Farhad Limonadi

Incidence, Etiology, and Management of Cerebrospinal Fluid Leaks Following Trans-Sphenoidal Surgery†

Objectives/Hypothesis The incidence of cerebrospinal fluid (CSF) leak following trans‐sphenoidal surgery ranges from 0.5% to 15.0%. Factors predicting which patients are likely to develop postoperative leaks and optimal management of these patients are poorly defined. The objective was to determine 1) the incidence of CSF leak following trans‐sphenoidal surgery; 2) demographic or intraoperative factors associated with postoperative leaks; 3) techniques and efficacy of postoperative leak management at Oregon Health and Science University, (Portland, OR).

Design of an Artificial Neural Network for Diagnosis of Facial Pain Syndromes

A classification scheme for facial pain syndromes describing seven categories has previously been proposed. Based on this classification scheme and a binomial (yes/no) facial pain questionnaire, we have designed and trained an artificial neural network (ANN) and as an initial feasibility assessment of such an ANN system examined its ability to recognize and correctly diagnose patients with different facial pain syndromes. One hundred patients with facial pain were asked to respond to a facial pain questionnaire at the time of their initial visit. After interview, an independent diagnosis was assigned to each patient. The patients’ responses to the questionnaire and their diagnoses were input to an ANN. The ANN was able to retrospectively predict the correct diagnosis for 95 of 100 patients (95%), and prospectively determine a correct diagnosis of trigeminal neuralgia Type 1 with 84% sensitivity and 83% specificity in 43 new patients. The ability of the ANN to accurately predict a correct diagnosis for the remaining types of facial pain was limited by our clinic sample size and hence less exposure to those categories. This is the first demonstration of the utilization of an ANN to diagnose facial pain syndromes.

Unanticipated complication of percutaneous radiofrequency trigeminal rhizotomy: rhinorrhea: report of three cases and a cadaver study.

OBJECTIVE AND IMPORTANCE:Several neurosurgical procedures have been developed for the treatment of idiopathic trigeminal neuralgia: vascular decompression of the trigeminal root in the brainstem, percutaneous trigeminal ganglion procedures, and external beam radiosurgery. Percutaneous radiofrequency electrodes target the trigeminal fibers in the gasserian ganglion through the foramen ovale. Several complications of radiofrequency trigeminal rhizotomy (RF-TR) have been described, including puncture of the carotid artery, the cavernous sinus, and the cranial nerves. This study presents a very rare complication of percutaneous RF-TR, rhinorrhea, and attempts to define its mechanism. CLINICAL PRESENTATION:Of 2375 patients with idiopathic trigeminal neuralgia who underwent 2958 percutaneous RF-TR procedures, 3 developed subsequent rhinorrhea, which resolved spontaneously in 2 to 3 days. TECHNIQUE:Two formalin-fixed cadavers were dissected to demonstrate the relationship between the foramen ovale and the tuba auditiva and the mechanism of rhinorrhea. CONCLUSION:This article presents a very rare complication of RF-TR. Rhinorrhea and/or cerebrospinal fluid fistulae in the nasopharyngeal cavity are benign complications of RF-TR that result from puncturing both the membranous portion of the tuba auditiva (eustachian tube) and Meckels cave with the rhizotomy needle.

An easy-to-use intraoperative digital videography, still photography, and X-ray-capture system

OBJECTIVEThe goal was to evaluate an easy-to-construct digital system for documentation of intraoperative still and motion photography. In addition, the management of pre- and postoperative images was considered. METHODSA Macintosh system (both hardware and software) is described in detail, as are techniques and use. RESULTSThe system has proved to be easy to use. It is user-friendly and makes it possible to rapidly edit and store data from preoperative studies, as well as intraoperative videography and still photography. The cost is minimal, compared with other commercially available systems. CONCLUSIONDigital videography and still photography can easily be accomplished with minimal modifications to existing hardware and software systems. Patient x-rays can also be incorporated into this system, for easy retrieval.