The greater occipital nerve is the largest of the three occipital nerves, a branch of the C2 posterior primary ramus that supplies sensation to the posterior scalp all the way to the vertex. It is the most commonly implicated nerve in occipital neuralgia, producing a characteristic unilateral pain that radiates from the occipital base over the scalp toward the eye. Its course through and beneath the semispinalis capitis and trapezius muscles makes it susceptible to entrapment from cervical muscle tension and joint dysfunction.
| Origin | Posterior primary ramus of C2 |
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Occipital neuralgia produces severe, lancinating or aching pain starting at the occipital base and radiating along the distribution of the nerve over the posterior and lateral scalp, often with associated hypersensitivity of the scalp to touch. The diagnosis is confirmed by reproduction of symptoms with pressure at the nerve's emergence point 2 centimetres lateral to the occipital protuberance and relief with local anaesthetic injection at that point. Greater occipital nerve blocks are both diagnostic and therapeutic.
Greater occipital nerve entrapment or irritation producing severe unilateral posterior scalp pain radiating from the occipital base to the vertex, confirmed by tender point palpation at the nerve emergence site and relief with diagnostic nerve block.
