Horner syndrome is classically described as a triad of symptoms including ptosis, miosis, and anhydrosis that is caused by disruption anywhere along the three-neuron oculosympathetic chain. In pediatric patients, the etiology of Horner syndrome can be classified as congenital or acquired. Congenital causes include birth trauma (most common) and vascular malformations. Acquired cases include surgical causes (thoracotomy tube placement, central venous catheter insertion, neck surgery, epidural block, radiofrequency tonsil ablation, and cardiothoracic surgery), trauma, infections, and, the most worrisome, malignancies.1–4 Based on the localization of the nerve pathway interruption, Horner syndrome is classified as central, pre-ganglionic, and post-ganglionic.
A 4-month-old girl diagnosed as having congenital pulmonary airway malformation prenatally was admitted to the pediatric surgery service of University Hospitals Rainbow Babies & Children's Hospital for planned video-assisted thoracoscopic surgery resection of a left upper lobe mass (Figure 1). She was delivered vaginally at full term. Her birth history was complicated by a right pneumothorax at 36 hours of age, which required a chest tube and neonatal intensive care unit admission. She was hospitalized for 15 days total without any other significant events and was discharged home to follow up for resection of a left upper lobe cystic mass.
Patient in the supine position with left pigtail catheter in place for pleural drainage after video-assisted thoracoscopic surgery.
At 4 months of age, the patient underwent uncomplicated chest surgery under general anesthesia and tolerated the procedure well without any complications. Perioperatively, a spinal epidural was placed by the pediatric pain team for analgesia (Figure 2). A pigtail drain was left in place postoperatively and there were no immediate anesthetic complications. Six hours after surgery, the parents noted that the left pupil was larger than the right and the right eyelid was droopy. The ophthalmology department was consulted to evaluate anisocoria.
Patient placed in the right lateral decubitus to show the epidural catheter in place before its removal after the diagnosis of Horner syndrome.
On examination, the patient blinked to light and was able to fixate and follow briefly. Pupils were reactive but unequal (3 to 2 and 5 to 3 mm in the right and left eyes, respectively), with greater anisocoria noted in the dark. She also had ptosis of the right upper eyelid and mild reverse ptosis of the lower eyelid (Figure 3). The rest of the examination, including dilated fundus examination, was unremarkable. After consulting with the pediatric pain medicine team, a decision was made to discontinue the spinal epidural.
(A) Normal pupils before surgery. (B) Miosis and ptosis in the right eye. (C) Resolved miosis and ptosis in the right eye.
On reevaluation the next day, the team and parents reported that the anisocoria resolved within hours of removal of the epidural catheter. On examination, there was no ptosis and the pupils were equal, round, and reactive to light, although slightly sluggish (Figure 3).
There are anatomical considerations in evaluating spinal anesthesia complications. Magnetic resonance imaging of the thoracic spinal canal shows that the spinal cord touches the dura only anteriorly, in contrast to the lumbar region where the spinal cord touches the dura posteriorly. In a study by Imbelloni and Gouveia,5 this anatomical variation is mentioned as the reason for the low incidence of neurologic complications in thoracic epidural blocks in the event of accidental perforation of the dura mater.
Pain control after a thoracotomy is important for proper function of the thoracic cage. Pain can prevent patients from breathing normally and clearing secretions, which can lead to complications such as atelectasis, infections, and hypoxia.6,7 Thoracic epidural analgesia is considered the preferred method for pain control following thoracotomy.6
Although long-term complications of epidural anesthesia are rare, there can be many immediate complications. These include accidental dural perforation, sixth nerve palsy, unsuccessful catheter placement, insufficient analgesia, sanguineous rupture, pleural puncture, epidural bleeding, and epidural hematoma. Horner syndrome is a rare but important complication.5,6,8
Unilateral symptoms of Horner syndrome may be secondary to the anatomical placement of the epidural catheter, septations within the epidural space, and positioning of the patient.4,9,10 Cowie et al.9 noted the importance of including epidural anesthesia within the differential diagnosis of Horner syndrome. They advocated for direct visualization when placing the epidural catheter and, if Horner syndrome develops, recommended reducing the epidural rate and performing a thorough ophthalmological and neurological examination.9
Horner syndrome after epidural anesthesia is most commonly seen in obstetric patients due to epidural venous engorgement promoting the upward spread of anesthesia.4 The volume of the infusion may play a role, but cephalad spread of the anesthetic solution is an important cause.4,10
There is not widespread agreement as to the best approach to evaluate causation in Horner syndrome. The most significant concern of Horner syndrome is missing a potentially fatal etiology. In pediatrics, neuroblastoma is the most common malignancy associated with Horner syndrome. Smith et al.2 conducted a retrospective study of children younger than 19 years who were diagnosed as having Horner syndrome in a 40-year period. Current recommendations for evaluation of Horner syndrome without a known surgical cause include urinary catecholamine testing and magnetic resonance imaging of the brain, neck, and chest. Smith et al.2 suggested that extensive imaging can be reserved for selected idiopathic cases of Horner syndrome. Similarly, Mahoney et al.11 recommended that Horner syndrome in a child of any age without any surgical history requires magnetic resonance imaging of the brain, neck, and chest, and urinary catecholamine metabolite testing.
