A Rare Case of Glomus Jugulare Tumor Presenting as Papilledema

Letters to the Editor A Rare Case of Glomus Jugulare Tumor Presenting as Papilledema W e wish to share our experience of paragangliomas as a cause of pseudotumor cerebri syndrome as recently reported by Lertakyamanee et al (1). A 53-year-old woman experienced a painless decrease of vision in her right eye for 1 month. Visual acuity was perception of light in the right eye and 20/30 in the left eye. There was a right relative afferent pupillary defect, a right esotropia, and limited abduction of the right eye consistent with a right sixth nerve palsy. Fundus examination revealed bilateral optic disc edema (Fig. 1). Cranial nerve testing showed involvement of the right fifth, seventh, and eighth cranial nerves. Brain magnetic resonance imaging (MRI) demonstrated a 4.1 · 3.6 · 3.7 cm skull base mass (Fig. 2). The lesion extended caudally into the right jugular foramen for a length of approximately 2.4 cm where the lesion and the jugular bulb could not be visualized separately. Bony erosions of the petrous bone abutting the internal auditory canal and the region of the right vestibular aqueduct were present. There was mild hydrocephalus with compression of the fourth ventricle. MRI features were highly suggestive of a glomus jugulotypanicum. The patient was referred to neurosurgery but declined treatment. Because of the anatomic location of glomus jugulare, this tumor typically involves the seventh, ninth, tenth, and eleventh cranial nerves (2). Symptoms of these tumors usually include pulsatile tinnitus, hearing loss, facial nerve paralysis, vertigo, otalgia, dysphagia, hoarseness, throat sore, episodic hypertension with headaches, and tachycardia (3). Yet on occasion, as our case illustrates, glomus jugulare tumors may cause raised intracranial pressure (ICP) leading to papilledema and, if unrecognized, severe vision loss. Impaired cerebral venous sinus outflow appears to be one likely mechanism causing increased ICP. This may be due to the tumor mass itself or following therapeutic intervention (embolization, surgery). Another possible mechanism of raised ICP may be mass effect in the middle cranial fossa affecting the flow of cerebrospinal fluid and leading to hydrocephalus. FIG. 1. Bilateral optic disc edema is present with peripapillary exudates. FIG. 2. Glomus jugulare tumor. Axial fluid-attenuated inversion recovery (A) coronal T2 (B) and postcontrast T1 sagittal (C) scans show a skill base tumor involving the right cerebellopontine angle and the region of the right jugular foramen. 110 Letters to the Editor: J Neuro-Ophthalmol 2016; 36: 110-114 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. Letters to the Editor We are in complete agreement with Lertakyamanee et al that clinicians need to be aware that glomus jugulare tumors must not be overlooked as a potential cause of pseudotumor cerebri syndrome with papilledema and potential vision loss. Virna M. Shah, DO Vishma Prabhu, DNB Department of Neuro-Ophthalmology, Aravind Eye Hospital & Postgraduate Institute of Ophthalmology, Coimbatore, India Asymmetric Papilledema in Idiopathic Intracranial Hypertension: Comment W e found the article by Bidot et al (1) and Dr Killer's response letter (2) regarding astronauts very interesting and supportive of the concept that some forms of compartmentation may be involved in the etiology of asymmetric optic disc edema. Bidot et al propose that the narrower optic canal is associated with less disc edema because restricted cerebrospinal fluid (CSF) flow from the brain to the optic nerve (ON) sheath results in lower intraorbital CSF sheath pressure. In this scenario, compartmentation is believed to offer a protective effect. For this theory to hold true, there would have to be a sufficient narrowing and restriction through the optic canal so that the CSF flow into the ON sheath is severely restricted but return flow to the brain is not. This is in contrast to the larger optic canal side where the full force of increased CSF pressure from the brain would presumably be transmitted through the normal sized canal. This theory assumes that the CSF pressure within the orbital ON sheath on the "normal" side is equal to that of the brain CSF. Asymmetry of the optic canal certainly is a possible etiology for our astronauts' findings. Four of 7 long-duration astronauts with optic disc edema have displayed optic disc edema asymmetry. However, astronaut disc edema seems to have some unique findings (3). First, in those astronauts with optic disc edema asymmetry after long-duration space flight, the higher degree of disc edema has always been documented in the right eye. Of 4 astronauts with asymmetric disc edema after long-duration flights, 3 had Frisen Grade 1 right disc edema with a normal left disc as documented by retinal photography. One had highly asymmetric disc edema with Frisen Grade 3, right eye, and Grade 1, left eye. In contrast, Bidot et al found the higher grade disc edema on the right side in only 9 of 20 patients (45%). For the Bidot protective theory to hold true in astronauts, the optic canal would have to be consistently narrower on the left in each of these astronauts. Such a consistent anatomical finding in 4 astronauts would be unlikely. Second, in one previous astronaut case Letters to the Editor: J Neuro-Ophthalmol 2016; 36: 110-114 The authors report no conflicts of interest. REFERENCES 1. Lertakyamanee P, Srinivasan A, DeLott LB, Trobe JD. Papilledema and vision loss caused by jugular paragangliomas. J Neuroophthalmol. [published online ahead of print June 12, 2015]. doi: 10.1097/WNO.0000000000000281. 2. O'Leary MJ, Shelton C, Giddings NA, Kwartler J, Brackmann DE. Glomus tympanicum tumors: a clinical perspective. Laryngoscope. 1991;101:1038-1043. 3. Fayad JN, Keles B, Brackmann DE. Jugular foramen tumors: clinical characteristics and treatment outcomes. Otol Neurotol. 2010;31:299-305. report, a normal opening pressure on lumbar puncture was documented after a mission in the presence of asymmetric disc edema (4). In this same astronaut, we documented unilateral loss of spontaneous venous pulsations in the same eye during space flight that continued to be absent 21 months after return to Earth (5). We also documented, with optical coherence tomography and retinal photography, an astronaut with persistent asymmetric disc edema (right . left) 6 months following his mission in the presence of lumbar puncture opening pressures of 22 cm and 16 cm H2O, performed at one week and one year post mission, respectively (personal communication A.G.L.). These reports suggest that perhaps a unilateral ON sheath compartmentation existed on return to Earth in the presence of intracranial CSF pressures that had returned to normal after the mission. Although optic canal asymmetry could create ON sheath pressure differences in conjunction with elevated CSF pressure, it would not account for continued disc edema asymmetry in the presence of normal postmission opening pressure measurements. We are in agreement with Dr Killer than an examination of optic canal size in astronauts would be very informative and may shed light on the etiology of optic disc edema asymmetry in astronauts. Because of a paucity of objective information, this is currently a very hypothetical area of study. It might be appropriate to measure optic canal size in astronauts who have displayed well-documented disc asymmetry on previous long-duration missions. We suspect that computed tomography scan may be the best technique to measure optic canal size. A comparison of each of these astronaut's canal sizes with their degree of disc edema may provide very useful information. Thomas H. Mader, MD COL(R) US Army, Moab, Utah C. Robert Gibson, OD Coastal Eye Associates, Webster, Texas Stephen F. Hart, MD Life Sciences Division, NASA, Houston, Texas 111 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited.