Abstract
Dear Sir,
Lacrimal neuralgia has been recently described as a cause of orbital and periorbital pain (1). The two previously reported patients had continuous pain in the territory of the lacrimal nerve: one of them felt the pain in the lateral aspect of her left superior eyelid and an adjacent area of the temple, while the other localized her pain to a small area of her left temple. They also had local tenderness at the emergence of the lacrimal nerve and experienced short-lasting relief upon anaesthetic blockade of the nerve. The technique employed for the nerve blockades was the same as that used in oculofacial surgery, with the needle inserted deeply along the lateral wall of the orbit (2,3). Here we report a third case of lacrimal neuralgia and a more simple method for blocking the lacrimal nerve. This procedure not only confirmed the diagnosis, but also provided the patient with long-lasting pain relief.
A 63-year-old woman, with former migraine with aura and no history of trauma or other relevant diseases, started suffering from constant pain in a small area of her left temple at age 60. The painful area was adjacent to the lateral angle of her left eye and had oval shape, with a horizontal diameter of 2 cm and a vertical diameter of 4 cm. The pain was always located at the same site, although it could occasionally expand over a wider area. It was described as severe in intensity – up to 9 out of 10 – and pressing in character. The temporal pattern was chronic and continuous since onset. The patient herself noticed that the symptomatic area was tender and that light touch could be perceived as painful. She had been treated with gabapentin 300 mg t.i.d. for 6 months, but the pain persisted with low-to-moderate intensity.
She came to our office with low-grade pain scored as 2 out of 10. Persistent pain was confined to the small skin area supplied by the lacrimal nerve on the left temple. Sensory exam demonstrated superficial hyperaesthesia and allodynia, but no hypoaesthesia, in the painful area. Moreover, palpation of the nerve at the superoexternal angle of the orbit caused local pain and suddenly increased the pain over the temple (Figure 1(A)). An anaesthetic blockade of the left lacrimal nerve was performed by injecting 0.5 cc of bupivacaine 5% with a 30 gauge, 0.5 inch (0.3 mm × 13 mm) needle. The needle was inserted through the lateral edge of the eyebrow fat pad and directed superiorly and laterally towards the temple (Figure 1(B–D)). This procedure resulted in immediate and complete pain relief and confirmed the diagnosis of lacrimal neuralgia. The medication was discontinued and the patient remained pain-free during a 3-month follow-up.
(A) Palpation of the lacrimal nerve on its emergence at the superoexternal angle of the orbit. (B–D) Lacrimal nerve block: the needle is inserted through the lateral edge of the eyebrow and directed superiorly and laterally towards the temple; the anaesthetic solution is injected subcutaneously.
No specific cause for the neuralgia could be detected. Contrast-enhanced magnetic resonance imaging of the orbit and the head did not show any underlying lesion. Urine and blood tests, including erythrocyte sedimentation rate, thyroid tests, angiotensin-converting enzyme levels and immunological screening, were also normal.
In conclusion, the lacrimal nerve may be easily blocked by inserting the needle on the emergence of the nerve and injecting the anaesthetic solution subcutaneously, just as is recommended for the supratrochlear and supraorbital nerves (4). This procedure might facilitate the diagnosis of new cases of lacrimal neuralgia and also become a therapeutic option for upcoming patients. Further reports are needed to better characterize lacrimal neuralgia and its management.
Footnotes
Conflict of interest
None declared.