Headache is a common disease encountered in clinical pain management, and there are many causes of it. Among them, there is a type of headache with neck pressure and headache related to stimulation of cervical nerve, which has a high incidence, complex clinical manifestations, long duration of headache, and difficulty in treatment, and has attracted increasing attention. This kind of headache was once called “neurogenic headache”, “neurovascular headache”, “occipital neuralgia”, “otalgia “neuropathic headache”, “neurovascular headache”, “occipital neuralgia”, “otalgia”, etc. In the past, it was thought that this kind of headache was caused by the action of the nerves and blood vessels in the head under the action of pathogenic factors, so the treatment was mainly oral non-steroidal anti-inflammatory drugs, head acupuncture, physical therapy, massage, painful head injections, and nerve trunk block in the head, including occipital or auricular nerve block. However, a considerable number of patients do not improve or the effect of treatment does not last, resulting in a situation where “the patient has a headache and the doctor has a headache”. Pathogenesis of cervicogenic headache Cervicogenic headache can be divided into neurogenic pain and myogenic pain according to the different parts of the nerve roots involved. The stimulation of sensory root fibers of nerve roots causes neurogenic pain, while its ventral motor nerve roots are stimulated with myogenic pain. (A) Relationship between anatomical basis and cervicogenic headache The high cervical nerve includes the 1st to 4th cervical nerve, which is closely related to headache. Originally, it was thought that the 1st cervical nerve was a motor nerve and did not contain sensory fibers. Recent studies have found that the 1st cervical nerve emits a posterior branch of the 1st cervical nerve above the posterior atlantoaxial arch, which distributes to the posterior rectus muscle of the head and the superior and inferior oblique muscles, and this posterior branch of the nerve contains abundant sensory nerve fibers. The 2nd cervical nerve emerges from the intervertebral space and its posterior branches are divided into a medial branch, a lateral branch, a superior communicating branch, an inferior communicating branch, and an inferior cephalic oblique branch. The medial branch, together with fibers from the 3rd cervical nerve, forms the greater occipital nerve, lesser occipital nerve, and greater auricular nerve, which are the main nerves that conduct cervicogenic headaches. The lateral branch distributes to the longest cephalic muscle, the cephalic splinters, and the cephalic semispinals. The superior communicating branch of the posterior branch of the 2nd cervical nerve connects with the posterior branch of the 1st cervical nerve in the intersegmental sulcus of the transverse process, and its inferior communicating branch connects with the posterior branch of the 3rd cervical nerve down into the articular eminence of the 2nd and 3rd cervical vertebrae. The posterior branches of the 1st, 2nd, and 3rd cervical nerves are connected by traffic branches to form a nerve ring (or called the superior cervical plexus, or posterior cervical plexus of Cruveihier). The 3rd cervical nerve exits the intervertebral foramen posterior to the vertebral artery and gives rise to the posterior branch of the 3rd cervical nerve, the medial branch of which distributes to the multifidus muscle and the lateral branch to the longest cephalic muscle, the cephalicus muscle, and the cephalicus semispinalis muscle. These nerve branches are close to the angle of the vertebral artery before entering the cranial cavity through the foramen magnum, and are susceptible to irritation and injury by the vertebral prominence and muscles at the attachment. Compression and stimulation of these nerves may result in hyperalgesia, hypersensitivity or sensory loss on the scalp. The terminal fibers from the afferent branches of the olfactory, facial, linguopharyngeal, vagus, and trigeminal nerves are connected to the afferent fibers of the posterior roots of the 1st to 3rd cervical nerves in the 1st to 2nd posterior horn of the cervical medulla. The sensory range of these cervical nerves may extend forward to the forehead and infraorbital region, and may present with involvement head pain, tinnitus, eye swelling, and altered olfaction and taste when stimulated by entrapment or inflammation, similar to the manifestations of sinus, ear, or eye disease. Most of the path of the 1st, 2nd and 3rd cervical nerves leaving the spinal canal is within the soft muscular tissues. Inflammation, ischemia, injury, compression and even inappropriate massage of the soft tissues can affect the function of the nerves and trigger cervicogenic headache. (2) Cervical spine and intervertebral disc degeneration causes intervertebral foraminal stenosis. The cervical intervertebral disc degeneration or protrusion becomes “hard” through “fibrosis”, and later, with tissue repair and calcification, osteophytes can be formed. The vertebrae with osteophytes are in close proximity to each other, and the lateral leptomeningeal joints are also in close proximity to each other, losing the normal relationship of the articular surfaces and deforming the intervertebral foramen. Violation of the intervertebral foramina and encroachment of the intervertebral foraminal space can cause pain and neurological dysfunction. The size and shape of the intervertebral foramina depend heavily on the integrity of the intervertebral discs. When the spine is at normal rest, a normal disc is able to maintain the vertebral body and posterior joints separate from each other, leaving the foramen intact. When the neck is active, the disc is deformed as one vertebra slides over another. Normal discs allow for deformation within physiological limits and can recover. When a disc herniates, either statically or dynamically, it can affect the interrelationship between the parts of adjacent vertebrae and change the size and shape of the intervertebral foramen. At this time, the nerves and blood vessels passing within the intervertebral foramen can be stimulated by compression, strain, angulation and inflammation. (iii) Non-bacterial inflammation caused by cervical disc degeneration and herniation Cervical disc degeneration and herniation, and release of disc material can directly cause non-bacterial inflammation and edema; as the adult intervertebral disc without blood vessels under normal circumstances is an immune immune immune immune area, the immune system regards the disc material as a foreign body and produces immune rejection inflammation, causing cervical discogenic radiculitis. In addition to direct production of radicular pain, terminal release of inflammatory mediators causing soft tissue inflammation within the distribution area can also produce pain, which is the mechanism by which intractable cervicogenic headaches occur in some patients. (iv) Muscle spasm Cervicogenic headache can also arise in the muscle tissue of the neck. On the one hand, compression or inflammation of the nerve roots, especially the ventral motor nerve roots (anterior roots), can cause reflex cervical muscle spasm; on the other hand, persistent chronic muscle spasm causes tissue ischemia, metabolites gather in the muscle tissue, and the end products of metabolism cause myofasciitis and produce pain, and can directly stimulate the nerve trunks traveling in the soft tissue. On the other hand, persistent chronic muscle spasm causes tissue ischemia, metabolic products accumulate in muscle tissue, and metabolic end products cause myofasciitis, resulting in pain, and can directly stimulate the nerve trunks and nerve endings that travel through the soft tissue to produce pain. Long hours of work with head down, continuous muscle contraction to maintain posture, which reduces muscle blood supply, causes muscle spasm, and makes ligaments and myofascia prone to injury; long and tedious mental talk or physical labor, which is most likely to cause tension in the nerves and muscles of the neck among all parts of the body, are common causes of cervicogenic headache in adolescents.