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Open access

Misato Nagumo, Syoichi Tashiro, Nanako Hijikata, Aiko Ishikawa, Takenori Akiyama, and Tetsuya Tsuji

BACKGROUND

Blood pressure (BP) dysregulation is frequently observed in patients after surgical management of brainstem lesions; however, there has been no standard rehabilitation. Considering the conflicting risks for hypoperfusion and disuse syndrome in these patients, a safe and effective rehabilitative strategy is warranted.

OBSERVATIONS

A 50-year-old man who had undergone craniotomy for resection of a recurrent dorsal medullary epidermoid cyst developed persistent orthostatic hypotension. It was resistant to physical exercise, pharmacological therapy, abdominal binders, and compression stockings; therefore, it inhibited postoperative rehabilitation. Although the responsible lesion was not clearly visible on the postoperative image, accompanying symptoms, including segmental sensory impairment, implied an improvement in BP control. Although there was a trade-off between the risk of developing disuse syndrome and a delay in functional recovery, the authors decided to continue a conservative rehabilitation strategy rather than increasing the workload. The patient’s BP control was gradually restored by the seventh postoperative week, and the authors proceeded with basic activity training.

LESSONS

A conservative prognostic prediction-based rehabilitation strategy was applied in this case. The precise evaluation of the accompanying neurological symptoms was helpful in deciding the treatment regimen. The conflicting risks for hypoperfusion and disuse syndrome in such cases must be considered.

Open access

Myranda B. Robinson, Peter Shin, Robert Alunday, Chad Cole, Michel T. Torbey, and Andrew P. Carlson

BACKGROUND

Severe traumatic brain injury (TBI) requires individualized, physiology-based management to avoid secondary brain injury. Recent improvements in quantitative assessments of metabolism, oxygenation, and subtle examination changes may potentially allow for more targeted, rational approaches beyond simple intracranial pressure (ICP)-based management. The authors present a case in which multimodality monitoring assisted in decision-making for decompressive craniectomy.

OBSERVATIONS

This patient sustained a severe TBI without mass lesion and was monitored with a multimodality approach. Although imaging did not seem grossly worrisome, ICP, pressure reactivity, brain tissue oxygenation, and pupillary response all began worsening, pushing toward decompressive craniectomy. All parameters normalized after decompression, and the patient had a satisfactory clinical outcome.

LESSONS

Given recent conflicting randomized trials on the utility of decompressive craniectomy in severe TBI, precision, physiology-based approaches may offer an improved strategy to determine who is most likely to benefit from aggressive treatment. Trials are underway to test components of these strategies.

Open access

Shota Tamagawa, Takatoshi Okuda, Hidetoshi Nojiri, Rei Momomura, and Muneaki Ishijima

BACKGROUND

Although malpositioning of pedicle screws into the spinal canal and intervertebral foramen can cause spinal nerve root injuries, there are few reports of L5 nerve root injuries when S1 pedicle screws have been inserted anterolaterally. The authors report two cases of L5 nerve root injury caused by anterolateral malpositioning of loosened S1 pedicle screws.

OBSERVATIONS

In both patients, S1 pedicle screws were inserted toward the outside of the S1 anterior foramen, and the tip of the screws perforated the anterior sacral cortex. L5 nerve root impairment was not observed immediately after surgery. However, severe leg pain in the L5 area was observed after the S1 pedicle screws became loosened. In case 1, the symptoms could not be controlled with conservative treatment. Reoperation was performed 3 months after the initial surgery. In case 2, the symptoms gradually improved with conservative treatment because the area around the loosened S1 screw was surrounded by newly formed bone that stabilized the screws, as observed with computed tomography 1 year after surgery.

LESSONS

Surgeons should recognize that anterolateral malpositioning of S1 pedicle screws can cause L5 nerve root injury. The screws should be inserted in the correct direction without loosening.

Open access

Xuemiao Zhao, Xinmu Zhou, Xiao Chen, Junqiao Pan, and Bingrong Li

BACKGROUND

To the best of the authors’ knowledge, this is the first case of microcystic/reticular schwannoma arising in the frontal bone.

OBSERVATIONS

An 18-year-old man presented to the authors’ orthopedic clinic with a complaint of a progressively enlarging, painless mass in the frontal bone. It showed significant hyperintensity on T2-weighted imaging with progressive enhancement. Computed tomography combined with three-dimensional reconstruction showed expansive bone destruction with a soft tissue mass in the left side of the frontal bone, without calcification inside or a sclerotic margin around it. The mass was a microcystic/reticular schwannoma as confirmed by surgical pathology.

