Optimization of Radiofrequency Needle Placement in Percutaneous Cordotomy Using Electromyography in the Deeply Sedated Patient.

BACKGROUND AND OBJECTIVES: Cordotomy, the selective disconnection of the nociceptive fibers in the spinothalamic tract, is used to provide pain palliation to oncological patients suffering from intractable cancer-related pain. Cordotomies are commonly performed using a cervical (C1-2) percutaneous approach under imaging guidance and require patients' cooperation to functionally localize the spinothalamic tract. This can be challenging in patients suffering from extreme pain. It has recently been demonstrated that intraoperative neurophysiology monitoring by electromyography may aid in safe lesion positioning. The aim of this study was to evaluate the role of compound muscle action potential (CMAP) in deeply sedated patients undergoing percutaneous cervical cordotomy (PCC). METHODS: A retrospective analysis was conducted of all patients who underwent percutaneous cordotomy while deeply sedated between January 2019 and November 2022 in 2 academic centers. The operative report, neuromonitoring logs, and clinical medical records were evaluated. RESULTS: Eleven patients underwent PCC under deep sedation. In all patients, the final motor assessment prior to ablation was done using the electrophysiological criterion alone. The median threshold for evoking CMAP activity at the lesion site was 0.9 V ranging between 0.5 and 1.5 V (average 1 V ± 0.34 V SD). An immediate, substantial decrease in pain was observed in 9 patients. The median pain scores (Numeric Rating Scale) decreased from 10 preoperatively (range 8-10) to a median 0 (range 0-10) immediately after surgery. None of our patients developed motor deficits. CONCLUSION: CMAP-guided PCC may be feasible in deeply sedated patients without added risk to postoperative motor function. This technique should be considered in a group of patients who are not able to undergo awake PCC.

Open Thoracic Cordotomy for Cancer Pain with Intraoperative Neuromonitoring: A Case Series and Critical Review of the Literature.

OBJECTIVE: Cordotomy is a viable option for patients with intractable cancer pain and limited survival. Open thoracic cordotomy is offered when patients are not candidates for percutaneous cordotomy. After the open procedure, traditionally performed purely based on anatomic landmarks, up to 22% of patients experience postoperative limb weakness. The objective of this study is to report our experience with neurophysiology-guided open cordotomy along with a critical review of the literature. METHODS: Between 2019 and 2022, 5 open thoracic cordotomies were performed in our center. Intraoperative neurophysiologic monitoring was used in all cases to guide the lesion and standard single-level laminectomy or hemilaminectomy was performed for exposure. Outcome measures were retrospectively reviewed focusing on pain control and neurologic status. Existing literature on cordotomy was critically reviewed. RESULTS: There was satisfactory pain relief with preservation of motor function in all 5 cases. Temperature sensation was preserved in all but 1 patient, who lost it after the previous ipsilateral percutaneous cordotomy (PCC). No procedural complications were experienced. We found that the neurophysiology monitoring lesion was guided anterior compared with what would have been lesioned on an anatomic basis. CONCLUSIONS: Open thoracic cordotomy is a safe and effective procedure for intractable cancer-related pain. Technical advancements significantly reduced mortality and major morbidity of PCC. Our series suggests that neurophysiology monitoring alters the location of the lesion and may help better targeting of pain fibers within the spinothalamic tract and preserve other long tracts. The safety profile of open cordotomy with neurophysiology compares favorably with the PCC.

Cervical Cordotomy in Terminal Cancer: Pain Relieving in Oncological Treatment

Cordotomy consists in the discontinuation of the lateral spinothalamic tract (LST) in the anterolateral quadrant of the spinal cord, which aims to reduce the transference of nociceptive information in the dorsal horn of the gray matter of the spinal cord to the somatosensory cortex. The main indication is for patients with terminal cancer that have a low life expectancy. It improves the quality of life by relieving pain. The results are promising and the pain relief rate varies between 69 and 100%. Generally speaking, the complications are mostly temporary and not remarkable.

