Painful thalamic nucleus depletion

Created by Spiegel and Wycis (1948, 1953), it has grown considerably in the past 20 years. It is generally believed that there are two transmission systems for pain: one is the relatively new lateral part of the phylogeny, which constitutes the lateral branch of the spinal thalamus, and the subthalamic sensory nucleus (the posteromedial nucleus) reaches the parietal cortex, called the specific spinal cord. The thalamus projection system; the second is that there is a bundle of less dense ascending fibers on the inside of the bundle, which is characterized by shorter fibers and more synapses, which reach the central mid-beam in the core group of the thalamus via the brainstem network. (CM-PF) cluster, paracentral nucleus and central lateral nucleus (Fig. 4.10.4.1-0-1). This multi-synaptic pathway is formed earlier in biological evolution and is called a non-specific projection system. Through this system, pain is linked to other neurological functions. The destruction of this system does not cause additional neurological symptoms, and the analgesic effect is relatively constant. Stereotactic surgery for pain is developed on this basis. At present, the commonly used surgical targets are the plate core group (central central nucleus, parafascicular PF, central paranuclear PC, central lateral nuclear CL) and the nucleus. The inner medullary plate, the hypothalamic posterior lower part, and the thalamus occipital can be selected. Nuclear and thalamic to parietal cortical projection fibers (radiation crown) for surgical targets. Pain and emotion are inseparable, so psychiatric surgery, especially in the limbic system, is chosen as a destructive lesion to achieve analgesic effects. Patients with intractable pain can achieve certain analgesic effects after stereotactic surgery destroys the target. Because the transmission pathway of pain and its physiological effects are quite complicated, many unsatisfactory results may also occur. In recent years, transcutaneous electrical stimulation and burying electrodes are used to stimulate pain relief. This method has superiority, benign pain is available, and some of the malignant tumor pain can be treated by this method. The range of indications for stereotactic thalamic nucleus destruction for pain has narrowed. Curing disease: Indication 1. The pain caused by the late stage of malignant tumor, the life prediction is still good. 2. Other non-malignant intractable pain, which can not be tolerated by medication, electrical stimulation or peripheral nerve surgery. 3. Facial intractable pain. Contraindications The condition of the whole body is very poor or there are other serious diseases that cannot tolerate the operator. Preoperative preparation 1, before the operation should do a full physical examination, a variety of tests and necessary auxiliary examinations, according to the condition to choose the best treatment. 2. Conduct a comprehensive psychological examination and evaluation before surgery. 3, comprehensive treatment should be actively carried out before surgery to improve the patient's overall condition and observe the patient's response to treatment. 4, the amount of painkillers should be gradually reduced before surgery to eliminate the patient's dependence on drugs. 5, the right amount of barbiturate, purine or atropine can be used before surgery. Surgical procedure 1. There are a variety of orientation guides installed. When installing, it is necessary to strictly follow the requirements of various types of orientation instruments and strive for standards. For example, Bintian Orientation, the patient's head position must be adjusted so that the earplugs on both sides of the frame are aligned with the external auditory canal, and the midline of the skull is aligned with the center hole before and after the frame (ie, the instrument centerline). The Leksell directional instrument must be installed with the sagittal midline of the frame coincident with the midline of the skull. The Y axis of the frame is parallel to the GI line. The head in the anteroposterior direction is located at the center of the frame, avoiding the frame reclining, leaning forward or rotating, and eliminating positioning errors as much as possible. Before the coronal suture, a 2.5 cm long longitudinal incision was made 2.5 cm beside the midline of the surgical side. The skull is drilled in the center of the incision, and the dura mater is cut in a "T" shape, and then electrocoagulated on the surface of the cortex for preparation of cerebral puncturing and target puncture. 2. The target point is 7.5~10mm behind the midpoint of the AC-PC line, 0~3mm below, and 7mm from the center line. Electrical stimulation (bipolar, square pulse, 1, 3, 6Hz or 60 ~ 100Hz, pulse width 1ms, 5 ~ 20V) Pf-CM can cause burning pain in the opposite side of the body, can also cause bilateral burning pain, can be used as an intraoperative Check the basis of the target position. 3. The damaged stove can be made by RF electric heating or freezing. From the trend point of view, the production of large damaged lesions, especially to the dorsal medial nucleus on the dorsal side and the posterior occipital nucleus, has a better analgesic effect. complication Hemiplegia, intracerebral hemorrhage, mental changes and other complications can occur.

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