Aneurysm of the extracranial internal carotid artery presenting as the syndrome of glossopharyngeal pain and syncope
- 1Department of Neurology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
- 2Division of Vascular Surgery, Asan Medical Center
- Correspondence to: Dr Lee, Department of Neurology, Asan Medical Center, 388-1, Pungnap-dong, Songpa-gu, Seoul, 138-736, Korea;
The syndrome of glossopharyngeal pain and/or syncope mimicking idiopathic glossopharyngeal neuralgia has been reported to be associated with a variety of intracranial or extracranial conditions1 including mass lesions in the parapharyngeal space,2,3 the elongated styloid process,4 and multiple sclerosis.5 However, aneurysm of the cervical portion of the internal carotid artery (ICA) presenting as episodic glossopharyngeal pain and syncope has not been reported previously to the best of our knowledge. We report here the first such case that was successfully treated by surgical resection of the aneurysm.
A 66 year old woman with a two year history of paroxysmal attacks of pharyngeal pain with occasional syncopal episodes was admitted to our hospital. She had been in good health until two years previously, when she first noticed pain in the region of the left pharynx, sometimes with radiation to the ipsilateral ear and submandibular area. The pain was neither stabbing nor triggered by swallowing and eating. The attacks recurred about 10 times a day and lasted from several seconds to five minutes. During the year before admission, the attacks had become more frequent, and the duration of pain increased to 30 minutes. She had also felt foreign body sensations in her throat regardless of painful episodes. During the four months before admission, the painful episodes were occasionally accompanied by abdominal pain, diarrhoea, and syncope. The episodes of syncope recurred about twice a month. She had no hypertension or diabetes. There was no past history of infection or trauma. Neurological examination was normal. In particular, there were no definite abnormalities in deglutition, movement of the soft palate, and the gag reflex; there was no palpable mass or bruit in the neck, and no trigger zone was noted. Complete blood cell count and serum chemistry were normal. Antinuclear antibody and a serological test for syphilis were negative. Brain magnetic resonance imaging and cervical computed tomography showed a round mass in the upper portion of the left carotid space, compressing the parapharyngeal space forward (fig 1). Four vessel angiography showed a large aneurysm (3.9 × 3.0 cm) of the distal cervical portion of the left ICA (fig 2), which was located near the skull base above the Blaisdell line.6 There were no aneurysms elsewhere. A computed tomography scan of the neck showed no evidence of the elongated styloid process.
Treatment with phenytoin (300 mg a day) caused the paroxysmal pain to disappear completely within three days. Under general anaesthesia, the aneurysm was approached by a presternocleidomastoid cervicotomy without subluxation of the mandible or transection of the digastric muscle. The cutaneous incision was extended along the posterior border of the mastoid process. The aneurysm was found 5 cm above the carotid bifurcation. The anatomical relation between the aneurysm and the glossopharyngeal nerve was not identified in the surgical field. The aneurysm was resected, with replacement with a saphenous vein graft. Surgical and pathological findings indicated a true aneurysm. After surgery, there were no neurological deficits except incomplete Horner's syndrome on the left side. Postoperative angiography showed satisfactory reconstruction (fig 2). Phenytoin was not given after surgery. No episodes of pain or syncope recurred during the follow up period of six months after surgery.
Our case was characterised by episodic pain in the distribution of the glossopharyngeal nerve, sometimes associated with syncope, and a dramatic response to phenytoin. A huge aneurysm of the extracranial ICA was found to be the cause of the glossopharyngeal pain and syncope syndrome, which was confirmed by successful surgical resection. The syndrome of glossopharyngeal pain and/or syncope may be caused by a variety of conditions. In this case, glossopharyngeal neuralgia was considered to be unlikely because of the absence of a stabbing feeling, precipitating factors, or trigger zones. Also, there was no radiological evidence of mass lesions in the parapharyngeal space or the elongated styloid process.
The pathogenetic mechanism in our patient was considered to be similar to that involved in glossopharyngeal neuralgia and syncope. Sobol et al2 reported two cases of glossopharyngeal neuralgia-asystole syndrome associated with ipsilateral lesions of the parapharyngeal space, and postulated that parapharyngeal space lesions may induce neural irritation to the afferent pain fibres of the glossopharyngeal nerve and reflex within the nerve of Hering to produce the syndrome.
The causes of aneurysm of the ICA are multiple and include atherosclerosis, dysplasia, trauma, and infectious lesions.7 The cause in our patient was not known despite the histological examination. Welling et al8 reported that 41 of 1118 aneurysms of the peripheral arteries arose from the extracranial carotid system. Only four of them were saccular aneurysms of the ICA. Although aneurysms of the extracranial ICA do not usually produce neurological symptoms, they may result in potentially serious problems, such as cerebrovascular events, as a consequence of thromboembolic phenomena or impairment of flow in the proximal carotid artery. Isolated cranial neuropathies can also occur as the result of direct nerve compression.9 In this case, the aneurysmal parapharyngeal mass produced episodic glossopharyngeal pain and syncope.