Impact of changes in intraoperative somatosensory evoked potentials on stroke rates after clipping of intracranial aneurysms

Robert T. Wicks, Gustavo Pradilla, Shaan M. Raza, Uri Hadelsberg, Alexander Coon, Judy Huang, Rafael J Tamargo

Research output: Contribution to journalArticle

Abstract

BACKGROUND: Somatosensory evoked potential (SSEP) monitoring is used during intracranial aneurysm surgery to track the effects of anesthesia, surgical manipulation, and temporary clipping. OBJECTIVE: To present the outcomes of 663 consecutive patients (691 cases) treated surgically for intracranial aneurysms who underwent intraoperative SSEP monitoring and to analyze the sensitivity and specificity of significant SSEP changes in predicting postoperative stroke. METHODS: Of 691 surgeries analyzed, 403 (391 anterior circulation, 12 posterior circulation) were unruptured aneurysms and 288 (277 anterior, 11 posterior) were ruptured. Postoperatively, symptomatic patients underwent computed tomography imaging. Positive predictive value, negative predictive value, sensitivity, and specificity were calculated with a Fisher exact test (2-tailed P value). RESULTS: Changes in SSEP occurred in 45 of 691 cases (6.5%): 16 of 403 (4.0%) in unruptured aneurysms and 29 of 288 (10%) in ruptured aneurysms. In unruptured aneurysms, reversible SSEP changes were associated with a 20% stroke rate, but irreversible changes were associated with an 80% stroke rate. In ruptured aneurysms, however, reversible changes were associated with a 12% stroke rate, and irreversible changes were associated with a 42% stroke rate. The overall accuracy of SSEP changes in predicting postoperative stroke was as follows: positive predictive value, 30%; negative predictive value, 94%; sensitivity, 25%; and specificity, 95%. CONCLUSION: Intraoperative SSEP changes are more reliable in unruptured aneurysm cases than in ruptured cases. Whereas irreversible changes in unruptured cases were associated with an 80% stroke rate, such changes in ruptured cases did not have any adverse ischemic sequelae in 58% of patients. This information is helpful during the intraoperative assessment of reported SSEP changes.

Original languageEnglish (US)
Pages (from-to)1114-1124
Number of pages11
JournalNeurosurgery
Volume70
Issue number5
DOIs
StatePublished - May 2012

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Somatosensory Evoked Potentials
Intracranial Aneurysm
Stroke
Aneurysm
Ruptured Aneurysm
Sensitivity and Specificity
Anesthesia
Tomography

Keywords

  • Aneurysms
  • Somatosensory evoked potentials

ASJC Scopus subject areas

  • Clinical Neurology
  • Surgery

Cite this

Impact of changes in intraoperative somatosensory evoked potentials on stroke rates after clipping of intracranial aneurysms. / Wicks, Robert T.; Pradilla, Gustavo; Raza, Shaan M.; Hadelsberg, Uri; Coon, Alexander; Huang, Judy; Tamargo, Rafael J.

In: Neurosurgery, Vol. 70, No. 5, 05.2012, p. 1114-1124.

Research output: Contribution to journalArticle

Wicks, Robert T. ; Pradilla, Gustavo ; Raza, Shaan M. ; Hadelsberg, Uri ; Coon, Alexander ; Huang, Judy ; Tamargo, Rafael J. / Impact of changes in intraoperative somatosensory evoked potentials on stroke rates after clipping of intracranial aneurysms. In: Neurosurgery. 2012 ; Vol. 70, No. 5. pp. 1114-1124.
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abstract = "BACKGROUND: Somatosensory evoked potential (SSEP) monitoring is used during intracranial aneurysm surgery to track the effects of anesthesia, surgical manipulation, and temporary clipping. OBJECTIVE: To present the outcomes of 663 consecutive patients (691 cases) treated surgically for intracranial aneurysms who underwent intraoperative SSEP monitoring and to analyze the sensitivity and specificity of significant SSEP changes in predicting postoperative stroke. METHODS: Of 691 surgeries analyzed, 403 (391 anterior circulation, 12 posterior circulation) were unruptured aneurysms and 288 (277 anterior, 11 posterior) were ruptured. Postoperatively, symptomatic patients underwent computed tomography imaging. Positive predictive value, negative predictive value, sensitivity, and specificity were calculated with a Fisher exact test (2-tailed P value). RESULTS: Changes in SSEP occurred in 45 of 691 cases (6.5{\%}): 16 of 403 (4.0{\%}) in unruptured aneurysms and 29 of 288 (10{\%}) in ruptured aneurysms. In unruptured aneurysms, reversible SSEP changes were associated with a 20{\%} stroke rate, but irreversible changes were associated with an 80{\%} stroke rate. In ruptured aneurysms, however, reversible changes were associated with a 12{\%} stroke rate, and irreversible changes were associated with a 42{\%} stroke rate. The overall accuracy of SSEP changes in predicting postoperative stroke was as follows: positive predictive value, 30{\%}; negative predictive value, 94{\%}; sensitivity, 25{\%}; and specificity, 95{\%}. CONCLUSION: Intraoperative SSEP changes are more reliable in unruptured aneurysm cases than in ruptured cases. Whereas irreversible changes in unruptured cases were associated with an 80{\%} stroke rate, such changes in ruptured cases did not have any adverse ischemic sequelae in 58{\%} of patients. This information is helpful during the intraoperative assessment of reported SSEP changes.",
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AU - Raza, Shaan M.

