Cervicogenic headache, sometimes misdiagnosed as MIGRAINE, is a syndrome characterized by chronic hemicranial pain that is referred to the head from either bony structures or soft tissues of the neck. The trigeminocervical nucleus is a region of the upper cervical spinal cord where sensory nerve fibers in the descending tract of the trigeminal nerve (trigeminal nucleus caudalis) are believed to interact with sensory fibers from the upper cervical roots.This functional convergence of upper cervical and trigeminal sensory pathways allows the bidirectional referral of painful sensations between the neck and trigeminal sensory receptive fields of the face and head. A functional convergence of sensorimotor fibers in the spinal accessory nerve (CN XI) and upper cervical nerve roots ultimately converge with the descending tract of the trigeminal nerve and might also be responsible for the referral of cervical pain to the head.
Diagnostic criteria have been established for cervicogenic headache, but its presenting characteristics occasionally may be difficult to distinguish from primary headache disorders such as migraine, tension-type headache, or hemicrania continua.
Hemicrania continua, or continuous headache, is a rare type of headache that doesn't stop. The pain is felt on one side of the face or head. It varies in severity. Patients with hemicrania continua describe a dull ache or throb that is interrupted by periods of pain that is jolting, sharp, or stabbing. These attacks usually happen three to five times a day. Some patients will have these headaches steadily for months or years. In others, the pain will go away for weeks or months. But then it returns for extended periods. Experts consider a diagnosis of hemicrania continua if the pain has been present, without switching sides or disappearing even briefly, for at least three months. The cause of hemicrania continua headaches is unknown. They affect women more often than men.
Fortunately, this condition can be treated. Patients who are able to tolerate daily anti-inflammatory, neck manipulations, exercises, pressure points applications and Ayurveda interventions.
Neck pain and cervical muscle tenderness are common and prominent symptoms of primary headache disorders. Less commonly, head pain may actually arise from bony structures or soft tissues of the neck, a condition known as cervicogenic headache. Cervicogenic headache can be a perplexing pain disorder that is refractory to treatment if it is not recognized. The condition's pathophysiology and source of pain have been debated, but the pain is likely referred from one or more muscular, neurogenic, osseous, articular, or vascular structures in the neck.
The trigeminocervical nucleus is a region of the upper cervical spinal cord where sensory nerve fibers in the descending tract of the trigeminal nerve (trigeminal nucleus caudalis) are believed to interact with sensory fibers from the upper cervical roots. This functional convergence of upper cervical and trigeminal sensory pathways allows the bidirectional referral of painful sensations between the neck and trigeminal sensory receptive fields of the face and head.
Patients with cervicogenic headache will often have altered neck posture or restricted cervical range of motion. The “head pain” can be triggered or reproduced by active neck movement, passive neck positioning especially in extension or extension with rotation toward the side of pain, or on applying digital pressure to the involved facet regions or over the ipsilateral greater occipital nerve. Muscular trigger points are usually found in the suboccipital, cervical, and shoulder musculature, and these trigger points can also refer pain to the head when manually or physically stimulated. There are no neurologic findings of cervical radiculopathy, though the patient might report scalp paresthesia or dysesthesia.
A comprehensive history, review of systems, and physical examination including a complete neurologic assessment will often identify the potential for an underlying structural disorder or systemic disease. Imaging is then primarily used to search for suspected secondary causes of pain that may require surgery or other more aggressive forms of treatment. The differential diagnosis in cases of suspected cervicogenic headache could include posterior fossa tumor, Arnold-Chiari malformation, cervical spondylosis or arthropathy, herniated intervertebral disc, spinal nerve compression or tumor, arteriovenous malformation, vertebral artery dissection, and intramedullary or extramedullary spinal tumors.
A laboratory evaluation may be necessary to search for systemic diseases that may adversely affect muscles, bones, or joints (ie, rheumatoid arthritis, systemic lupus erythematosus, thyroid or parathyroid disorders, primary muscle disease, etc).
Zygapophyseal joint, cervical nerve or medial branch blockade is used to confirm the diagnosis of cervicogenic headache and predict the treatment modalities that will most likely provide the greatest efficacy. The first three cervical spinal nerves and their rami are the primary peripheral nerve structures that can refer pain to the head.
The suboccipital nerve (dorsal ramus of C1) innervates the atlanto-occipital joint; therefore, a pathologic condition or injury affecting this joint is a potential source for head pain that is referred to the occipital region.
The C2 spinal nerve and its dorsal root ganglion have a close proximity to the lateral capsule of the atlantoaxial (C1–2) zygapophyseal joint and innervate the atlantoaxial and C2–3 zygapophyseal joints; therefore, trauma to or pathologic changes around these joints can be a source of referred head pain. Neuralgia of C2 is typically described as a deep or dull pain that usually radiates from the occipital to parietal, temporal, frontal, and periorbital regions. A paroxysmal sharp or shocklike pain is often superimposed over the constant pain. Ipsilateral eye lacrimation and conjunctival injection are common associated signs. Arterial or venous compression of the C2 spinal nerve or its dorsal root ganglion has been suggested as a cause for C2 neuralgia in some cases. The third occipital nerve (dorsal ramus C3) has a close anatomic proximity to and innervates the C2–3 zygapophyseal joint. This joint and the third occipital nerve appear most vulnerable to trauma from acceleration-deceleration (“whiplash”) injuries of the neck. Pain from the C2–3 zygapophyseal joint is referred to the occipital region but is also referred to the frontotemporal and periorbital regions. Injury to this region is a common cause of cervicogenic headache. The majority of cervicogenic headaches, occurring after whiplash resolve within a year of the trauma.
Occipital neuralgia is a specific pain disorder characterized by pain that is isolated to sensory fields of the greater or lesser occipital nerves. The classic description of occipital neuralgia includes the presence of constant deep or burning pain with superimposed paroxysms of shooting or shocklike pain. Paresthesia and numbness over the occipital scalp are usually present. It is often difficult to determine the true source of pain in this condition. In its classic description, the pain of occipital neuralgia is believed to arise from trauma to or entrapment of the occipital nerve within the neck or scalp, but the pain may also arise from the C2 spinal root, C1–2, or C2–3 zygapophyseal joints or pathologic change within the posterior cranial fossa.
Occipital nerve blockade, as it is typically done in the clinic setting, often results in a nonspecific regional blockade rather than a specific nerve blockade and might result in a misidentification of the occipital nerve as the source of pain. This “false localization” might lead to unnecessary interventions aimed at the occipital nerve, such as surgical transection or other neurolytic procedures.
A regional myofascial pain syndrome (MPS) affecting cervical, pericranial, or masticatory muscles can be associated with referred head pain. Sensory afferent nerve fibers from upper cervical regions have been observed to enter the spinal column by way of the spinal accessory nerve before entering the dorsal spinal cord. The close association of sensorimotor fibers of the spinal accessory nerve with the spinal sensory nerves is believed to allow for a functional exchange of somatosensory, proprioceptive, and nociceptive information from the trapezius, sternocleidomastoid, and other cervical muscles to converge in the trigeminocervical nucleus and ultimately resulting in the referral of pain to trigeminal sensory fields of the head and face.
Ayurveda Pain management and intervention provide remarkable results in Cervicogenic Headache.