RESUMEN
Pharmacological classification, based on a so-called drug challenge test (DCT), is one method to evaluate intractable pain following experimental administration of medicines. In this scenario, the appropriate medicine is prescribed for a patient with intractable pain based on the result of the DCT. A 61-year-old man was healthy until 2003, when he sustained a brachial plexus injury caused by a gas explosion. He had experienced fulgurant pain in his left upper limb since 2006, and had undergone stellate ganglion blocks, and treatment with amitriptyline. He was admitted for further treatment in 2010 because these treatments did not alleviate his fulgurant pain. He could not move his shoulder, elbow, wrist and fingers because of severe paralysis and arthrodesis of his left shoulder joint, and complained of fulgurant pain and persistent dullness in his left upper limb. He was diagnosed to have complex regional pain syndrome (CRPS) due to the brachial plexus injury, and electromyographic examinations showed evidence of a partial regrowth after sural nerve transplantation. Gabapentin was prescribed for the patient's CRPS based on the remarkable effect of thiamilal on this fulgurant pain. The frequency of the fulgurant pain decreased following the initiation of gabapentin therapy, and the persistent dullness disappeared. DCT is recommended for patients with intractable pain such as CRPS, in addition to neurological and electromyographic examinations, in order to elucidate the details of the pain and select the appropriate medication.
RESUMEN
The definition of Pain, “an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage” (International Association for the Study of Pain : IASP, 1994), which is often used to explain its subjectivity. It is necessary to evaluate the pain objectively for diagnosis and effectiveness of therapy.<BR>As an evaluation method of chronic pain, Visual Analog Scale (VAS) and Numerical Rating Scale (NRS) are used. Recent years, face visual analog scale and Current Perception Threshold (CPT) testing are also used commonly. Drug challenge test draws attention as it combines an evaluation method and an effective therapy. Meanwhile as a therapy of chronic pain, the reports of epiduroscopy and phototherapy are increasing. The epiduroscopy is an endoscopic operation for patients with the chronic low back pain. In Japan the therapy is performed increasingly for patients with the low back pain of spinal canal stenosis, failed back syndrome and lumbar disc herniation. Regarding the phototherapy, the reports which show the effectiveness of linear polarized infrared raytherapy and xenon phototherapy are mainly observed. Though the nerve block is still the dominant therapy in pain clinics, acupuncture therapy and phototherapy are prospected to increase their demands in future.