The outcome of Horner syndrome varies in the literature, with some cases completely resolving and others only partially or not resolving at all. Zagrodnik and Kline12 reported a complete resolution in only one-third of their cases. Alternatively, Park et al.4 reported complete resolution in all patients who developed Horner syndrome after epidural anesthesia within 180 minutes of stopping the infusion. In our case, the patient had complete resolution within the first hours after removing the epidural catheter.
Horner syndrome secondary to spinal anesthesia has been well reported in the literature in obstetric/gynecologic patients who receive an epidural catheter, but is rarely reported in children.4 Martinez-Garcia et al.10 reported another similar case in a pediatric patient who developed Horner syndrome on postoperative day 3 that completely resolved after 3 to 4 hours of removing the epidural catheter. As previously mentioned, iatrogenic Horner syndrome should be in the differential diagnosis, and decreasing the infusion rate or removal of the epidural catheter should be done as soon as possible. In our case, an ophthalmic evaluation was promptly performed and, because there was a known intervention (left video-assisted thoracoscopic surgery and spinal epidural), we deferred imaging. Given that the patient had Horner syndrome contra-lateral to the procedure site and there was no longer a mass in the region, we believe that the cause was the spinal epidural and not the video-assisted thoracoscopic surgery. Furthermore, the quick resolution of Horner syndrome after removal of the catheter suggests iatrogenic Horner syndrome secondary to epidural catheterization. We agree with Smith et al.2 that prompt and thorough ophthalmic and neurologic evaluation should be performed prior to extensive work-up and imaging, reserving these resources for idiopathic cases with a high clinical suspicion for a potentially fatal pathology.
- Nasser BA, Mesned A, Moazamy YE, Kabbani MS. Horner's syndrome after paediatric cardiac surgery: case report and review of the literature. Cardiol Young. 2015;25:569–572. doi:10.1017/S1047951114000456 [CrossRef]
- Smith SJ, Diehl N, Leavitt JA, Mohney BG. Incidence of pediatric Horner syndrome and the risk of neuroblastoma: a population-based study. Arch Ophthalmol. 2010;128:324–329. doi:10.1001/archophthalmol.2010.6 [CrossRef]
- Kadom N, Rosman NP, Jubouri S, Trofimova A, Egloff AM, Zein WM. Neuroimaging experience in pediatric Horner syndrome. Pediatr Radiol. 2015;45:1535–1543. doi:10.1007/s00247-015-3341-9 [CrossRef]
- Park SY, Chun HR, Kim MG, et al. Transient Horner's syndrome following thoracic epidural anesthesia for mastectomy: a prospective observational study. Can J Anesth. 2015;62:252–257. doi:10.1007/s12630-014-0284-9 [CrossRef]
- Imbelloni LE, Gouveia MA. Low incidence of neurologic complications during thoracic epidurals: anatomic explanation. AJNR Am J Neuroradiol. 2010;31:E84. doi:10.3174/ajnr.A2227 [CrossRef]
- Gulbahar G, Gundogdu AG, Alkan G, Baysalman HB, Kaplan T. Unilateral anhidrosis: a rare complication of thoracic epidural analgesia. Asian Cardiovasc Thorac Ann. 2016;24:211–213. doi:10.1177/0218492315618508 [CrossRef]
- Gerner P. Postthoracotomy pain management problems. Anesthesiol Clin. 2008;26:355–367. doi:10.1016/j.anclin.2008.01.007 [CrossRef]
- Freise H, Van Aken HK. Risks and benefits of thoracic epidural anaesthesia. Br J Anaesth. 2011;107:859–868. doi:10.1093/bja/aer339 [CrossRef]
- Cowie S, Gunn L, Madhavan P. Horner's syndrome secondary to epidural anaesthesia following posterior instrumented scoliosis correction. Asian Spine J. 2015;9:121–126. doi:10.4184/asj.2015.9.1.121 [CrossRef]
- Martinez-Garcia E, Del Rey P, Tormo C, de Santiago J, Porto R, Serrano-Gonzalez A. Horner's syndrome because of thoracic epidural analgesia with levobupivacaine in a pediatric patient. Paediatr Anaesth. 2008;18:1119–1120. doi:10.1111/j.1460-9592.2008.02625.x [CrossRef]
- Mahoney NR, Liu GT, Menacker SJ, Wilson MC, Hogarty MD, Maris JM. Pediatric horner syndrome: etiologies and roles of imaging and urine studies to detect neuroblastoma and other responsible mass lesions. Am J Ophthalmol. 2006;142:651–659. doi:10.1016/j.ajo.2006.05.047 [CrossRef]
- Zagrodnik DF 2nd, Kline AL. Horner's syndrome: a delayed complication after thoracostomy tube removal. Curr Surg. 2002;59:96–98. doi:10.1016/S0149-7944(01)00565-7 [CrossRef]