Somatosensory evoked potential monitoring in anterior thoracic vertebrectomy

2000 ◽  
Vol 92 (2) ◽  
pp. 155-161 ◽  
Author(s):  
Harel Deutsch ◽  
Marc Arginteanu ◽  
Karen Manhart ◽  
Noel Perin ◽  
Martin Camins ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Vertebral Body ◽  
Evoked Potential ◽  
False Negative ◽  
False Negative Rate ◽  
Neurological Deterioration ◽  
Somatosensory Evoked Potential ◽  
Content Type ◽  
Spinal Cord Function ◽  
Fine Print

Object. Spine surgeons have used intraoperative cortical and subcortical somatosensory evoked potential (SSEP) monitoring to detect changes in spinal cord function when intraoperative procedures can be performed to prevent neurological deterioration. However, the reliability of SSEP monitoring as applied to anterior thoracic vertebral body resections has not been rigorously assessed. Methods. The authors retrospectively reviewed hospital charts and operating room records obtained between August 1993 and December 1998 and found that SSEP monitoring was used in 44 surgical procedures involving an anterior approach for thoracic vertebral body resections. There were no patients in whom SSEP changes did not return to baseline during the surgical procedure. Patients in four cases, despite their stable SSEP recordings throughout the procedure, were noted immediately postoperatively to have experienced significant neurological deterioration. The false-negative rate in SSEP monitoring was 9%. Sensitivity was determined to be 0%. Conclusions. It is important to recognize high false-negative rates and low sensitivity of SSEP monitoring when it is used to record spinal cord function during anterior approaches for thoracic vertebrectomies. The insensitivity of SSEPs for motor deterioration during anterior thoracic vertebrectomies is likely due to the limitation of SSEPs, which monitor only posterior column function whereas motor paths are conveyed in the anterior and anterolateral spinal cord. The authors believe that SSEPs can not be relied on to detect reversible spinal damage during anterior thoracic vertebrectomies.

Prevention of postoperative posterior tethering of spinal cord after resection of ependymoma

2003 ◽  
Vol 99 (2) ◽  
pp. 181-187 ◽  
Author(s):  
Takeo Goto ◽  
Kenji Ohata ◽  
Toshihiro Takami ◽  
Misao Nishikawa ◽  
Akimasa Nishio ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Neurological Deterioration ◽  
Fisher Exact Test ◽  
Content Type ◽  
Exact Test ◽  
Spinal Ependymoma ◽  
Group A ◽  
Delayed Neurological Deterioration ◽  
Group B ◽  
Fine Print

Object. The authors evaluated an alternative method to avoid postoperative posterior tethering of the spinal cord following resection of spinal ependymomas. Methods. Twenty-five patients with spinal ependymoma underwent surgery between 1978 and 2002. There were 16 male and nine female patients whose ages at the time of surgery ranged from 14 to 64 years (mean 41.8 years). The follow-up period ranged from 6 to 279 months (mean 112.4 months). In the initial 17 patients (Group A), the procedure to prevent arachnoidal adhesion consisted of the layer-to-layer closure of three meninges and laminoplasty. In the subsequently treated eight patients (Group B), the authors performed an alternative technique that included pial suturing, dural closure with Gore-Tex membrane—assisted patch grafting, and expansive laminoplasty. In Group A, postoperative adhesion was radiologically detected in eight cases (47%), and delayed neurological deterioration secondary to posterior tethering of the cord was found in five cases. In Group B, there was no evidence of adhesive posterior tethering or delayed neurological deterioration. A significant intergroup statistical difference was demonstrated for radiologically documented posterior tethering (p < 0.05, Fisher exact test). Moreover, patients with radiologically demonstrated posterior tethering suffered a significant delayed neurological functional deterioration (p < 0.01, Fisher exact test). Conclusions. This new technique for closure of the surgical wound is effective in preventing of postoperative posterior spinal cord tethering after excision of spinal ependymoma.

