Use of zero-profile device for contiguous three-level anterior cervical discectomy and fusion: comparison with cage and plate construct

J Neurosurg Spine 35:219–226, 2021

The aim of this study was to compare a traditional cervical cage with a zero-profile (ZP) fixation device in patients who underwent three-level anterior cervical decompression and fusion (ACDF) in terms of patient-reported outcomes (visual analog scale [VAS], Japanese Orthopaedic Association [JOA], and Neck Disability Index [NDI] scores), radiographic findings (sagittal alignment 2 years after surgery and likelihood of fusion), and complications.

METHODS This study was a retrospective case series. Between January 2012 and December 2016, 58 patients with cervical spondylotic myelopathy (CSM) who required three-level ACDF procedures, as identified by spinal surgeons, were treated with three-level ACDF and an anterior cage-plate construct (ACPC) (n = 38) or a three-level stand-alone ZP device (n = 20). On the basis of patient choice, patients were divided into two groups (ACPC group and ZP group). All patients completed a minimum of 2 years of follow-up. Patient-reported outcome scores included VAS, JOA, and NDI scores. The radiographic findings included sagittal alignment and likelihood of fusion 2 years after surgery. Data related to patient-reported outcomes and sagittal alignment were collected preoperatively, postoperatively, and at the final follow-up. Intraoperative and postoperative complications were also documented and analyzed.

RESULTS The clinical outcomes, including VAS, JOA, and NDI scores, showed improvement in both groups, and no significant difference was observed between the two groups. Sagittal alignment and height of the fused segments were restored in all patients. However, the authors found no differences between the ZP and ACPC groups, and the groups exhibited similar fusion rates. The authors found no differences in complications, including dysphagia, adjacent-segment degeneration, and postoperative hematoma, between the groups.

CONCLUSIONS Use of ZP implants yielded satisfactory long-term clinical and radiological outcomes that were similar to those of the standard ACPC. Additionally, the rates of complications between the groups were not significantly different. Although the best surgical option for multilevel CSM remains controversial, the results of this work suggest that ACDF with the ZP device is feasible, safe, and effective, even for multilevel CSM.

Resection of tumors within the primary motor cortex using high-frequency stimulation

J Neurosurg 133:642–654, 2020

Brain mapping techniques allow one to effectively approach tumors involving the primary motor cortex (M1). Tumor resectability and maintenance of patient integrity depend on the ability to successfully identify motor tracts during resection by choosing the most appropriate neurophysiological paradigm for motor mapping. Mapping with a highfrequency (HF) stimulation technique has emerged as the most efficient tool to identify motor tracts because of its versatility in different clinical settings. At present, few data are available on the use of HF for removal of tumors predominantly involving M1.

METHODS The authors retrospectively analyzed a series of 102 patients with brain tumors within M1, by reviewing the use of HF as a guide. The neurophysiological protocols adopted during resections were described and correlated with patients’ clinical and tumor imaging features. Feasibility of mapping, extent of resection, and motor function assessment were used to evaluate the oncological and functional outcome to be correlated with the selected neurophysiological parameters used for guiding resection. The study aimed to define the most efficient protocol to guide resection for each clinical condition.

RESULTS The data confirmed HF as an efficient tool for guiding resection of M1 tumors, affording 85.3% complete resection and only 2% permanent morbidity. HF was highly versatile, adapting the stimulation paradigm and the probe to the clinical context. Three approaches were used. The first was a “standard approach” (HF “train of 5,” using a monopolar probe) applied in 51 patients with no motor deficit and seizure control, harboring a well-defined tumor, showing contrast enhancement in most cases, and reaching the M1 surface. Complete resection was achieved in 72.5%, and 2% had permanent morbidity. The second approach was an “increased train approach,” that is, an increase in the number of pulses (7–9) and of pulse duration, using a monopolar probe. This second approach was applied in 8 patients with a long clinical history, previous treatment (surgery, radiation therapy, chemotherapy), motor deficit at admission, poor seizure control, and mostly high-grade gliomas or metastases. Complete resection was achieved in 87.5% using this approach, along with 0% permanent morbidity. The final approach was a “reduced train approach,” which was the combined use of train of 2 or train of 1 pulses associated with the standard approach, using a monopolar or bipolar probe. This approach was used in 43 patients with a long clinical history and poorly controlled seizures, harboring tumors with irregular borders without contrast enhancement (low or lower grade), possibly not reaching the cortical surface. Complete resection was attained in 88.4%, and permanent morbidity was found in 2.3%.

