Fluoroscopy and Sonographic Guided Injection of Obliquus Capitis Inferior Muscle in an Intractable Occipital Neuralgia

Abstract

Occipital neuralgia is a form of headache that involves the posterior occiput in the greater or lesser occipital nerve distribution. Pain can be severe and persistent with conservative treatment. We present a case of intractable occipital neuralgia that conventional therapeutic modalities failed to ameliorate. We speculate that, in this case, the cause of headache could be the greater occipital nerve entrapment by the obliquus capitis inferior muscle. After steroid and local anesthetic injection into obliquus capitis inferior muscles under fluoroscopic and sonographic guidance, the visual analogue scale was decreased from 9-10/10 to 1-2/10 for 2-3 weeks. The patient eventually got both greater occipital neurectomy and partial resection of obliquus capitis inferior muscles due to the short term effect of the injection. The successful steroid and local anesthetic injection for this occipital neuralgia shows that the refractory headache was caused by entrapment of greater occipital nerves by obliquus capitis inferior muscles.

Sonographic Evaluation of the Greater Occipital Nerve in Unilateral Occipital Neuralgia

“…At this most proximal point, Janis et al 13 described the source of compression existing within a tight fascia surrounding the belly of the obliquus capitis inferior near the spinous process. Previous studies have described treatment at this site with neurolysis of the greater occipital nerve and sectioning of the obliquus capitis inferior, which resulted in favorable outcomes in selected patients 8 , 14 …”

“…Previous studies have described treatment at this site with neurolysis of the greater occipital nerve and sectioning of the obliquus capitis inferior, which resulted in favorable outcomes in selected patients. 8,14 To have qualified for this study, the patient must have fulfilled at least 2 of the 3 criteria set forth by the International Headache Society. 1 We attempted to strengthen the homogeneity of the sample population by augmenting the qualification that 1 of the 2 International Headache Society criteria must have included a positive criterion B (Table 1) with the course of the greater occipital nerve established by sonography.…”

“…3,4 Increases in the cross-sectional areas of nerves in cases of peripheral neuropathy have been well described, especially for the ulnar and median nerves. [5][6][7] Although a pathologic report describing axonal swelling of the greater occipital nerve in a patient with occipital neuralgia was previously reported, 8 to our knowledge, sonographic evidence of greater occipital nerve swelling has not been reported.…”