Omary Rawan, Bockisch Christopher J, Landau Klara, Kardon Randy H, Weber Konrad P
Department of Ophthalmology, University Hospital Zurich, University of Zurich, Zurich, Switzerland.
Department of Neurology, University Hospital Zurich, University of Zurich, Zurich, Switzerland.
Front Neurol. 2019 Feb 21;10:107. doi: 10.3389/fneur.2019.00107. eCollection 2019.
Patients with suspected Horner's syndrome having equivocal pupil dilation lag and pharmacologic testing may undergo unnecessary MR imaging and work up in the case of false positive pupil test results. Our goal was to increase the diagnostic accuracy of pupillometry by accentuating the inter-ocular asymmetry of sympathetic innervation to the iris dilator with surface electrical stimulation of the median nerve using a standard electromyography machine. We hypothesized that an accentuated difference in sympathetic response between the two eyes would facilitate the diagnosis of Horner's syndrome. Eighteen patients with pharmacologically proven Horner's syndrome were compared to ten healthy volunteers tested before and after monocular instillation of 0.2% brimonidine tartrate ophthalmic solution to induce pharmacological Horner's syndrome. Pupillary responses were measured with binocular pupillometry in response to sympathetic activation by electrical stimulation of the median nerve in darkness and at various times after extinction of a light stimulus. Sudomotor sympathetic responses from the palm of the stimulated arm were recorded simultaneously. In subjects with Horner's syndrome and pharmacologically induced unilateral sympathetic deficit, electrical stimulation in combination with the extinction of light greatly enhanced the anisocoria during the evoked pupil dilation, while there was no significant increase in anisocoria in healthy subjects. The asymmetry of the sympathetic response was greatest when the electrical stimulus was given 2 s after termination of the light or under constant low light conditions. When given 2 s after termination of light, the electrical stimulation increased the mean anisocoria from 1.0 to 1.2 mm in Horner's syndrome ( = 0.01) compared to 0.22-0.26 mm in healthy subjects ( = 0.1). In all subjects, the maximal anisocoria induced by the electrical stimulation appeared within a 2 s interval after the stimulus. Correspondingly, the largest change in anisocoria between light and dark without electrical stimulation was seen between 3 and 4 s after light-off. While stronger triple stimulation further enhanced the anisocoria, it was less well tolerated. Electrical stimulation 2 s after light-off greatly enhances the sensitivity of pupillometry for diagnosing Horner's syndrome. This new method may help to rule in or rule out a questionable Horner's syndrome, especially if the results of topical pharmacological testing are inconclusive.
疑似霍纳综合征且瞳孔散大滞后不明确以及药物测试结果存疑的患者，若瞳孔测试结果为假阳性，可能会接受不必要的磁共振成像检查及进一步检查。我们的目标是通过使用标准肌电图仪对正中神经进行表面电刺激，突出虹膜开大肌交感神经支配的眼间不对称性，以提高瞳孔测量的诊断准确性。我们假设双眼交感反应的差异增大将有助于霍纳综合征的诊断。将18例经药物证实的霍纳综合征患者与10名健康志愿者进行比较，这些志愿者在单眼滴注0.2%酒石酸溴莫尼定滴眼液以诱发药物性霍纳综合征前后接受测试。在黑暗中以及光刺激消失后的不同时间，通过对正中神经进行电刺激激活交感神经，用双眼瞳孔测量法测量瞳孔反应。同时记录受刺激手臂手掌的汗腺交感反应。在患有霍纳综合征和药物诱发的单侧交感神经功能缺陷的受试者中，电刺激结合光熄灭在诱发瞳孔散大期间极大地增强了瞳孔不等大，而健康受试者的瞳孔不等大没有显著增加。当在光终止后2秒给予电刺激或在持续低光条件下，交感反应的不对称性最大。在光终止后2秒给予电刺激时，霍纳综合征患者的平均瞳孔不等大从1.0毫米增加到1.2毫米（P = 0.01），而健康受试者为0.22 - 0.26毫米（P = 0.1）。在所有受试者中，电刺激诱发的最大瞳孔不等大出现在刺激后2秒内。相应地，在无光刺激时，瞳孔不等大在熄灯后3至4秒之间变化最大。虽然更强的三联刺激进一步增强了瞳孔不等大，但耐受性较差。熄灯后2秒进行电刺激极大地提高了瞳孔测量法诊断霍纳综合征的敏感性。这种新方法可能有助于明确或排除可疑的霍纳综合征，特别是在局部药物测试结果不确定的情况下。
