Erichsen A K, Server A, Landrø N I, Sandvik L, Tallaksen C M E
Department of Neurology, Ullevål University Hospital, Oslo, Norway.
J Neurol Sci. 2009 Feb 15;277(1-2):124-9. doi: 10.1016/j.jns.2008.10.030. Epub 2008 Dec 12.
The hereditary spastic paraplegias (HSP) are heterogeneous neurodegenerative disorders characterized by progressive spasticity and weakness in the lower limbs. Axonal loss in the long corticospinal tracts has been shown. Supraspinal symptoms and findings in the most common dominant HSP type, SPG4, support the theory that the disease also causes cerebral neuronal damage in specific parts of the brain. To investigate whether SPG4-HSP is associated with neuronal biochemical changes detectable on MR spectroscopy (MRS), single-voxel proton MRS of the brain was performed in eight subjects from four families with genetically confirmed SPG4-type HSP and eight healthy age-matched controls. Volumes of interest (VOI) were located in the frontal white matter and motor cortex. N-acetyl-aspartate-to-creatine ratio (NAA/Cr), N-acetyl-aspartate-to-choline (NAA/Cho), cholin to creatin (Cho/Cr) and myo-inositol-to-creatine (Ins/Cr) ratios were calculated for both locations. Neuropsychological tests were performed to support the neuroradiological findings. The Cho/Cr ratio in motor cortex (MC) of SPG4-HSP subjects was significantly lower than in controls. This reduction of the Cho/Cr ratio in SPG4 subjects was significantly associated with age-related verbal learning- and memory (CVLT) reduction. Our findings support involvement of motor cortex in SPG4-HSP. Proton MRS could be a useful tool for detecting metabolite abnormalities in areas of brain that appear normal on MRI. Cho/Cr ratio may be a marker of neurodegenerative process in SPG4-HSP.
遗传性痉挛性截瘫（HSP）是一组异质性神经退行性疾病，其特征为下肢进行性痉挛和无力。已有研究表明皮质脊髓长束存在轴突损失。在最常见的显性HSP类型SPG4中，脊髓以上的症状和发现支持了该疾病也会导致大脑特定区域神经元损伤的理论。为了研究SPG4-HSP是否与磁共振波谱（MRS）可检测到的神经元生化变化相关，对来自四个家族的八名经基因确诊为SPG4型HSP的受试者和八名年龄匹配健康对照者进行了脑部单体素质子MRS检查。感兴趣区（VOI）位于额叶白质和运动皮层。计算了两个部位的N-乙酰天门冬氨酸与肌酸比值（NAA/Cr）、N-乙酰天门冬氨酸与胆碱比值（NAA/Cho）、胆碱与肌酸比值（Cho/Cr）以及肌醇与肌酸比值（Ins/Cr）。进行了神经心理学测试以支持神经放射学检查结果。SPG4-HSP受试者运动皮层（MC）的Cho/Cr比值显著低于对照组。SPG4受试者中Cho/Cr比值的降低与年龄相关的言语学习和记忆（CVLT）下降显著相关。我们的研究结果支持运动皮层参与SPG4-HSP。质子MRS可能是检测MRI上看似正常的脑区代谢物异常的有用工具。Cho/Cr比值可能是SPG4-HSP神经退行性过程的一个标志物。
