Hedera Peter
Department of Neurology, Vanderbilt University, Nashville, TN, USA.
Handb Clin Neurol. 2016;136:769-85. doi: 10.1016/B978-0-444-53486-6.00038-7.
Hereditary and metabolic myelopathies are a heterogeneous group of neurologic disorders characterized by clinical signs suggesting spinal cord dysfunction. Spastic weakness, limb ataxia without additional cerebellar signs, impaired vibration, and positional sensation are hallmark phenotypic features of these disorders. Hereditary, and to some extent, metabolic myelopathies are now recognized as more widespread systemic processes with axonal loss and demyelination. However, the concept of predominantly spinal cord disorders remains clinically helpful to differentiate these disorders from other neurodegenerative conditions. Furthermore, metabolic myelopathies are potentially treatable and an earlier diagnosis increases the likelihood of a good clinical recovery. This chapter reviews major types of degenerative myelopathies, hereditary spastic paraplegia, motor neuron disorders, spastic ataxias, and metabolic disorders, including leukodystrophies and nutritionally induced myelopathies, such as vitamin B12, E, and copper deficiencies. Neuroimaging studies usually detect a nonspecific spinal cord atrophy or demyelination of the corticospinal tracts and dorsal columns. Brain imaging can be also helpful in myelopathies caused by generalized neurodegeneration. Given the nonspecific nature of neuroimaging findings, we also review metabolic or genetic assays needed for the specific diagnosis of hereditary and metabolic myelopathies.
遗传性和代谢性脊髓病是一组异质性神经系统疾病，其临床体征提示脊髓功能障碍。痉挛性肌无力、无其他小脑体征的肢体共济失调、振动觉受损和位置觉障碍是这些疾病的标志性表型特征。遗传性以及在一定程度上的代谢性脊髓病现在被认为是更广泛的系统性疾病，伴有轴突丢失和脱髓鞘。然而，主要为脊髓疾病的概念在临床上仍有助于将这些疾病与其他神经退行性疾病区分开来。此外，代谢性脊髓病有可能得到治疗，早期诊断可增加临床良好恢复的可能性。本章回顾了退行性脊髓病、遗传性痉挛性截瘫、运动神经元疾病、痉挛性共济失调和代谢性疾病的主要类型，包括脑白质营养不良和营养性脊髓病，如维生素B12、E和铜缺乏症。神经影像学研究通常可检测到非特异性脊髓萎缩或皮质脊髓束和后索的脱髓鞘。脑成像对由全身性神经退行性变引起的脊髓病也有帮助。鉴于神经影像学结果的非特异性，我们还回顾了遗传性和代谢性脊髓病特异性诊断所需的代谢或基因检测。
