Occipital Neuralgia  Download PDF

• Steven D. Waldman

Pain Management, Chapter 55, 503-505

• Chapter outline

• Signs and Symptoms 503
• Testing 503
• Differential Diagnosis 503
• Treatment 504
• Complications and Pitfalls 505
• Conclusion 505

Perhaps one of the most overdiagnosed headache syndromes, occipital neuralgia represents a diagnostic and therapeutic challenge to the clinician. Further complicating any discussion of this painful condition is the contention by some headache specialists that the syndrome does not exist and represents a variant of cervicogenic headache emanating from the C1-C4 nerve roots.  Assuming that occipital neuralgia is a clinical entity distinct from cerviogenic headache, it is usually the result of blunt trauma to the greater and lesser occipital nerves.  Repetitive microtrauma from working with the neck hyperextended (e.g., painting ceilings, or working for prolonged periods with computer monitors whose focal point is too high, causing extension of the cervical spine) may also cause occipital neuralgia. The pain of occipital neuralgia is characterized as persistent pain at the base of the skull with occasional sudden shock-like paresthesias in the distribution of the greater and lesser occipital nerves ( Fig. 55.1 ). Tension-type headache, which is much more common than occipital neuralgia, occasionally mimics the pain of occipital neuralgia.  Less commonly, primary or metastatic tumors involving this anatomic region may cause pain that may be misdiagnosed as occipital neuralgia. 

Fig. 55.1

Occipital neuralgia is caused by trauma to the greater and lesser occipital nerves.

(From Waldman SD: Atlas of common pain syndromes, Philadelphia, 2002, Saunders, p 23.)

Signs and Symptoms

The greater occipital nerve arises from fibers of the dorsal primary ramus of the second cervical nerve and to a lesser extent fibers from the third cervical nerve. The greater occipital nerve pierces the fascia just below the superior nuchal ridge along with the occipital artery. It supplies the medial portion of the posterior scalp as far anterior as the vertex.

The lesser occipital nerve arises from the ventral primary rami of the second and third cervical nerves. The lesser occipital nerve passes superiorly along the posterior border of the sternocleidomastoid muscle, dividing into cutaneous branches that innervate the lateral portion of the posterior scalp and the cranial surface of the pinna of the ear (see Fig. 55.1 ).

The patient with occipital neuralgia experiences neuritic pain in the distribution of the greater and lesser occipital nerve when the nerves are palpated at the level of the nuchal ridge.  Some patients can elicit pain with rotation or lateral bending of the cervical spine.

Testing

No specific test for occipital neuralgia exists. Testing is aimed primarily at identification of occult pathology or other diseases that may mimic occipital neuralgia (see subsequent section Differential Diagnosis). All patients with the recent onset of headache thought to be occipital neuralgia should undergo magnetic resonance imaging (MRI) testing of the brain and of the cervical spine ( Fig. 55.2 ). MRI testing should also be performed in those patients with previously stable occipital neuralgia who have experienced a recent change in headache symptomatology or in whom traditional therapeutic interventions fail to provide long-lasting pain relief. Screening laboratory testing consisting of complete blood count, erythrocyte sedimentation rate, and automated blood chemistry testing should be performed if the diagnosis of occipital neuralgia is in question. 

Fig. 55.2

Medulloblastoma with metastatic spread to the meninges within the posterior fossa and with a large intramedullary deposit. Sagittal and axial MRI, T1-weighted gadolinium contrast enhancement.

(From Alba A, Brandes EF, Tosoni A, et al: Adult neuroectodermal tumors of posterior fossa (medulloblastoma) and of supratentorial sites (stPNET), Crit Rev Oncol Hematol 71:167, 2009, p 167.)

Neural blockade of the greater and lesser occipital nerves can serve as a diagnostic maneuver to help confirm the diagnosis and separate it from tension-type headache (see subsequent discussion). The greater and lesser occipital nerves can easily be blocked at the nuchal ridge.

