A Case of SUNCT With Neurovascular Compression

A 79-year-old man with a medical history of coronary artery disease, peripheral vascular disease, and atrial fibrillation; presented for the evaluation of a stabbing headache around the right eye.

Photo and Video Essay Section Editors: Melissa W. Ko, Dean M. Cestari, Peter Quiros, Kimberly M. Winges, MD MD MD MD A Case of SUNCT With Neurovascular Compression Matthew C. Santos, MD, Rami W. Eldaya, MD, Gregory P. Van Stavern, MD A 79-year-old man with a medical history of coronary artery disease, peripheral vascular disease, and atrial fibrillation presented for the evaluation of a stabbing headache around the right eye. He described short-lived episodes, lasting for 30 seconds on average, with complete interictal resolution. Symptoms occurred intermittently throughout the past 10 years. Clusters of daily episodic eye pain began every few years, lasted for several months at a time, and then, completely resolved for some years. He reported right eye redness and tearing accompanying each episode. The severity of the pain halted him in conversation, severely debilitating his daily functioning, with the patient now refraining from driving independently. He denied associated photophobia, nausea, vision loss, trauma, or migraine history. Each recurrence of this eye pain had the same semiology throughout the years. These episodes began again 8 months before presentation without abating, prompting his referral for further evaluation. He had a normal ocular and neuro-ophthalmic examination, including normal CN V1 sensation, normal intraocular pressure, anterior segment, and gonioscopy with deep angles in both eyes. An episode was witnessed during our encounter and did include unilateral conjunctival injection and lacrimation. Taken together, this unilateral stabbing eye pain lasting roughly 30–60 seconds with an otherwise normal examination and concurrent conjunctival injection and lacrimation raised concern for short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT). He had tried nortriptyline previously, and this did not control his symptoms. He had undergone a brain MRI without gadolinium which was reportedly normal, although this image was not available at the time of our evaluation. To better assess for structural causes, the patient underwent MRI brain/orbits with and without gadolinium, with special attention directed toward pathology affecting the ipsilateral trigeminal nerve. In the interim, the patient was started on a trial of oral gabapentin. Figures 1–3 display the MRI brain/orbits findings: neurovascular compression of the right trigeminal nerve by the right superior cerebellar artery, causing mass effect, John F. Hardesty Department of Ophthalmology and Visual Sciences (MCS, GPvS); and Mallinckrodt Institute of Radiology (RE). Supported by an unrestricted grant to the Department of Ophthalmology and Visual Sciences from Research to Prevent Blindness. The authors report no conflicts of interest. Address correspondence to Matthew C. Santos, MD, 660S Euclid Avenue, CB 8096, St. Louis, MO 63110; E-mail: [e-mail] Santos et al: J Neuro-Ophthalmol 2022; 42: e593-e595 and likely explaining this patient’s symptoms. Representative images are taken from the SPACE sequence (sampling perfection with application-optimized contrasts using different flip-angle evolution) of a Siemens Espree scanner with a 1.5 T magnet. Sagittal views show the superior cerebellar artery (black arrow) traversing and compressing the cisternal segment of CN V (blue arrow) shortly after its root entry zone (circle, Fig. 1A). The left, normal side is displayed for comparison, showing the cisternal segment of CN V without evidence of vascular compression (blue arrow, Fig. 1B). Coronal views highlight the caliber difference between the compressed CN V (blue arrow) and the normal left CN V (green arrow, Fig. 2A). This is demonstrated in a more anterior coronal cut as well (Fig. 2B). Axial views also provide evidence of this compression in the cisternal segment of CNV on the right, and the normal left CN V is presented for comparison (Fig. 3A and 3B). SUNCT is a trigeminal cephalgia defined in the International Classification of Headache Disorders, Third Edition, as a unilateral moderate or severe stabbing or throbbing orbital or temporal pain. The clinical diagnosis requires at least 20 attacks lasting 1–600 seconds with ipsilateral conjunctival injection and lacrimation (1). This entity shares many features with short-lasting unilateral neuralgiform headache attacks with cranial autonomic symptoms (SUNA), the latter presenting with concurrent autonomic symptoms other than the combination of conjunctival injection and tearing. These disorders also overlap significantly with trigeminal neuralgia. The presence of pronounced autonomic symptoms is a distinguishing feature of SUNCT and SUNA. Patients with trigeminal neuralgia also have pain-free periods between attacks, whereas SUNCT/ SUNA often display a background headache between attacks. Some debate exists whether SUNCT, SUNA, and