I. Pathogenesis of cervicogenic neck, shoulder and back pain
Just as lumbar disc degeneration, lumbar small joint degeneration and lumbar myofascial ligament lesions can cause lumbosacral hip and leg pain, cervical disc small joint and myofascial ligament lesions can cause pain in the upper back and upper extremities of the neck and shoulder.
Compression of the cervical spinal nerve root trunk by cervical disc herniations, locally enlarged ligamentum flavum, and bony redundancies is an important group of causes. However, it is not uncommon to find cervical disc herniations, locally enlarged ligamentum flavum, and bony redundancies that also cause significant compression of the cervical spinal nerve trunk on imaging without clinical symptoms. On the other hand, there is a significant proportion of patients who do have severe and persistent neck, shoulder, and arm pain without these obvious imaging changes.
For the latter group of phenomena, studies in the last decade have suggested that the involvement of new nociceptive nerve fibers and sympathetic nerves in the fibrous annulus of the degenerated disc is an important cause of pain of cervical origin, both in the presence and absence of significant compression. Taking cervical disc degeneration as an example, the discs responsible for the development of cervicogenic neck, shoulder and back pain are C56, C45 and C67 in that order.
II. Pathogenesis of cervicogenic headache
Sjaastad, a Norwegian neurologist, first proposed the concept of “cervicogenic headache” (CEH) in 1983 in the journal Headache, and then proposed the definition and diagnostic criteria of cervicogenic headache in 1990 and 1998.
1.Cervical symptoms and signs.
(1)The headache is aggravated by the following conditions: when the neck is moved and/or the head is maintained in an abnormal position; when pressure is applied to the upper neck or occipital area on the side of the headache.
(2) Restricted range of motion of the neck;
(3) Ipsilateral non-root pain in the neck, shoulder or upper extremity, or occasional root pain in the upper extremity.
2.Diagnostic anesthetic block can clarify the diagnosis;
(3) Unilateral headache without transfer to the contralateral side.
He proposed that headache is caused by organic or functional lesions of the cervico-occipital and/or shoulder tissues, chronic usually unilateral head pain, a group of syndromes, and the nature of the pain is referred pain, and diagnostic anesthetic block is one of the diagnostic criteria for cervicogenic headache. Patients mostly present with pain in the occipital region, which may radiate to the top and temporal and frontal areas of the affected side of the head. The headache may present on one side, or alternately on both sides. A small number of patients have blurred vision, ear discomfort and tinnitus. Patients tend to have stiffness in the neck, and the headache worsens with head and neck movement or continuous fixation of the head and neck position.
In 2004, the International Headache Society (IHS) separated craniocervical tension headache, whiplash headache and retropharyngeal tendonitis headache from cervicogenic headache in the first edition of the second edition of the classification of headache disorders. A narrower definition of cervicogenic headache was developed.
Herniated discs in the upper cervical region, localized enlarged ligamentum flavum and bony redundancy, and compression of the cervical spinal nerve, which constitutes the occipito-occipital nerve and the third occipital nerve, by the cervical occipital myofascia are an important group of causes. However, there is also a significant proportion of patients with severe and persistent headache or head, neck, shoulder, and arm pain without these obvious imaging changes.
In our treatment of upper extremity radicular pain associated with cervical disc herniation using radiofrequency cervical discoplasty, we have repeatedly induced cephalofacial pain during treatment by stimulating the discs, which patients had and mostly still have, and even continue to feel. The pain disappeared either briefly or permanently after the molding procedure. After repeated observations and review of the literature, we believe that there are neural structures associated with headache within the fibrous annulus and posterior longitudinal ligament of the degenerated cervical disc.
Anatomical findings suggest that fibers emanating from the cervical sympathetic ganglion anastomose with the corresponding spinal branches of the C2-6 cervical nerves to form sinus nerves distributed through the intervertebral foramina into the spinal canal and peri-intervertebral tissues, including the posterior longitudinal ligament. Immunohistochemical studies have confirmed the distribution of a large number of sensory and sympathetic nerve fibers not only in the posterior longitudinal ligament but also in the intervertebral disc. Gu Tao (2008) found that a large number of sympathetic postganglionic fibers in the posterior longitudinal cervical ligament of experimental rabbits were mainly distributed in a network of intersecting nerves and were very densely distributed in the intervertebral disc area. Anatomically, it is known that the sinus vertebral nerve enters the spinal canal and sends ascending and descending branches up and down in the intervertebral disc area and continues distally and deeply into the network.
Under normal physiological conditions the sympathetic nerves and the sensory nerves that feel pain do not cross functionally. However, after nerve injury the two become anatomically coupled not only through sympathetic odontogenesis, but also chemically coupled through the influence of sympathetic transmitters. Sympathetic nerves exacerbate painful stimuli by releasing amine transmitters such as neuropeptide Y, which causes sensory nerves to release more substance P. Sympathetic nerve fibers in the outer annulus of the cervical disc and the posterior longitudinal ligament are the neural basis not only for cervicogenic neck, shoulder, and arm pain, but also for cervicogenic head and facial pain.
Bogduk believes that the structures innervated by the high cervical nerves (C1-C3), including the circumoccipital and cricoarticular joints C23 and C34, the intervertebral discs, and the associated musculofascial joints, are involved in the development of cervicogenic headache through the afferent fibers of the above-mentioned high cervical nerves and their central convergence with the trigeminal nerves, causing the center to misinterpret the headache, i.e., cervicogenic headache is The cervicogenic headache is an involved pain. In contrast, the ophthalmic branch of the trigeminal nerve has the greatest convergence with the high cervical nerve, so cervicogenic headache is often found in the frontal region.
