Autonomic Medicine Section, Clinical Neurosciences Program, Division of Intramural Research, National Institute of Neurological Disorders and Stroke, 9000 Rockville Pike MSC-1620, Bethesda, MD, 20892, USA.
Department of Neurology, University of Utah, Salt Lake City, UT, 84108, USA.
Clin Auton Res. 2021 Dec;31(6):677-684. doi: 10.1007/s10286-021-00829-y. Epub 2021 Oct 20.
Pure autonomic failure (PAF) is a rare disease in which chronic neurogenic orthostatic hypotension (nOH) dominates the clinical picture. Longitudinal studies have reported that PAF can phenoconvert to a central synucleinopathy with motor or cognitive involvement-i.e., to Parkinson disease (PD), dementia with Lewy bodies (DLB), or multiple system atrophy (MSA). These studies have classified patients clinically as having PAF based on nOH without an identified secondary cause or clinical evidence of motor or cognitive impairment due to central neurodegeneration. This approach lumps together two nOH syndromes that are pathologically and neurochemically distinct. One is characterized by intraneuronal cytoplasmic alpha-synuclein aggregates (i.e., Lewy bodies) and degeneration of postganglionic sympathetic neurons, as in PD and DLB; the other is not, as in MSA. Clinical and postmortem data show that the form of PAF that involves sympathetic intraneuronal synucleinopathy and noradrenergic deficiency can phenoconvert to PD or DLB-but not to MSA. Conversely, PAF without these features leaves open the possibility of premotor MSA.
单纯自主神经衰竭（PAF）是一种罕见的疾病，其特征为慢性神经源性直立性低血压（nOH）占主导地位。纵向研究报告称，PAF 可能表型转化为伴有运动或认知障碍的中枢突触核蛋白病，即帕金森病（PD）、路易体痴呆（DLB）或多系统萎缩（MSA）。这些研究根据无明确继发性原因或由于中枢神经退行性病变导致运动或认知障碍的临床证据，将 nOH 患者临床分类为 PAF。这种方法将两种病理和神经化学上明显不同的 nOH 综合征混为一谈。一种以神经元内细胞质 α-突触核蛋白聚集（即路易体）和节后交感神经元变性为特征，如在 PD 和 DLB 中；另一种则不然，如在 MSA 中。临床和尸检数据表明，涉及交感神经元内突触核蛋白病和去甲肾上腺素能缺陷的 PAF 形式可能表型转化为 PD 或 DLB，但不会转化为 MSA。相反，没有这些特征的 PAF 则存在前运动性 MSA 的可能性。
