Connectivity of the human periventricular—periaqueductal gray region

2005 ◽  
Vol 103 (6) ◽  
pp. 1030-1034 ◽  
Author(s):  
Emma Sillery ◽  
Richard G. Bittar ◽  
Matthew D. Robson ◽  
Timothy E. J. Behrens ◽  
John Stein ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Imaging System ◽  
Periaqueductal Gray ◽  
Intractable Pain ◽  
Magnetic Resonance Imaging System ◽  
Posterior Commissure ◽  
Healthy Human ◽  
Content Type ◽  
Diffusion Tractography ◽  
Fine Print

Object. The periventricular gray (PVG) zone and its continuation, the periaqueductal gray (PAG) substance, have been targets for deep brain stimulation (DBS) in the alleviation of intractable pain for longer than two decades. Nevertheless, the anatomical connectivity of this region has been fairly poorly defined. The effects of DBS in this region are probably related to the release of endogenous endorphins, but until the connectivity of this region is better understood the mechanisms will remain unclear. Methods. Diffusion tractography was used to trace the pathways of the PVG—PAG region in seven healthy human volunteers. Images were acquired with the aid of a 1.5-tesla magnetic resonance imaging system. The region of interest was located just lateral to the posterior commissure and extended caudally to the level of the superior colliculus. Probabilistic diffusion tractography was performed from each voxel in each patient's PVG—PAG region. The PVG—PAG region was found to yield descending projections to the spinal cord and cerebellum. Ascending projections to the thalamus and frontal lobes were also observed. Conclusions. These findings suggest that the PVG—PAG region may modulate pain by two mechanisms: one involving the antinociceptive system in the spinal cord and the other involving influences on the central pain network.

Minimally invasive implantation of epidural spinal cord neurostimulator electrodes by using a tubular retractor system

2004 ◽  
Vol 100 (6) ◽  
pp. 1119-1121 ◽  
Author(s):  
Matthew R. Johnson ◽  
Daniel J. Tomes ◽  
John S. Treves ◽  
Lyal G. Leibrock
Keyword(s):  
Spinal Cord ◽  
Postoperative Pain ◽  
Minimally Invasive ◽  
Intractable Pain ◽  
Tubular Retractor ◽  
Content Type ◽  
Novel Technique ◽  
Pain Syndromes ◽  
Hospital Stays ◽  
Fine Print

✓ The authors describe a novel technique for the implantation of multipolar epidural spinal cord neurostimulator electrodes with the aid of a tubular retractor system. Spinal cord neurostimulation is used as a neuroaugmentive tool for treating chronic intractable pain syndromes. Minimally invasive placement of the multipolar neurostimulator electrodes may allow for shorter hospital stays and less postoperative pain associated with the incision.

Neurophysiological effects of dorsal column stimulation in man and monkey

1974 ◽  
Vol 41 (2) ◽  
pp. 217-223 ◽  
Author(s):  
Sanford J. Larson ◽  
Anthony Sances ◽  
Donald H. Riegel ◽  
Glenn A. Meyer ◽  
Donald E. Dallmann ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Evoked Potentials ◽  
Evoked Potential ◽  
Intractable Pain ◽  
Current Application ◽  
Content Type ◽  
Bipolar Recording ◽  
Stimulating Electrodes ◽  
Recording Electrodes ◽  
Fine Print

✓ In 18 patients with cancer and intractable pain, capacitatively coupled pulses of 0.25 msec duration were delivered transcutaneously at 100 Hz to sets of five in-line electrodes implanted subdurally over the dorsal columns. Averaged somatosensory-evoked potentials were recorded from scalp electrodes before, during, and after application of current. All but one patient experienced relief of pain during stimulation, persisting for as long as several hours afterward. Eleven patients developed hyperactive deep reflexes, pathological reflexes, and decreased perception of joint rotation, pain, and touch below the level of current application. Somatosensory-evoked potential amplitudes were markedly reduced. All neurological findings returned to control values within 1 hour after each of repeated applications of current. Histological examination of spinal cord sections from four cancer patients showed no changes secondary to long-term current application. Similar currents were applied to the spinal cord of 15 monkeys with chronically implanted bipolar recording or stimulating electrodes over the lower, middle, and upper thoracic cord, in nucleus ventralis posterior lateralis (VPL), and over the sensory motor cortex (SMC). With application of current, the responses in VPL and SMC to peripheral stimulation were abolished. Evoked potential responses were abolished between bipolar stimulating electrodes and bipolar recording electrodes separated by the five in-line electrodes used to supply the 100 Hz current. However, when both stimulating and recording electrodes were either above or below the five in-line electrode set, evoked responses were unaffected. The findings indicate that applied currents blocked neuronal transmission by producing local changes in the cord. The prolonged alteration of cerebral evoked potentials and relief of pain, however, could also be related to involvement of supraspinal neurons.

