Subarachnoid bleeding into the superior cerebellopontine cistern after radiofrequency trigeminal rhizotomy: case report

Abstract

Sir, We would like to report an unusual case of a patient suffering from trigeminal neuralgia, who underwent percutaneous radiofrequency trigeminal rhizotomy (RF-TR), and complicated with subarachnoidal bleeding in the superior cerebellopontine cistern. A 68-year-old woman had been suffering from medically intractable trigeminal neuralgia. She had a 6-year history of trigeminal neuralgia at the ophthalmic and maxillary branches of the left trigeminal nerve. Cranial magnetic resonance imaging scans revealed no structural or vascular abnormality. Routine preoperative analyses, including coagulation studies, were normal. The patient underwent RF-TR under intravenously administered sedation and analgesia. The localization was confirmed within the nerve by electrical stimulation at 0.5 V (100 Hz, 0.2 m); and a lesion was made at a temperature of 70°C for 60 s. After the procedure, the patient’s pain resolved completely. However, 12 h after the procedure, sudden onset of severe headache, vomiting and neck stiffness occurred. The initial cranial computed tomography (CT) scan was normal. Lumbar puncture examination revealed bloody cerebrospinal fluid (CSF); the lymphocyte and monocyte proportions were normal. The control cranial CT scan showed subarachnoidal bleeding in the left superior cerebellopontine cistern (Fig. 1). The patient underwent conservative treatment, and neck stiffness and headache improved. She was discharged 7 days after the procedure. Trigeminal RF-TR is an effective and commonly performed procedure for control of medically refractory pain. Surgical procedures, such RF-TR, microvascular decompression, etc, may lead to serious complications. Anesthesia dolorosa, painful dysesthesia, absence of corneal reflex, corneal keratitis, masseter paralysis, septic-aseptic meningitis, cranial nerve palsy (cranial nerves III, IV, VI, VII, and VIII), blindness, carotid puncture, and carotidcavernous fistulae are all potential complications of the RFTR procedure [2]. Thus, all surgeons should be aware of these risks and not consider any of these methods as easy and safe. Meckel’s cave and root entry zone, which are the focus of these intervention methods, are at the same time the areas where multiple anatomic variations and vital structures are located [3]. Meckel’s cave opens through a porus into the cerebellopontine cistern. Meckel’s segment of the trigeminal nerve, which begins at the porus and extends to the trigeminal ganglion, is differentiated from the cavernous segment in the wall of the cavernous sinus. Meckel’s segment is narrower adjacent to the porus and fans out as it approaches the posterior edge of the gasserian ganglion, which is embedded in the dura just anterior to the anterior edge of Meckel’s cave. The superior petrosal sinus extends medially through the upper edge of the porus of Meckel’s cave and above the trigeminal nerve to join the cavernous sinus [1]. Some superior petrosal veins may join the sinus on the medial side of the trigeminal nerve. The SCA A. Savas Department of Neurosurgery, School of Medicine, Ankara University, Ankara, Turkey