Spinal Schwannomas: A Proposal for a New Classification to Aid Surgical Planning.

Background The treatment of spinal schwannomas, which is the most common nerve sheath tumor, is total microsurgical resection. The localization, size and relationship with the surrounding structures of these tumors are crucial in terms of preoperative planning. A new classification method is presented in this study for the surgical planning of spinal schwannoma. Methods All patients who underwent surgery for spinal schwannoma between 2008 and 2021 were reviewed retrospectively, along with radiological images, clinical presentation, surgical approach, and postoperative neurological status. Results A total of 114 patients, 57 male, and 57 females were included in the study. Tumor localizations were cervical in 24 patients, cervicothoracic in one patient, thoracic in 15 patients, thoracolumbar in eight patients, lumbar in 56 patients, lumbosacral in two patients, and sacral in eight patients. All tumors were divided into seven types according to the classification method. Type 1 and Type 2 groups were operated on with a posterior midline approach only, Type 3 tumors were operated on with a posterior midline approach and extraforaminal approach, and Type 4 tumors were operated on with only an extraforaminal approach. While the extraforaminal approach was sufficient in type 5 patients, partial facetectomy was required in 2 patients. Combined surgery including hemilaminectomy and extraforaminal approach was performed in the type 6 group. A posterior midline approach with partial sacrectomy/corpectomy was performed in Type 7 group. Conclusion Effective treatment of spinal schwannoma depends on preoperative planning, which includes correctly classifying tumors. In this study, we present a categorization scheme that covers bone erosion and tumor volume for all spinal localizations.

Identifying overall survival in 98 glioblastomas using VASARI features at 3T.

PURPOSE: This study aims to evaluate qualitative and quantitative imaging metrics along with clinical features affecting overall survival in glioblastomas and to classify them into high survival and low survival groups based on 12, 19, and 24 months thresholds using machine learning. METHODS: The cohort consisted of 98 adult glioblastomas. A standard brain tumor magnetic resonance (MR) imaging protocol, was performed on a 3T MR scanner. Visually Accessible REMBRANDT Images (VASARI) features were assessed. A Kaplan-Meier survival analysis followed by a log-rank test and multivariate Cox regression analysis were used to investigate the effects of VASARI features along with the age, gender, the extent of resection, pre- and post-KPS, ki67 and P53 mutation status on overall survival. Supervised machine learning algorithms were employed to predict the survival of glioblastoma patients based on 12, 19, and 24 months thresholds. RESULTS: Tumor location (p<0.001), the proportion of non-enhancing component (p=0.0482), and proportion of necrosis (p=0.02) were significantly associated with overall survival based on Kaplan-Meier analysis. Multivariate Cox regression analysis revealed that increases in proportion of non-enhancing component (p=0.040) and proportion of necrosis (p=0.039) were significantly associated with overall survival. Machine-learning models were successful in differentiating patients living longer than 12 months with 96.40% accuracy (sensitivity=97.22%, specificity=95.55%). The classification accuracies based on 19 and 24 months survival thresholds were 70.87% (sensitivity=83.02%, specificity=60.11%) and 74.66% (sensitivity=67.58%, specificity=82.08%), respectively. CONCLUSION: Employing clinical and VASARI features together resulted in a successful classification of glioblastomas that would have a longer overall survival.

Limited positive predictive value of diffusion tensor tractography in determining clinically relevant white matter damage in brain stem cavernous malformations: A retrospective study in a single center surgical cohort.

PURPOSE: Diffusion tensor tractography (DTT) might reflect the postoperative clinical outcome of the patients with brain stem (BS) tumors correlating well with the neurological symptoms, but cavernous malformation (CM) is a hemorrhagic tumor prone to artifacts that may limit DTT. We set out to determine the correlation of DTT findings with the neurological examination before and after surgical resection in patients with BSCMs. MATERIALS AND METHODS: DTT findings were evaluated bilaterally for fiber tract displacement or deviation, deformation and interruption in every patient before and after the surgery. Neurological examination was performed at admission, discharge and outpatient follow-up visit. The sensitivity, specificity, positive and negative predictive values of DTT were calculated both pre- and post-operatively. RESULTS: There were 25 patients (9 men 16 women) with a mean age of 39.5±13.9 years. The mean size of the CMs was 6909±8374mm3 (range: 180-38,220mm3) The mean follow-up time was 42.7±23.2 months (range: 8 to 112 months). Preoperatively, the sensitivity, specificity, positive and negative predictive values of DTT for corticospinal tracts (CST) and medial lemnisci (ML) were 100%, 60%, 38.4%, 100% and 87.5%, 11.7%, 31.8%, 66.6%, respectively. Postoperatively, the sensitivity, specificity, positive and negative predictive values of DTT for CSTs and ML were 100%, 64.7%, 40%, 100% and 100%, 0%, 33.3%, 66.6%, respectively. CONCLUSION: Positive findings on DTT such as fiber tract deviation, deformation, disruption or interruption should be taken cautiously before drawing conclusions of a clinically relevant damage of white matter tracts.