Most of the cervicogenic headaches we see clinically are related to cervical degeneration above cervical 4. However, in our radiofrequency treatment of C56, C67, and C45, cervical discs that are closely associated with neck, shoulder, and arm pain, we have also induced several instances of pre-existing headaches and more lasting relief after radiofrequency molding. Not coincidentally, the same finding was reported by Diener (2007), a German orthopedic surgeon. However, there is no evidence whether there is convergence of the fibrous rings of the low cervical discs C56, C67 and C45 and the posterior longitudinal ligament with the trigeminal nerve. However, because of the networked nature of the spinal nerve and sympathetic nerve connections, it is unlikely that such a network is separate in the upper and lower cervical segments, so the convergence with the trigeminal nerve should also be more pronounced in the upper cervical segment and gradually weaken in the lower cervical segment.
Common treatment methods for cervicogenic pain
The common treatments for cervicogenic pain mentioned in this paper are also the treatments that anesthesiologists specialize in.
(i) Conventional pharmacotherapy Non-steroidal anti-inflammatory drugs and muscle relaxants, tricyclic antidepressants.
(ii) Injection therapy and acupuncture treatment
Injecting anesthetic and analgesic anti-inflammatory drugs in the corresponding focal areas and around the nerves has obvious diagnostic effects, and at the same time, it can play a therapeutic role such as pain relief and relief of local muscle spasm. Injection therapy is an effective means of pain relief in both the acute and chronic phases. Needle knife treatment, on the other hand, has a local micro-cutting and loosening effect, sometimes in line with the injection site, and separate or simultaneous treatment depends on the experience of the physician depending on the condition.
1, cervical transverse process injection (available needle knife treatment) is particularly suitable for patients with localized pressure pain.
Puncture injection of anesthetic analgesic and anti-inflammatory drugs in the 2nd cervical transverse process has good therapeutic effect on most patients with cervicogenic headache. Injections of anesthetic analgesic and anti-inflammatory drugs in the 5th and 6th cervical transverse process have been shown to be effective in most patients with cervicogenic neck, shoulder and arm pain. The drug solution injected into the 2nd cervical transverse process diffuses in the intertransverse process sulcus and can flow into the 1st and 3rd cervical nerves and surrounding soft tissues, exerting anti-inflammatory, analgesic and stabilizing effects on nerve responsiveness. Similarly, it is also suitable for the injection treatment of the lower cervical spine.
2.Joint surface injection
Cervical 23 joint and cervical 34 synovial joint surface injection (available for acupuncture treatment) is particularly suitable for headache patients with localized pressure pain. Similarly, cervical 4-7 joint surface injection (also available for acupuncture treatment) is particularly suitable for patients with cervicogenic neck, shoulder and arm pain with localized pressure pain.
3.Injections around the occipito-occipital nerve in the superior collar line (can be treated with needle and knife) are especially suitable for patients with acute attacks of severe pain and pressure pain in the superior collar line.
4.Cervical epidural injection has good therapeutic effect for most patients with cervicogenic neck, shoulder and arm pain, and also has good therapeutic effect for most patients with cervicogenic headache.
5.Cervical epidural cavity placement catheter continuous injection, the treatment effect is more durable.
(iii) Radiofrequency destruction treatment of cervical nerve
1.Radiofrequency thermal coagulation of the posterior medial branch of the cervical nerve
Puncture at the lateral and transverse inter-nodal groove of the articular eminence. Internationally, the puncture needle is usually punctured under X-ray fluoroscopy near the lateral inferior 1/2 of the articular eminence and the second cervical transverse process of the internodal sulcus, respectively, and radiofrequency thermocoagulation is performed. To improve the efficacy, Bogduk proposed that the needle should be punctured obliquely downward from above so that the electrode is in an orthotropic position with the joint and parallel to the nerve, and the temperature should be chosen to be 90° with a continuous heating time of 60 seconds. The cure rate of this treatment method is about 40%, with poor long-term results. In order to improve the treatment effect, some physicians often inject 6% phenol solution or alcohol into the needle. We use two electrodes pierced in parallel, bipolar radiofrequency, to improve the effect of a cure. This should be preceded by a local anesthetic block at the same site, effective before doing radiofrequency.
2.Pulse radiofrequency and standard radiofrequency treatment for occipital major nerve, third occipital nerve and occipital minor nerve in the upper collar line
3, cervical intervertebral disc radiofrequency molding also namely intervertebral disc fiber ring and posterior longitudinal ligament involved in painful nerve destruction.
Animal experiments and clinical experience in cervical spine surgery and minimally invasive treatment suggest that there are a large number of sensory and sympathetic nerve fibers distributed in the degenerated posterior longitudinal ligament and intervertebral disc of the cervical spine in patients with cervicogenic pain. Radiofrequency therapy can inactivate these pain-involved nerve fibers by localized thermocoagulation without open surgery. This eliminates cervicogenic pain. After the coupling of sympathetic and sensory nerve fibers and the convergence mechanism of sensory nerves and trigeminal nerves in cervicogenic pain is clarified, the mechanism of action of radiofrequency therapy is clearer.