Supratentorial cavernous malformations adjacent to the corticospinal tract: surgical outcomes and predictive value of diffusion tensor imaging findings

Abstract

OBJECTIVE Diffusion tensor imaging (DTI) findings may facilitate clinical decision making in patients with supratentorial cavernous malformations adjacent to the corticospinal tract (CST-CMs). The objective of this study was to determine the predictive value of preoperative DTI findings for surgical outcomes in patients with CST-CMs. METHODS A prospectively maintained database of patients with CM referred to the authors' hospital between September 2012 and October 2015 was reviewed to identify all consecutive surgically treated patients with CST-CM. All patients had undergone sagittal T1-weighted anatomical imaging and DTI before surgery. Both DTI findings and clinical characteristics of the patients and lesions were analyzed with respect to surgery-related motor deficits. DTI findings included lesion-to-CST distance (LCD) and the alteration (i.e., deviation, interruption, or degeneration due to the CM) of CST on preoperative DTI images. Surgery-related motor deficits at 1 week and the last clinic visit (≥ 3 months) after surgery were defined as short-term and long-term deficits, respectively. Preoperative and final modified Rankin Scale scores were also analyzed to identify the surgical outcomes in these patients. RESULTS A total of 56 patients with 56 CST-CMs were included in this study. The mean LCD was 3.9 ± 3.2 mm, and alterations of the CST were detected in 20 (36.7%) patients. One week after surgery, 21 (37.5%) patients had short-term surgery-related motor deficits, but only 14 (25.0%) patients had long term deficits at the last clinical visit. The mean patient follow-up was 14.7 ± 10.1 months. The difference between preoperative and final modified Rankin Scale scores was not statistically significant (p = 0.490). Multivariate analysis showed that both short-term (p < 0.001) and long-term (p = 0.002) surgery-related motor deficits were significantly associated with LCD. Receiver operating characteristic (ROC) curve results were as follows: for short-term surgery-related motor deficits, the area under the ROC curve (AUC) was 0.860, and the cutoff point was LCD = 2.55 mm; for long-term deficits, the AUC was 0.894, and the cutoff point was LCD = 2.30 mm. Both univariate (p = 0.012) and multivariate (p = 0.049) analyses revealed that CST alteration on preoperative DTI was significantly correlated with short-term surgery-related motor deficits. On univariate analysis, deep location of the CST-CMs was significantly correlated with long-term motor deficits (p = 0.016). Deep location of the CST-CMs had a trend toward significance with long-term motor deficits on the multivariate analysis (p = 0.060). CONCLUSIONS To facilitate clinical practice, the authors propose that 3.00 mm (2.55 to ∼3.00 mm) may be the safe LCD for surgery in patients with CST-CMs. A CST alteration on preoperative DTI and a deep location of the CST-CM may be risk factors for short- and long-term surgery-related motor deficits, respectively. A randomized controlled trial is needed to demonstrate the predictive value of preoperative DTI findings...

The role of diffusion tensor imaging and tractography in the surgical management of brainstem gliomas

“…By qualitatively and quantitively evaluating the DTI/DTT results, Lin et al found that CST score and lesion-to-CST distance were correlated with short-term postoperative neurological function, whereas others did not find such a correlation of DTI/DTT changes to mRS score at follow-up. [10][11][12]19,21 In comparison, we found that the CST score was an independent predictor of postoperative muscle strength and mRS score at discharge. As CST scores reflect the severity of injury to the pyramidal tracts, a high score indicates that the tracts have already been damaged and are more vulnerable to surgical manipulation; in this case, patients are very likely to suffer from deteriorated or new neurological deficits, thus correlating with weaker muscle strength and worse postoperative mRS score.…”

“…Additionally, it may have promising value for the prediction of postoperative neurological function. 12,15,19 However, as brainstem gliomas behave differently from cavernous malformations and their ability to infiltrate the normal brain may vary depending on their genetic characteristics, the role of DTI/DTT in brainstem glioma surgery merits investigation. In our study, the number of changes in the CSTs in the deviation, deformation, and interruption groups were very similar.…”

“…Understanding the anatomical relationship between the tumor and tracts is helpful to determine the approach, and many studies have shown that DTI/DTT is a highly valuable tool in preoperative surgical planning. 9,10,12,19 In our series, more than one-third of the approaches were adjusted after taking the DTI/DTT results into account. The main reason for this adjustment was that the white matter tracts were displaced more superficially by the tumor in the surgical corridor, which prevented adequate exposure and safe resection.…”

High-Flow Vascular Malformations in Children

“…A preoperative neuronavigation MRI with diffusion tensor imaging, and/or functional imaging obtained prior to surgery, may facilitate selection of safer surgical routes, and thereby reduce the likelihood of causing new postoperative deficits. 44,45…”

Maximum Nidus Depth as a Risk Factor of Surgical Morbidity in Eloquent Brain Arteriovenous Malformations

“…In addition to factors such as well-known hemorrhagic onset, unruptured BAVM, size, and deep venous drainage that are included in the Spetzler-Martin (S-M) grading scale [1][2][3][4], several surgical risk factors for eloquent BAVM have been reported in recent years, such as cortical reorganization and plasticity of motor area visualized via functional magnetic resonance imaging (fMRI) [5], BAVM lesion-tocorticospinal tract (CST) distance assessed by diffusion tensor imaging (DTI) [6,7], and BAVM lesion-to-activation area distance (LAD) assessed by fMRI [8]. They can help predict postoperative neurological outcomes in the eloquent area and these factors contributed to acceptable long-term outcomes [6,9], along with transient but finally reversible surgical morbidity.…”