trigeminal neuralgia are unique entities or represent a spectrum of the same pathology (2). Although these conditions may present as a primary headache disorder, they warrant investigation into secondary causes. Rates of neurovascular compression in SUNCT and SUNA vary in the literature. Favoni et al (3) reviewed 222 published SUNCT/SUNA cases in 2013, finding that 34 of these cases were due to neurovascular compression. Of these 34 patients, 27 had SUNCT attacks, 5 were diagnosed with SUNA, and 2 had both SUNCT and SUNA attacks. There was a wide variability of neurovascular compression e593 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. Photo and Video Essay FIG. 1. Sagittal views of the SPACE sequence (sampling perfection with application-optimized contrasts using different flipangle evolution). A. Sagittal 3D SPACE shows the superior cerebellar artery traversing (White arrows) and compressing the cisternal segment of CN V (Black arrows) shortly after its root entry zone (circle). B, Normal side for comparison showing the cisternal segment of CN V without vascular compression (Black arrows). FIG. 2. Coronal views of the SPACE sequence. A, Coronal SPACE shows the SCA (White arrow) approaching the compressed CN V in the cistern (Black arrowhead). Note normal left CN V (Black arrow) and difference in nerve caliber. B, Coronal SPACE (more anterior) shows the SCA (White arrow) compressing CN V in the cistern (Black arrowhead). Note normal left CN V (Black arrow) and difference in nerve caliber. FIG. 3. Axial views of the SPACE sequence. A, Axial SPACE shows compression of the right CN V at its cisternal segment (Black arrows) shortly after its root entry zone by the SCA (White arrows). B, Axial SPACE shows the normal left CNV cisternal segment (Black arrows). reported in this review, ranging from 88% (15 of 17) in a smaller series to only 6% (3 of 52) in the largest series. This larger percentage came from a study using dedicated views of the trigeminal nerve, and the authors speculate that this may contribute to the wide variability in reported rates (4). This review found that the superior cerebellar artery was the culprit in 17 of 34 of these cases (50%), making it the most commonly implicated vessel (3). Lambru et al investigated e594 trigeminal neurovascular contact in 159 patients with 165 symptomatic and 153 asymptomatic trigeminal nerves, finding a greater degree of neurovascular contact in symptomatic nerves (80% vs 59%) (5). In our case, the patient responded quite well to his gabapentin trial and was able to resume driving independently with better control of his attacks. However, this entity is often difficult to control with medical management Santos et al: J Neuro-Ophthalmol 2022; 42: e593-e595 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. Photo and Video Essay or neuromodulation, including occipital nerve and deep brain stimulation (3,6). Neurovascular compression of the trigeminal nerve may be a secondary cause of many facial pain syndromes. Dedicated imaging to detect pathology affecting the trigeminal nerve may be paramount in arriving at this diagnosis. This may help identify microvascular decompression as a potential treatment option in cases refractory to medical management or neuromodulation (6,7). STATEMENT OF AUTHORSHIP Category 1: a. Conception and design: G. P. Van Stavern and M. Santos; b. Acquisition of data: R. Eldaya, G. P. Van Stavern, and M. Santos; and c. Analysis and interpretation of data: R. Eldaya, G. P. Van Stavern, and M. Santos. Category 2: a. Drafting the manuscript: M. Santos and b. Revising it for intellectual content: G. P. Van Stavern and Matthew Santos. Category 3: a. Final approval of the completed manuscript: G. P. Van Stavern and M. Santos. Santos et al: J Neuro-Ophthalmol 2022; 42: e593-e595 REFERENCES 1. Headache Classification Committee of the International Headache S. The international classification of headache disorders, 3rd edition (beta version). Cephalalgia. 2013;33:629–808. 2. Lambru G, Matharu MS. SUNCT, SUNA and trigeminal neuralgia: different disorders or variants of the same disorder? Curr Opin Neurol. 2014;27:325–331. 3. Favoni V, Grimaldi D, Pierangeli G, Cortelli P, Cevoli S. SUNCT/ SUNA and neurovascular compression: new cases and critical literature review. Cephalalgia. 2013;33:1337–1348. 4. Williams MH, Broadley SA. SUNCT and SUNA: clinical features and medical treatment. J Clin Neurosci. 2008;15:526–534. 5. Lambru G, Rantell K, O’Connor E, Levy A, Davagnanam I, Zrinzo L, Matharu M. Trigeminal neurovascular contact in SUNCT and SUNA: a cross-sectional magnetic resonance study. Brain. 2020;143:3619–3628. 6. Hassan S, Lagrata S, Levy A, Matharu M, Zrinzo L. Microvascular decompression or neuromodulation in patients with SUNCT and trigeminal neurovascular conflict? Cephalalgia. 2018;38:393–398. 7. Sebastian S, Schweitzer D, Tan L, Broadley SA. Role of trigeminal microvascular decompression in the treatment of SUNCT and SUNA. Curr Pain Headache Rep. 2013;17:332. e595 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited.