Journal of the Neurological Sciences 323 (2012) 248–249 Contents lists available at SciVerse ScienceDirect Journal of the Neurological Sciences journal homepage: www.elsevier.com/locate/jns Short communication Intermittent hypoglossal nerve palsy caused by a calcified persistent hypoglossal artery: An uncommon neurovascular compression syndrome ☆ Dan Meila a, b,⁎, Axel Wetter c, Friedhelm Brassel a, Wilhelm Nacimiento d a Department of Radiology and Neuroradiology, Klinikum Duisburg‐Sana Kliniken, Zu den Rehwiesen 9, D-47055 Duisburg, Germany Department of Diagnostic and Interventional Neuroradiology, Medical School Hannover, Carl-Neuberg-Str.1, 30625 Hannover, Germany Institute of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Germany d Department of Neurology, Klinikum Duisburg‐Sana Kliniken, Germany b c a r t i c l e i n f o Article history: Received 3 April 2012 Received in revised form 20 August 2012 Accepted 27 August 2012 Available online 25 September 2012 Keywords: Dysarthria Hypoglossal nerve palsy Hypoglossal artery Neurovascular compression Trigeminal neuralgia Hemifacial spasm Carbamazepine a b s t r a c t Neurovascular compression is assumed to cause symptoms like trigeminal neuralgia, hemifacial spasm and vestibular paroxysmia. We present a patient with recurrent episodes of transient dysarthria due to isolated right hypoglossal nerve (HN) palsy. We describe the first case of a calcified persistent hypoglossal artery (PHA) as the putative cause of a hypoglossal neurovascular compression syndrome. Our patient received a daily low-dose medication of carbamazepine resulting in complete relief of symptoms. In conclusion, PHA is not only an anatomic variation but also a possible cause of a neurovascular compression syndrome leading to intermittent HN palsy. © 2012 Elsevier B.V. All rights reserved. 1. Introduction Neurovascular compression is assumed to cause symptoms like trigeminal neuralgia, hemifacial spasm and vestibular paroxysmia. We present a patient with recurrent episodes of transient dysarthria due to isolated right hypoglossal nerve (HN) palsy. We describe the first case of a calcified persistent hypoglossal artery (PHA) as the putative cause of a hypoglossal neurovascular compression syndrome. 2. Case report A 71-year-old woman was transferred to our hospital with recurrent numbness on the right side of the head and dysarthria. For about one week, she had at least one or two times a day, episodes of about 1 min in duration with “slurred speech”. The patient described a “sensation like lead within the tongue”. No other neurological symptoms were noted. Arterial hypertension had previously been appropriately treated for several years. Initial cranial magnetic resonance angiography (MRA) ☆ There is no study sponsorship or funding (industry, government, or institutional). ⁎ Corresponding author at: Department of Radiology and Neuroradiology, Klinikum Duisburg‐Sana Kliniken, Zu den Rehwiesen 9, D-47055 Duisburg, Germany. E-mail addresses: dan.meila@sana.de (D. Meila), axel.wetter@uk-essen.de (A. Wetter), friedhelm.brassel@sana.de (F. Brassel), wilhelm.nacimiento@sana.de (W. Nacimiento). 0022-510X/$ – see front matter © 2012 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.jns.2012.08.018 performed in the other hospital revealed a stenosis of the intracranial cavernous segment of the left internal carotid artery. MRI findings did not show any signs of previous ischemic injuries. Thus, it was initially assumed that recurrent arterioarterial emboli resulted in transitory ischemic attacks. Under general anesthesia, digital subtracted angiography was performed in our department, in order to treat the stenosis with percutaneous transluminal angioplasty and stent. Injection of the left internal carotid artery did not confirm the intracranial stenosis that was seen by MRA. Moreover, stenosis of other extra- or intracranial arteries was excluded. Instead, after angiography of the right common carotid artery, a PHA supplying the entire vertebrobasilar system was noted (Fig. 1A). Re-evaluation of cross-sectional imaging was performed. Magnetic resonance imaging showed an enlarged right side hypoglossal channel with a 5.0 mm diameter PHA (Fig. 1B), that was initially not noted. Only upon a second look on initial CT, we detected calcification of the PHA along the extra- and intracranial course, as well as inside the hypoglossal channel (Fig. 1C). A neurovascular compression syndrome of the HN, possibly facilitated by arterial hypertension, has been assumed. After treatment with carbamazepine retard (200 mg per day) the patient remained symptom-free at the three-month clinical follow-up. 3. Discussion HN palsy is a common finding in neurological diseases, caused by tumors, trauma, medullary infarctions, multiple sclerosis and infections D. Meila et al. / Journal of the Neurological Sciences 323 (2012) 248–249 249 Fig. 1. Imaging demonstrating persistent hypoglossal artery. A: Catheter angiography, lateral projection, right extracranial internal carotid artery injection. Demonstration of PHA (arrow) filling the entire vertebro-basilar system. B: Axial magnestic resonance angiography showing a right PHA with 5.0 mm diameter (arrow) coursing through the enlarged hypoglossal channel. C: Noncontrast head CT at initial clinical presentation. Note the calcification of the right-sided PHA (arrow). [1]. However, isolated HN palsies have been shown in single case reports. Ectatic vertebral arteries impinging on the HN were assumed as the cause of a so-called hypoglossal-vertebral entrapment syndrome [2,3]. We present the first case of a calcified PHA, presumably leading to a neurovascular compression syndrome. The PHA is the second most common persistent embryonic anastomosis between the internal carotid artery and the vertebrobasilar system. The reported angiographic frequency ranges from 0.027 to 0.1% [4]. Usually, the PHA itself is an incidental and asymptomatic finding. However, one interesting case of a unilateral HN palsy due to an aneurysm of the stump of a PHA has been reported by Al-Memar and Thrush [5]. Neurovascular compression can lead to episodic symptoms like trigeminal neuralgia, hemifacial spasm and vestibular paroxysmia. We believe that the symptoms of our patient became clinically manifest in increasing age due to dilative and atherosclerotic vessel wall changes. This phenomenon is well known for trigeminal neuralgia, typically becoming manifest in the elderly population. Thus, we assume that the documented dilated and calcified PHA was the putative reason for her intermittent symptoms in periods or peaks of arterial hypertension. Carbamazepine is the first medical treatment of choice in neurovascular compression syndromes. For patients refractory to medical therapy, neurosurgical microvascular decompression may be considered amongst other options [6,7]. Our patient received a daily low-dose medication of carbamazepine resulting in complete relief of symptoms strongly supporting our hypothesis of the pathomechanisms of neurovascular compression. 4. Conclusion In conclusion, PHA is not only an anatomic variation but also a possible cause of a neurovascular compression syndrome leading to intermittent HN palsy. Conflict of interest statement All authors report no disclosures. References [1] Keane J. Twelfth nerve palsy: analysis of 100 cases. Arch Neurol 1996;53:561-6. [2] Aladdin Y, Siddiqi ZA, Khan K, Ahmed SN. Hypoglossal-vertebral entrapment syndrome. Neurology 2008;71(6):461. [3] Rollnik JD, Sindern E, Mosler F, Spring B, Malin JP. Isolated peripheral hypoglossal palsy caused by a kinking of the left vertebral artery (hypoglossal vertebral entrapment syndrome). Eur Neurol 1996;36:324-5. [4] Vasovic L, Milenkovic Z, Jovanovic I, Cukuranovic R, Jovanovic P, Stefanovic I. 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