Here was a 55-year-old female patient with episodic stabbing pain on the right superior eyelid for 2 years. The VAS score was eight. The onset time was about 1 minute and the remission period was completely pain free. The pain could be triggered by daily activities like smiling, washing face, speaking and eating. Any contact with the upper eyelid could lead to pain outbreak. Apart from the allodynia on the skin of upper eyelid, no abnormality was found in neurological examinations. Also, the ophthalmologic exams including funduscopy, intraocular pressure, visual field testing was normal. The head CT and MRI scan were also normal. The patient had no history of surgical operation and trauma, no history of diabetes mellitus, high blood pressure, chronic heart diseases, hepatitis, and some other relevant chronic diseases. The patient was diagnosed as primary TN.
The treatment was initiated by oral carbamazepine. The pain could be relieved by carbamazepine 200 mg daily at first. Gradually increasing dose of carbamazepine was reported during the medication period. About 2 weeks prior to the treatment, the pain could not be controlled by carbamazepine 800 mg daily, and dizziness and vertigo developed simultaneously.
Peripheral branch neurolysis was planned. Firstly, right supraorbital nerve block was implemented as a diagnostic test. After identifying the supraorbital notch through palpation, a 25-gauge needle was inserted at the level of supraorbital notch. 0.5 ml 1 % lidocaine was injected slowly. Ten minutes later, hypoaesthesia in the skin of the forehead instead of the upper eyelid was observed, and the pain continues. This result indicated that supraorbital nerve was not involved. Then, diagnostic blocks to lacrimal, infratrochlear and supratrochlear nerves were successively performed. The puncture point slightly above the lateral canthus along outer border of the orbit was selected for the lacrimal nerve block. As infratrochlear and supratrochlear exiting points were located closely together, we chose the point where the bridge of the nose abuts the supraorbital ridge as the single puncture point (Fig. 1). The patient was put in supine position while eyes firmly closed. After disinfection, a 25-gauge needle was punctured at the lacrimal nerve point described above. The needle was slid over the edge of the orbit, and advanced about 4 mm along the lateral wall of the orbit. With no aspiration of blood, 0.3 ml 1 % lidocaine was injected slowly. Five minutes later, hypoesthesia was found on the lateral part of the upper eyelid, while the medial part remained allodynic. Then the infratrochlear and supratrochlear nerve blocks were performed. The needle was inserted in the previously mentioned point, just slid over the edge, with the same depth along the medial wall. The same amount of lidocaine was injected slowly. The whole upper eyelid and adjacent areas were found hypoesthetic. The patient was completely pain free for the whole day. Then lacrimal, infratrochlear and supratrochlear nerves radiofrequency thermocoagulation (RT) was planned the next day. With supine position, the skin of upper eyelid and adjacent areas was disinfected. From the two puncture points above-mentioned, a 22 G radiofrequency needle with a working tip of 4 mm was slowly inserted successively. Slide over the edge of the orbit and advance about 4 mm. Repositioning the needle slightly to the point where sensory test stimulation at 0.3 mA and 50 Hz could evoke obvious paresthesia in the periocular region. As for infratrochlear and supratrochlear nerves RT, with the aim to ablate both the two nerves, redirect the needle tip superiorly and inferiorly along the medial wall of the orbit to make additional ablation. After local anaesthesia, RT with tip temperature of 80  C and duration of 80 s was performed.
The patient was discharged after 2 h observation. There were no complications, except for hypoesthesia in the upper eyelid and eyelid swelling for 2 days. The pain was completely relieved within the follow-up period of 6 months without any medication.