Mesencephalotomy, How I Do It: Analysis of 34 Cases

The present paper aims to demystify the use of rostral mesencephalic reticulotomy (mesencephalotomy) in the treatment of chronic pain in cancer patients. A retrospective review of the medical records from the Central Pain and Stereotaxy Department of the A. C. Camargo Cancer Center, São Paulo, state of São Paulo, Brazil, between 2005 and 2012, was performed. Surgical indication was restricted to patients with cancer pain refractory to etiological and symptomatic treatments, > 2 months of expected survival, preserved cognition, and absence of coagulation disorders, of systemic infection, and of intracranial hypertension. We have selected 34 patients, with an average follow-up of 9.4 months, an average age of 54.3 years-old, and an average follow-up time until death of 6.4 months. Lung cancer was themost frequent diagnosis. Satisfactory and immediate pain relief was achieved in 91% of the cases, and 83% of these patients had no relapses. Among the complications, ocular movement disorder was the most frequent, but often transient. Permanent disturbances occurred in 8.8% of the cases (diplopia, rubral tremor, and paresthesia). Compared to the pharmacological treatment, mesencephalotomy was economically feasible, more effective, and improved quality of life. According to the data presented, it can be concluded that mesencephalotomy is a viable procedure for cancer pain control in selected cases.

O-Arm-Guided Percutaneous Radiofrequency Cordotomy.

BACKGROUND: Pain is often one of the most debilitating symptoms in patients with advanced oncological disease. Patients with localized pain due to malignancy refractory to medical treatment can benefit from selective percutaneous cordotomy that disconnects the ascending pain fibers in the spinothalamic tract. OBJECTIVES: Over the past year, we have been performing percutaneous radiofrequency cordotomy with the use of the O-Arm intraoperative imaging system that allows both 2D fluoroscopy and 3D reconstructed computerized tomography imaging. We present our experience using this technique, focusing on technical nuances and complications. METHODS: A retrospective analysis was conducted of all patients who underwent percutaneous cordotomy between March 2016 and March 2017. RESULTS: Nineteen patients underwent percutaneous cordotomy procedures. Two patients developed intraoperative delirium and were unable to tolerate the procedure. In 16 out of 17 completed procedures, we achieved excellent immediate pain relief (94%). At 1 month after operation, 15 of the 17 (88%) patients were pain free, and at 3 months 5 out of 5 patients available for follow-up were still free of their original pain. Mirror pain developed in 6 of the 17 patients (35%), but was mild in 4 of these cases and controlled with medications. We experienced 1 serious complication (6%) of ipsilateral hemiparesis. CONCLUSION: Percutaneous cordotomy using the O-Arm is safe and effective in the treatment of intractable oncological pain.

Palliative CT-Guided Cordotomy for Medically Intractable Pain in Patients with Cancer.

Palliative cervical cordotomy can be performed via percutaneous radiofrequency ablation of the lateral C1-2 spinothalamic tract. This rare procedure can be safe, effective, and advantageous in mitigating medically intractable unilateral extremity pain for selected patients with end-stage cancer. This report reviews the indications, techniques, risks, and potential benefits of cordotomy. We describe our recent experience treating 3 patients with CT-guided C1-2 cordotomy and provide the first characterization of spinal cord diffusion MR imaging changes associated with successful cordotomy.

Microendoscopy-guided percutaneous cordotomy for intractable pain: case series of 24 patients.

OBJECTIVE: The aim of this study was to show that microendoscopic guidance using a double-channel technique could be safely applied during percutaneous cordotomy and provides clear real-time visualization of the spinal cord and surrounding structures during the entire procedure. METHODS: Twenty-four adult patients with intractable cancer pain were treated by microendoscopic-guided percutaneous radiofrequency (RF) cordotomy using the double-channel technique under local anesthesia. A percutaneous lateral puncture was performed initially under fluoroscopy guidance to localize the target. When the subarachnoid space was reached by the guiding cannula, the endoscope was inserted for visualization of the spinal cord and surrounding structures. After target visualization, a second needle was inserted to guide the RF electrode. Cordotomy was performed by a standard RF method. RESULTS: The microendoscopic double-channel approach provided real-time visualization of the target in 91% of the cases. The other 9% of procedures were performed by the single-channel technique. Significant analgesia was achieved in over 90% of the cases. Two patients had transient ataxia that lasted for a few weeks until total recovery. CONCLUSIONS: The use of percutaneous microendoscopic cordotomy with the double-channel technique is useful for specific manipulations of the spinal cord. It provides real-time visualization of the RF probe, thereby adding a degree of safety to the procedure.

Treatment of medically refractory cancer pain with a combination of intrathecal neuromodulation and neurosurgical ablation: case series and literature review.

