Ultrasonographic Diagnosis of Recurrent Occipital Neuralgia Caused by Venous Plexus Enlargement

Introduction

According to the International Headache Society (IHS), occipital neuralgia is defined as a paroxysmal stabbing pain, with or without persistent aching between paroxysms, in the distributions of the greater, lesser, and third occipital nerves and sensory disturbances which usually improve with local anesthetic infiltrations of the nerve (Cho JC et al. J Ultrasound. 2012; 31(1):37–42).

The pain starts in the occipital region and radiates to the vertex region. It is usually unilateral and can also affect other areas like retroauricular, frontal, temporal and parietal zones.

Many etiologies that are associated with this pathology such as trauma, infections, tumors, rheumatoid arthritis, neuralgia post-surgery and vascular malformation, among others, which have been described (Samer Narouze. Headache. 2016,56(4): 801–7; Cesmebasi A et al. Clin Anat. 2015, 28(1):101–8).

It has been reported that the greater occipital nerve (GON) is affected in 90% of cases. The GON mostly originates in C2 (in minor part from C3) and then it continues between the obliquus capitis inferior muscle and the semispinalis capitis muscle. Then, it extends to the trapezius and pierces the semispinalis capitis at the level of superior nuchal line where the nerve becomes subcutaneous in this plane. The GON is medial to the occipital artery. However, it has been described with variations in its itinerary.

Due to the subcutaneous location of the GON, ultrasound is useful to visualize it and this allows identification of abnormal structures that can produce entrapment of the occipital nerve. Apart from that, it can be useful when precision is needed for occipital nerve blocks (Samer Narouze. Headache. 2016, 56(4):801–7).

In this article we describe the case of recurrent occipital neuralgia in which we decided to perform ultrasonography and we observed venous plexus enlargement and entrapment of the GON, causing the headache.