Vora Maulik, Kumar Suresh, Sharma Sanjiv, Sharma Sudhir, Makhaik Sushma, Sood R G
Department of Radiodiagnosis and Imaging, Indira Gandhi Medical College, Shimla, Himachal Pradesh, India.
Department of Neurology, Indira Gandhi Medical College, Shimla, Himachal Pradesh, India.
J Neurosci Rural Pract. 2016 Jan-Mar;7(1):102-8. doi: 10.4103/0976-3147.165423.
Amyotrophic lateral sclerosis (ALS) is a fatal and most common motor neuron disease, caused by progressive loss of motor neurons. Diffusion tensor imaging (DTI) and magnetic resonance spectroscopic (MRS) studies detect pathological changes in neuronal fibers in vivo. We evaluated the role of DTI and MRS in early course of the disease, which may prove beneficial in the early diagnosis and better management.
Twenty-one patients with ALS and 13 age-matched controls received 1.5T DTI and three-dimensional multi-voxel MRS. Fractional anisotropy (FA), apparent diffusion coefficient, N-acetyl aspartate (NAA)/Creatine (Cr), and NAA/Choline (Ch) ratios were analyzed in various regions of the brain and compared with healthy controls. ALS patients were classified as definite, possible, and probable category, and patients were also studied in limb versus bulbar onset.
Decreased FA and increase mean diffusivity values in regions of corticospinal tract (CST) and corpus callosum (CC) was consistent finding in definite and probable disease category (P < 0.05). In possible disease, CC involvement was not significant. NAA/Cr and NAA/Ch ratios were lower in CC and regions of CST. However, in possible disease, CC involvement was not significant, while regions of CST were showing significant reduction in NAA/Cr and NAA/Ch ratios (P < 0.05).
DTI and MRS detect changes associated with ALS even in the early phase of the disease. Bulbar onset and limb onset ALS patients show different pattern of involvement. Extramotor involvement suggested by CC involvement is a feature seen in bulbar onset patient and can suggest poor outcome in such patients. The present findings may be helpful for designing further studies in the direction of more early diagnosis of disease and its management.
肌萎缩侧索硬化症（ALS）是一种致命且最常见的运动神经元疾病，由运动神经元的进行性丧失引起。扩散张量成像（DTI）和磁共振波谱（MRS）研究可在体内检测神经元纤维的病理变化。我们评估了DTI和MRS在该疾病早期病程中的作用，这可能对早期诊断和更好的治疗有益。
21例ALS患者和13例年龄匹配的对照者接受了1.5T DTI和三维多体素MRS检查。分析了大脑各个区域的分数各向异性（FA）、表观扩散系数、N-乙酰天门冬氨酸（NAA）/肌酸（Cr）以及NAA/胆碱（Ch）比值，并与健康对照者进行比较。ALS患者被分为确诊、可能和疑似类别，还对肢体起病与延髓起病的患者进行了研究。
在确诊和疑似疾病类别中，皮质脊髓束（CST）和胼胝体（CC）区域的FA降低和平均扩散率值增加是一致的发现（P < 0.05）。在可能的疾病中，CC受累不显著。CC和CST区域的NAA/Cr和NAA/Ch比值较低。然而，在可能的疾病中，CC受累不显著，而CST区域的NAA/Cr和NAA/Ch比值显著降低（P < 0.05）。
DTI和MRS即使在疾病早期也能检测到与ALS相关的变化。延髓起病和肢体起病的ALS患者表现出不同的受累模式。CC受累提示的运动外受累是延髓起病患者的一个特征，可提示此类患者预后不良。目前的发现可能有助于在疾病更早期诊断及其治疗方向上设计进一步的研究。
