Referred Trigeminal Pain from Greater Occipital Nerve Entrapment: Importance of Accurate Greater Occipital Nerve Decompression

Abstract

Occipital neuralgia is a unilateral or bilateral paroxysmal, shooting, or stabbing pain in the posterior part of the scalp, in the distribution of the greater, lesser occipital nerves 7) . In Trigeminocervical complex (TCC) sensitization by chronic entrapment of the greater occipital nerve (GON) often causes difficult-to-understand referred trigeminal facial pain along with occipital neuralgia. This report emphasizes the importance of accurate diagnosis and GON decompression by describing a case of a 51-year-old female patient with referred trigeminal pain from occipital neuralgia misdiagnosed as chronic migraine. The patient underwent incomplete decompression surgery. She presented with a relentless stinging and stabbing pain in her left hemiface and temporo-occipital area for 8 years. The pain occurred suddenly without improvement after long-term medical and injection treatment. She was diagnosed with chronic migraine and underwent so-called "migraine surgery" three years ago, but to no avail. Incomplete decompression of the bilateral GONs within the trapezial tunnel was confirmed under a microscopic oblique-paramedian approach. After accurate decompression, the chronic stabbing pain in the left facial and temporo-occipital region disappeared. Only intermittent numbness was felt. It is important to recognize occipital neuralgia caused by chronic GON entrapment and referred facial pain caused by TCC sensitization. Referred pain still often seems to be misunderstood as various other diseases. Direct decompression of the trapezial tunnel using a neurosurgical microscopic approach based on an accurate assessment of anatomical considerations may be important for GON decompression.