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.

Effect of vasodilators and myelotomy on recovery after acute spinal cord injury in rats

1979 ◽  
Vol 50 (3) ◽  
pp. 349-352 ◽  
Author(s):  
Alex S. Rivlin ◽  
Charles H. Tator
Keyword(s):  
Spinal Cord ◽  
Quantitative Method ◽  
Cord Compression ◽  
Central Canal ◽  
Compression Injury ◽  
Dorsal Midline ◽  
Content Type ◽  
Cord Injury ◽  
Spinal Cord Function ◽  
Fine Print

✓ The effect of papaverine, nitroprusside, or myelotomy on the recovery of spinal cord function was studied in rats after acute cord-compression injury. Spinal cord recovery was measured by a quantitative method of clinical assessment previously developed in our laboratory. Neither papaverine nor nitroprusside improved recovery of cord function. Dorsal midline myelotomy extending anteriorly as far as the central canal did not produce significant improvement (p > 0.05). However, when the myelotomy extended completely through the cord in the anteroposterior plane significant improvement (p < 0.01) was obtained.

Thoracic idiopathic spinal cord herniation at the vertebral body level: a subgroup with a poor prognosis?

2002 ◽  
Vol 97 (3) ◽  
pp. 369-374 ◽  
Author(s):  
Giuseppe M. V. Barbagallo ◽  
Laurence A. G. Marshman ◽  
Carl Hardwidge ◽  
Richard W. Gullan
Keyword(s):  
Spinal Cord ◽  
Vertebral Body ◽  
Prosthetic Material ◽  
Dural Defect ◽  
Content Type ◽  
Distinct Subgroup ◽  
Surgical Reduction ◽  
Spinal Cord Herniation ◽  
Idiopathic Spinal Cord Herniation ◽  
Fine Print

✓ The authors present two cases of thoracic idiopathic spinal cord herniation (TISCH) occurring at the vertebral body (VB) level in whom adequate surgical reduction failed to reverse symptoms. In the second case, in which TISCH occurred into a VB cavity, presentation was atypical (subacute spinal cord syndrome) and there was persistent postoperative deterioration. In both cases, adequate surgical reduction was achieved via a posterior midthoracic laminectomy, and reduction was maintained by closure of the anterior dural defect by using prosthetic material. Thoracic idiopathic spinal cord herniation occurring at a VB level may be technically well treated by surgical reduction, but the outcome appears less predictable. Herniation that occurs directly into a VB cavity may form a distinct subgroup in which the presentation is atypical and the prognosis worse.

Spinal cord arteriovenous malformation in a neonate

1986 ◽  
Vol 64 (2) ◽  
pp. 322-324 ◽  
Author(s):  
T. S. Park ◽  
Wayne S. Cail ◽  
Johnny B. Delashaw ◽  
John Kattwinkel
Keyword(s):  
Spinal Cord ◽  
Arteriovenous Malformation ◽  
Clinical Manifestation ◽  
Neurological Deterioration ◽  
Ischemic Damage ◽  
Aneurysmal Dilatation ◽  
Content Type ◽  
Spinal Cord Arteriovenous Malformation ◽  
Fine Print

✓ A 2-day-old neonate with a spinal cord arteriovenous malformation developed severe paraparesis. The abrupt neurological deterioration was not associated with hemorrhage or aneurysmal dilatation. Ischemic damage of the spinal cord is suggested as the cause of the clinical manifestation.

