para>ON must be distinguished from occipital referral of pain from the C1, C2, or upper facet joints or from tender trigger points in neck muscles or their insertions.
Epidemiology
Incidence
Estimated to be 3.2/100,000 per year (1)[C]
Prevalence
Unknown
Etiology and Pathophysiology
- ON is often posttraumatic or idiopathic, but diverse vascular (e.g., giant cell arteritis), neurogenic (e.g., C2 schwannoma), muscular/tendinous, and osteogenic mechanisms may underlie the nerve root irritation (2)[C].
- The etiology of ON is unknown. Whiplash injuries causing nerve injury have been suggested. Entrapment and irritation due to myofascial spasm has been described at various locations of the nerve path.
Alert
ON may be mimicked by upper cervical myelitis, dural arteriovenous fistulas, cervical cord cavernous angiomas, neurosyphillis, and multiple sclerosis (MS).
Risk Factors
Most cases of ON are idiopathic. Whiplash and posterior cranial trauma are considered risk factors for ON.
General Prevention
As the etiology is unknown in many cases, there are no specific prevention strategies available. Avoiding posterior head trauma with proper safety measures for sports and driving and following surgical steps to avoid injury to the occipital nerve branches during surgery may help in prevention of trauma-related ON.
Commonly Associated Conditions
Associated conditions include tinnitus, scalp paresthesia, nausea, dizziness, and visual disturbances.
Diagnosis
History
International Classification of Headache Disorders (ICHD) criteria (3)[A]
- Most often unilateral or bilateral pain fulfilling criteria B " E
- Pain is located in the distribution of the greater, lesser, and/or third occipital nerves.
- Pain has two of the following three characteristics:
- Recurring in paroxysmal attacks lasting from a few seconds to minutes
- Severe intensity
- Shooting, stabbing, or sharp in quality
- Pain is associated with both of the following:
- Dysesthesia and/or allodynia apparent during innocuous stimulation of the scalp and/or hair
- Either or both of the following:
- Tenderness over the affected nerve branches
- Trigger points at the emergence of the greater occipital nerve or in the area of distribution of C2
- Pain is eased temporarily by local anesthetic block of the affected nerve.
Alert
ON is diagnosed when IHCD criteria are met and symptoms are not better accounted for by another ICHD-3 diagnosis.
Physical Exam
Cranial nerve examination, palpation of the involved area to test for dysesthesia or tenderness, and careful cervical examination to rule out secondary causes
Differential Diagnosis
- ON symptoms overlap with other primary headache disorders such as migraine, cluster headache, hemicranias continua, and tension headache.
- Secondary causes of ON symptoms include temporal arteritis, cervical myelitis, C2 neuralgia, cervicogenic headaches, posterior head and neck trauma, vascular or other structural lesions along the path of the occipital nerve, MS, and neurosyphillis.
Diagnostic Tests & Interpretation
Initial Tests (lab, imaging)
- Lab
- Laboratory testing is directed at evaluating for secondary causes, for example, C-reactive protein and sedimentation rate if temporal arteritis is suspected, and at assessment of existing conditions such as diabetes or clotting disorders if treatments such as steroids or surgical intervention are planned.
- Imaging
- Head and neck MRI is indicated in all patients due to the possibility of secondary causes.
Diagnostic Procedures/Other
Nerve block with a local anesthetic and corticosteroid gives temporary relief. During this time, a neuropathic pain medication (e.g., gabapentin) can be given. Response to nerve block is a diagnostic criteria in the ICHD description.
Test Interpretation
There are no specific pathology findings.
Treatment
General Measures
Rest, warm or cold compresses, and physical therapy can mitigate ON in many cases (4)[C].
Medication
First Line
NSAIDs and muscle relaxants
Second Line
- Antiepileptic drugs (AEDs) such as carbamazepine, gabapentin, and pregabalin; baclofen
- Antidepressants (TCAs) have reported efficacy in reducing the frequency and severity of attacks but have not been systematically evaluated in the treatment of ON.
- Gabapentin 300 " 600 mg qhs or nortriptyline 25 " 50 mg qhs has been recommended as effective for many patients (5)[C].
Issues for Referral
- As noted earlier, ON can result from a number of secondary causes. Neurology or neurosurgery referral is indicated if there are focal neurologic findings, history, or imaging findings to suggest a secondary cause.
- If conservative measures are not effective, pain management or headache specialist may be required.
Surgery/Other Procedures
If the initial injection with local anesthetic (with or without corticosteroid) does not provide lasting relief and conservative measures outlined in general care and medications are not effective, then nerve decompression may be considered. Although botulinum toxin has been discussed as a treatment, there is some question in the literature as to the effectiveness (6)[A]. Other treatment modalities include pulsed radiofrequency treatment or subcutaneous occipital nerve stimulation. The most widely studied surgical method is decompression.
Inpatient Considerations
Admission Criteria/Initial Stabilization
Admission may be indicated as a result of secondary causes with care as dictated by findings.
Ongoing Care
Follow-up Recommendations
Follow-up plans are determined by the treatment needed, efficacy of selected treatments, and need for coordinated care for physical therapy or psychological care. Following any surgical procedure appointments are necessary to monitor for potential complications.
Diet
There are no specific dietary recommendations.
Patient Education
Behavior modifications, including stress reduction, may help in some cases. Ongoing physical therapy may be recommended.
Prognosis
Many patients with ON will improve with general care with heat or cold, rest, anti-inflammatory medications, and muscle relaxants. Gabapentin and nortriptyline are effective in many cases as well.
Complications
Complications will occur depending on treatment modality required. Surgical procedures such as decompression may be complicated by cellulitis, numbness, pruritus, weakness, hematoma, postincisional alopecia, or postoperative migraine.
References
1.Gadient PM, Smith JH. The neuralgias: diagnosis and management. Curr Neurol Neurosci Rep. 2014;14(7):459 " 467.
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2.Vincent MB. Headache and neck. Curr Pain Headache Rep. 2011;15(4):324 " 331.
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3.Headache Classification Committee of the International Headache Society. International Classification of Headache Disorders, 3rd edition (beta version). Cephalalgia. 2013;33(9):629 " 808.
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4.Vanelderen P, Lataster L, Levy R, et al. Occipital neuralgia. Pain Pract. 2010;10(2):137 " 144.
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5.Dougherty C. Occipital neuralgia. Curr Pain Headache Rep. 2014;18(5):411 " 416.
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6.Ducic I, Felder M, Fantus S. A systematic review of peripheral nerve interventional treatments for chronic headaches. Ann Plast Surg. 2014;72(4):439 " 445.
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Additional Reading
http://ihs-classification.org/en/
Codes
ICD09
- 723.8 Other syndromes affecting cervical region
- 782.0 Disturbance of skin sensation
ICD10
- M54.81 Occipital neuralgia
- R20.8 Other disturbances of skin sensation
SNOMED
- 71760005 Cervico-occipital neuralgia (finding)
- 279079003 dysesthesia (finding)
- 247404004 Allodynia (finding)
Clinical Pearls
- Diagnosis of ON is determined by characteristic symptoms in the distribution of the greater or lesser occipital nerves or of the third occipital nerve.
- Diagnosis of ON requires response to nerve block.
- Diagnosis of ON requires ruling out secondary causes by exam and imaging.
- Diagnosis of ON requires ruling out other primary headache disorders.
- Conservative measures with physical therapy, heat or cold, and NSAIDs are effective in many cases.