Horner’s Syndrome as Complication of Extracorporeal Membrane Oxygenation in a Neonate
Article Outline
A term-born baby girl had a perinatal course complicated by meconium aspiration syndrome, pulmonary hemorrhage, and shock. She was placed on extracorporeal membrane oxygenation (ECMO) on day of life 3 after high-frequency ventilation failed to maintain adequate oxygenation. She was taken off ECMO on day of life 13, and neurology was consulted for facial asymmetry at 3 weeks of age (Figure 1). She had partial ptosis of the right eye with miosis (right pupil 2 mm less than left, both reactive to light); extraocular movements were normal. Her face appeared symmetric, and she had normal tone, strength, and reflexes.
Figure 1
Photograph showing right-sided partial ptosis. Miosis is not well appreciated because of a dark iris.
Magnetic resonance angiography revealed complete occlusion of the right internal carotid artery (ICA) with reconstitution at the cavernous segment (Figure 2). At 1-year follow-up, the patient’s ptosis and anisocoria had improved significantly.
Figure 2
Magnetic resonance angiogram of the neck and brain showing absence of signal along the course of the right ICA (arrow), with reconstitution at the level of the proximal cavernous segment. The flow in the right middle cerebral artery is minimally decreased compared with that in the left middle cerebral artery.
The classic triad of Horner's syndrome comprises ptosis, miosis, and facial anhidrosis, attributable to oculosympathetic dysfunction.1 The pathway extends from the hypothalamus to the intraocular muscles and is divided into 3 orders of neurons. First-order neurons extend from the posterolateral hypothalamus through the lateral brainstem and intermediolateral cell column of the spinal cord before synapsing at the ciliospinal center (C8-T1 region). Second-order neurons exit through the anterior root of C8-T1, arch over the lung apex, and synapse in the superior cervical ganglion in the neck. Third-order neurons then travel along the common carotid artery. Some fibers before the common carotid artery bifurcation travel along the external carotid artery to provide vasomotor and sudomotor innervation to the lower half of the ipsilateral face, and the remainder travel along the ICA before entering the orbit along trigeminal nerve branch V1. They supply Muller’s muscles (loss of innervation leads to ptosis) and iris dilators (loss of innervation leads to miosis). Thus, lesions distal to the common carotid artery bifurcation (as noted in the present case) spare the face without causing anhidrosis.1
Common causes of first-order neuron involvement are brainstem strokes/tumors, syringomyelia, and cervical cord tumors. Second-order neuron injury can result from lung tumors, brachial plexus injury, neuroblastoma, trauma, and surgery, whereas third-order neuron injury may be due to neck surgery involving ICA, ICA dissection/aneurysm, cavernous sinus lesions, and trauma.2
ECMO is a well-established mechanical support modality used for cardiac and or respiratory failure in neonates and children in which cannulas are inserted into the ICA and internal jugular vein.3 The processes of cannulation and decannulation carry a risk of vessel injury. As sympathetic neurons form a plexus around the ICA, they are prone to injury. The exact incidence of Horner's syndrome after ECMO is unknown.
Our patient had right-sided Horner's syndrome secondary to third-order sympathetic neuron injury. This report highlights a less commonly recognized complication after ECMO with good outcome.
References
- . Horner’s syndrome revisited: with an update of the central pathway. Clin Anat. 1999;12:345–361
- . Topographical analysis of Horner's syndrome. Otolaryngol Head Neck Surg. 1986;94:451–457
- . Extracorporeal membrane oxygenation for severe respiratory failure in newborn infants. Cochrane Database Syst Rev. 2008;3:CD001340
PII: S0022-3476(11)00826-2
doi:10.1016/j.jpeds.2011.08.031
© 2012 Mosby, Inc. All rights reserved.