Evoked potentials from direct cerebellar stimulation for monitoring of the rodent spinal cord

1992 ◽  
Vol 76 (2) ◽  
pp. 280-291 ◽  
Author(s):  
R. John Hurlbert ◽  
Charles H. Tator ◽  
Michael G. Fehlings ◽  
Greg Niznik ◽  
R. Dean Linden
Keyword(s):  
Spinal Cord ◽  
Evoked Potentials ◽  
Posterior Fossa ◽  
Evoked Potential ◽  
Thoracic Spinal Cord ◽  
Content Type ◽  
Thoracic Spinal ◽  
Ventral Funiculus ◽  
Fine Print ◽  
Cerebellar Stimulation

✓ Although the assessment of spinal cord function by electrophysiological techniques has become important in both clinical and research environments, current monitoring methods do not completely evaluate all tracts in the spinal cord. Somatosensory and motor evoked potentials primarily reflect dorsal column and pyramidal tract integrity, respectively, but do not directly assess the status of the ventral funiculus. The present study was undertaken to evaluate the use of evoked potentials, elicited by direct cerebellar stimulation, in monitoring the ventral component of the rodent spinal cord. Twenty-nine rats underwent epidural anodal stimulation directly over the cerebellar cortex, with recording of evoked responses from the lower thoracic spinal cord, both sciatic nerves, and/or both gastrocnemius muscles. Stimulation parameters were varied to establish normative characteristics. The pathways conducting these “posterior fossa evoked potentials” were determined after creation of various lesions of the cervical spinal cord. The evoked potential recorded from the thoracic spinal cord consisted of five positive (P1 to P5) and five negative (N1 to N5) peaks. The average conduction velocity (± standard deviation) of the earliest wave (P1) was 53 ± 4 m/sec, with a latency of 1.24 ± 0.10 msec. The other components followed within 4 msec from stimulus onset. Unilateral cerebellar stimulation resulted in bilateral sciatic nerve and gastrocnemius muscle responses; there were no significant differences (p > 0.05) in the thresholds, amplitudes, or latencies of these responses elicited by right- versus left-sided stimulation. Recordings performed following creation of selective lesions of the cervical cord indicated that the thoracic response was carried primarily in the ventral funiculus while the sciatic and gastrocnemius responses were mediated through the dorsal half of the spinal cord. It is concluded that the posterior fossa evoked potential has research value as a method of monitoring pathways within the ventral spinal cord of the rat, and should be useful in the study of spinal cord injury.

Intraoperative monitoring of blood flow insufficiency during surgery of middle cerebral artery aneurysms

2005 ◽  
Vol 103 (2) ◽  
pp. 275-283 ◽  
Author(s):  
Kazuomi Horiuchi ◽  
Kyouichi Suzuki ◽  
Tatsuya Sasaki ◽  
Masato Matsumoto ◽  
Jun Sakuma ◽  
...  
Keyword(s):  
Blood Flow ◽  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Evoked Potential ◽  
Control Level ◽  
The Other ◽  
Somatosensory Evoked Potential ◽  
Content Type ◽  
Sep Monitoring ◽  
Fine Print

Object. The usefulness of motor evoked potential (MEP) monitoring to detect blood flow insufficiency (BFI) in the cortical branches of the middle cerebral artery (MCA) and lenticulostriate arteries (LSAs) during MCA aneurysm surgery was investigated based on the correlation between MEP and somatosensory evoked potential (SEP) monitoring. Methods. Fifty-three patients with MCA aneurysms underwent surgery accompanied by intraoperative MEP and SEP monitoring. There was no postoperative motor paresis in 43 patients in whom MEP and SEP results remained unchanged. In the other 10 patients, nine manifested transient MEP changes; in five of these, SEP changes did not occur. The transient MEP changes were thought to be attributable to BFI of the MCA cortical branches in two patients, the LSA in three, and either the MCA branches or the LSA in four patients. Of these nine patients, six did not present with postoperative motor paresis; transient motor paresis was recognized in the other three. In the 10th patient, MEP waves disappeared and did not recover. This patient's SEPs remained at 70% of the control level, and he developed severe hemiparesis. A postoperative computerized tomography scan revealed a new low-density area in the corona radiata and putamen. Conclusions. Blood flow insufficiency in both the LSA and MCA cortical branches that perfuse the corticospinal tract can be detected by intraoperative MEP monitoring. Somatosensory evoked potential monitoring is not reliable enough to detect BFI in the MCA branches and the LSAs.

