Suzuki Junichiro, Nakamura Tomohiko, Hirayama Masaaki, Mizutani Yasuaki, Okada Akinori, Ito Mizuki, Watanabe Hirohisa, Sobue Gen
Department of Neurology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho Showa-ku Nagoya, 466-8550, Japan.
Department of Neurology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho Showa-ku Nagoya, 466-8550, Japan; Department of Pathophysiological Laboratory Science, Nagoya University Graduate School of Medicine, Nagoya, Japan.
Parkinsonism Relat Disord. 2015 Aug;21(8):917-22. doi: 10.1016/j.parkreldis.2015.05.023. Epub 2015 May 29.
Most patients with multiple system atrophy (MSA) develop autonomic dysfunction; however, orthostatic hypotension is not always present. Failure of the vasoconstrictor response is thought to be responsible for orthostatic hypotension, but the degree of impairment of this response in patients with MSA is unclear. We assessed autonomic function in patients with MSA by evaluating the vasoconstrictive response during a head-up tilt test and determining its relationship to orthostatic hypotension. As an additional examination, the efficacy of norepinephrine in treating orthostatic hypotension was also assessed.
The study included 82 patients with MSA and 28 controls. Measures of total peripheral resistance were obtained during a head-up tilt test. Norepinephrine was administered to the patients lacking a vasoconstrictive response to evaluate its ability to treat orthostatic hypotension.
At a 60° tilt, orthostatic hypotension occurred in 47.6% of the patients and 0% of controls. Reduction in total peripheral resistance from baseline at a 60° tilt was observed in 69.5% of the patients and 0% of controls. In patients with MSA, changes in systolic blood pressure from the baseline at a 60° tilt correlated positively with changes in the total peripheral resistance (r = 0.69, p < 0.0001). Norepinephrine prevented the reduction of total peripheral resistance and development of orthostatic hypotension.
A large number of patients with MSA with and without orthostatic hypotension have an impaired peripheral vasoconstrictive response, suggesting a high frequency of cardiovascular dysautonomia with an associated risk of developing orthostatic hypotension. A norepinephrine infusion was effective for treating orthostatic hypotension.
多数多系统萎缩（MSA）患者会出现自主神经功能障碍；然而，体位性低血压并非总是存在。血管收缩反应功能衰竭被认为是体位性低血压的病因，但MSA患者中这种反应的受损程度尚不清楚。我们通过评估头高位倾斜试验期间的血管收缩反应并确定其与体位性低血压的关系，来评估MSA患者的自主神经功能。作为一项附加检查，还评估了去甲肾上腺素治疗体位性低血压的疗效。
该研究纳入了82例MSA患者和28例对照。在头高位倾斜试验期间获取总外周阻力的测量值。对缺乏血管收缩反应的患者给予去甲肾上腺素，以评估其治疗体位性低血压的能力。
在60°倾斜时，47.6%的患者出现体位性低血压，而对照组无一人出现。60°倾斜时，69.5%的患者总外周阻力较基线降低，而对照组无一人降低。在MSA患者中，60°倾斜时收缩压相对于基线的变化与总外周阻力的变化呈正相关（r = 0.69，p < 0.0001）。去甲肾上腺素可防止总外周阻力降低和体位性低血压的发生。
大量有或无体位性低血压的MSA患者存在外周血管收缩反应受损，提示心血管自主神经功能障碍的发生率较高，且伴有发生体位性低血压的风险。静脉输注去甲肾上腺素治疗体位性低血压有效。
