Geriatric Psychiatry, Department of Clinical Sciences, Lund University, Klinikgatan 22, 22185 Lund, Sweden.
BMC Neurol. 2011 Jan 26;11:13. doi: 10.1186/1471-2377-11-13.
The clinical presentation in progressive supranuclear palsy (PSP), an atypical parkinsonian disorder, includes varying degrees of frontal dysexecutive symptoms. Using diffusion tensor imaging (DTI) and tractography (DTT), we investigated whether diffusion changes and atrophy of the inferior fronto-occipital fasciculus (IFO) occurs in PSP and if these changes correlate with disease stage and clinical phenotype. The corticospinal tract (CST), which is often involved in PSP, was investigated for comparison.
DTI of the whole brain was performed with a 3 T MR scanner using a single shot-EPI sequence with diffusion encoding in 48 directions. Scans were obtained in patients with PSP (n = 13) and healthy age-matched controls (n = 12). DTT of the IFO and CST was performed with the PRIDE fibre tracking tool (Philips Medical System). Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) were calculated and correlated with disease stage and clinical phenotype.
In patients with PSP, significantly decreased FA and increased ADC was found in the frontal part of IFO compared with the medial and occipital parts of IFO, as well as compared to controls. Four of the thirteen patients with PSP showed a marked decrease in the number of tracked voxels in the frontal part of IFO. These findings were most pronounced in patients with severe frontal cognitive symptoms, such as dysexecutive problems, apathy and personality change. There was a strong correlation (r2 = -0.84; p < 0,001) between disease stage and FA and ADC values in the CST.
DTT for identification of neuronal tracts with subsequent measurement of FA and ADC is a useful diagnostic tool for demonstrating patterns of neuronal tract involvement in neurodegenerative disease. In selected tracts, FA and ADC values might act as surrogate markers for disease stage.
进行性核上性麻痹（PSP）是一种非典型帕金森病，其临床表现包括不同程度的额执行功能障碍。我们使用弥散张量成像（DTI）和轨迹（DTT）研究了下额枕束（IFO）的弥散变化和萎缩是否发生在 PSP 中，以及这些变化是否与疾病阶段和临床表型相关。同时还对常受累的皮质脊髓束（CST）进行了研究。
使用 3T 磁共振扫描仪对整个大脑进行 DTI 检查，采用单次激发 EPI 序列，以 48 个方向进行弥散编码。对 13 名 PSP 患者和 12 名年龄匹配的健康对照组进行了扫描。使用 PRIDE 纤维追踪工具对 IFO 和 CST 进行 DTT。计算各向异性分数（FA）和表观扩散系数（ADC），并与疾病阶段和临床表型相关。
与 IFO 的内侧和枕部相比，PSP 患者的 IFO 前部 FA 降低，ADC 升高，与对照组相比差异有统计学意义。13 名 PSP 患者中有 4 名患者 IFO 前部的跟踪体素数量明显减少。这些发现与严重的额认知症状患者（如执行功能障碍、冷漠和人格改变）的情况最为吻合。在 CST 中，疾病阶段与 FA 和 ADC 值之间存在强烈相关性（r2=-0.84，p<0.001）。
用于识别神经束的 DTT 以及随后的 FA 和 ADC 值测量是一种有用的诊断工具，可用于显示神经束在神经退行性疾病中的受累模式。在选定的束中，FA 和 ADC 值可能作为疾病阶段的替代标志物。