Reversible spinal cord trauma: a model for electrical monitoring of spinal cord function

1972 ◽  
Vol 36 (4) ◽  
pp. 402-406 ◽  
Author(s):  
Thomas J. Croft ◽  
Jerald S. Brodkey ◽  
Frank E. Nulsen
Keyword(s):  
Spinal Cord ◽  
Evoked Potentials ◽  
Sensitive Indicator ◽  
Spinal Cord Trauma ◽  
Content Type ◽  
Cortical Evoked Potentials ◽  
Spinal Cord Damage ◽  
Sensory Transmission ◽  
Spinal Cord Function ◽  
Fine Print

✓ Cortical evoked potentials in anesthetized cats were recorded by a noninvasive averaging technique as a means of estimating spinal cord damage. Graded pressure on the spinal cord produced reversible blocking of these potentials. With this type of trauma, block of motor transmission through the cord paralleled the block of sensory transmission, and each seemed to be a sensitive indicator of spinal cord function. The possible use of such monitoring in anesthetized patients undergoing spinal operations is discussed.

Chemotherapy as the initial treatment of spinal cord compression due to disseminated neuroblastoma

1989 ◽  
Vol 70 (5) ◽  
pp. 688-690 ◽  
Author(s):  
I. R. Sanderson ◽  
Jon Pritchard ◽  
Henry T. Marsh
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Compression ◽  
Initial Treatment ◽  
Cord Compression ◽  
Response To Treatment ◽  
Trial Period ◽  
Content Type ◽  
Sick Children ◽  
Spinal Cord Function ◽  
Fine Print

✓ During a 12-month trial period, all children attending the Hospitals for Sick Children, London, England, for management of spinal cord compression due to disseminated neuroblastoma were given chemotherapy as initial treatment rather than radiotherapy or laminectomy. Response to treatment was evaluated by a neurosurgeon as well as by oncologists. Four children were treated in this way and all made a full recovery of spinal cord function.

Intraoperative SEP monitoring in neurosurgery around the brain stem and cervical spinal cord: differential recording of subcortical components

1994 ◽  
Vol 81 (2) ◽  
pp. 213-220 ◽  
Author(s):  
Wolfgang Wagner ◽  
Lydia Peghini-Halbig ◽  
Johannes C. Mäurer ◽  
Axel Perneczky
Keyword(s):  
Spinal Cord ◽  
Brain Stem ◽  
Cervical Spinal Cord ◽  
False Negative ◽  
False Negative Rate ◽  
Content Type ◽  
Negative Rate ◽  
Neurosurgical Patients ◽  
The Brain

✓ The results of intraoperative monitoring of median nerve somatosensory evoked potentials (SEP's) were evaluated in 75 neurosurgical patients in order to assess the role of differential derivation of brain stem (P14) and spinal cord (N13) wave activity. These components were compared with the conventionally recorded neck potential (“N13”) that reflects overlap of P14 and N13. The spinal cord N13 wave was recorded from the posterior to anterior lower aspect of the neck and the brain stem P14 wave from the midfrontal scalp to the nasopharynx; both derivations enabled isolated low-artifact recording of these components. In 18.7% of patients, moderate to major latency and/or amplitude shifts of N13 or P14 were found that were masked in conventional neck-scalp recordings of “N13”. There was a 6.7% false-negative rate in this series. Using a neck-scalp derivation alone, a 14.7% false-negative rate would have resulted and an isolated worsening of the P14 component (with stable neck potential) in six cases would have been overlooked. It is concluded that the proposed SEP recording technique allows independent assessment of spinal cord and brain stem activity. It is, therefore, superior to the conventional neck-scalp derivation technique, in which important information may be concealed or even lost due to the overlap of the brain stem P14 and spinal cord N13 potentials.

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