CONCLUSIONS Resection of M1 tumors is feasible and safe. By adapting the stimulation paradigm and probe appropriately to the clinical context, the best resection and functional results can be achieved.

Uncertainty in the Relationship Between Sagittal Alignment and Patient-Reported Outcomes

Neurosurgery 86:485–491, 2020

Previous studies have reported correlations and precise quantitative relationships between sagittal alignment and health-related quality-of-life (HRQOL) scores. These studies have not reported the extent of uncertainty in these relationships.

OBJECTIVE: To explore the uncertainty in the overall relationships between sagittal alignment and HRQOL and in the predictions of individual patient pain and disability.

METHODS: A retrospective analysis of all new adult patients with long-cassette radiographs and complete outcomes questionnaires presenting to the senior author from 2012 to 2014 was performed. Univariable maximum a posteriori linear regression analyses using Bayesian methods were performed. High-density probability intervals for mean regression relationships and for individual values were calculated using minimally informative prior distributions.

RESULTS: A total of 134 patients satisfied inclusion criteria and were included. For Oswestry Disability Index (ODI) vs pelvic incidence-lumbar lordosis (LL), the 90% high-density probability interval ranged from –0.04 to 0.23, indicating that both the magnitude and direction of the relationship were uncertain. For both ODI vs sagittal vertical axis and ODI vs LL, there was uncertainty in the magnitude of the slope.Wide regions of uncertainty were also seen for predicting individual patient scores.

CONCLUSION: We report the previously unpublished degree of uncertainty in the mean quantitative relationships between radiographic sagittal alignment and patient-reported outcomes and in individual patient outcomes scores. Based on these results, establishing treatment thresholds or predicting an individual’s outcome is unreliable. Further research efforts should be focused on developing multilevel hierarchical models incorporating parameter uncertainty and heterogeneous effects.

Trigeminal Nerve Atrophy Predicts Pain Recurrence After Gamma Knife Stereotactic Radiosurgery for Classical Trigeminal Neuralgia

Neurosurgery 84:927–934, 2019

Trigeminal nerve atrophy and neurovascular compression (NVC) are frequently observed in classical trigeminal neuralgia (CTN).

OBJECTIVE: To determine whether nerve characteristics contribute to Gamma Knife (ElektaAB, Stockholm, Sweden) surgery (GKS) outcomes in unilateral CTN without previous surgery.

METHODS: From 2006 to 2012, 67 patients with unilateral CTN without previous surgery received GKS with a maximal dose of 90 Gy delivered to the trigeminal nerve juxta brainstem. Two evaluators, blinded to the side of pain, analyzed the magnetic resonance images before GKS to obtain the parameters, including nerve cross-sectional area (CSA), vessel type of NVC, and site of NVC along the nerve. Correlations of the parameters with pain relief (Barrow Neurological Institute [BNI] grades I-IIIb) and recurrence (BNI grades VIV) were made by using Cox regression and Kaplan–Meier analyses.

RESULTS: The median CSA of the symptomatic nerves was significantly smaller than that of the asymptomatic nerves (4.95 vs 5.9 mm2, P < .001). After adjustment for age and sex, larger nerve CSA was associated with lower initial pain relief (hazard ratio 0.81, P=.03) and lower pain recurrence after initial response (hazard ratio 0.58, P= .02). Patients with nerve atrophy (CSA of ≤ 4.4 mm2 after receiver operating characteristic curve analysis) had a lower 5-yr probability of maintaining pain relief after initial response than those without nerve atrophy (65% vs 86%, P= .04).

