acquisition (FIESTA) can depict the anterior optic pathways in patients with large suprasellar tumors. MATERIALS AND METHODS: Institutional review board approval was obtained. Twenty-eight patients with large suprasellar tumors undergoing surgical treatment (19 pituitary adenomas, six meningiomas, and three additional miscellaneous tumors) underwent preoperative magnetic resonance (MR) imaging, including CE FIESTA, at 3.0 T. Two radiologists assessed the visibility of five segments of the optic pathways (bilateral optic nerves and optic tracts, optic chiasm) with CE FIESTA and conventional MR imaging, including thin-section coronal T2-weighted imaging and CE T1-weighted imaging, by using a three-point scale. Moreover, the preoperative signal intensity of the optic pathways was correlated with pre- and postoperative visual impairment to determine whether high signal intensity at CE FIESTA is predictive of persistence of visual impairment after surgery. The χ(2) test was used to compare scores assigned to CE FIESTA and conventional MR images. RESULTS: The percentage of anterior optic pathways rated as visible was significantly higher with CE FIESTA than with conventional MR imaging (100% [140 of 140 segments] vs 78% [109 of 140 segments], P < .05). Thirty-one of the 140 segments (22%) were not depicted with conventional MR imaging; all of these 31 segments were visualized with CE FIESTA. For 12 patients who underwent transcranial surgery, the anatomic locations of the optic pathways at CE FIESTA were compatible with the surgical findings. CE FIESTA helped predict persistent visual impairment after surgical treatment with a sensitivity of 75% (three of four patients) and a specificity of 96% (23 of 24 patients). The accuracy of CT FIESTA in the prediction of visual loss was significantly higher than that of T2-weighted imaging (93% [26 of 28 patients] vs 50% [14 of 28 patients], P < .05). CONCLUSION: CE FIESTA is useful for the preoperative localization of the anterior optic pathways in patients with large suprasellar tumors and offers the potential to predict persistent visual impairment after decompression.

Six-month treatment with atypical antipsychotic drugs decreased frontal-lobe levels of glutamate plus glutamine in early-stage first-episode schizophrenia.

OBJECTIVE: To study the effects of treatment with atypical antipsychotic drugs on brain levels of glutamate plus glutamine in early-stage first-episode schizophrenia. PARTICIPANTS: Sixteen patients (eight males, eight females; aged 30 ± 11 years) completed the study. METHODS: We used administered 6 months of atypical antipsychotic drugs and used proton magnetic resonance spectroscopy to evaluate the results. RESULTS: We found that the administration of atypical antipsychotic drugs for 6 months decreased the glutamate plus glutamine/creatine ratio in the frontal lobe. These results suggest that the administration of atypical antipsychotic drugs for at least 6 months decreased glutamatergic neurotransmissions in the frontal lobe in early-stage first-episode schizophrenia, but there was no difference in frontal-lobe levels between patients and control subjects before administration. CONCLUSION: Taking these findings into account, the glutamatergic and GABAergic neurons are implicated in early-stage first-episode schizophrenia, but in complex ways.

No alterations of brain GABA after 6 months of treatment with atypical antipsychotic drugs in early-stage first-episode schizophrenia.

We investigated the effects of atypical antipsychotic drugs on GABA concentrations in early-stage, first-episode schizophrenia patients. Sixteen (8 males, 8 females; age, 30±11 years old) patients were followed up for six months. We also included 18 sex- and age-matched healthy control subjects. All patients were treated with atypical antipsychotic drugs (5 patients with risperidone, 5 patients with olanzapine, 4 patients with aripiprazole, and 2 patients with quetiapine). In all three regions measured (frontal lobe, left basal ganglia, and parieto-occipital lobe), no differences in GABA concentrations were observed in a comparison of pre-treatment levels and those six months after treatment. These results suggest that relatively short-term treatment with atypical antipsychotic drugs may not affect GABAergic neurotransmission; however, it is also possible that such treatment prevents further reductions in brain GABA levels in people with early-stage, first-episode schizophrenia.