Abstract
Although pathologic vascular contact between the occipital artery and the greater
occipital nerve (GON) at the crossing point in the nuchal subcutaneous layer can cause
occipital neuralgia, referred hemifacial trigeminal pain from chronic occipital neuralgia
owing to this cause is extremely rare.
A 61-year-old female patient with left-sided occipital neuralgia for 4 years presented
with a new onset of left-sided hemifacial pain. Decompression of the left GON from
pathologic contacts with the occipital artery resulted in immediate relief for hemifacial
pain and chronic occipital neuralgia. The present case implies that sensitization
and hyperactivity of the trigeminocervical complex that receives the convergent input
from trigeminal and high cervical occipital nociceptive pathways can be a pathogenic
mechanism in referred hemifacial pain from occipital neuralgia. In the present case,
a branching tributary of the occipital artery at the crossing point forming a constricting
loop above the course of the GON was found to be the cause of entrapment. Because
the occipital artery is reported to be consistently located superficial to the GON
at the crossing point, a spatial relationship between the occipital artery and the
GON rather than a mere adhesion or contact might have pathologic significance in the
development of occipital neuralgia.
Keywords
greater occipital nerve - occipital artery - occipital neuralgia - surgical decompression
- trigeminocervical complex
