Occipital neuralgia (ON) is a relatively rare primary headache disorder. The cause of occipital neuralgia is unknown, however, entrapment and irritation of the nerves have been proposed. When conservative measures are ineffective, occipital nerve blocks are a convenient and relatively benign tool for diagnosis and management of occipital neuralgia. Nerve ablation techniques (pulsed radiofrequency) can provide sustained pain relief in some patients.
Often, damage or irritation of the greater or lesser occipital nerve is the cause of the neuralgia. There are various potential causes of irritation: vascular, neurogenic, muscular and osteogenic.
Patients complain of a shooting or stabbing pain in the neck radiating over the cranium. Constant pain can persist between the paroxysms. The pain can be perceived in the retro-orbital area caused by overlap of the C2 dorsal root and the trigeminal nucleus. Vision impairment/ocular pain (67%), tinnitus (33%), dizziness (50%), nausea (50%), and congested nose (17%) can be present because of connections with cranial nerves VIII, IX, and X, and the sympathetic trunk.
Hypoasthesia or dysesthesia in the area of the greater and lesser occipital nerve as well as tenderness to pressure over the course of the nerve can be observed. A positive Tinel’s sign (pain upon percussion over the nerve) can be present. Clinical presentation and a temporary improvement with a local anesthetic diagnostic block of the occipital nerve confirm the diagnosis. False-positive results can occur with migraine and cluster headaches.
Tumors, infection, and congenital anomalies (Arnold- Chiari malformation) should be ruled out. Occipital neuralgia can be mistaken for migraine, cluster headache, tension headache, and hemicrania continua. Other structures may cause similar pain, such as the upper cervical facet joints (C2-C3), osteoarthritis of the atlantooccipital or atlantoaxial joint, giant cell arteritis and tumors of the cervical spinal column.
Conservative treatment focuses on reducing secondary muscle tension and on improving posture. Non-pharmacological treatments like TENS and acupuncture can be tried.
Anti neuropathic drugs like tricyclic antidepressants and antiepileptics (gabapentin, pregabalin) can help relieve the symptoms.
Infiltration of local anaesthetic and steroid around the occipital nerve can be diagnostic and therapeutic as well. The injection is performed under real-time ultrasound guidance for greater accuracy and safety.
Pulsed radiofrequency lesioning of the occipital nerve is indicated in patients who show a positive response to diagnostic occipital nerve blocks. This procedure can relieve symptoms associated with occipital neuralgia on a long-term basis.
Injection of botulinum toxin can be helpful in relieving symptoms associated with occipital neuralgia.