OBJECTIVE: Up to 90% of patients with advanced cancer experience intractable pain. For these patients, oral analgesics are the mainstay of therapy, often augmented with intrathecal drug delivery. Neurosurgical ablative procedures have become less commonly used, though their efficacy has been well-established. Unfortunately, little is known about the safety of ablation in the context of previous neuromodulation. Therefore, the aim of this study is to present the results from a case series in which patients were treated successfully with a combination of intrathecal neuromodulation and neurosurgical ablation. DESIGN: Retrospective case series and literature review. SETTING: Three institutions with active cancer pain management programs in the United States. METHODS: All patients who underwent both neuroablative and neuromodulatory procedures for cancer pain were surveyed using the visual analog scale prior to the first procedure, before and after a second procedure, and at long-term follow-up. Based on initial and subsequent presentation, patients underwent intrathecal morphine pump placement, cordotomy, or midline myelotomy. RESULTS: Five patients (2 male, 3 female) with medically intractable pain (initial VAS = 10) were included in the series. Four subjects were initially treated with intrathecal analgesic neuromodulation, and 1 with midline myelotomy. Each patient experienced recurrence of pain (VAS ≥ 9) following the initial procedure, and was therefore treated with another modality (intrathecal, N = 1; midline myelotomy, N = 1; percutaneous radiofrequency cordotomy, N = 3), with significant long-term benefit (VAS 1-7). CONCLUSION: In cancer patients with medically intractable pain, intrathecal neuromodulation and neurosurgical ablation together may allow for more effective control of cancer pain.

Cervical cordotomy for the treatment of oncological pain / Cordotomia cervical para tratamento da dor oncológica: revisâo de literatura

Cordotomy consists in the discontinuation of the spinothalamic tract in the anterolateral quadrant of the spinal cord and aims to reduce the transference of nociceptive information in the dorsal horn of the grey matter of the spinal cord (CPME) for rostral units at the neural axis. Many modalities of cordotomy may be employed: anterior transdiscal between C4-C5; endoscopic infra mastoid tip between C1-C2; percutaneous guided by fluoroscopy infra mastoid tip between C1-C2; percutaneous guided by CT infra mastoid tip between C1-C2; open cordotomy by means of laminectomy. The main indication is for patients in advanced cancer disease with severe neuropathic pain bellow the neck in whom the period of survival due to cancer disease is inferior to 3-4 months. The results for immediate pain relieve ranges from 69% to 100% of the cases, while preoperative Karnofsky scores were 20 and 70, respectively versus post operative Karnofsky scores of 20 and 100 respectively; the difference was determined to be highly significant (p < 0.001).

A cordotomia consiste na discontinuação do trato espinotâmico no quadrante ântero-lateral da medula espinal e visa reduzir a transferência de informação nociceptiva no corno dorsal da substância cinzenta da medula espinal (CPME) para as unidades rostrais no neuroeixo. Muitas modalidades de cordotomia podem ser empregadas: transdiscal anterior entre C4-C5; endoscópica inframastoidea entre C1-C2; Percutânea inframastoidea entre C1-C2 guiada por fluoroscopia; percutânea inframastoidea entre C1-C2 guiada por TC; cordotomia aberta por laminectomia. A principal indicação é para pacientes com câncer avançado com dor neuropática severa abaixo do pescoço nos quais a sobrevida devido ao câncer é inferior a 3-4 meses. Os resultados para alívio imediato da dor varia de 69% a 100% dos casos, enquanto os escores de Karnofsky foram de 20 e 70 no período pré-operatório, para 20 e 100 no período pós-opertaório; a diferença foi estatisticamente significativa (p < 0.001).

CT-guided percutaneous cordotomy for intractable pain in what is more than a disease: lung malignancies.

AIM: Lung cancer is the leading cause of cancer-related mortality worldwide. Pain is a common problem in these patients, yet inadequate or dissatisfactory management is prevalent. MATERIAL AND METHODS: Between 1987 and 2012, 224 patients with intractable pain were treated with computerized tomography (CT)- guided cordotomy. Among them, 210 had intractable pain due to malignancies. The majority of the cases were diagnosed as pulmonary malignancies (108 patients). Sixty-seven were pulmonary carcinoma, 26 mesothelioma and 15 Pancoast tumors. RESULTS: After cordotomy, 98.13% of cancer patients reported initial pain relief. Minimum and maximum preoperative scores of the Karnofsky Performance Scale were 20 and 70, versus postoperative scores of 40 and 90 (p < 0.001). The median preoperative VAS score was 8 (6-9). On the first postoperative day, the score dropped sharply to 0 (0-8) (p < 0.001). In this selected series of 108 percutaneous cordotomy procedures, as well as in the total series of 224 patients, there was no mortality or major morbidity. CONCLUSION: CT-guided percutaneous cordotomy is an effective procedure that should be used in the treatment of cancer-related pain problems. We suggest that cordotomy should be preferred as soon as possible in patients who fail to respond to the classic analgesic therapy.

