The Relation of Pain Value and Touch Threshold of Patient with Trigeminal Neuralgia-The Effect of Gamma Knife Stereotactic Radiosurgery

application/pdfTrigeminal neuralgia (TN) is a chronic neuropathic pain disorder that makes daily life difficult. Recently, gamma knife surgery (GKS) has been employed for treating intractable pain control such as trigeminal neuralgia (TN) or cancer pain. Nine patients (4 males and 5 females) with TN of second branch were investigated in this study. All patients (mean age: 66.7±7.5) were irradiated a maximum dose of 90 Gy at retro Gasserian after the target area were coordinated with magnetic resonance imaging (MRI) and computed tomography (CT). They were asked symptom, medical history and what induces the pain attack. We also assessed visual analog scale(VAS) of pain, presence or absence of allodynia, cold sensation dullness and touch threshold on the lateral of nasal wing using Semmes-Weinstein monofilaments before and 1, 3, 6, and 12 months after GKS. The relation of the pain value and touch threshold were estimated. There were two kinds of pain character, like an electric shock (5 patients) and like prickling (4 patients). The mean±SD of pain VAS value was 8.5±1.4 and touch threshold on disease side (6.0±2.8 gf/mm2) was significant higher than the healthy side (3.7±1.3 gf/mm2) at first visiting (paired t-test; P