MR Neurographic Evaluation of Facial and Neck Pain: Normal and Abnormal Craniospinal Nerves below the Skull Base

Abstract

Cranial nerve disease outside the skull base is a common cause of facial and/or neck pain, which causes significant disability for patients and frustration for clinicians. Neuropathy in this region can be traumatic, idiopathic, or iatrogenic secondary to dental and surgical procedures. MR neurography is a modification of conventional MRI techniques dedicated to evaluation of peripheral nerves and is being increasingly used for imaging of peripheral neuropathies at various sites in the body. MR neurography facilitates assessment of different causes of craniofacial pain and cranial nerves and allows elegant depiction of a multitude of regional neuropathies. This article discusses the anatomy, pathologic conditions, and imaging findings of the commonly implicated but difficult to image infratentorial nerves, such as the peripheral trigeminal nerve and its branches, facial nerve, glossopharyngeal nerve, vagus nerve, hypoglossal nerve, and greater and lesser occipital nerves. RSNA, 2018.

Imaging Evaluation of Patients with Cranial Nerve Disorders

“…All extracranial cranial nerves close to the sinuses and temporal bone can be affected by fungal infection and aggressive bacterial infection: frontal sinus (V 1 ), ethmoid and sphenoid (II, III, IV, V 1 , V 2 , VI-orbital apex and superior orbital fissure), temporal bone (VII). Periapical and periodontal dental disease may cause maxillary (V 2 ) and mandibular (V 3 ) neuropathy which can be seen on postcontrast FS T1-WI or MR neurography [27].…”

Invited Commentary on “MR Neurographic Evaluation of Facial and Neck Pain”

“…Chhabra et al (7) illustrate many applications of MR neurography in the head and neck, and it is my opinion that MR neurography holds potential for even more. One possible application of head and neck MR neurography is assessment for perineural tumor spread.…”

“…In summary, this timely article by Chhabra et al (7) describes how to perform MR neurography of the head and neck, illustrates MR neurographic applications in diagnostic evaluation of face and neck pain, and would serve as an excellent reference for any radiologist interested in adding head and neck MR neurography to his or her clinical practice. The authors' expert handling of the subject material renders advanced techniques, difficult anatomy, and associated disease easily accessible, and their impressive case material makes it easy to foresee increasing demand for head and neck MR neurography from our referring physicians as well as from patients experiencing face and neck pain.…”

The cranial nerves: extensions of the central nervous system or components of the peripheral nervous system - how should we evaluate them?

“…Such sequences can also be used for the assessment of infectious processes and tumors, as well as for the assessment of congenital, traumatic, and vascular diseases of the cranial nerves, as discussed and illustrated in the pictorial essay authored by Dalaqua et al ( 7 ) , published in this issue of Radiologia Brasileira. The muscle fiber integrity in the muscle groups innervated by a given nerve can be evaluated in T1-weighted sequences, and short-tau inversion-recovery sequences can be used in order to map the extent of denervation, thus allowing the assessment not only of the anatomy of a nerve but also of its function ( 2 , 8 ) .…”

“…Another way to assess the peripheral nervous system is with neurography ( 8 , 9 ) . Using several 3D sequences, including 3D fast imaging with steady-state precession and 3D short-tau inversion-recovery sequences, together with intravenous contrast administration, the neurography examination allows the evaluation of the course of the nerve and its thickness, as well as the organization of the fascicles, signal intensity, and pattern of contrast enhancement.…”