CONCLUSION: Trigeminal nerve atrophy may predict pain recurrence in patients with initial post-GKS relief of CTN.Arterial and proximalNVCare not predictive ofGKS outcomes. Future studies are required to determine optimal treatments for long-term pain relief in patients with CTN and trigeminal nerve atrophy.

Predictors of Poor Outcome in Patients Submitted to Minimally Invasive Transforaminal Lumbar Interbody Fusion

World Neurosurg. (2018) 119:488-493

Minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) has become an increasingly popular method for lumbar arthrodesis. While having similar long-term outcomes when compared with open TLIF, it decreases the amount of intraoperative blood loss and iatrogenic muscle damage, the intensity of postoperative pain, and the duration of hospital stay. However, uncertainty remains about which factors contribute to outcomes in these patients. The purpose of this study was to retrospectively analyze a cohort of patients submitted to MI-TLIF and to identify factors that can be associated with a worse postoperative outcome.

METHODS: Clinical records from 283 patients were assessed and, according to Odom’s criteria, postoperative clinical outcome at 12 months was classified as excellent, good, fair, and poor. Demographic variables, clinical data, and surgery-related data were analyzed, looking for associations between them and clinical outcome. A binomial logistic regression analysis was then performed to include those associations.

RESULTS: The main variables associated with worse prognosis (“poor” class according to Odom’s criteria) were a period of sick leave longer than 3 months before the surgery, age younger than 50 years, lytic spondylolisthesis, L5-S1 level, and occurrence of complications. These 5 conditions were included in a logistic regression analysis, and 3 of them were independently associated with poor outcome: operative complications, age younger than 50 years, and sick leave longer than 3 months before surgery. –

CONCLUSIONS: Younger patients, those on a sick leave for more than 3 months before surgery, or those who suffered surgical complications tended to have less satisfactory results after MI-TLIF.

Suprafloccular approach via the petrosal fissure and venous corridors for microvascular decompression of the trigeminal nerve

J Neurosurg 129:324–333, 2018

Surgical exposure and decompression of the entire trigeminal nerve in a conventional lateral supracerebellar approach can be challenging because of blockages from the superior petrosal vein complex, cerebellum, and vestibulocochlear nerve. The authors demonstrate a novel suprafloccular approach via the petrosal fissure and venous corridors that can be used as a substitute for the conventional route used to treat trigeminal neuralgia and present a consecutive series of patients and their clinical outcomes.

METHODS Preoperative and postoperative clinical data from 420 patients who underwent this modified approach at Hangzhou First People’s Hospital between March 2012 and May 2014 were reviewed. The technique expands the working space by opening the petrosal fissure and dissecting adhesions between the vein of the cerebellopontine fissure and the simple lobule as needed. Via 3 surgical corridors, the entire trigeminal nerve is exposed and decompressed thoroughly with minimal retraction of the surrounding vital structures.

RESULTS The medial one-third of the trigeminal nerve accounted for the majority (275 [65.5%] cases) of neurovascular conflict sites. The lateral corridor was used in 219 (52.1%) cases, the medial corridor was used in 175 (41.7%) cases, and the intermediate corridor was used in 26 (6.2%) cases. The entire trigeminal nerve in each patient was accessed directly and decompressed properly. At the end of the 24-month follow-up period, the rate of excellent results (Kondo score of T0 or T1) was stable at approximately 90.5%. No complications were related directly to petrosal vein or vestibulocochlear nerve injury.