Four-decade maintenance of analgesia with percutaneous cordotomy.

The management of severe, medically intractable pain is a significant challenge for neurosurgeons and pain management physicians. An existing technique that can effectively alleviate contralateral chronic pain is cordotomy, interruption of the lateral spinothalamic tract of the spinal cord. Since 1912, cordotomy has evolved from a relatively morbid open surgical procedure to a percutaneous radiofrequency procedure with low morbidity. However, since cordotomy is utilized primarily in cancer pain patients, long-term patient follow-up is rare, and the potential duration of analgesia following cordotomy is not known. Here we describe a case with a 41-year follow-up of percutaneous cordotomy for noncancer pain that resulted in over 35 years of complete analgesia, the longest recorded in the literature to date. This case demonstrates that percutaneous cordotomy can provide long-lasting, complete analgesia in some patients and merits continuation as a part of the neurosurgical arsenal of pain therapies.

Cortical hyperexcitability in response to preserved spinothalamic inputs immediately after spinal cord hemisection.

Chronic injury of the main somatosensory pathways ascending along the spinal cord - the dorsal columns and the spinothalamic tract - can produce both changes in the organization of cortical somatotopic maps and neuropathic pain. Little is known, however, about the early neurophysiological changes occurring immediately after injury. We bilaterally recorded the neural activity of the hindpaw representation of the primary somatosensory cortex evoked by stimuli delivered to the hindpaws before and immediately after a thoracic spinal cord hemisection in anesthetized rats. This unilateral spinal cord injury allowed us to separately investigate the cortical effects of deafferenting the dorsal column (stimuli ipsilateral to the hemisection) or the spinothalamic tract (stimuli contralateral to the hemisection). The hemisection produced immediate bilateral changes in the cortical responses evoked by stimuli delivered to the hindpaw ipsilateral to the hemisection (deafferented dorsal column): an expected loss of classical short-latency cortical responses, accompanied by an unexpected appearance of long-latency activations. At the population level, these activations reflected a progressive stimulus-induced transition of the hindpaw somatosensory cortex from up-and-down states to a sustained activated state. At the single-cell level, these cortical activations resembled the "wind-up" typically observed - with the same type of stimuli - in the dorsal horn cells originating the spinothalamic tract. Virtually no changes were observed in the responses evoked by stimuli delivered to the hindpaw contralateral to the hemisection (deafferented spinothalamic tract). These results suggest that spinal cord hemisection immediately produces an abnormal hyperexcitability of the primary somatosensory cortex in response to preserved spinothalamic inputs from the hindpaw. This immediate cortical hyperexcitability could be important to understand the long-term development of cortical reorganization and neuropathic pain after incomplete spinal cord lesions.

Neurosurgical advances in cancer pain management.

Neurosurgical procedures to treat pain are mainly destructive and involve the spinal cord and occasionally the brain. Targets include the spinothalamic tract, the trigeminal tract nucleus, the midline ascending visceral pain pathway, the brainstem spinal lemniscus, the thalamus, and the cingulate gyrus. Since the introduction of intrathecal opioids, the need for neurosurgical destructive procedures has been in decline. In recent years, cordotomy, trigeminal tractotomy, and dorsal root entry zone (DREZ) operations are the neurosurgical procedures most often utilized to treat cancer pain. The addition of CT guidance to spinal cord pain pathway ablation was a major addition and refinement to the procedure. Here the authors review the latest techniques and recently published results for CT-guided cordotomy, CT-guided trigeminal tractotomy, and DREZ operations utilized to treat cancer pain.

Computed tomography-guided percutaneous cordotomy for intractable pain in malignancy.