LESSONS

The authors report a rare case of a microcystic/reticular schwannoma arising in the frontal bone, with relatively comprehensive imaging data that enabled them to learn more about this tumor.

Open access

Atsushi Shimizu, Koji Yamaguchi, Yoshikazu Okada, Takayuki Funatsu, Tatsuya Ishikawa, Motohiro Hayashi, Noriko Tamura, Ayako Horiba, and Takakazu Kawamata

BACKGROUND

Gamma Knife radiosurgery (GKRS) is a safe and effective treatment, but it has a risk of bleeding. Herein, the authors describe their experience with some patients who required surgical removal of cerebral arteriovenous malformations (AVMs) located mainly in eloquent areas of the brain after GKRS, and they consider the advantages of surgical removal after GKRS.

OBSERVATIONS

Twelve patients who had undergone surgical removal of AVMs after GKRS at Tokyo Women’s Medical University between April 2013 and July 2019 were selected for analysis. All participants underwent GKRS as first-line therapy for AVMs located in an eloquent region or if requested by the patient. Complete obliteration was achieved in 7 patients, and the size of the nidus decreased in 3 patients during the follow-up period. The Spetzler-Martin grade decreased in 11 patients. Three patients experienced symptomatic intracerebral hemorrhage before and after confirmation of complete obliteration of the nidus via GKRS, and 7 patients experienced some neurological deficits because of an encapsulated expanding hematoma. All patients underwent resection of the nidus without complications. The preoperative neurological deficits improved in 6 patients and remained unchanged in 6 patients.

LESSONS

This report indicates that performing GKRS before surgery may be useful for future multimodal therapy.

Open access

Yoshichika Kikuta, Koji Yamaguchi, Tatsuya Ishikawa, Takayuki Funatsu, Yoshikazu Okada, and Takakazu Kawamata

BACKGROUND

Unlike in aneurysms of the adult-type posterior cerebral artery (PCA), in aneurysms of the fetal-type PCA, parent artery occlusion (PAO) results in vascular insufficiency and major ischemic strokes. Preservation or reconstruction of fetal-type PCAs is necessary to prevent these complications. Furthermore, it is necessary to select an appropriate bypass method and approach for revascularization of the PCA.

OBSERVATIONS

The authors report 2 cases of aneurysms of fetal-type PCAs that were successfully treated with PAO with revascularization. A 38-year-old man with a large unruptured right PCA aneurysm at the postcommunicating (P2) segment underwent trapping with superficial temporal artery–PCA bypass via the anterior temporal and subtemporal approaches. In addition, a 45-year-old woman with a left PCA aneurysm at the quadrigeminal (P3)–cortical (P4) segments resulting in subarachnoid hemorrhage underwent proximal clipping of the P3 segment via the occipital interhemispheric approach with an occipital artery–PCA bypass. Although she had perforator infarction, major ischemic stroke was prevented, and aneurysm occlusion was accomplished in both cases.

LESSONS

Aneurysms of fetal-type PCAs pose a risk of ischemia due to PAO. The combined use of bypass and revascularization should be considered to prevent major ischemic stroke after occlusion of the fetal-type PCA. However, perforator infarction is a concern.

Restricted access

Piyanat Wangsawatwong, Anna G. U. Sawa, Bernardo de Andrada Pereira, Jennifer N. Lehrman, Luke K. O’Neill, Jay D. Turner, Juan S. Uribe, and Brian P. Kelly

OBJECTIVE

Cortical screw–rod (CSR) fixation has emerged as an alternative to the traditional pedicle screw–rod (PSR) fixation for posterior lumbar fixation. Previous studies have concluded that CSR provides the same stability in cadaveric specimens as PSR and is comparable in clinical outcomes. However, recent clinical studies reported a lower incidence of radiographic and symptomatic adjacent-segment degeneration with CSR. No biomechanical study to date has focused on how the adjacent-segment mobility of these two constructs compares. This study aimed to investigate adjacent-segment mobility of CSR and PSR fixation, with and without interbody support (lateral lumbar interbody fusion [LLIF] or transforaminal lumbar interbody fusion [TLIF]).