CONCLUSIONS Based on data from the large patient series, the authors found this suprafloccular approach via the petrosal fissure and venous corridors provides full exposure and decompression of the entire trigeminal nerve, a high cure rate, and a low neurovascular morbidity rate.

trigeminal neuralgia,suprafloccular,petrosal fissure, cerebellopontine fissure,venous corridor, clinical outcome, functional neurosurgery, pain

Outcome after Hunt and Hess Grade V subarachnoid hemorrhage: a comparison of pre-coiling era (1980–1995) versus post-ISAT era (2005–2014)

J Neurosurg 128:100–110, 2018

Outcome analysis of comatose patients (Hunt and Hess Grade V) after subarachnoid hemorrhage (SAH) is still lacking. The aims of this study were to analyze the outcome of Hunt and Hess Grade V SAH and to compare outcomes in the current period with those of the pre–International Subarachnoid Aneurysm Trial (ISAT) era as well as with published data from trials of decompressive craniectomy (DC) for middle cerebral artery (MCA) infarction.

METHODS The authors analyzed cases of Hunt and Hess Grade V SAH from 1980–1995 (referred to in this study as the earlier period) and 2005–2014 (current period) and compared the results for the 2 periods. The outcomes of 257 cases were analyzed and stratified on the basis of modified Rankin Scale (mRS) scores obtained 6 months after SAH. Outcomes were dichotomized as favorable (mRS score of 0–2) or unfavorable (mRS score of 3–6). Data and number needed to treat (NNT) were also compared with the results of decompressive craniectomy (DC) trials for middle cerebral artery (MCA) infarctions.

RESULTS Early aneurysm treatment within 72 hours occurred significantly more often in the current period (in 67% of cases vs 22% in earlier period). In the earlier period, patients had a significantly higher 30-day mortality rate (83% vs 39% in the current period) and 6-month mortality rate (94% vs 49%), and no patient (0%) had a favorable outcome, compared with 23% overall in the current period (p < 0.01, OR 32), or 29.5% of patients whose aneurysms were treated (p < 0.01, OR 219). Cerebral infarctions occurred in up to 65% of the treated patients in the current period. Comparison with data from DC MCA trials showed that the NNTs were significantly lower in the current period with 2 for survival and 3 for mRS score of 0–3 (vs 3 and 7, respectively, for the DC MCA trials).

CONCLUSIONS Early and aggressive treatment resulted in a significant improvement in survival rate (NNT = 2) and favorable outcome (NNT = 3 for mRS score of 0–3) for comatose patients with Hunt and Hess Grade V SAH compared with the earlier period. Independent predictors for favorable outcome were younger age and bilateral intact corneal reflexes. Despite a high rate of cerebral infarction (65%) in the current period, 29.5% of the patients who received treatment for their aneurysms during the current era (2005–2014) had a favorable outcome. However, careful individual decision making is essential in these cases.

Microendoscopic laminotomy versus conventional laminoplasty for cervical spondylotic myelopathy: 5-year follow-up study

J Neurosurg Spine 27:403–409, 2017

The goal of this study was to characterize the long-term clinical and radiological results of articular segmental decompression surgery using endoscopy (cervical microendoscopic laminotomy [CMEL]) for cervical spondylotic myelopathy (CSM) and to compare outcomes to conventional expansive laminoplasty (ELAP).

METHODS Consecutive patients with CSM who required surgical treatment were enrolled. All enrolled patients (n = 78) underwent CMEL or ELAP. All patients were followed postoperatively for more than 5 years. The preoperative and 5-year follow-up evaluations included neurological assessment (Japanese Orthopaedic Association [JOA] score), JOA recovery rates, axial neck pain (using a visual analog scale), the SF-36, and cervical sagittal alignment (C2–7 subaxial cervical angle).

RESULTS Sixty-one patients were included for analysis, 31 in the CMEL group and 30 in the ELAP group. The mean preoperative JOA score was 10.1 points in the CMEL group and 10.9 points in the ELAP group (p > 0.05). The JOA recovery rates were similar, 57.6% in the CMEL group and 55.4% in the ELAP group (p > 0.05). The axial neck pain in the CMEL group was significantly lower than that in the ELAP group (p < 0.01). At the 5-year follow-up, cervical alignment was more favorable in the CMEL group, with an average 2.6° gain in lordosis (versus 1.2° loss of lordosis in the ELAP group [p < 0.05]) and lower incidence of postoperative kyphosis.

