Peripheral Neurectomy for Trigeminal Neuralgia: Is the Cause Peripheral or Central?

Objectives: Trigeminal neuralgia is one of chronic head and neck pain. TN is characterized by unilateral interrupted electric like pain affecting mainly the mandibular and maxillary branches. TN is mainly treated medically by anticonvulsive drugs; and surgically by gamma knife and microvascular decompression. It is believed that the main cause of TN is the compression of cerebral artery on the gasserian ganglia therefore peripheral neurectomy will not be effective. However; some theories has been told that the demyelination cause could be due to muscle friction, periodontitis, dental extraction, dental injection, infection and etc. Therefore, the pain was similar to dental pulpitis and extraction of the teeth in the affected side was commonly found.
Methods: The study was done for twenty patients (3male&17female) and followed for 8 years. The patients clinically had the criteria of TN pain; unilateral, intermittent, triggered, electric like and no medical response. The duration of their complaints ranged from 5 to 15 years. All cases were first injected local anesthetic solution with long acting corticosteroids to relieve the pain and for diagnosis. The patients were asked for the location of the trigger pain either lower or upper jaw. The mixture of local anesthesia may stop the pain for minutes or hours only. MRI was done to eliminate the central cause.
Peripheral neurectomy ( infraorbital- mental- inferior alveolar) was done for all the patients. These nerves were legated, cut and sutured with surrounding muscle or periosteum to avoid the surgical neuroma. In addition to this, greater palatine nerve was cut in single patient because of pain in the palatal region.
Results: No neuralgic pain in the face following the operations was seen during the time of study. The complaint of some patients (3female) was numbness in the operated side. The study can be assured the cause of TN is due to peripheral demyelination. If the affection was due to central cause as compression, tumor, multiple sclerosis and etc the pain would be continue following the operations.
Conclusions: This study coincided with other studies that peripheral neurectomy could be suitable approach for the treatment of TN.