METHODS

A retroactive analysis was done using normalized range of motion (ROM) data at levels adjacent to single-level (L3–4) bilateral screw–rod fixation using pedicle or cortical screws, with and without LLIF or TLIF. Intact and instrumented specimens (n = 28, all L2–5) were tested using pure moment loads (7.5 Nm) in flexion, extension, lateral bending, and axial rotation. Adjacent-segment ROM data were normalized to intact ROM data. Statistical comparisons of adjacent-segment normalized ROM between two of the groups (PSR followed by PSR+TLIF [n = 7] and CSR followed by CSR+TLIF [n = 7]) were performed using 2-way ANOVA with replication. Statistical comparisons among four of the groups (PSR+TLIF [n = 7], PSR+LLIF [n = 7], CSR+TLIF [n = 7], and CSR+LLIF [n = 7]) were made using 2-way ANOVA without replication. Statistical significance was set at p < 0.05.

RESULTS

Proximal adjacent-segment normalized ROM was significantly larger with PSR than CSR during flexion-extension regardless of TLIF (p = 0.02), or with either TLIF or LLIF (p = 0.04). During lateral bending with TLIF, the distal adjacent-segment normalized ROM was significantly larger with PSR than CSR (p < 0.001). Moreover, regardless of the types of screw-rod fixations (CSR or PSR), TLIF had a significantly larger normalized ROM than LLIF in all directions at both proximal and distal adjacent segments (p ≤ 0.04).

CONCLUSIONS

The use of PSR versus CSR during single-level lumbar fusion can significantly affect mobility at the adjacent segment, regardless of the presence of TLIF or with either TLIF or LLIF. Moreover, the type of interbody support also had a significant effect on adjacent-segment mobility.

Open access

Marco Rossi, Guglielmo Puglisi, Marco Conti Nibali, Luca Viganò, Tommaso Sciortino, Lorenzo Gay, Antonella Leonetti, Paola Zito, Marco Riva, and Lorenzo Bello

OBJECTIVE

Resection of glioma in the nondominant hemisphere involving the motor areas and pathways requires the use of brain-mapping techniques to spare essential sites subserving motor control. No clear indications are available for performing motor mapping under either awake or asleep conditions or for the best mapping paradigm (e.g., resting or active, high-frequency [HF] or low-frequency [LF] stimulation) that provides the best oncological and functional outcomes when tailored to the clinical context. This work aimed to identify clinical and imaging factors that influence surgical strategy (asleep motor mapping vs awake motor mapping) and that are associated with the best functional and oncological outcomes and to design a “motor mapping score” for guiding tumor resection in this area.

METHODS

The authors evaluated a retrospective series of patients with nondominant-hemisphere glioma—located or infiltrating within 2 cm anteriorly or posteriorly to the central sulcus and affecting the primary motor cortex, its fibers, and/or the praxis network—who underwent operations with asleep (HF monopolar probe) or awake (LF and HF probes) motor mapping. Clinical and imaging variables were used to design a motor mapping score. A prospective series of patients was used to validate this motor mapping score.

RESULTS

One hundred thirty-five patients were retrospectively analyzed: 69 underwent operations with asleep (HF stimulation) motor mapping, and 66 underwent awake (LF and HF stimulation and praxis task evaluation) motor mapping. Previous motor (strength) deficit, previous treatment (surgery/radiotherapy), tumor volume > 30 cm3, and tumor involvement of the praxis network (on MRI) were identified and used to design the mapping score. Motor deficit, previous treatment, and location within or close to the central sulcus favor use of asleep motor mapping; large tumor volume and involvement of the praxis network favor use of awake motor mapping. The motor mapping score was validated in a prospective series of 52 patients—35 underwent operations with awake motor mapping and 17 with asleep motor mapping on the basis of the score indications—who had a low rate of postoperative motor-praxis deficit (3%) and a high extent of resection (median 97%; complete resection in > 70% of patients).

CONCLUSIONS

Extensive resection of tumor involving the eloquent areas for motor control is feasible, and when an appropriate mapping strategy is applied, the incidence of postoperative motor-praxis deficit is low. Asleep (HF stimulation) motor mapping is preferable for lesions close to or involving the central sulcus and/or in patients with preoperative strength deficit and/or history of previous treatment. When a patient has no motor deficit or previous treatment and has a lesion (> 30 cm3) involving the praxis network, awake mapping is preferable.

