Duvoisin R C
Adv Neurol. 1984;41:5-12.
The OPCAs are not, as Dejerine and Thomas (6) and subsequent writers have suggested, a unitary morbid entity. They comprise a heterogeneous group of disorders sharing certain major clinical and morphologic features with the hereditary and acquired ataxias and with the extrapyramidal system disorders, such as Parkinson's disease and the hereditary and acquired choreas, yet distinct from both these general groups of neurodegenerative diseases. Some of the OPCAs are sharply defined morbid entities of known etiology identified on combined genetic and clinical grounds or by a unique biochemical defect; most are of uncertain provenance and may themselves represent a collection of multiple, as yet undetermined entities. The nosologic concept of OPCA survives today in part because of its (Formula: see text) clinical usefulness in categorizing patients with mixed cerebellar and extrapyramidal syndromes and its importance in the differential diagnosis of both extrapyramidal and cerebellar disorders.
橄榄体脑桥小脑萎缩（OPCAs）并不像德热里纳（Dejerine）和托马斯（Thomas）（6）以及后来的作者所认为的那样，是一种单一的病态实体。它们是一组异质性疾病，与遗传性和获得性共济失调以及锥体外系疾病（如帕金森病、遗传性和获得性舞蹈病）具有某些共同的主要临床和形态学特征，但又不同于这两组神经退行性疾病。一些OPCAs是基于遗传学和临床综合依据或独特的生化缺陷而明确界定的已知病因的病态实体；大多数OPCAs的病因不明，可能本身就代表了多种尚未确定的实体的集合。OPCAs的疾病分类概念如今仍然存在，部分原因在于它在对伴有小脑和锥体外系混合综合征的患者进行分类方面具有临床实用性，以及在锥体外系和小脑疾病的鉴别诊断中具有重要意义。
