CASE LETTER First-bite syndrome: a novel complication of carotid body paraganglioma resection
First-bite syndrome is a relatively uncommon and recently identified problem associated with surgeries involving the parotid gland and/or the parapharyngeal space.1 The current description of the syndrome was initially reported in 1998 by Netterville,2 and the term “first-bite” syndrome was thought to be an appropriate name for the findings. In 1986, a gastrointestinal surgeon, Haubrich, had associated “first-bite syndrome” with a different clinical syndrome: esophageal dysfunction in patients who complained of an inability to swallow the first few bites of a meal ac companied by retrosternal pain. These individuals’ symptoms were relieved by regurgitation. 3
The true incidence of “first-bite syndrome” as characterized by Netterville is unknown, but cases have been reported after surgery of the parotid gland, neck tumors, parapharyngeal-space masses, and paragangliomas (Table 1).4–7 Those with the syndrome typically develop an intense, sharp, and sometimes cramping pain in the ipsilateral parotid region after the first bite of each meal.3 The severe pain lessens with each subsequent bite of the meal only to return at the first bite of the next meal.2
Netterville et al2 proposed that firstbite syndrome is due to the loss of sympathetic innervation to the parotid gland, resulting in the denervation and supersensitivity of the sympathetic receptors that control the myoepithelial cells. The pain comes from a supramaximal response of the myoepithelial cells stimulated by parasympathetic neurotransmitters, causing a spasm with the initial intake of food after a period of salivary rest (Figure 1). This etiology holds true in the majority of cases, although not all. A common feature for those afflicted with first-bite syndrome is residual parotid gland tissue. In some cases, even the thought of eating may cause a reaction by the salivary glands.
Tumors of the parapharyngeal space are rare; they typically evade diagnosis until found incidentally on imaging for another reason or grow to a size that becomes symptomatic or deforming. Imaging should be performed to evaluate the extent of the mass in the parapharyngeal area and the surrounding vascular structures preoperatively and to assure appropriate surgical planning and patient advisement.1 Biopsy is not recommended for carotid body tumors due to the risk of vascular injury, bleeding, and more severe complications.
Common surgical procedures that a b can result in first-bite syndrome include parotidectomy, neck dissection, transcervical excision of a sympathetic chain schwannoma, paraganglioma excision, and excision of a deep lobe parotid pleomorphic adenoma.8 In a retrospective study by Kawashima et al,4 9 of 22 patients who underwent surgery to remove a tumor in the parapharyngeal space postoperatively developed first-bite syndrome. All five patients who had external carotid artery ligation and resection of the deep lobe in the parotid gland during surgery developed first-bite syndrome. One patient underwent ligation of the external carotid artery from the sympathetic pathway and ligation of the auriculotemporal nerve from the parasympathetic pathway (Figure 1) and did not develop first-bite syndrome.