Horner’s syndrome and Harlequin syndrome are both caused by disruptions to the sympathetic supply to the face. They have a varied aetiology, including intraneural dysfunction, extra- or intraneural compression, and idiopathic as well as iatrogenic causes. Horner’s syndrome can occur as a rare complication of thyroid surgery and the Harlequin sign has only been documented as a complication of cervical surgery in a handful of paediatric patients. We present a patient who developed both conditions subsequent to excision of a papillary carcinoma with a neck dissection. We illustrate the anatomical basis for this presentation and highlight the need for its appreciation. This is of particular interest as it impacts on several specialities operating in the cervical and thoracic fields.
Patients undergoing head and neck surgery are routinely consented for potential iatrogenic injury to peripheral nerves, such as the facial nerve or the accessory nerve. It is less customary to include in the consent process the local autonomic supply. Such nerve injuries though rare, may be quite alarming for patient and surgeon alike.
Harlequin syndrome refers to hemifacial flushing and sweating. This rare condition occurs as a result of dysfunction in sudomotor and vasomotor sympathetic innervation to the face. These clinical features affect the side contralateral to the site of injury. At the same time there is normal bilateral ophthalmic sympathetic innervation. It is named after the bicolour-masked character in the 16th century Italian commedia dell’arte.
Horner’s syndrome is also caused by sympathetic chain dysfunction. This more common syndrome presents with ocular signs on the ipsilateral side. Bernard (1853) and Horner (1869) originally described the syndrome as miosis, ptosis, apparent enophthalmos, and facial anhidrosis.
Co-existing Horner’s and Harlequin syndromes is very rare and has only been reported as a complication of surgery; all cases occurred in children. We present the first adult case where these syndromes resulted from complications of thyroid surgery, with neck dissection. This is of particular interest as it impacts on several specialities operating in the cervical and thoracic fields.
An 84-year-old male with a background history of type 2 diabetes and hypertension, was referred by his general practitioner for a left-sided neck lump. Clinical examination identified a mass in the left anterior triangle. A computed tomography scan of the neck noted a 3-cm calcified, solitary irregular mass located between the common carotid artery, internal jugular vein, and vertebral artery at the level of T1, separate to the left thyroid lobe. However, an ultrasound scan of the thyroid identified a hypoechoic nodule within the left lobe of the thyroid, with no calcification. Fine-needle aspiration cytology of the thyroid nodule showed papillary carcinoma of the thyroid.
The patient underwent a total thyroidectomy with a left-sided level VI neck dissection, and the left-sided mass was excised with a level III–V neck dissection. It was adherent to the internal jugular vein, carotid sheath, and vagus nerve, which were all preserved.
Two hours postoperatively, the patient was reviewed on the ward and noted to have a dramatic right-sided hemifacial flush, well demarcated to the midline but not involving the chest or limbs. He was also noted to have a mild left-sided ptosis with associated miosis ( Fig. 1 ).
Histology confirmed the thyroid gland contained two foci of papillary carcinoma. The thyroid left lobe contained a 2.5-mm papillary carcinoma. The histology of the separate mass consisted of papillary carcinoma. It enveloped a nerve, but without direct invasion of the perineural space. Lymphovascular invasion was noted. The associated lymph node dissection also contained metastatic nodes. It was unclear as to whether the calcified mass was a primary tumour from ectopic thyroid parenchyma or metastases of carcinoma that had replaced a local lymph node. Assuming the ectopic calcified mass was a node replaced by tumour, with extranodal invasion, a total of five nodes out of 14 were positive, although the levels of these were not specified in the pathology report.
At the 2-week follow-up, the hemifacial flushing had resolved but the symptoms of Horner’s syndrome persisted. The patient then underwent a course of adjuvant ablative radio-iodine treatment (3.7 GBq) on the advice of the multidisciplinary team. He is currently still within his first year of surveillance for recurrence, with no evidence of persistent Horner’s syndrome and normal thyroglobulin levels.
Harlequin syndrome has a varied aetiology. It has been associated with autoimmune conditions as well as structural lesions or disease. It is often idiopathic, but iatrogenic causes have been reported, secondary to procedures in the cervical region.
The clinical features of flushing are thought to arise due to sympathetic dysfunction preventing thermoregulatory facial cutaneous vasodilatation on the ipsilateral side of the affected sympathetic chain. In effect, the hemifacial flushing is a compensatory reaction to the lack of sudomotor and vasomotor function of the denervated side. It can be induced by heat, exercise, or emotion. It is also possible for these features to extend from the face to involve the arm and or trunk.
Oculosympathetic innervation comprises sympathetic fibres to Müller’s muscle and the iris dilator muscle. Thus Horner’s syndrome presents with miosis (i.e. lack of dilator tone, thus relative constriction) and mild ptosis (i.e. lack of tone to Müller’s muscle, which contributes only 1 mm of upper lid elevation).
The occurrence of concurrent Harlequin and Horner’s syndromes has not, to our knowledge, been documented previously as a complication of surgery in the adult population. This is perhaps surprising when considering the underlying anatomical pathology.
The sympathetic innervation to the face exits the lateral horn of the spinal cord at the thoracic level (T1–3). These pre-ganglionic neurones exit the spinal cord and ascend through to the cervical sympathetic chain, which is adjacent to the spinal cord. They synapse within the chain with post-ganglionic tertiary fibres. There are different levels of ganglions within the chain, which are more focally identified as the superior cervical ganglion (SCG), middle cervical ganglion, and the stellate ganglion. These ganglia are found in close proximity to the great vessels of the neck.
Oculosympathetic fibres leave from T1, with sudomotor and vasomotor fibres from T2 and T3. They ascend within the sympathetic chain and synapse at the SCG. From there, fibres of the oculosympathetic supply reach their destination via the internal carotid artery, whilst facial sudomotor and vasomotor fibres supply the face with the external carotid artery.
Both syndromes occur when there is a disruption to the sympathetic innervation to the face. This pathway allows for many potential sites of damage, with clinical manifestations that can be localized ( Fig. 2 ).