J Neurosurg 55:935-937, 1981 Evaluation of endorphin content in the CSF of patients with trigeminal neuralgia before and after Gasserian ganglion thermocoagulation GIUSEPPE SALAR, M.D., SALVATOREMINGRINO, M.D., MARCO TRABUCCHI, M.D., ANGELO BOSIO, M.D., AND CARLO SEMENZA, M.D. Departments of Neurosurgery and Neurology, University of Padua, Padua, and Department of Pharmacology, University of Milan, Milan, ltaly ~/ The fl-endorphin content in cerebrospinal fluid (CSF) was evaluated in 10 patients with idiopathic trigeminal neuralgia during medical treatment (with or without carbamazepine) and after selective thermocoagulation of the Gasserian ganglion. These values were compared with those obtained in a control group of seven patients without pain problems. No statistically significant difference was found between patients suffering from trigeminal neuralgia and those without pain. Furthermore, neither pharmacological treatment nor surgery changed CSF endorphin values. It is concluded that there is no pathogenetic relationship between trigeminal neuralgia and endorphins. KEY WORDS 9 trigenlinal neuralgia 9 Gasserian ganglion thermocoagulation 9 carbamazepine 9 endorphin pathogenesis I N the last few years, morphine-like endogenous substances (namely, the endorphins and the en- kephalins) have been associated with the problem of pain. 6,9,1~176 Observations by Almay, et al., 4 von Knorring, eta/., 21 Lindblom and Tegn6r, 11 and Ter- enius 19 showed that the concentration of these mor- phine-like substances in the cerebrospinal fluid (CSF) changes according to the kind of pain, whether psy- chological or organic. These observations are based on two lines of investigation. On the one hand, phar- macological studies with naloxone and other inhibi- tors of morphine-like substances indirectly demon- strate the presence and analgesic action of such endogenous substances. 1,2,s,ll,la,14,16On the other hand, endorphins have been found and measured in the CSF of patients suffering from pain before and after adequate treatment. 3,7,~7,19,21 To determine if endorphins play a role in the pathogenesis of idiopathic neuralgia, and if this kind of neuralgia might be connected with an altered (low- ered) endorphin content in the CSF, we measured the CSF endorphin content in patients with pharmaco- logically treated trigeminal neuralgia and in another group not treated pharmacologically. The CSF en- dorphin values were further compared in the same patients with the values obtained after Gasserian gan- glion thermocoagulation and complete remission of pain. In addition, these endorphin values were com- pared with those of a group of subjects who had no pain problem. Clinical Material and Methods Ten patients with idiopathic trigeminal neuralgia were studied. Their ages ranged from 35 to 55 years (mean 46 years). Five were men and five women. Four patients complained of both second and third division neuralgia, three of second, and three of third division neuralgia. In six, a typical trigger zone was present. All of these patients had previously been treated with carbamazepine. All 10 patients underwent surgical treatment with thermocoagulation of the Gasserian ganglion. In five cases, surgical treatment was undertaken because drug therapy had become ineffective with time. At the time of operation, the patients had not received medication for at least 1 week and were still suffering pain crises. In the other five cases, surgery was decided upon because a continuous dose of 600 rag/day of carba- mazepine to control pain was resulting in blood dys- crasia. Until the time of operation, these latter five J. Neurosurg. / Volume 55/December, 1981 935