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AU - Huang, Judy

AU - Tamargo, Rafael J

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N2 - BACKGROUND: Somatosensory evoked potential (SSEP) monitoring is used during intracranial aneurysm surgery to track the effects of anesthesia, surgical manipulation, and temporary clipping. OBJECTIVE: To present the outcomes of 663 consecutive patients (691 cases) treated surgically for intracranial aneurysms who underwent intraoperative SSEP monitoring and to analyze the sensitivity and specificity of significant SSEP changes in predicting postoperative stroke. METHODS: Of 691 surgeries analyzed, 403 (391 anterior circulation, 12 posterior circulation) were unruptured aneurysms and 288 (277 anterior, 11 posterior) were ruptured. Postoperatively, symptomatic patients underwent computed tomography imaging. Positive predictive value, negative predictive value, sensitivity, and specificity were calculated with a Fisher exact test (2-tailed P value). RESULTS: Changes in SSEP occurred in 45 of 691 cases (6.5%): 16 of 403 (4.0%) in unruptured aneurysms and 29 of 288 (10%) in ruptured aneurysms. In unruptured aneurysms, reversible SSEP changes were associated with a 20% stroke rate, but irreversible changes were associated with an 80% stroke rate. In ruptured aneurysms, however, reversible changes were associated with a 12% stroke rate, and irreversible changes were associated with a 42% stroke rate. The overall accuracy of SSEP changes in predicting postoperative stroke was as follows: positive predictive value, 30%; negative predictive value, 94%; sensitivity, 25%; and specificity, 95%. CONCLUSION: Intraoperative SSEP changes are more reliable in unruptured aneurysm cases than in ruptured cases. Whereas irreversible changes in unruptured cases were associated with an 80% stroke rate, such changes in ruptured cases did not have any adverse ischemic sequelae in 58% of patients. This information is helpful during the intraoperative assessment of reported SSEP changes.

AB - BACKGROUND: Somatosensory evoked potential (SSEP) monitoring is used during intracranial aneurysm surgery to track the effects of anesthesia, surgical manipulation, and temporary clipping. OBJECTIVE: To present the outcomes of 663 consecutive patients (691 cases) treated surgically for intracranial aneurysms who underwent intraoperative SSEP monitoring and to analyze the sensitivity and specificity of significant SSEP changes in predicting postoperative stroke. METHODS: Of 691 surgeries analyzed, 403 (391 anterior circulation, 12 posterior circulation) were unruptured aneurysms and 288 (277 anterior, 11 posterior) were ruptured. Postoperatively, symptomatic patients underwent computed tomography imaging. Positive predictive value, negative predictive value, sensitivity, and specificity were calculated with a Fisher exact test (2-tailed P value). RESULTS: Changes in SSEP occurred in 45 of 691 cases (6.5%): 16 of 403 (4.0%) in unruptured aneurysms and 29 of 288 (10%) in ruptured aneurysms. In unruptured aneurysms, reversible SSEP changes were associated with a 20% stroke rate, but irreversible changes were associated with an 80% stroke rate. In ruptured aneurysms, however, reversible changes were associated with a 12% stroke rate, and irreversible changes were associated with a 42% stroke rate. The overall accuracy of SSEP changes in predicting postoperative stroke was as follows: positive predictive value, 30%; negative predictive value, 94%; sensitivity, 25%; and specificity, 95%. CONCLUSION: Intraoperative SSEP changes are more reliable in unruptured aneurysm cases than in ruptured cases. Whereas irreversible changes in unruptured cases were associated with an 80% stroke rate, such changes in ruptured cases did not have any adverse ischemic sequelae in 58% of patients. This information is helpful during the intraoperative assessment of reported SSEP changes.

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