AJR:206, March 2016 595 MRI of the Trigeminal Nerve in Patients With Trigeminal Neuralgia Secondary to Vascular Compression Marion A. Hughes 1 Andrew M. Frederickson 2 Barton F. Branstetter 1,3 Xiao Zhu 2 Raymond F. Sekula, Jr. 2 Hughes MA, Frederickson AM, Branstetter BF, Zhu X, Sekula RF Jr 1 Department of Radiology, University of Pittsburgh Medical Center, Pittsburgh, PA. 2 Department of Neurosurgery, University of Pittsburgh Medical Center, 200 Lothrop St, Ste B-400, Pittsburgh, PA 15213. Address correspondence to R. F. Sekula ([email protected]). 3 Department of Otolaryngology, University of Pittsburgh Medical Center, Pittsburgh, PA. Neuroradiology/Head and Neck Imaging • Clinical Perspective This article is available for credit. Supplemental Data Available online at www.ajronline.org. AJR 2016; 206:595–600 0361–803X/16/2063–595 © American Roentgen Ray Society Keywords: cranial nerves, microvascular decompres- sion, neurovascular compression, trigeminal nerve, trigeminal neuralgia DOI:10.2214/AJR.14.14156 Received November 24, 2014; accepted after revision August 18, 2015. the trigeminal nerve and permanently sep- arated from the trigeminal nerve, typically with hand-rolled pledgets made of soft ma- terial (e.g., shredded Teflon [DuPont]). Ab- lative procedures, which injure the Gasseri- an ganglion, include percutaneous balloon rhizotomy, percutaneous glycerol rhizoto- my, and percutaneous radiofrequency rhi- zotomy. Ablative procedures, which injure a portion of the cisternal segment of the tri- geminal nerve, include stereotactic radiosur - gical rhizolysis (e.g., using the CyberKnife [Accuray] or Gamma Knife [Elekta Instru- ments]) [6]. Of all the operative procedures for TN, MVD is the most durable with the lowest risk of sensory deficits [7–10]. Success rates for MVD, however, depend on a number of clinical features and the imag- ing findings. Paroxysmal pain, the presence of trigger points, and a positive response to carbamazepine all portend a good outcome, whereas patients with a constant aching pain have less-successful outcomes [7, 11]. Al- though vascular compression or contact may occur at one or more points along the nerve’s cisternal segment, not all vascular compres- sion of the nerve is equally clinically relevant [12–14]. Thus, it is important for clinicians to understand not only which imaging tech- niques are optimal for detecting neurovascu- lar compression but also which segments of the trigeminal nerve are vulnerable to symp- tomatic vascular compression. The purpose of this article is to review the trigeminal nerve’s anatomy relevant to TN and to describe the imaging appearance of T rigeminal neuralgia (TN) is a de- bilitating disorder that presents with a sudden onset of severe, unilateral, paroxysmal, and lan- cinating pain in one or more of the distribu- tions of the trigeminal nerve. Although TN has many causes, vascular compression of the trigeminal nerve is a known cause, as first suggested by Dandy in 1932 [1, 2]. This is analogous to hemifacial spasm, which is often caused by vascular compression of fa- cial nerves. In addition to arterial compres- sion, a number of other lesions occurring anywhere along the trigeminal nerve, from the pons to the trigeminal nerve’s most distal branches, can cause facial pain. Such lesions include tumors, arachnoid cysts, idiopathic inflammation, injury, demyelination (e.g., multiple sclerosis), and others. Vascular decompression of the trigemi- nal nerve was first reported by Gardner and Miklos in 1959 [3], and its description was substantially refined and popularized by Jan- netta and colleagues [4] with the addition of microscopic illumination. Antiseizure med- ications such as carbamazepine are often the first-line treatment for TN, and opera- tive procedures traditionally are considered for patients, even elderly patients, for whom symptoms become refractory to medication or for whom the adverse effects of medica- tion are intolerable [5]. Operative treatments for TN include microvascular decompression (MVD) and a variety of ablative procedures. With MVD, the compressing or contacting vessel is decompressed or transposed from OBJECTIVE. Trigeminal neuralgia is a debilitating facial pain disorder, frequently caused by vascular compression of the trigeminal nerve. Vascular compression that results in trigeminal neuralgia occurs along the cisternal segment of the nerve. CONCLUSION. Imaging combined with clinical information is critical to correctly identify patients who are candidates for microvascular decompression. The purpose of this article is to review trigeminal nerve anatomy and to provide strategies for radiologists to rec- ognize important MRI findings in patients with trigeminal neuralgia. Hughes et al. MRI of Trigeminal Nerve in Trigeminal Neuralgia Neuroradiology/Head and Neck Imaging Clinical Perspective Downloaded from www.ajronline.org by 27.79.76.86 on 05/11/23 from IP address 27.79.76.86. Copyright ARRS. For personal use only; all rights reserved
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