Differential Diagnosis

Occipital neuralgia is an infrequent cause of headaches and rarely occurs in the absence of blunt trauma to the greater and lesser occipital nerves. More often, the patient with headaches that involve the occipital region does in fact have tension-type or cervicogenic headaches. Tension-type headaches do not respond to occipital nerve blocks but are amenable to treatment with antidepressant compounds such as amitriptyline in conjunction with cervical steroid epidural nerve blocks.  Therefore, the clinician should reconsider the diagnosis of occipital neuralgia in those patients whose symptoms are consistent with occipital neuralgia but do not respond to greater and lesser occipital nerve blocks. As mentioned previously, occult tumor may rarely mimic the pain of occipital neuralgia (see Fig. 55.2 ).

Treatment

The treatment of occipital neuralgia consists primarily of neural blockade with local anesthetic and steroid combined with the judicious use of nonsteroidal anti-inflammatory drugs, muscle relaxants, tricyclic antidepressants, and physical therapy. Neural blockade of the greater and lesser occipital nerve is carried out with the following technique: The patient is placed in a sitting position with the cervical spine flexed and the forehead on a padded bedside table. A total of 8 mL of local anesthetic is drawn up in a 12-mL sterile syringe. With treatment of occipital neuralgia or other painful conditions that involve the greater and lesser occipital nerve, a total of 80 mg of depot steroid is added to the local anesthetic with the first block and 40 mg of depot steroid is added with subsequent blocks. 

The occipital artery is then palpated at the level of the superior nuchal ridge. After preparation of the skin with antiseptic solution, a 22-gauge11/2-inch needle is inserted just medial to the artery and is advanced perpendicularly until the needle approaches the periosteum of the underlying occipital bone. A paresthesia may be elicited, and the patient should be warned of such. The needle is then redirected superiorly, and after gentle aspiration, 5 mL of solution is injected in a fan-like distribution, with care taken to avoid the foramen magnum, which is located medially ( Fig. 55.3 ). 

Fig. 55.3

Technique for greater and lesser occipital nerve block.

The lesser occipital nerve and a number of superficial branches of the greater occipital nerve are then blocked by directing the needle laterally and slightly inferiorly. After gentle aspiration, an additional 3 to 4 mL of solution is injected (see Fig. 55.3 ). In rare cases, radiofrequency lesioning of the occipital nerves may be necessary to provide long-lasting pain relief ( Fig. 55.4 ).  

Fig. 55.4

Proper needle position for radiofrequency lesioning of the greater occipital nerve.

(From Waldman SD: Atlas of interventional pain management, ed 3, Philadelphia, 2009, Saunders, p 30.)

Complications and Pitfalls

The scalp is highly vascular, and this—coupled with the fact that both the greater and the lesser occipital nerves are in close proximity to arteries—means that the clinician should carefully calculate the total milligram dosage of local anesthetic that may be safely given, especially if bilateral nerve blocks are being performed. This vascularity and proximity to the arterial supply gives rise to an increased incidence of postblock ecchymosis and hematoma formation. These complications can be decreased if manual pressure is applied to the area of the block immediately after injection. Application of cold packs for 20-minute periods after the block also decrease the amount of postprocedure pain and bleeding the patient may experience. Care must be taken to avoid inadvertent needle placement into the foramen magnum because the subarachnoid administration of local anesthetic in this region results in an immediate total spinal anesthetic.

Conclusion

As with other headache syndromes, the clinician must be sure that the diagnosis is correct and that no coexisting intracranial pathology or diseases of the cervical spine may be erroneously attributed to occipital neuralgia.

The most common reason that greater and lesser occipital nerve block fails to relieve headache pain is that the headache syndrome being treated has been misdiagnosed as occipital neuralgia. Any patient with headaches bad enough to need neural blockade as part of the treatment plan should undergo an MRI scan of the head to rule out unsuspected intracranial pathology. Furthermore, cervical spine radiographs should be considered to rule out congenital abnormalities, such as Arnold-Chiari malformations, which may be the hidden cause of the patient's occipital headaches.