Unveiling the natural history of paralysis in metastatic cervical spinal tumor: An experimental study.

Introduction: Despite the relatively low prevalence of metastatic cervical spinal tumor, these entities give rise to more profound complications than thoracic and lumbar spinal tumor. However, it is regrettable that experimental investigation has thus far shown a dearth of attention to metastatic cervical spinal tumor. Research question: What is the conceptualization and realization of quadriparesis resulting from metastatic cervical spinal tumor? Material and methods: Using Fischer 344 rats as the experimental cohort, this study orchestrated the engraftment of tumor cells procured from the 13762 MAT B III cell line (RRID: CVCL_3475), which represents mammary adenocarcinoma. These cells were engrafted into the vertebrae of the cervical spine. A comprehensive inquiry encompassing behavioral assessments, histological evaluations, and microangiographic analyses conducted after the aforementioned cellular transplantation was subsequently pursued. Results: The incidence of cervical paralysis was 61.1%. Notably, the evolution of paralysis was unfurled by two distinctive temporal phases within its natural history. A meticulous histological examination facilitated delineation of the tumor's posterior expansion within the spinal canal. Simultaneously, the tumor exhibited anterior and lateral encroachment on the spinal cord, inducing compression from all sides. Augmented by microangiographic investigations, conspicuous attenuation of stained blood vessels within the affected anterior horn and funiculus of the spinal cord was observed. Discussion and conclusion: The pathological advancement of paralysis stemming from metastatic cervical spinal tumor is now apprehended to unfurl through a biphasic phase. The initial phase is characterized by gradual unfurling spanning several days, juxtaposed against the second phase marked by swift and accelerated progression.

Mechanism of forelimb motor function restoration in rats with cervical spinal cord hemisection-neuroanatomical validation.

PURPOSE: The purpose of this study is neuroanatomical validation of forelimb motor function restoration in rats with cervical spinal cord injury. MATERIALS AND METHODS: We used eight cervical hemisected rats and eight normal rats. We cut in half the C3/4 cervical spinal cord of 18-weeks-old normal rats. We used 24-weeks-old rats that had reached a nearly steady state of forelimb motor function after the hemisection (Hemisection group). Normal 24-week-old rats were used as Control group. To evaluate the corticospinal tracts, neuro-tracing by biotynirated dextran-amine (BDA) was used. BDA was injected into the damaged side of the cerebral primary motor cortex. In order to quantitatively analyze the specimen, we recorded a site where nerve fibers appear in each specimen in the image analysis (1) and defined the increase rate of immunostaining area using ImageJ in the image analysis (2). Based on the evaluation in the image analysis (1) and the image analysis (2), the Hemisection group and the Control group were compared. RESULTS: In the image analysis (1), a region with robust appearance of aberrant nerve fibers was observed in the cephalad side of the Hemisection site in Hemisection group than Control group. In the spinal cord caudal to the hemisection, such region was generally more in Hemisection group, however, disappeared or reduced appearance was observed in some regions. In the image analysis (2), no statistical significant difference was noted in each level. CONCLUSION: There is a high probability that these aberrant nerve fibers beyond the midline could be involved in forelimb motor function restoration in rats with cervical cord hemisection.

Corrigendum to "Mechanism of Restoration of Forelimb Motor Function after Cervical Spinal Cord Hemisection in Rats: Electrophysiological Verification".

[This corrects the article DOI: 10.1155/2017/7514681.].

Does corrective spine surgery improve the standing balance in patients with adult spinal deformity?

BACKGROUND CONTEXT: The effect of corrective spine surgery on standing stability in adult spinal deformity (ASD) has not been fully documented. PURPOSE: To compare pre- and postoperative standing balance and posture in patients with ASD. STUDY DESIGN/SETTING: This study is a prospective case series. PATIENT SAMPLE: Standing balance before and after corrective spine surgery was compared in 35 consecutive female patients with ASD (65.6±6.9 years, body mass index 22.3±2.7 kg/m2, Cobb angle 50.2±19.2°, C7 plumb line 9.3±5.6 cm, and pelvic incidence-lumbar lordosis mismatch 40.8±23.3°). OUTCOME MEASURES: The Scoliosis Research Society Patient Questionnaire, the Oswestry Disability Index, and force-plate analysis were used to evaluate the patient outcomes. MATERIALS AND METHODS: We reviewed patient charts and X-rays and compared standing balance before and after corrective spine surgery. All subjects were assessed by force-plate analysis using optical markers while standing naturally on a custom-built force platform. The spinal tilt, pelvic obliquity, pelvic tilt, and joint angle were calculated. The lower leg lean volume was obtained by whole-body dual X-ray absorptiometry to assess muscle strength. RESULTS: ASD patients showed significant differences between the left and right sides in ground reaction force (dGRFs), hip (dHip), and knee angle (dKnee) while standing (dGRF 15.1±8.7%, dHip 7.1±6.6°, dKnee 5.9±5.5°). The recorded center-of-gravity (CoG) area was not improved after surgery, whereas the dGRF, dHip, and dKnee all decreased. The spinal tilt, pelvic obliquity, and pelvic tilt were all significantly improved after surgery. We found significant correlations between the radiographic trunk shift and the postoperative coronal CoG distance and recorded CoG area, and between the sagittal CoG distance and the age and the lean volume of the lower extremities (trunk shift R=0.33, 0.45; age R=0.32; lean volume R=0.31). CONCLUSIONS: Corrective spinal surgery improved the spinal alignment and joint angles in patients with ASD but did not improve the standing stability. A correlation found between the sagittal CoG distance and the lean volume of the lower extremities indicated the importance of the leg muscles for stability when standing, whereas a correlation found between the coronal CoG distance and trunk shift reflected the attenuated postural response in the ASD patients.