Percutaneous cervical cordotomy: a review of 181 operations on 146 patients with a study on the location of “pain fibers” in the C-2 spinal cord segment of 29 cases

1994 ◽  
Vol 80 (6) ◽  
pp. 975-985 ◽  
Author(s):  
Juan Lahuerta ◽  
David Bowsher ◽  
Simpson Lipton ◽  
Peter H. Buxton
Keyword(s):  
Spinal Cord ◽  
Tissue Damage ◽  
Intractable Pain ◽  
Pain Sensation ◽  
Content Type ◽  
Somatotopic Organization ◽  
Current Series ◽  
Spinal Cord Segment ◽  
Pathological Pain ◽  
Fine Print

✓ The authors present a review of 146 patients who underwent 181 percutaneous cervical cordotomies for intractable pain. In addition, an anatomical-clinical correlation was carried out for 29 of these patients. It was found that the fibers subserving pain sensation in the C-2 segment lie in the anterolateral funiculus between the level of the denticulate ligament and a line drawn perpendicularly from the medial angle of the ventral gray-matter horn to the surface of the cord. The best analgesic results have been obtained by creating lesions that extend 5.0 mm deep to the surface of the cord and destroy about 20% of the hemicord. There is a somatotopic organization with sacral fibers running ventromedially and cervical fibers running dorsolaterally. The authors believe that the ascending fibers subserving the distinct sensations of pain induced by tissue damage and pinprick, although mixed (overlapping) in the anterolateral funiculus of the spinal cord, are physiologically distinct from one another. Whereas some cordotomies, both in the current series and as reported in the literature, may affect these functions differentially, optimum pain relief seems to be obtained only when pinprick sensation is also abolished in the affected segments. Evoked pain sensation is not abolished by cordotomy, but its threshold is greatly raised. When pathological pain is completely abolished, so is pinprick sensation. However, in a number of cases where pathological pain was only partially alleviated, pinprick sensation remained intact. The significance of these and other cases reported in the literature is discussed. The importance of clinically distinguishing between pain caused by tissue damage and pinprick sensation is emphasized, as well as that between return of pre-existing or new tissue-damage pain and painful dysesthesia.

Patient-interactive, computer-controlled neurological stimulation system: clinical efficacy in spinal cord stimulator adjustment

1992 ◽  
Vol 76 (6) ◽  
pp. 967-972 ◽  
Author(s):  
Richard B. North ◽  
Kim Fowler ◽  
Daniel J. Nigrin ◽  
Richard Szymanski
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Stimulation ◽  
Potential Operator ◽  
Intractable Pain ◽  
Stimulus Pulse ◽  
Content Type ◽  
Psychophysical Data ◽  
Time Required ◽  
Computerized System ◽  
Fine Print

✓ Over the past 20 years, continuing technical advances have rendered spinal cord stimulation an easily implemented low-morbidity technique for the management of chronic intractable pain in properly selected patients. Percutaneous methods for the insertion of arrays of multiple epidural electrodes, which are driven by noninvasively programmable “multichannel” implanted devices, have been among the most important of these technical improvements. The same implanted electronics may be used with peripheral nerve or intracerebral electrodes. If the capabilities of this new hardware are to be used to full advantage, a major investment of time and effort is required to adjust the system postoperatively for optimum effect. Ideally, these adjustments should be based upon psychophysical data, obtained in a manner that minimizes influences such as potential operator bias or stimulus presentation-order effects. These requirements have been met by the development of a computerized system designed for direct patient interaction and for greater ease of operation than the standard external devices used with these implants. The system has been tested clinically in 25 patients with spinal cord stimulation for pain. It rapidly tests the available electrode combinations and stimulus pulse parameters at a rate comparable to or greater than that of a skilled human operator using the standard device. It records detailed graphic data and patient analog ratings at varying thresholds and implements “pain drawing” methods with novel input and analytical techniques. This patient-interactive computerized system has proved to be safe and effective clinically. The time required by the average patient working with this system to adjust the stimulator is comparable to or less than the time required by the same patient working with a physician's assistant. Psychophysical data collected by the system may be correlated with clinical observations. Ongoing development will permit delivery of novel pulse sequences and protocols to assess the mechanisms by which stimulation affords relief from pain.

