We describe a patient with neurogenic orthostatic hypotension (nOH) after brainstem neurosurgery in whom baroreflex-cardiovagal function was normal despite baroreflex-sympathoneural failure. We also cite other conditions entailing differential alterations in the two efferent limbs of the baroreflex. Any condition involving nOH from selective loss of sympathetic noradrenergic innervation, interference with sympathetic pre-ganglionic transmission in the thoracolumbar spinal cord, sympathectomies, or attenuated intra-neuronal synthesis, storage, or release of norepinephrine would be expected to manifest with selective baroreflex-sympathoneural dysfunction. We advise caution in relying on indices of baroreflex-cardiovagal function for diagnosing nOH, since normal values for these indices do not exclude nOH.

我们描述了一名在脑干神经外科手术后患有神经源性体位性低血压 (nOH) 的患者，尽管压力反射交感神经衰竭，但压力反射心迷走神经功能正常。我们还引用了其他条件，导致压力反射的两个传出肢发生不同的改变。任何因交感神经去甲肾上腺素能神经支配选择性丧失、干扰胸腰段脊髓中交感神经节前传递、交感神经切除术或神经元内合成、储存或去甲肾上腺素释放减弱而导致的任何 nOH 病症都预计会表现为选择性压力反射-交感神经功能障碍。我们建议谨慎依赖压力反射-心迷走神经功能指标来诊断 nOH，因为这些指标的正常值不排除 nOH。