CONCLUSIONS CMEL is a novel, less invasive technique that allows for multilevel posterior cervical decompression for the treatment of CSM. This 5-year follow-up data demonstrates that after undergoing CMEL, patients have similar neurological outcomes to conventional laminoplasty, with significantly less postoperative axial pain and improved subaxial cervical lordosis when compared with their traditional ELAP counterparts.

Four-year results of a prospective single-arm study on 200 semi-constrained total cervical disc prostheses


J Neurosurg Spine 25:556–565, 2016

Recent studies have described encouraging outcomes after cervical total disc replacement (cTDR), but there are also critical debates regarding the long-term effects of heterotopic ossification (HO) and the prevalence of adjacent-level degeneration. The aim in this paper was to provide 4-year clinical and radiographic outcome results on the activ C disc prosthesis.

Methods A total of 200 subjects underwent single-level activ C (Aesculap AG) implantation between C-3 and C-7 for the treatment of symptomatic degenerative disc disease. Clinical and radiographic assessments were performed preoperatively, intraoperatively, at discharge, and again at 6 weeks, 6 months, 1 year, 2 years, and 4 years. Radiographic evaluations were done by an independent core laboratory using a specific software for quantitative motion analysis.

Results Neck Disability Index (NDI) and visual analog scale (VAS) score for neck and arm pain decreased significantly from baseline to the 4-year follow-up. The mean improvement for NDI was 20, for VAS severity and frequency of neck pain 26.4 and 28, and for VAS severity and frequency of arm pain 30.7 and 35.1, respectively. The neurological situation improved for the majority of patients (86.4%); 76.1% of cases were asymptomatic. Subsequent surgical interventions were reported in 7% of the cases, including device removals in 3%. In 2.5% a subsidence greater than 3 mm was recorded; 1 of these cases also had a migration greater than 3 mm. No device displacement, expulsion, disassembly, loose or fractured device, osteolysis, or facet joint degeneration at the index level was observed. Segmental lordotic alignment changed from -2.4° preoperatively to -6.2° at 4 years, and postoperative height was maintained during the follow-up. Advanced HO (Grade III and IV) was present in 27.1% of the cases; 82.4% showed segmental mobility. A progression of radiographic adjacent-segment degeneration occurred in 28.2%, but only 4.5% required surgical treatment.

Conclusions The activ C is a safe and effective device for cervical disc replacement confirming the encouraging results after cTDR.

Treatment Outcomes of Unruptured Arteriovenous Malformations With a Subgroup Analysis of ARUBA Eligible Patients


Neurosurgery 76:563–570, 2015

The design and conclusions of A Randomized Trial of Unruptured Brain Arteriovenous Malformations (ARUBA) trial are controversial, and its structure limits analysis of patients who could potentially benefit from treatment.

OBJECTIVE: To analyze the results of a consecutive series of patients with unruptured brain arteriovenous malformations (BAVMs), including a subgroup analysis of ARUBAeligible patients.

METHODS: One hundred five patients with unruptured BAVMs were treated over an 8-year period. From this series, 90 adult patients and a subgroup of 61 patients determined to be ARUBA eligible were retrospectively reviewed. A subgroup analysis for Spetzler-Martin grades I/II, III, and IV/V was performed. The modified Rankin Scale was used to assess functional outcome.

RESULTS: Persistent deficits, modified Rankin Scale score deterioration, and impaired functional outcome occurred less frequently in ARUBA-eligible grade I/II patients compared with grade III to V patients combined (P = .04, P = .04, P = .03, respectively). Twenty-two of 39 patients (56%) unruptured grade I and II BAVMs were treated with surgery without and with preoperative embolization, and all had a modified Rankin Scale score of 0 to 1 at the last follow-up. All patients treated with surgery without and with preoperative embolization had radiographic cure at the last follow-up.