Mechanism of Restoration of Forelimb Motor Function after Cervical Spinal Cord Hemisection in Rats: Electrophysiological Verification.

The objective of this study was to electrophysiologically assess the corticospinal tracts of adult rats and the recovery of motor function of their forelimbs after cervical cord hemisection. Of 39 adult rats used, compound muscle action potentials (CMAPs) of the forelimbs of 15 rats were evaluated, before they received left C5 segmental hemisection of the spinal cord, by stimulating the pyramid of the medulla oblongata on one side using an exciting microelectrode. All 15 rats exhibited contralateral electrical activity, but their CMAPs disappeared after hemisection. The remaining 24 rats received hemisection first, and CMAPs of 12 rats were assessed over time to study their recovery time. All of them exhibited electrical activity of the forelimbs in 4 weeks after surgery. The remaining 12 rats received additional right C2 segmental hemisection, and variation of CMAPs between before and after surgery was examined. The right side of the 12 rats that received the additional hemisection exhibited no electrical activity in response to the stimulation of the pyramids on both sides. These results suggest that changes in path between the resected and healthy sides, activation of the ventral corticospinal tracts, and propriospinal neurons were involved in the recovery of motor function after cervical cord injury.

Walking balance and compensatory gait mechanisms in surgically treated patients with adult spinal deformity.

BACKGROUND CONTEXT: Gait patterns and their relationship to demographic and radiographic data in patients with adult spinal deformity (ASD) have not been fully documented. PURPOSE: This study aimed to assess gait pattern in patients with ASD and the effect of corrective spinal surgery on gait. DESIGN/SETTING: This is a prospective case series. PATIENT SAMPLE: The gait patterns of 33 consecutive women with ASD (age 67.1 years; body mass index [BMI] 22.5±2.5 kg/m2, Cobb angle 46.8±18.2°, coronal vertical axis [CVA] 1.5±3.7 cm, C7 sagittal vertical axis [SVA] 9.1±6.4 cm, pelvic incidence minus lumbar lordosis [PI-LL] 38.2±22.1°, and lean volume of the lower leg, 5.5±0.6 kg) before and after corrective surgery were compared with those of 33 age- and gender-matched healthy volunteers. OUTCOME MEASURES: Scoliosis Research Society Patient Questionnaire (SRS22r), Oswestry Disability Index (ODI), and forceplate analysis. METHODS: All subjects underwent gait analysis on a custom-built forceplate using optical markers placed on all joints and spinal processes. Dual X-ray absorptiometry scores were used to calculate the lean composition of the lower legs. Subjects with ASD were followed for at least 2 years post operation. RESULTS: Preop mean values showed that patients with ASD had a significantly worse gait velocity (54±10 m/min vs. 70.7±12.9 m/min, p<.01) and stride (97.8±13.4 cm vs. 115.3±15.1 cm, p<.01), but no difference was observed in the stance-to-swing ratio. The right and left ground reaction force vectors were also discordant in the ASD group (vertical direction; r=0.84 vs. r=.97, p=.01). The hip range of motion (ROM) was also significantly decreased in ASD. Correlation coefficient showed moderate correlations between the preoperative gait velocity and the gravity line (GL), PI, ROM of the lower extremity joints, and lean volume, and between the stride and the lean volume, GL, and PI-LL. Gait pattern, stride, and velocity all improved significantly in the patients with ASD after surgery, but were still not as good as in healthy volunteers. The SRS22r satisfaction domain correlated moderately with postoperative gait velocity (r=0.34). CONCLUSIONS: The patients with ASD had an asymmetric gait pattern and impaired gait ability compared with healthy volunteers. Gait ability correlated significantly with the GL, spinopelvic alignment, lower extremity joint ROM, and lean volume. The surgical correction of spinopelvic alignment and exercises to build muscle strength may improve the gait pattern and ability in patients with ASD.

Mechanism of Forelimb Motor Function Restoration after Cervical Spinal Cord Hemisection in Rats: A Comparison of Juveniles and Adults.

The aim of this study was to investigate forelimb motor function after cervical spinal cord injury in juvenile and adult rats. Both rats received a left segmental hemisection of the spinal cord after C3-C4 laminectomy. Behavioral evaluation of motor function was monitored and assessed using the New Rating Scale (NRS) and Forelimb Locomotor Scale (FLS) and by measuring the range of motion (ROM) of both the elbow and wrist. Complete left forelimb motor paralysis was observed in both rats. The NRS showed motor function recovery restored to 50.2 ± 24.7% in juvenile rats and 34.0 ± 19.8% in adult rats. FLS was 60.4 ± 26.8% in juvenile rats and 46.5 ± 26.9% in adult rats. ROM of the elbow and wrist were 88.9 ± 20.6% and 44.4 ± 24.1% in juvenile rats and 70.0 ± 29.2% and 40.0 ± 21.1% in adult rats. Thus, the NRS and ROM of the elbow showed a significant difference between age groups. These results indicate that left hemisection of the cervical spinal cord was not related to right-sided motor functions. Moreover, while motor paralysis of the left forelimb gradually recovered in both groups, the improvement was greater in juvenile rats.