Headache is a common disease encountered in clinical pain management, and there are many causes of it. Among them, there is a group of headache with cervical pressure and headache related to cervical nerve irritation, which has a high incidence, complex clinical manifestations, long duration of headache and difficult treatment, and has attracted increasing attention.
In 1995, Bogduk pointed out that cervical degeneration and muscle spasm are the direct causes of cervicogenic headache. He believed that cervicogenic headache could also be called posterior cervical nerve branch headache. Recently, some scholars have also referred to cervicogenic headache as high neurogenic cervical spondylosis.
I. 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 sensory root fibers of nerve roots are stimulated to cause neurogenic pain, while their ventral motor nerve roots are stimulated with myogenic pain.
(I) Relationship between anatomical basis and cervicogenic headache
The higher cervical nerves include the 1st to 4th cervical nerves, which are closely related to headache. Originally, it has been thought that the 1st cervical nerve is a motor nerve and does 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 form the greater occipital nerve, the lesser occipital nerve, and the 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 semispinalis muscle.
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 muscle of the head, 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 muscle tissue. Inflammation, ischemia, injury, compression and even inappropriate massage of the soft tissue can affect the function of the nerves and trigger cervicogenic headache.
(B), cervical spine and intervertebral disc degeneration causing intervertebral foramen stenosis
The cervical intervertebral disc degeneration or protrusion becomes “hard” by “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 through the intervertebral foramen can be stimulated by compression, strain, angulation and inflammation.
(C), cervical intervertebral disc degeneration, herniation caused by non-bacterial inflammation
Cervical disc degeneration, herniation, and release of disc material can directly cause nonbacterial inflammation and edema; as the adult intervertebral disc is normally non-vascular is an immune immune immune immune immune immune system views the disc material as a foreign body and produces immune rejection inflammation, causing cervical discogenic radiculitis. In addition to directly producing radicular pain, the terminal release of inflammatory mediators that cause soft tissue inflammation in the distribution area can also produce pain, which is the mechanism by which intractable cervicogenic headache occurs in some patients.
(iv) Muscle spasm
Cervicogenic headache can also arise from the muscle tissue of the neck. On the one hand, the nerve roots, especially the motor nerve roots (anterior roots) on its ventral side, can cause reflex cervical muscle spasm when they are compressed or inflamed; 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 and nerve endings that travel through the soft tissue to produce pain. The nerve trunks and nerve endings can be directly stimulated to produce pain.
Long hours of work with low head, 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 the common causes of cervicogenic headache in adolescents.
II. Clinical manifestations of cervicogenic headache
The age of patients with cervicogenic headache is mostly between 20 and 60 years old, but it is not uncommon for young people to suffer from cervicogenic headache. This disease is more common in females. In the early stage, it is mostly discomfort in the occipital area, behind the ear, and the lower part of the ear, but later it turns into stuffiness or soreness, and gradually pain appears. The pain may extend to the forehead, D, top, and neck. In some cases, pain in the upper extremity of the ipsilateral shoulder and back may occur at the same time.
The pain may have a remission period. As the disease progresses, the pain gradually worsens, persists, shortens the remission period, and worsens episodically. Cold, exertion, alcohol consumption, and emotional stress can trigger the pain to worsen.
Cervicogenic headache often does not manifest at the site of its pathological changes, but the pain site is often indistinct, diffuse and distantly involved, and may present with involvement pain similar to sinus or eye disease. In some patients, the pain is accompanied by tinnitus, ear swelling, eye stuffiness, and neck stiffness. Most patients prefer to apply hand pressure to the painful area for relief during painful episodes. Oral non-steroidal anti-inflammatory drugs can reduce the headache.
The incidence of cervicogenic headache is higher in ambulatory workers. Those with longer duration of the disease have decreased work efficiency, reduced concentration and memory, depressed mood, irritability, irritability, easy fatigue, and significantly reduced quality of life and work.
Examination may reveal significant pressure pain in the paracervical vertebrae below the ear and behind the inframammary region. Those with longer disease duration may have pressure pain points at the back of the neck, D, top, and occipital areas. In some patients, local tactile and pinprick sensations are diminished, and some patients have decreased sensation of smell, taste and tongue and cheek on the affected side. Some patients may have positive pressure-top test and head-rest test. However, there are also patients with no obvious signs. Some patients have more gray hair on the affected side than on the opposite side.
The cervical intervertebral foramen is narrowed, the anterior and posterior edges of the vertebral body are enlarged, or the spinous process is widened and thickened, and the supraspinous ligament is calcified.
III. Diagnosis
(A) Unilateral headache without involvement of the contralateral side. The diagnosis of cervicogenic headache can be quickly determined according to the location, nature and signs of pain and excluding other organic diseases that can cause headache. The upper paracervical spine, the posterior part of the inferior mastoid process, and the pressure points in the head are important in the diagnosis of cervicogenic headache. However, it is important to note that a significant number of patients have typical cervicogenic headache symptoms but lack signs of radicular irritation and no positive findings on imaging.
For patients with atypical symptoms and signs, a diagnostic cervical nerve block with local anesthetics or an experimental treatment with anti-inflammatory and analgesic drugs injected into the second cervical transverse process can be performed. If the pain is rapidly reduced or disappears after the injection, it helps to establish the diagnosis.
(B) Signs and symptoms of cervical involvement.
1, pain characteristics.
(1) The pain is similar in nature and is caused by neck movements and/or a single long-lasting head posture.
(2) The distribution and characteristics of the pain are similar and can be caused by extrinsic pressure from the unilateral upper neck, posterior or occipital region.
(2) Non-root pain in the unilateral neck, shoulder and upper extremity.
3. Decreased range of motion of the cervical spine.
IV. Treatment of cervicogenic headache
(I) General treatment
For patients with short duration and mild pain, rest, head and neck acupuncture, traction and physiotherapy can be taken together with oral NSAIDs. A part of the patient’s condition can be improved. But the massage should be cautious, many patients aggravated by massage, some also occurred serious injury.
(B), paracervical lesion injection
Puncture injection of anti-inflammatory and analgesic drugs in the 2nd cervical transverse process has good therapeutic effect on most patients with cervicogenic headache. The drug solution can flow into the 1st and 3rd cervical nerves and surrounding soft tissues by diffusion in the intertransverse process groove, exerting anti-inflammation, analgesia and promoting the recovery of nerve function. The efficacy is better because the medicinal solution is injected directly into the lesion area.
(iii) Cervical epidural cavity injection
Injections via the cervical paravertebral and head pressure pain points have poor therapeutic effects, mostly because the lesion is located in the spinal canal, and discogenic radiculitis is common, and the drug injected into the paravertebral area cannot reach the lesion. The cervical epidural cavity injection method can be used. For unilateral pain, puncture can be made at the spinous process gap of the 2nd and 3rd cervical vertebrae, and the oblique side of the needle is turned to the affected side for placement of the tube, or puncture can be made at the spinous process gap of the 5th and 6th cervical vertebrae, and the tube is placed to the cephalic side for drug injection treatment.
(iv) Cervical nerve destruction treatment and surgical treatment
If the non-surgical treatment is not effective, the nerve root should be considered for surgical treatment because of the abnormal bony changes in the spinal canal. For patients with contraindications to surgery, or greater risk of surgery, cervical nerve ethanol block can be used with the consent of the patient, and the treatment should be carried out under X-ray fluoroscopic guidance. Radiofrequency thermocoagulation to destroy the posterior branch of the cervical nerve may also be used for treatment.