CONCLUSION: The results of ARUBA-eligible and unruptured grade I/II patients overall show that excellent outcomes can be obtained in this subgroup of patients, especially with surgical management. Functional outcomes for ARUBA-eligible patients were similar to those of patients who were randomized to medical management in ARUBA. On the basis of these data, in appropriately selected patients, we recommend treatment for low-grade BAVMs.

Jugulotympanic paragangliomas treated with Gamma Knife radiosurgery

Jugulotympanic paragangliomas treated with Gamma Knife radiosurgery- a single-center review of 58 cases

J Neurosurg 121:1158–1165, 2014

Jugulotympanic paragangliomas (JTPs) are rare benign tumors whose surgical treatment is usually associated with partial resection of the lesion, high morbidity, and even death. Gamma Knife radiosurgery (GKRS) has been reported as a useful treatment option. The goal of this retrospective study is to analyze the role of GKRS in tumor volume control and clinical outcomes of these patients.

Methods. A total of 75 patients with JTPs were treated with GKRS at the authors’ center from 1995 to 2012. The authors analyzed those treated during this period to allow for a minimal observation time of 2 years. The MR images and clinical reports of these patients were reviewed to assess clinical and volumetric outcomes of the tumors. The radiological and clinical assessments, along with a group of prognostic factors measured, were analyzed using descriptive methods. The time to volumetric and clinical progression was analyzed using the Kaplan-Meier method. Prognostic factors were identified using log-rank statistics and multivariate Cox regression models.

Results. The mean follow-up was 86.4 months. The authors observed volumetric tumor control in 94.8% of cases. In 67.2% of cases, tumor volume decreased by a mean of 40.1% from the original size. Of patients with previous tinnitus, 54% reported complete recovery. Improvement of other symptoms was observed in 34.5% of cases. Overall, clinical control was achieved in 91.4% of cases. Previous embolization and familial history of paraganglioma were selected as significant prognostic factors for volumetric response to GKRS treatment in the univariate analysis. In multivariate analysis, no factors were significantly correlated with progression-free survival. No patient died of side effects related to GKRS treatment or tumor progression.

Conclusions. Gamma Knife radiosurgery is an effective, safe, and efficient therapeutic option for the treatment of these tumors as a first-line treatment or in conjunction with traditional surgery, endovascular treatment, or conventional fractionated radiotherapy.

Radiographic outcomes of adult spinal deformity surgeries

Spinal adult deformity

Neurosurg Focus 36 (5):E13, 2014

Various surgical approaches, including open, minimally invasive, and hybrid techniques, have gained momentum in the management of adult spinal deformity. However, few data exist on the radiographic outcomes of different surgical techniques. The objective of this study was to compare the radiographic and clinical outcomes of the surgical techniques used in the treatment of adult spinal deformity.

Methods. The authors conducted a retrospective review of two adult spinal deformity patient databases, a prospective open surgery database and a retrospective minimally invasive surgery (MIS) and hybrid surgery database. The time frame of enrollment in this study was from 2007 to 2012. Spinal deformity patients were stratified into 3 surgery groups: MIS, hybrid surgery, and open surgery. The following pre- and postoperative radiographic parameters were assessed: lumbar major Cobb angle, lumbar lordosis, pelvic incidence minus lumbar lordosis (PI-LL), sagittal vertical axis, and pelvic tilt. Scores on the Oswestry Disability Index (ODI) and a visual analog scale (VAS) for both back and leg pain were also obtained from each patient.