OBJECTIVE: Pain, usually a response to tissue damage, is accepted as an unpleasant feeling generating a desire to escape from the causative stimulus. Although, in the early stages of malignant diseases, pain is seen in 5% to 10% of cases, this rate reaches nearly 90% in the terminal stage, and pain becomes a primary symptom. Cordotomy is one of the treatment choices in pain caused by malignancies localized unilaterally to the extremities as well as the thorax and the abdomen. METHODS: The target of computed tomography (CT)-guided percutaneous cordotomy is the lateral spinothalamic tract located in the anterolateral region of the spinal cord at the C1-C2 level. Between 1987 and 2007, CT-guided percutaneous cordotomies were performed in 207 patients; most (193 patients) suffered from intractable pain related to malignancy. The patients' pain scores and Karnofsky Performance Scale scores were evaluated pre- and postoperatively. RESULTS: The initial success rate of CT-guided percutaneous cordotomy was 92.5%. The success rate was higher in the malignancy group. In the cancer group, selective cordotomy (pain sensation denervated only in the painful region of the body) was achieved in 83%. In 12 cases, bilateral selective percutaneous cordotomy was successfully applied. CONCLUSION: In the treatment of intractable pain, CT-guided cordotomy is an option in specially selected cases with malignancy. In this study, anatomic and technical details of the procedure and the experience gained from treating 207 patients over a 20-year period are discussed.

Bilateral high-level percutaneous cervical cordotomy in cancer pain due to lung cancer: a case report.

BACKGROUND: Computed tomography-guided high-level percutaneous cordotomy has been used unilaterally or bilaterally for the treatment of localized intractable pain in malignancies. CASE DESCRIPTION: A 57-year-old man was admitted to the hospital with the complaint of intractable pain involving the left side of the chest, axillary region, and shoulder. He was operated for small cell lung cancer on the left side in December 2003 and received radiotherapy and chemotherapy. His neurological examination was normal. Magnetic resonance imaging of the thorax revealed contrast-enhancing lesions on the left side extending to mediastinum and pleura. His pain was relieved completely after the first cordotomy procedure, and he was discharged from the hospital on the second postoperative day. The patient was readmitted to the hospital with the complaint of severe unilateral chest pain like the initial pain on the right side 4 days after cordotomy. The CT-guided bilateral high-level percutaneous cordotomy was performed with a 15-day interval. CONCLUSION: The CT-guided bilateral high-level percutaneous cordotomy can be used in the treatment of intractable upper trunk pain in patients with cancer without pulmonary dysfunction.

The present role of percutaneous cervical cordotomy for the treatment of cancer pain.

The results obtained by percutaneous cervical cordotomy (PCC) were analysed in 43 terminally ill cancer patients treated in our institution from 1998 to 2001. We wished to determine whether there is still a place for PCC in the actual clinical situation with its wide choice of pain therapies. All patients had severe unilateral pain due to cancer, resistant to opioids and co-analgesics. Following PCC, mean pain intensity was reduced from Numeric Rating Scale (NRS) 7.2 to 1.1. At the end of life, pain had increased to NRS 2.9. Initially following PCC a good result (NRS<3) was obtained in 95% of patients. At the end of life, a good result was still present in 69% of patients. Mean duration of survival after the intervention was 118 days (2-1460). In general, complications were mild and mostly subsided within 3-4 days. There was one case of partial paresis of the ipsilateral leg. PCC remains a valuable treatment in patients with treatment-resistant cancer pain and still deserves a place in the treatment of terminal cancer patients with severe unilateral neuropathic or incidence pain.

Percutaneous computed tomography-guided transdiscal low cervical cordotomy for cancer pain as a method to avoid sleep apnea.

OBJECTIVE: Study of percutaneous computed tomography (CT)-guided transdiscal low cervical cordotomy undertaken to treat pain in cancer patients. METHODS: At the Department of Neurosurgery, Ain Shams University, Cairo, Egypt, 8 cancer pain patients, with either impaired pulmonary function or a previous cordotomy on an opposite side (sleep apnea was a feared complication) that prevented the possibility of undergoing a C(1-2) cordotomy, underwent a percutaneous CT-guided transdiscal low cervical cordotomy (C(4-5) or C(5-6)) to treat cancer pain. RESULTS: Seven patients experienced initial improvement. One patient re-experienced pain within 2 weeks and 1 patient experienced no pain relief. In 6 patients in whom the cordotomy procedure was completed, satisfactory or complete pain relief, throughout a 6-month follow-up period was reported. In contrast, in 2 patients in whom the cordotomy was not completed there was no persistent pain relief. CONCLUSION: Percutaneous CT-guided cordotomy remains a successful procedure to control pain in cancer patients, and is an affordable viable option under circumstances where economic disadvantage is an overriding determinate.