Safety and efficacy of stereotactic radiosurgery for tumors of the spine

2004 ◽  
pp. 413-418 ◽  
Author(s):  
Deborah L. Benzil ◽  
Mehran Saboori ◽  
Alon Y. Mogilner ◽  
Ronald Rocchio ◽  
Chitti R. Moorthy
Keyword(s):  
Spinal Cord ◽  
Single Dose ◽  
Pain Relief ◽  
Total Dose ◽  
Stereotactic Radiosurgery ◽  
Medical Center ◽  
Primary Tumors ◽  
Content Type ◽  
Increased Risk ◽  
Fine Print

Object. The extension of stereotactic radiosurgery treatment of tumors of the spine has the potential to benefit many patients. As in the early days of cranial stereotactic radiosurgery, however, dose-related efficacy and toxicity are not well understood. The authors report their initial experience with stereotactic radiosurgery of the spine with attention to dose, efficacy, and toxicity. Methods. All patients who underwent stereotactic radiosurgery of the spine were treated using the Novalis unit at Westchester Medical Center between December 2001 and January 2004 are included in a database consisting of demographics on disease, dose, outcome, and complications. A total of 31 patients (12 men, 19 women; mean age 61 years, median age 63 years) received treatment for 35 tumors. Tumor types included 26 metastases (12 lung, nine breast, five other) and nine primary tumors (four intradural, five extradural). Thoracic tumors were most common (17 metastases and four primary) followed by lumbar tumors (four metastases and four primary). Lesions were treated to the 85 to 90% isodose line with spinal cord doses being less than 50%. The dose per fraction and total dose were selected on the basis of previous treatment (particularly radiation exposure), size of lesion, and proximity to critical structures. Conclusions. Rapid and significant pain relief was achieved after stereotactic radiosurgery in 32 of 34 treated tumors. In patients treated for metastases, pain was relieved within 72 hours and remained reduced 3 months later. Pain relief was achieved with a single dose as low as 500 cGy. Spinal cord isodoses were less than 50% in all patients except those with intradural tumors (mean single dose to spinal cord 268 cGy and mean total dose to spinal cord 689 cGy). Two patients experienced transient radiculitis (both with a biological equivalent dose (BED) > 60 Gy). One patient who suffered multiple recurrences of a conus ependymoma had permanent neurological deterioration after initial improvement. Pathological evaluation of this lesion at surgery revealed radiation necrosis with some residual/recurrent tumor. No patient experienced other organ toxicity. Stereotactic radiosurgery of the spine is safe at the doses used and provides effective pain relief. In this study, BEDs greater than 60 Gy were associated with an increased risk of radiculitis.

Posterior approach for cervical intramedullary arteriovenous malformation with diffuse-type nidus

1999 ◽  
Vol 91 (1) ◽  
pp. 105-111 ◽  
Author(s):  
Kenji Ohata ◽  
Toshihiro Takami ◽  
Alaa El-Naggar ◽  
Michiharu Morino ◽  
Akimasa Nishio ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Poor Prognosis ◽  
Posterior Approach ◽  
The Other ◽  
Anterior Spinal Artery ◽  
Neural Element ◽  
Feeding Artery ◽  
Diffuse Type ◽  
Content Type ◽  
Fine Print

✓ The treatment of spinal intramedullary arteriovenous malformations (AVMs) with a diffuse-type nidus that contains a neural element poses different challenges compared with a glomus-type nidus. The surgical elimination of such lesions involves the risk of spinal cord ischemia that results from coagulation of the feeding artery that, at the same time, supplies cord parenchyma. However, based on evaluation of the risks involved in performing embolization, together with the frequent occurrence of reperfusion, which necessitates frequent reembolization, the authors consider surgery to be a one-stage solution to a disease that otherwise has a very poor prognosis. Magnetic resonance (MR) imaging revealed diffuse-type intramedullary AVMs in the cervical spinal cords of three patients who subsequently underwent surgery via the posterior approach. The AVM was supplied by the anterior spinal artery in one case and by both the anterior and posterior spinal arteries in the other two cases. In all three cases, a posterior median myelotomy was performed up to the vicinity of the anterior median fissure that divided the spinal cord together with the nidus, and the feeding artery was coagulated and severed at its origin from the anterior spinal artery. In the two cases in which the posterior spinal artery fed the AVM, the feeding artery was coagulated on the dorsal surface of the spinal cord. Neurological outcome improved in one patient and deteriorated slightly to mildly in the other two patients. Postoperative angiography demonstrated complete disappearance of the AVM in all cases. Because of the extremely poor prognosis of patients with spinal intramedullary AVMs, this surgical technique for the treatment of diffuse-type AVMs provides acceptable operative outcome. Surgical intervention should be considered when managing a patient with a diffuse-type intramedullary AVM in the cervical spinal cord.

Traumatic arteriovenous fistula of the vertebral artery with spinal cord symptoms

1977 ◽  
Vol 46 (5) ◽  
pp. 681-687 ◽  
Author(s):  
Chikao Nagashima ◽  
Takashi Iwasaki ◽  
Seiichi Kawanuma ◽  
Arata Sakaguchi ◽  
Akira Kamisasa ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Vertebral Artery ◽  
Arteriovenous Fistula ◽  
Rapid Improvement ◽  
Direct Closure ◽  
Content Type ◽  
Vertebral Arteriovenous Fistula ◽  
Fine Print

✓ The authors report a case of a traumatic vertebral arteriovenous fistula with spinal cord symptoms. Direct closure of the fistula was followed by rapid improvement.