Results. Of the 234 patients with adult spinal deformity, 184 patients had pre- and postoperative radiographs and were thus included in the study (MIS, n = 42; hybrid, n = 33; open, n = 109). Patients were a mean of 61.7 years old and had a mean body mass index of 26.9 kg/m2. Regarding radiographic outcomes, the MIS group maintained a significantly smaller mean lumbar Cobb angle (13.1°) after surgery compared with the open group (20.4°, p = 0.002), while the hybrid group had a significantly larger lumbar curve correction (26.6°) compared with the MIS group (18.8°, p = 0.045). The mean change in the PI-LL was larger for the hybrid group (20.6°) compared with the open (10.2°, p = 0.023) and MIS groups (5.5°, p = 0.003). The mean sagittal vertical axis correction was greater for the open group (25 mm) compared with the MIS group (≤ 1 mm, p = 0.008). Patients in the open group had a significantly larger postoperative thoracic kyphosis (41.45°) compared with the MIS patients (33.5°, p = 0.005). There were no significant differences between groups in terms of pre- and postoperative mean ODI and VAS scores at the 1-year follow-up. However, patients in the MIS group had much lower estimated blood loss and transfusion rates compared with patients in the hybrid or open groups (p < 0.001). Operating room time was significantly longer with the hybrid group compared with the MIS and open groups (p < 0.001). Major complications occurred in 14% of patients in the MIS group, 14% in the hybrid group, and 45% in the open group (p = 0.032).

Conclusions. This study provides valuable baseline characteristics of radiographic parameters among 3 different surgical techniques used in the treatment of adult spinal deformity. Each technique has advantages, but much like any surgical technique, the positive and negative elements must be considered when tailoring a treatment to a patient. Minimally invasive surgical techniques can result in clinical outcomes at 1 year comparable to those obtained from hybrid and open surgical techniques.

Low triiodothyronine syndrome as a predictor of poor outcomes in patients undergoing brain tumor surgery


A low triiodothyronine (T3) state is highly prevalent and is associated with a poor prognosis in critically ill patients. The authors investigated, in patients undergoing brain tumor surgery, the direct association of a perioperative low T3 syndrome with clinical outcomes and also with symptoms of depression and anxiety.

Methods. Ninety consecutive patients (71% women, median age 55 years), on admission for brain tumor surgery, were evaluated for sociodemographic and clinical characteristics. Their thyroid function profile was assessed on the morning of brain tumor surgery and on the morning after brain tumor surgery. Patients with free T3 concentrations of 3.1 pmol/L or less were considered to have low T3 syndrome. The patients were evaluated for symptoms of depression and anxiety using the Hospital Anxiety and Depression Scale (HADS) before and after surgery and for clinical outcomes using the Glasgow Outcome Scale (GOS) at discharge.

Results. After brain tumor surgery, free T3 concentrations decreased (p < 0.001) and the proportion of patients with low T3 levels increased from 38% to 54% (p = 0.02). Lower preoperative (rho = 0.30, p = 0.004) and postoperative (rho = 0.33, p = 0.002) free T3 concentrations correlated with low GOS scores at discharge. Preoperative low T3 syndrome (OR 5.49, 95% CI 1.27–23.69, p = 0.02) and postoperative low T3 syndrome (OR 8.73, 95% CI 1.49–51.21, p = 0.02) both increased risk for unfavorable clinical outcomes (GOS scores < 5) at discharge, after adjusting for age, sex, histological diagnosis of brain tumor, preoperative functional impairment, previous treatment for brain tumor, and depressive symptoms. Preoperative low T3 syndrome increased the risk for preoperative (HADS-depression subscale score ≥ 11; OR 4.12, 95% CI 1.16–14.58, p = 0.03) but not postoperative depressive symptoms independently from sociodemographic and clinical factors.

Conclusions. Low T3 syndrome is a strong independent predictor of unfavorable clinical outcomes and depressive symptoms, and its diagnosis and preoperative management should be considered in patients undergoing neurosurgery for the treatment of brain tumors.