CT-guided percutaneous selective cordotomy for treatment of intractable pain in patients with malignant pleural mesothelioma.

Malignant mesotheliomas are neoplasms that arise from mesothelial cells and cause intractable pain in the chest wall, usually located unilaterally. This local pain can be well controlled by computerized tomography (CT)-guided percutaneous cordotomy (PC). One hundred and fifty-three patients suffering from intractable pain due to malignancy were treated with CT-guided cordotomy between 1988 and 2001. Seventy of the 153 patients had pulmonary malignancy. Among these, 40 had bronchogenic carcinoma, 11 had Pancoast tumors and the remaining 19 had mesothelioma. The latter 19 cases with malignant mesothelioma suffering from unilateral pain were treated with CT-guided PC. In 18 cases, pain was controlled totally and, in one, partial pain control was obtained. Selective pain control was obtained in 15 cases, in whom narcotic drugs were discontinued postoperatively. Post-cordotomy dysesthesia was noted in only one case, and no complication or mortality was observed. In the treatment of intractable pain, CT-guided cordotomy is a perfect method in selected cases with malignancy. This is the most effective and suitable treatment modality for local pain due to malignant mesothelioma.

The crossing of the spinothalamic tract.

The question whether the spinothalamic and spinoreticular fibres cross the cord transversely or diagonally was investigated in cases of anterolateral cordotomy and in a case of thrombosis of the anterior spinal artery. The pattern of sensory loss following transection of the anterolateral quadrant of the cord consists of a narrow area of decreased nociception and thermanalgesia at the level of the incision; it extends for 1-2 segments cranial and cordal to the incision. This area is immediately cranial to the area of total loss of these modalities. This pattern of sensory loss is explained as follows. The cordotomy incision transects two groups of fibres: those that are already within the anterior and anterolateral funiculi and those that are crossing the cord. The area of total thermanaesthesia and analgesia is due to transection of fibres that are already within this region. The area of partial sensory loss is due to transection of the fibres that are crossing the cord at that level. Owing to the craniocaudal extent of the branches of the dorsal roots, there is an overlap of their collaterals that results in every spinothalamic neurone receiving an input from several dorsal roots. The narrow cordotomy incision thus divides the few fibres crossing at that level, causing diminished noxious and thermal sensibility over a few segments above and below the incision. These facts can be accounted for only on the assumption that these spinothalamic fibres are crossing the cord transversely. This evidence of transverse crossing was found in the cervical, thoracic and lumbar segments. There were three of 63 cordotomies for which this explanation of the partial sensory loss could not be maintained. Although no explanation has been suggested, this is unlikely to be due to the fibres crossing the cord diagonally.

Myelotomy through the years.

Although myelotomy was first designed to treat somatic pain by interruption of the decussating fibers of the spinothalamic tract, it was soon recognized that pain relief may be obtained in a wider distribution than the dermatomes represented by the interrupted nerves. In 1970, Hitchcock described relief of pain throughout the body by stereotactic production of a single lesion in the middle of the spinal cord at the cervico-medullary junction, a procedure named extra-lemniscal myelotomy by Schvarcz several years later. This led me to the observation reported in 1984 that pelvic pain might be controlled by a non-stereotactic lesion at the thoraco-lumbar area, which appeared to be particularly effective against visceral pain of cancer, in a procedure termed limited myelotomy. In 2000, Kim recognized that thoracic pain might be treated by a similar lesion in the high thoracic area, and termed his procedure thoracic dorsal column midline myelotomy. Up to that time, all authors had considered that pain relief was the result of interruption of a multi-synaptic pathway just dorsal to or within the central canal, which had not yet been defined. However, Willis identified a new pathway in the ventromedial dorsal columns in the post mortem spinal cord provided to him by my coauthor, which he further documented by animal physiologic studies. Nauta, at that same institution, reintroduced limited myelotomy based on those anatomical findings, naming the procedure punctate myelotomy. It must be recognized that all of these procedures have involved interruption of the same pathway, even before it was defined anatomically, and all authors provided similar observations about relief of particularly visceral pain.