Klockgether Thomas
Department of Neurology, University Hospital Bonn, Germany.
Handb Clin Neurol. 2012;103:253-62. doi: 10.1016/B978-0-444-51892-7.00015-2.
Sporadic adult-onset ataxia of unknown etiology (SAOA) denotes the non-hereditary degenerative adult-onset ataxia disorders that are distinct from multiple system atrophy (MSA). Rather than being a defined disease entity, SAOA has to be regarded as a group of disorders of unknown etiology that are defined by a common clinical syndrome and the exclusion of known disease causes. Epidemiological studies have revealed prevalence rates ranging from 2.2 to 8.4 per 100000, which are higher than those of hereditary ataxias. Clinically, SAOA is characterized by a slowly progressive cerebellar syndrome starting around the age of 50 years. About one-third of SAOA patients have either polyneuropathy or pyramidal tract involvement accompanying cerebellar ataxia. Cognitive impairment is not the rule, and, if present, is only mild. More than half of SAOA patients have signs of mild autonomic dysfunction that do not meet the criteria of severe autonomic failure required for a diagnosis of MSA. Neuropathological and imaging studies show an isolated cerebellar cortical degeneration with no or only mild brainstem involvement. There is no established therapy for SAOA.
散发性成人起病的病因不明性共济失调（SAOA）指的是与多系统萎缩（MSA）不同的非遗传性退行性成人起病的共济失调疾病。SAOA并非一种明确的疾病实体，而应被视为一组病因不明的疾病，这些疾病由共同的临床综合征以及排除已知病因来定义。流行病学研究显示，其患病率为每10万人中2.2至8.4例，高于遗传性共济失调。临床上，SAOA的特征是约50岁左右起病的缓慢进展性小脑综合征。约三分之一的SAOA患者在小脑共济失调的同时伴有多发性神经病或锥体束受累。认知障碍并非普遍现象，若存在也仅为轻度。超过一半的SAOA患者有轻度自主神经功能障碍的体征，但不符合MSA诊断所需的严重自主神经功能衰竭标准。神经病理学和影像学研究显示孤立的小脑皮质变性，无或仅有轻度脑干受累。目前尚无针对SAOA的确立疗法。