Split spinal cord malformations in children

1998 ◽  
Vol 88 (1) ◽  
pp. 57-65 ◽  
Author(s):  
Yusuf Ersşahin ◽  
Saffet Mutluer ◽  
Sevgül Kocaman ◽  
Eren Demirtasş
Keyword(s):  
Spinal Cord ◽  
Neurological Deficits ◽  
Single Type ◽  
Type I ◽  
Type Ii ◽  
Content Type ◽  
Spinal Lesion ◽  
The Mean ◽  
Fine Print

Object. The authors reviewed and analyzed information on 74 patients with split spinal cord malformations (SSCMs) treated between January 1, 1980 and December 31, 1996 at their institution with the aim of defining and classifying the malformations according to the method of Pang, et al. Methods. Computerized tomography myelography was superior to other radiological tools in defining the type of SSCM. There were 46 girls (62%) and 28 boys (38%) ranging in age from less than 1 day to 12 years (mean 33.08 months). The mean age (43.2 months) of the patients who exhibited neurological deficits and orthopedic deformities was significantly older than those (8.2 months) without deficits (p = 0.003). Fifty-two patients had a single Type I and 18 patients a single Type II SSCM; four patients had composite SSCMs. Sixty-two patients had at least one associated spinal lesion that could lead to spinal cord tethering. After surgery, the majority of the patients remained stable and clinical improvement was observed in 18 patients. Conclusions. The classification of SSCMs proposed by Pang, et al., will eliminate the current chaos in terminology. In all SSCMs, either a rigid or a fibrous septum was found to transfix the spinal cord. There was at least one unrelated lesion that caused tethering of the spinal cord in 85% of the patients. The risk of neurological deficits resulting from SSCMs increases with the age of the patient; therefore, all patients should be surgically treated when diagnosed, especially before the development of orthopedic and neurological manifestations.

Astrocytomas of the spinal cord in children and adolescents

1985 ◽  
Vol 63 (5) ◽  
pp. 669-675 ◽  
Author(s):  
Ronald Reimer ◽  
Burton M. Onofrio
Keyword(s):  
Spinal Cord ◽  
Histological Grade ◽  
Extended Period ◽  
Spinal Deformities ◽  
Duration Of Symptoms ◽  
Female Ratio ◽  
Content Type ◽  
Orthopedic Procedure ◽  
Male To Female ◽  
Fine Print

✓ The authors review 32 cases of spinal cord astrocytoma in patients under 20 years of age who were treated at the Mayo Clinic between 1955 and 1980. There was a 1.3:1 male to female ratio. Twenty patients were between 6 and 15 years of age at the time of diagnosis. The duration of symptoms prior to definitive diagnosis varied from 5 days to 9 years, with an average of 24 months. The most common symptoms were pain (62.5%), gait disturbance (43.7%), numbness (18.8%), and sphincteric dysfunction (18.8%). The most common neurological findings were a Babinski response (50.0%), posterior column sensory dysfunction (40.6%), and paraparesis (37.5%). A median follow-up period of 8.6 years (range 0.8 to 25.5 years) revealed that the survival time diminished with increased histological grade of the astrocytoma (p < 0.001). The development of postlaminectomy spinal deformities represented a serious postoperative complication. This occurred in 13 patients and was first recognized between 8 and 90 months postoperatively. Six deformities occurred following cervical laminectomy, and eight patients required at least one orthopedic procedure. It is crucial to follow these patients for an extended period of time to watch for postoperative spinal deformities.

Intradural spinal teratoma: evidence for a dysembryogenic origin

1998 ◽  
Vol 89 (5) ◽  
pp. 844-851 ◽  
Author(s):  
Joseph L. Koen ◽  
Roger E. McLendon ◽  
Timothy M. George
Keyword(s):  
Spinal Cord ◽  
Germ Cells ◽  
Primordial Germ Cells ◽  
Split Cord Malformation ◽  
Rare Tumor ◽  
Content Type ◽  
Fine Print

✓ Intradural spinal teratoma is a rare tumor that can be associated with dysraphic defects. Although the origin of these tumors is traditionally thought to be secondary to primordial germ cells misplaced early in embryogenesis, the pathogenesis of intraspinal teratoma remains unclear. The authors present a series of patients in whom an intradural teratoma arose at the same site as a developmental spinal cord abnormality, including a split cord malformation, myelomeningocele, and lipomyelomeningocele. It is postulated that these lesions were the result of a dysembryogenic mechanism and were not neoplastic.

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