Flores Bruno C, Whittemore Anthony R, Samson Duke S, Barnett Samuel L
Departments of 1 Neurological Surgery and.
J Neurosurg. 2015 Mar;122(3):653-62. doi: 10.3171/2014.11.JNS13680. Epub 2015 Jan 9.
Resection of brainstem cavernous malformations (BSCMs) may reduce the risk of stepwise neurological deterioration secondary to hemorrhage, but the morbidity of surgery remains high. Diffusion tensor imaging (DTI) and diffusion tensor tractography (DTT) are neuroimaging techniques that may assist in the complex surgical planning necessary for these lesions. The authors evaluate the utility of preoperative DTI and DTT in the surgical management of BSCMs and their correlation with functional outcome.
A retrospective review was conducted to identify patients who underwent resection of a BSCM between 2007 and 2012. All patients had preoperative DTI/DTT studies and a minimum of 6 months of clinical and radiographic follow-up. Five major fiber tracts were evaluated preoperatively using the DTI/DTT protocol: 1) corticospinal tract, 2) medial lemniscus and medial longitudinal fasciculus, 3) inferior cerebellar peduncle, 4) middle cerebellar peduncle, and 5) superior cerebellar peduncle. Scores were applied according to the degree of distortion seen, and the sum of scores was used for analysis. Functional outcomes were measured at hospital admission, discharge, and last clinic visit using modified Rankin Scale (mRS) scores.
Eleven patients who underwent resection of a BSCM and preoperative DTI were identified. The mean age at presentation was 49 years, with a male-to-female ratio of 1.75:1. Cranial nerve deficit was the most common presenting symptom (81.8%), followed by cerebellar signs or gait/balance difficulties (54.5%) and hemibody anesthesia (27.2%). The majority of the lesions were located within the pons (54.5%). The mean diameter and estimated volume of lesions were 1.21 cm and 1.93 cm(3), respectively. Using DTI and DTT, 9 patients (82%) were found to have involvement of 2 or more major fiber tracts; the corticospinal tract and medial lemniscus/medial longitudinal fasciculus were the most commonly affected. In 2 patients with BSCMs without pial presentation, DTI/DTT findings were important in the selection of the surgical approach. In 2 other patients, the results from preoperative DTI/DTT were important for selection of brainstem entry zones. All 11 patients underwent gross-total resection of their BSCMs. After a mean postoperative follow-up duration of 32.04 months, all 11 patients had excellent or good outcome (mRS Score 0-3) at the time of last outpatient clinic evaluation. DTI score did not correlate with long-term outcome.
Preoperative DTI and DTT should be considered in the resection of symptomatic BSCMs. These imaging studies may influence the selection of surgical approach or brainstem entry zones, especially in deep-seated lesions without pial or ependymal presentation. DTI/DTT findings may allow for more aggressive management of lesions previously considered surgically inaccessible. Preoperative DTI/DTT changes do not appear to correlate with functional postoperative outcome in long-term follow-up.
切除脑干海绵状畸形（BSCMs）可能会降低因出血导致逐步神经功能恶化的风险，但手术的发病率仍然很高。扩散张量成像（DTI）和扩散张量纤维束成像（DTT）是神经成像技术，可有助于针对这些病变进行复杂的手术规划。作者评估术前DTI和DTT在BSCMs手术治疗中的效用及其与功能预后的相关性。
进行一项回顾性研究，以确定在2007年至2012年间接受BSCMs切除术的患者。所有患者均进行了术前DTI/DTT检查，并至少有6个月的临床和影像学随访。术前使用DTI/DTT方案评估五条主要纤维束：1）皮质脊髓束，2）内侧丘系和内侧纵束，3）小脑下脚，4）小脑中脚，5）小脑上脚。根据所见的变形程度进行评分，并将评分总和用于分析。使用改良Rankin量表（mRS）评分在入院、出院和最后一次门诊就诊时测量功能预后。
确定了11例接受BSCMs切除术和术前DTI检查的患者。就诊时的平均年龄为49岁，男女比例为1.75:1。脑神经缺损是最常见的就诊症状（81.8%），其次是小脑体征或步态/平衡困难（54.5%）和半身麻醉（27.2%）。大多数病变位于脑桥内（54.5%）。病变的平均直径和估计体积分别为1.21 cm和1.93 cm³。使用DTI和DTT，发现9例患者（82%）有两条或更多主要纤维束受累；皮质脊髓束和内侧丘系/内侧纵束是最常受影响的。在2例无软膜表现的BSCMs患者中，DTI/DTT结果对手术入路的选择很重要。在另外2例患者中，术前DTI/DTT结果对脑干进入区的选择很重要。所有11例患者均接受了BSCMs的全切除。术后平均随访32.04个月，所有11例患者在最后一次门诊评估时均获得了良好或优秀的预后（mRS评分0 - 3）。DTI评分与长期预后无关。
对于有症状的BSCMs切除术，应考虑术前DTI和DTT。这些影像学检查可能会影响手术入路或脑干进入区的选择，特别是对于没有软膜或室管膜表现的深部病变。DTI/DTT结果可能允许对以前认为无法手术切除的病变进行更积极的治疗。术前DTI/DTT变化在长期随访中似乎与术后功能预后无关。
