<Ol> <Li> The space between the C1 and C2 vertebrae </Li> <Li> The atlantoaxial ligament as the dorsal ramus emerges </Li> <Li> The deep to superficial turn around the inferiolateral border of the obliquus capitis inferior muscle and its tight investing fascia </Li> <Li> The deep side of semispinalis capitis, where initial piercing can involve entrapment in either the muscle itself or surrounding fascia </Li> <Li> The superficial side of semispinalis capitis, where completion of nerve piercing muscle and its fascia again poses risk </Li> <Li> The deep side of the trapezius as the nerve enters the muscle </Li> <Li> The tendinous insertion of the trapezius at the superior nuchal line </Li> <Li> The neurovascular intertwining of the greater occipital nerve and the occipital artery </Li> </Ol> <Li> The space between the C1 and C2 vertebrae </Li> <Li> The atlantoaxial ligament as the dorsal ramus emerges </Li> <Li> The deep to superficial turn around the inferiolateral border of the obliquus capitis inferior muscle and its tight investing fascia </Li>

Pain at base of skull and behind eyes