Open access

Bernardo de Andrada Pereira, Jennifer N. Lehrman, Anna G. U. Sawa, Derek P. Lindsey, Scott A. Yerby, Jakub Godzik, Alexis M. Waguespack, Juan S. Uribe, and Brian P. Kelly

OBJECTIVE

S2-alar-iliac (S2AI) screw fixation effectively ensures stability and enhances fusion in long-segment constructs. Nevertheless, pelvic fixation is associated with a high rate of mechanical failure. Because of the transarticular nature of the S2AI screw, adding a second point of fixation may provide additional stability and attenuate strains. The objective of the study was to evaluate changes in stability and strain with the integration of a sacroiliac (SI) joint fusion device, implanted through a novel posterior SI approach, supplemental to posterior long-segment fusion.

METHODS

L1-pelvis human cadaveric specimens underwent pure moment (7.5 Nm) and compression (400 N) tests in the following conditions: 1) intact, 2) L2–S1 pedicle screw and rod fixation with L5–S1 interbody fusion, 3) added S2AI screws, and 4) added bilateral SI joint fixation (SIJF). The range of motion (ROM), rod strain, and screw bending moments (S1 and S2AI) were analyzed.

RESULTS

S2AI fixation decreased L2–S1 ROM in flexion-extension (p ≤ 0.04), L5–S1 ROM in flexion-extension and compression (p ≤ 0.004), and SI joint ROM during flexion-extension and lateral bending (p ≤ 0.03) compared with S1 fixation. SI joint ROM was significantly less with SIJF in place than with the intact joint, S1, and S2AI fixation in flexion-extension and lateral bending (p ≤ 0.01). The S1 screw bending moment decreased following S2AI fixation by as much as 78% in extension, but with statistical significance only in right axial rotation (p = 0.03). Extending fixation to S2AI significantly increased the rod strain at L5–S1 during flexion, axial rotation, and compression (p ≤ 0.048). SIJF was associated with a slight increase in rod strain versus S2AI fixation alone at L5–S1 during left lateral bending (p = 0.048). Compared with the S1 condition, fixation to S2AI increased the mean rod strain at L5–S1 during compression (p = 0.048). The rod strain at L5–S1 was not statistically different with SIJF compared with S2AI fixation (p ≥ 0.12).

CONCLUSIONS

Constructs ending with an S2AI screw versus an S1 screw tended to be more stable, with reduced SI joint motion. S2AI fixation decreased the S1 screw bending moments compared with fixation ending at S1. These benefits were paired with increased rod strain at L5–S1. Supplementation of S2AI fixation with SIJF implants provided further reductions (approximately 30%) in the sagittal plane and lateral bending SI joint motion compared with fixation ending at the S2AI position. This stability was not paired with significant changes in rod or screw strains.

Restricted access

Ahmad M. Tarawneh, Shahnawaz Haleem, Daniel D’Aquino, and Nasir Quraishi

OBJECTIVE

The goal of this study was to evaluate the comparative accuracy and safety of navigation-based approaches for cervical pedicle screw (CPS) placement over fluoroscopic techniques.

METHODS

A systematic search of the literature published between January 2006 and December 2019 relating to CPS instrumentation and the comparative accuracy and safety of fluoroscopic and intraoperative computer-based navigation techniques was conducted. Several databases, including the Cochrane Library, PubMed, and EMBASE, were systematically searched to identify potentially eligible studies. Data relating to CPS insertion accuracy and associated complications, in particular neurovascular complications, were extrapolated from the included studies and summarized for analysis.

RESULTS

A total of 17 studies were identified from the search methodology. Eleven studies evaluated CPS placement under traditional fluoroscopic guidance and 6 studies addressed outcomes following navigation-assisted placement (3D C-arm or CT-guided placement). Overall, a total of 4278 screws were placed in 1065 patients. Misplacement rates of CPS were significantly lower (p < 0.0001) in navigation-assisted techniques (12.51% [range 2.5%–20.5%]) compared to fluoroscopy-guided techniques (18.8% [range 0%–43.5%]). Fluoroscopy-guided CPS insertion was associated with a significantly higher incidence of postoperative complications relating to neurovascular injuries (p < 0.038), with a mean incidence of 1.9% compared with 0.3% in navigation-assisted techniques.

CONCLUSIONS

This systematic review supports a logical conclusion that navigation-based techniques confer a statistically significantly more accurate screw placement and resultant lower complication rates.