Memory dysfunction in type 2 diabetes mellitus correlates with reduced hippocampal CA1 and subiculum volumes / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Little attention has been paid to the role of subcortical deep gray matter (SDGM) structures in type 2 diabetes mellitus (T2DM)-induced cognitive impairment, especially hippocampal subfields. Our aims were to assess the in vivo volumes of SDGM structures and hippocampal subfields using magnetic resonance imaging (MRI) and to test their associations with cognitive performance in T2DM.</p><p><b>METHODS</b>A total of 80 T2DM patients and 80 neurologically unimpaired healthy controls matched by age, sex and education level was enrolled in this study. We assessed the volumes of the SDGM structures and seven hippocampal subfields on MRI using a novel technique that enabled automated volumetry. We used Mini-Mental State Examination and Montreal Cognitive Assessment (MoCA) scores as measures of cognitive performance. The association of glycosylated hemoglobin (HbA1c) with SDGM structures and neuropsychological tests and correlations between hippocampal subfields and neuropsychological tests were assessed by partial correlation analysis in T2DM.</p><p><b>RESULTS</b>Bilaterally, the hippocampal volumes were smaller in T2DM patients, mainly in the CA1 and subiculum subfields. Partial correlation analysis showed that the MoCA scores, particularly those regarding delayed memory, were significantly positively correlated with reduced hippocampal CA1 and subiculum volumes in T2DM patients. Additionally, higher HbA1c levels were significantly associated with poor memory performance and hippocampal atrophy among T2DM patients.</p><p><b>CONCLUSIONS</b>These data indicate that the hippocampus might be the main affected region among the SDGM structures in T2DM. These structural changes in the hippocampal CA1 and subiculum areas might be at the core of underlying neurobiological mechanisms of hippocampal dysfunction, suggesting that degeneration in these regions could be responsible for memory impairments in T2DM patients.</p>

Amplitude of low-frequency oscillations in Parkinson's disease: a 2-year longitudinal resting-state functional magnetic resonance imaging study / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Neuroimaging studies have found that functional changes exist in patients with Parkinson's disease (PD). However, the majority of functional magnetic resonance imaging (fMRI) studies in patients with PD are task-related and cross-sectional. This study investigated the functional changes observed in patients with PD, at both baseline and after 2 years, using resting-state fMRI. It further investigated the relationship between whole-brain spontaneous neural activity of patients with PD and their clinical characteristics.</p><p><b>METHODS</b>Seventeen patients with PD underwent an MRI procedure at both baseline and after 2 years using resting-state fMRI that was derived from the same 3T MRI. In addition, 20 age- and sex-matched, healthy controls were examined using resting-state fMRI. The fractional amplitude of low-frequency fluctuation (fALFF) approach was used to analyze the fMRI data. Nonlinear registration was used to model within-subject changes over the scanning interval, as well as changes between the patients with PD and the healthy controls. A correlative analysis between the fALFF values and clinical characteristics was performed in the regions showing fALFF differences.</p><p><b>RESULTS</b>Compared to the control subjects, the patients with PD showed increased fALFF values in the left inferior temporal gyrus, right inferior parietal lobule (IPL) and right middle frontal gyrus. Compared to the baseline in the 2 years follow-up, the patients with PD presented with increased fALFF values in the right middle temporal gyrus and right middle occipital gyrus while also having decreased fALFF values in the right cerebellum, right thalamus, right striatum, left superior parietal lobule, left IPL, left precentral gyrus, and left postcentral gyrus (P < 0.01, after correction with AlphaSim). In addition, the fALFF values in the right cerebellum were positively correlated with the Unified PD Rating Scale (UPDRS) motor scores (r = 0.51, P < 0.05, uncorrected) and the change in the UPDRS motor score (r = 0.61, P < 0.05, uncorrected).</p><p><b>CONCLUSIONS</b>The baseline and longitudinal changes of the fALFF values in our study suggest that dysfunction in the brain may affect the regions related to cortico-striato-pallido-thalamic loops and cerebello-thalamo-cortical loops as the disease progresses and that alterations to the spontaneous neural activity of the cerebellum may also play an important role in the disease's progression in patients with PD.</p>

Detection of siderotic nodules in the liver with susceptibility weighted imaging: correlations to serum ferritin, Child-Pugh grade and hyaluronic acid levels / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Chronic liver disease causes aberrant formation of fibrous tissue that impedes normal liver function, ultimately resulting in liver cirrhosis. Iron uptake can occur within the hepatic parenchyma or within the various nodules that form in a cirrhotic liver, termed siderotic nodules (SN). We aimed to investigate the diagnostic performance of susceptibility weighted imaging (SWI) for detection of SN in patients with liver cirrhosis, and to evaluate the potential of SN numbers for assessing the degree of hepatic iron deposition, liver function, and liver fibrosis stage.</p><p><b>METHODS</b>Ninety-one patients with chronic liver cirrhosis, who underwent megnetic resonance imagine (MRI) scanning in our department between November 2010 and April 2011, were included in the study. A 3.0T MRI scanner was used to acquire T1WI, T2WI, T2WI, and SWI images. The number of nodules, signal intensity ratio (SIR), and contrast noise ratio (CNR) were recorded and analyzed by chi-square and ANOVA statistical tests. Correlation analysis was performed to evaluate the correlations between the number of SN and Child-Pugh classification, ferritin and hyaluronic acid levels.</p><p><b>RESULTS</b>The sensitivity of SWI, T1WI, T2WI, and T2 WI for detecting SN was 62.5%, 12.1%, 24.2% and 41.8%, respectively. SWI detected significantly more nodules than routine T1WI, T2WI, and T2 WI procedures (P < 0.05). The SIR was the lowest in SWI (0.361 ± 0.209), as compared to T1WI (0.852 ± 0.163), T2WI (0.584 ± 0.172), and T2 WI (0.497 ± 0.196). The CNR was the highest in SWI (13.932 ± 5.637), as compared to T1WI (9.147 ± 5.785), T2WI (9.771 ± 5.490), and T2 WI (11.491 ± 4.573). The correlation coefficients of the number of SN with ferritin, Child-Pugh classification, and hyaluronic acid levels were 0.672, -0.055, and 0.163, respectively.</p><p><b>CONCLUSIONS</b>The sensitivity and contrast of SWI for detecting SN in patients with liver cirrhosis are higher than conventional MRI. The number of SN can help to assess the degree of iron deposition in patients with liver cirrhosis.</p>