Midterm outcome after a microsurgical unilateral approach for bilateral decompression of lumbar degenerative spondylolisthesis

J Neurosurg Spine 16:68–76, 2012. DOI: 10.3171/2011.7.SPINE11222

The aim of this study was to evaluate the results and effectiveness of bilateral decompression via a unilateral approach in the treatment of lumbar degenerative spondylolisthesis (DS).

Methods. Operations were performed in 84 selected patients (mean age 62.1 ± 10 years) with lumbar DS between the years 2001 and 2008. The selection criteria included lower back pain with or without sciatica, neurogenic claudication that had not improved after at least 6 months of conservative treatment, and a radiological diagnosis of Grade I DS and lumbar stenosis. Decompression was performed at 3 levels in 15.5%, 2 levels in 54.8%, and 1 level in 29.7% of the patients with 1 level of spondylolisthesis. All patients were followed up for at least 24 months. For clinical evaluations, a visual analog scale, Oswestry Disability Index (ODI), and Neurogenic Claudication Outcome Score (NCOS) were used. Spinal canal size and (neutral and dynamic) slip percentages were measured both pre- and postoperatively.

Results. Neutral and dynamic slip percentages did not significantly change after surgery (p = 0.67 and p = 0.63, respectively). Spinal canal size increased from 50.6 ± 5.9 to 102.8 ± 9.5 mm2 (p < 0.001). The ODI decreased significantly in both the early and late follow-up evaluations, and good or excellent results were obtained in 64 cases (80%). The NCOS demonstrated significant improvement in the late follow-up results (p < 0.001). One patient (1.2%) required secondary fusion during the follow-up period.

Conclusions. Postoperative clinical improvement and radiological findings clearly demonstrated that the unilateral approach for treating 1-level and multilevel lumbar spinal stenosis with DS is a safe, effective, and minimally invasive method in terms of reducing the need for stabilization.

Less Invasive Surgical Correction of Adult Degenerative Scoliosis. Part II: Complications and Clinical Outcome

Neurosurgery 67:1609–1621, 2010 DOI: 10.1227/NEU.0b013e3181f918cf

Surgical correction of adult degenerative scoliosis is a technically demanding procedure with a considerable complication rate. Extensive blood loss has been identified as a significant factor linked to unfavorable outcome.

OBJECTIVE: To report on the complication profile and clinical outcomes obtained with less invasive image-guided surgical correction of degenerative (de novo) scoliosis in a high-risk population.

METHODS: Thirty patients (age, 64-88 years) with progressive postural impairment, back pain, radiculopathy, and neurogenic claudication caused by degenerative scoliosis were treated by less invasive image-guided correction (3-8 segments) by multisegmental transforaminal lumbar interbody fusion and facet fusions. With a mean follow-up of 19.6 months, intraoperative blood loss, curve correction, fusion and complication rates, duration of hospitalization, incidence of hardware-related problems, and clinical outcome parameters were assessed using multivariate analysis.

RESULTS: Satisfactory multiplanar correction was obtained in all patients. Mean intraoperative blood loss was 771.7±231.9 mL, time to full ambulation was 0.8 ± 0.6 days, and length of stay was 8.2 ± 2.9 days. After 12 months, preoperative SF12v2 physical component summary scores (20.2 ± 2.6), visual analog scale scores (7.5 ± 0.8), and Oswestry disability index (57.2 ± 6.9) improved to 34.6 ± 3.9, 2.63 ± 0.6, and 24.8 ± 7.1, respectively. The rate of major and minor complications was 23.4% and 59.9%, respectively. Ninety percent of patients rated treatment success as excellent, good, or fair.

CONCLUSION: Less invasive image-guided correction of degenerative scoliosis in elderly patients with significant comorbidity yields a favorable complication profile. Significant improvements in spinal balance, pain, and functional scores mirrored expedited ambulation and early resumption of daily activities. Less invasive techniques appear suitable to reduce periprocedural morbidity, especially in elderly patients and individuals with significant medical risk factors.