遗传性痉挛性截瘫并薄型胼胝体的MRI表现

Intracranial and Spinal MR Imaging Findings of Hereditary Spastic Paraparesis Associated with Thin Corpus Callosum

目的探讨遗传性痉挛性截瘫(hereditary spastic paraplegia,HSP)伴薄型胼胝体的颅脑和脊髓MRI特征,以期提高对该病的认识。方法回顾性分析5个家系8例临床和遗传学确诊为HSP伴薄型胼胝体患者的颅脑和脊髓MRI资料。分析每例患者的MRI特点,并分别测量胼胝体膝部、体部和压部的厚度,分别在C3和T2水平测量相应平面脊髓的前后径及横径,另选取20例在本院行颅脑平扫MRI及颈椎MRI的正常病例为对照组进行相应测量方法进行比较。结果 8例颅脑MRI均表现为胼胝体变薄,以膝部和体部明显,分别为(2.2±1.6)mm、(2.0±0.9)mm,与正常对照组比较差异有统计学意义(P<0.05);胼胝体压部未见明显变薄(P>0.05);C3、T2脊髓的前后径、横径明显小于对照组(P<0.05)。8例均出现双侧脑室周围白质内及额顶叶深部脑白质对称性异常信号灶,液体衰减反转恢复序列(FLAIR)呈高信号。7例有脑萎缩,7例有颈胸段脊髓萎缩且其中1例胸髓末段显示异常信号灶。结论 HSP伴薄型胼胝体的颅脑和脊髓具有典型的MRI特点,主要表现为胼胝体膝部及体部变薄、脑萎缩、侧脑室周围脑白质内及额顶叶深部脑白质对称性异常信号灶及脊髓萎缩。MRI对临床诊断和鉴别诊断有重要意义,但确诊还需结合临床表现和基因检查。

Objective To investigate the intracranial and spinal MRI features of hereditary spastic paraplegia associated with thin corpus callosum, so as to improve the diagnostic accuracy. Methods The MRI features of 8 cases in 5 families of hereditary spastic paraplegia associated with thin corpus callosum proved by clinic and genetics were analyzed retrospec- tively. The thickness of the body, genu, splenium of corpus callosum were measured respectively on the efilm workstation. Anteroposterior diameter,transverse diameter, cross sectional area of myeloid at the levels of vertebral body of C3 and T2 were measured respectively. MRI of 40 normal controls with matched age and sex were measured in the same methods. Results MRI showed thinning corpus callosum in 8 cases, especially at the body and genu of corpus callosum, with the thickness of （ 2.2 ±1.6） mm, （ 2.0 ± 0.9 ） mm respectively, and there were statistically significant differences between patients and controls. The thickness was （4.1 ±0. 9） mm at the splenium of corpus callosum, and there was no statistically signifieant difference between patients and controls. Abnormal high signal at FLAIR sequence was found in the white matter surrounding lateral ventricle in 8 cases. Cerebral atrophy was found in 7 cases, thoracic eord of myelatrophy was found in 7 cases, among them, one patient showed abnormal signal in thoracic cord. There were statistically significant differences of the anteroposterior diameters, transverse diameters and cross-sectional areas of myeloid at the C3 , T2 levels between patients and controls Conclusion There were typical MRI features of HSP-TCC, including the thinning of corpus callosum, brain atrophy, symmetric abnormal signal in the central intracerebroventricular white matter, and spinal cord atrophy. Recognizing the MRI findings may help to the clinical diagnosis and differential diagnosis of the disease. However the genetic test combined with clinical appearance stiU remained to obtain the ultimate diagnosis.