Diagnosis and treatment of occipital neuralgia: focus on greater occipital nerve entrapment syndrome

Background: Occipital neuralgia is defined as paroxysmal shooting, or stabbing pain in the posterior part of the scalp, in the distribution of the greater and lesser occipital nerves. Occipital neuralgia may present only as an intermittent stabbing pain, but different opinions exist on its cause and diagnostic criteria. Current Concepts: According to the latest version of headache classification, only paroxysmal stabbing pain is included in the diagnostic criteria, and persistent aching pain is excluded. Pain intensity was also limited to severe cases. It has therefore become difficult to classify existing occipital neuralgia, whose main symptom is persistent pain rather than paroxysmal stabbing pain. Occipital neuralgia is classified as either idiopathic or secondary. Secondary occipital neuralgia is caused by structural lesions innervating the trigeminocervical complex (TCC) in the upper spinal cord, the dorsal root of second cervical cord, and the greater occipital nerve (GON). Discussion and Conclusion: Although idiopathic occipital neuralgia has no cause, the entrapment of the GON in the tendinous aponeurotic attachment of the trapezius muscle at the superior nuchal line has recently been proposed as an etiology. Chronic, irritating afferent input of occipital neuralgia caused by entrapment of the GON seems to be associated with sensitization and hypersensitivity of the second-order neurons in the TCC receiving convergent input from trigeminal and occipital structures. TCC sensitization induces referred pain in the facial trigeminal area.