The Cutoff Amplitude of Transcranial Motor Evoked Potentials for Transient Postoperative Motor Deficits in Intramedullary Spinal Cord Tumor Surgery

Spine ◽  
2014 ◽  
Vol 39 (18) ◽  
pp. E1086-E1094 ◽  
Author(s):  
Akio Muramoto ◽  
Shiro Imagama ◽  
Zenya Ito ◽  
Kei Ando ◽  
Ryoji Tauchi ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Evoked Potentials ◽  
Motor Evoked Potentials ◽  
Spinal Cord Tumor ◽  
Motor Deficits ◽  
Tumor Surgery ◽  
Intramedullary Spinal Cord ◽  
Intramedullary Spinal Cord Tumor ◽  
Transcranial Motor Evoked Potentials

scholarly journals Intraoperative changes in transcranial motor evoked potentials and somatosensory evoked potentials predicting outcome in children with intramedullary spinal cord tumors

2014 ◽  
Vol 13 (6) ◽  
pp. 591-599 ◽  
Author(s):  
Jason S. Cheng ◽  
Michael E. Ivan ◽  
Christopher J. Stapleton ◽  
Alfredo Quinones-Hinojosa ◽  
Nalin Gupta ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Evoked Potentials ◽  
Somatosensory Evoked Potentials ◽  
Motor Evoked Potentials ◽  
Dorsal Column ◽  
Motor Deficits ◽  
Intramedullary Spinal Cord ◽  
Sensory Deficits ◽  
Motor Strength ◽  
Transcranial Motor Evoked Potentials

Object Intraoperative dorsal column mapping, transcranial motor evoked potentials (TcMEPs), and somatosensory evoked potentials (SSEPs) have been used in adults to assist with the resection of intramedullary spinal cord tumors (IMSCTs) and to predict postoperative motor deficits. The authors sought to determine whether changes in MEP and SSEP waveforms would similarly predict postoperative motor deficits in children. Methods The authors reviewed charts and intraoperative records for children who had undergone resection for IMSCTs as well as dorsal column mapping and TcMEP and SSEP monitoring. Motor evoked potential data were supplemented with electromyography data obtained using a Kartush microstimulator (Medtronic Inc.). Motor strength was graded using the Medical Research Council (MRC) scale during the preoperative, immediate postoperative, and follow-up periods. Reductions in SSEPs were documented after mechanical traction, in response to maneuvers with the cavitational ultrasonic surgical aspirator (CUSA), or both. Results Data from 12 patients were analyzed. Three lesions were encountered in the cervical and 7 in the thoracic spinal cord. Two patients had lesions of the cervicomedullary junction and upper spinal cord. Intraoperative MEP changes were noted in half of the patients. In these cases, normal polyphasic signals converted to biphasic signals, and these changes correlated with a loss of 1–2 grades in motor strength. One patient lost MEP signals completely and recovered strength to MRC Grade 4/5. The 2 patients with high cervical lesions showed neither intraoperative MEP changes nor motor deficits postoperatively. Dorsal columns were mapped in 7 patients, and the midline was determined accurately in all 7. Somatosensory evoked potentials were decreased in 7 patients. Two patients each had 2 SSEP decreases in response to traction intraoperatively but had no new sensory findings postoperatively. Another 2 patients had 3 traction-related SSEP decreases intraoperatively, and both had new postoperative sensory deficits that resolved. One additional patient had a CUSA-related SSEP decrease intraoperatively, which resolved postoperatively, and the last patient had 3 traction-related sensory deficits and a CUSA-related sensory deficit postoperatively, none of which resolved. Conclusions Intraoperative TcMEPs and SSEPs can predict the degree of postoperative motor deficit in pediatric patients undergoing IMSCT resection. This technique, combined with dorsal column mapping, is particularly useful in resecting lesions of the upper cervical cord, which are generally considered to be high risk in this population. Furthermore, the spinal cord appears to be less tolerant of repeated intraoperative SSEP decreases, with 3 successive insults most likely to yield postoperative sensory deficits. Changes in TcMEPs and SSEP waveforms can signal the need to guard against excessive manipulation thereby increasing the safety of tumor resection.