Volumetric Muscle Measurements Indicate Significant Muscle Degeneration in Single-Level Disc Herniation Patients.

BACKGROUND: There is a strong relationship between lower back pain and paraspinal muscle atrophy. In this study, we aimed to investigate the prevalence of lumbar paravertebral muscle atrophy in patients with and without single-level disc herniation. METHODS: The 110 retrospectively analyzed patients in this study were divided into 2 groups. Group A included 55 patients with radiologically confirmed single-level disc herniation with back pain and radiculopathy. Group B included 55 patients with back pain without radiologic lumbar disc herniation. The paravertebral muscle cross-sectional areas were measured in both groups by 2 independent observers. RESULTS: In total, 68 women and 42 men were examined. Their mean age was 40.85 years old. The mean ages of groups A and B were 42.49 and 39.22 years, respectively. The cross-sectional areas of the multifidus muscles (MM) and erector spinae muscles were significantly greater in group B than in group A (P < 0.0001). However, there were no statistically significant differences in the psoas major cross-sectional areas, disc heights, and perpendicular distances between the MM and the laminae. CONCLUSIONS: The MM and erector spinae muscle groups are innervated by the dorsal root of the spinal nerve arising from the same level; therefore, long-term pressure on the root caused by disc herniation can cause atrophy and degeneration of that muscle group.

Management of concomitant scoliosis and tethered cord syndrome in non-spina bifida pediatric population.

BACKGROUND: The management of concomitant scoliosis and tethered cord syndrome in the non-spina bifida pediatric population is challenging. In the present study, we evaluate the efficacy of different treatment modalities and propose a treatment plan for the management of affected patients. METHODS: A systematic literature review was conducted by querying the MEDLINE, PubMed, Cochrane, EMBASE, Scopus, and Web of Science databases for papers published between January 1996 and June 2016 and reporting on concomitant scoliosis and tethered cord. We excluded animal studies, non-English papers as well as papers reporting on patients with multiple concomitant intraspinal anomalies such as spina bifida. RESULTS: Out of 1993 articles, only 13 met our inclusion criteria. These 13 articles described six main management approaches: Observation, cord untethering only, cord untethering followed by deformity correction, simultaneous cord untethering and deformity correction, and deformity correction without untethering. Selection of the best approach is a function of the patient's symptomatology and Cobb angle. CONCLUSION: We propose treatment plan for the management of patients with concomitant tethered cord syndrome and spinal deformity. Asymptomatic patients can be followed conservatively and managed as scoliosis patients with no need for untethering. Surgical management in a staged fashion seems appropriate in symptomatic patients with a Cobb angle less than 35°. In these patients, deformity can improve following untethering, thus sparing the patient the risks of surgical correction of scoliosis. Staged or non-staged cord untethering and curve correction seem to be adequate in symptomatic patients with Cobb angle >35° as these patients are likely to require both untethering and deformity correction.

Vertebral augmentation by kyphoplasty and vertebroplasty: 8 years experience outcomes and complications.

BACKGROUND AND CONTEXT: Minimally invasive percutaneous vertebral augmentation techniques; vertebroplasty, and kyphoplasty have been treatment choices for vertebral compression fractures (VCFs). The purpose of this study is to evaluate the outcomes of the patients who underwent vertebroplasty or kyphoplasty regarding complications, correction of vertebral body height, kyphosis angle and pain relief assessment using visual analog score (VAS) for pain. MATERIALS AND METHODS: A retrospective review of the hospital records for 100 consecutive patients treated with kyphoplasty or vertebroplasty in our department database. Patients with osteoporotic compression fractures, traumatic compressions, and osteolytic vertebral lesions, including metastases, hemangiomas, and multiple myeloma, were included in the study. Preoperative and postoperative VAS pain scores, percentages of vertebral compression and kyphotic angles were measured and compared as well as demographic characteristics and postoperative complications. Mobilization and length of stay (LOS) were recorded. RESULTS: One hundred patients were treated by 110 procedures. 64 patients were operated on due to osteoporosis (72 procedures). Twelve patients were operated on because of metastasis (13 procedures), 8 patients were operated on because of multiple myeloma (9 procedures). Five patients had two surgeries, 1 patient had 3 surgeries, and 1 patient had 5 surgeries. The mean preoperative VAS was 74.05 ± 9.8. In total, 175 levels were treated, 46 levels by kyphoplasty and 129 by vertebroplasty. The mean postoperative VAS was 20.94 ± 11.8. Most of the patients were mobilized in the same day they of surgery. Mean LOS was 1.83 days. Six patients had nonsymptomatic leakage of polymethlymethacrylate, and patient had epidural hematoma, which was operated on performing hemi-laminectomy. CONCLUSIONS: Percutaneous vertebroplasty and balloon kyphoplasty are both effective and safe minimally invasive procedures for the stabilization of VCFs. However, complications should be kept in mind during decision making.