Neuromonitoring for Intramedullary Spinal Cord Tumor Surgery

2016 ◽  
Vol 95 ◽  
pp. 108-116 ◽  
Author(s):  
Terence Verla ◽  
Jared S. Fridley ◽  
Abdul Basit Khan ◽  
Rory R. Mayer ◽  
Ibrahim Omeis
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Tumor ◽  
Tumor Surgery ◽  
Intramedullary Spinal Cord ◽  
Intramedullary Spinal Cord Tumor

Surgical results of intramedullary spinal cord tumor with spinal cord monitoring to guide extent of resection

2009 ◽  
Vol 10 (5) ◽  
pp. 404-413 ◽  
Author(s):  
Yukihiro Matsuyama ◽  
Yoshihito Sakai ◽  
Yoshito Katayama ◽  
Shiro Imagama ◽  
Zenya Ito ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Tumor ◽  
Neurological Status ◽  
Subtotal Resection ◽  
Tumor Surgery ◽  
Total Excision ◽  
Intramedullary Spinal Cord ◽  
Intramedullary Spinal Cord Tumor ◽  
Ambulatory Ability ◽  
Postoperative Mobility

Object The authors investigated the outcome of intramedullary spinal cord tumor surgery, focusing on the effect of preoperative neurological status on postoperative mobility and the extent of tumor excision guided by intraoperative spinal cord monitoring prospectively. Methods Intramedullary spinal cord tumor surgery was performed in 131 patients between 1997 and 2007. The authors compared the pre- and postoperative neurological status and examined the type of surgery in 106 of these patients. A modified McCormick Scale (Grades I–V) was used to assess ambulatory ability (I = normal ambulation; II = mild motor sensory deficit, independent without external aid; III = independent with external aid; IV = care required; and V = wheelchair required). The type of surgery was classified into 4 levels: total resection, subtotal resection, partial resection, and biopsy. Results The 106 patients consisted of 47 females and 59 males, whose average age was 42.5 years (range 6–75 years). The mean follow-up period was 7.3 years (range 2.5 months–21 years). The tumor types included astrocytoma (12 cases), ependymoma (46 cases), hemangioblastoma (16 cases), cavernous hemangioma (17 cases), and others (15 cases overall: gangliocytoma, 1; germ cell tumor, 1; lymphoma, 3; neurinoma, 1; meningioma, 1; oligodendroglioma, 1; sarcoidosis, 2; glioma, 1; and unknown, 4). Initial total excision, subtotal resection, partial resection, biopsy, and duraplasty were performed in 59, 12, 22, 12, and 1 patients, respectively. According to the preoperative McCormick Scale, ambulatory status was classified as Grades I, II, III, IV, and V in 41(38%), 30 (28%), 14 (13%), 19 (19%), and 2 (2%) patients, respectively. Thirty-three (31%) of 106 patients suffered postoperative neurological deterioration. The number of patients who did not lose ambulatory ability or who achieved an ambulatory status of Grade I or II postoperatively was 33 (80%), 21 (70%), 10 (71%), 8 (42%), and 1 (50%) in patients with preoperative Grades I, II, III, IV, and V, respectively. Total excision was performed in 31 (79%) of 39 patients with preoperative Grade I, 12 (40%) of 30 patients with Grade II, 7 (50%) of 14 patients with Grade III, and 9 of 21 patients (38%) with Grade IV or V, indicating that the rate of total excision was significantly higher in patients with Grade I status. Conclusions The postoperative ambulatory ability was excellent in patients with a good preoperative neurological status. Total excision in patients with Grade I or II ambulation was associated with a good prognosis for postoperative mobility. However, the rate of postoperative deterioration was 31.5%, which is relatively high, and patients should be fully informed of this concern prior to intramedullary spinal cord tumor surgery.

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