Electrical stimulation promotes functional recovery after spinal cord injury by activating endogenous spinal cord-derived neural stem/progenitor cell: an in vitro and in vivo study.

BACKGROUND CONTEXT: Electrical stimulation is a noninvasive treatment method that has gained popularity in the treatment of spinal cord injury (SCI). Activation of spinal cord-derived neural stem/progenitor cell (SC-NSPC) proliferation and differentiation in the injured spinal cord may elicit considerable neural regenerative effects. PURPOSE: This study aimed to explore the effect of electrical stimulation on the neurogenesis of SC-NSPCs. STUDY DESIGN: This study analyzed the effects of electrical stimulation on neurogenesis in rodent SC-NSPCs in vitro and in vivo and evaluated functional recovery and neural circuitry improvements with electrical stimulation using a rodent SCI model. METHODS: Rats (20 rats/group) were assigned to sham (Group 1), SCI only (Group 2), SCI + electrode implant without stimulation (Group 3), and SCI + electrode with stimulation (Group 4) groups to count total SC-NSPCs and differentiated neurons and to evaluate morphological changes in differentiated neurons. Furthermore, the Basso, Beattie, and Bresnahan scores were analyzed, and the motor- and somatosensory-evoked potentials in all rats were monitored. RESULTS: Biphasic electrical currents enhanced SC-NSPC proliferation differentiation and caused qualitative morphological changes in differentiated neurons in vitro. Electrical stimulation promoted SC-NSPC proliferation and neuronal differentiation and improved functional outcomes and neural circuitry in SCI models. Increased Wnt3, Wnt7, and ß-catenin protein levels were also observed after electrical stimulation. CONCLUSIONS: Our study proved the beneficial effects of electrical stimulation on SCI. The Wnt/ß-catenin pathway activation may be associated with this relationship between electrical stimulation and neuronal regeneration after SCI. CLINICAL SIGNIFICANCE: The study confirmed the benefits of electrical stimulation on SCI based on cellular, functional, electrophysiological, and histological evidence. Based on these findings, we expect electrical stimulation to make a positive and significant difference in SCI treatment strategies.

Psoas weakness following oblique lateral interbody fusion surgery: a prospective observational study with an isokinetic dynamometer.

BACKGROUND CONTEXT: Although the surgical corridor used for oblique lateral interbody fusion (OLIF) protects the intrapsoas nerves by causing minimal compression, transient weakness remains the most commonly reported postoperative complication. PURPOSE: Using a dynamometer to evaluate how the hip flexor strength changes following OLIF. STUDY DESIGN/SETTING: A prospective observational study. PATIENT SAMPLE: Forty-six patients who underwent single or multi-level OLIF for lumbar spondylolisthesis. OUTCOME MEASURES: Isokinetic dynamometer values (peak torque, total work, average power), visual analogue scale (VAS) scores for leg pain, hypoesthesia, subjective weakness of the left hip flexor muscle, Oswestry disability index, body mass index, bone mineral density, radiologic findings of the psoas muscle (cross-sectional area, Hounsfield unit (HU), fat portion grade), and psoas retraction time. METHODS: The isokinetic muscle strength of the hip flexor was measured five times (preoperatively and postoperatively at 2 days, 1 week, 1 month, and 3 months) for both legs. The peak torque was defined as the postoperative strength of the left hip flexor muscles, and was compared to the preoperative baseline value. The strength of the left and right hip flexor muscles were also compared at each time point. For logistic regression analysis, when the peak torque was below the median value, it was defined as lower peak torque. RESULTS: Up to 1 week after surgery, the strength of the left hip flexor muscle decreased significantly (paired difference in peak torque was 22.6%, p<.001). In the results of multivariate logistic regression analysis, diabetes (odds ratio [OR]=8.43, p=.020) and the HU of the psoas muscle (OR=0.916, p=.034) were associated with lower peak torque 1 week after surgery. From 1 month after surgery, postoperative weakness of the psoas muscle was not significant. In the questionnaire survey, subjective left hip flexion weakness was reported in 8.5% (4/47) of patients 1 week after surgery, and it remained in only 2.1% (1/47) of patients after 3 months of operation. The frequency of left anterior thigh pain and hypoesthesia decreased from 85.1% (40/47) at 1 week to 2.1% (1/47) at 3 months after surgery. The mean VAS score for left anterior thigh or groin pain decreased significantly at 1 month after surgery (PO2D: 4.04±1.84, PO1M: 1.67±1.10, p<.001). CONCLUSIONS: Dynamometer measurement showed that psoas strength declined significantly up to 1 week after OLIF surgery. Patients with diabetes or lower HU of the psoas muscle showed delayed recovery from postoperative weakness of the psoas muscle. However, the weakness was insignificant from 1 month after surgery. At 3 months after surgery, the other psoas-related problems (left anterior thigh pain and hypoesthesia) also disappeared.

Development of Neuromonitoring Pedicle Screw - Results of Electrical Resistance and Neurophysiologic Test in Pig Model.

OBJECTIVE: To analyze the electrical resistance of a newly developed neuromonitoring pedicle screw (Neuro-PS) and to verify the electrophysiologic properties of the Neuro-PS in a pig model. METHODS: We developed 2 types of the Neuro-PS in which a gold lead was located internally (type I) and externally (type II). We measured the electrical resistance of the Neuro-PS and the conventional screw and analyzed the electrical thresholds of triggered EMG (t-EMG) of each screw by intentionally penetrating the medial pedicle wall and contacting the exiting nerve root in a pig model. RESULTS: The electrical resistances of the Neuro-PS were remarkably lower than that of the conventional screw. In electrophysiologic testing, only the type II Neuro-PS under the leadnerve contact condition showed a significantly lower stimulation threshold as compared to the conventional screw. CONCLUSION: The Neuro-PS demonstrated lower electrical resistances than the conventional screw. The type II Neuro-PS under the lead-nerve contact condition showed a significantly lower stimulation threshold compared to that of the other screws in the t-EMG test.

Dorsal Epidural Gas after Lumbar Microdiskectomy Treated with CT-guided Needle Aspiration.

To present a case of unusual dorsal epidural gas (EG) accumulation after a simple lumbar microdiskectomy (MD), treated with computed tomography (CT)-guided needle aspiration. A 78-year-old woman underwent simple lumbar MD at the L3-4 level. One week after the operation, the patient complained of severe back pain radiating to the right thigh. Follow-up magnetic resonance imaging (MRI) and CT revealed huge EG formation at the dorsal L3-4 epidural space. Conservative treatment did not resolve the patient's pain. We performed CT-guided needle aspiration after 1 week of conservative treatment. The patient's pain fully resolved after aspiration, but it recurred 1 week later. Follow-up MRI and CT revealed re-accumulation of the dorsal EG at the L3-4 level. CT-guided needle aspiration was repeated, again leading to full pain resolution. Follow-up CT 6 months after the second aspiration showed no recurrent dorsal EG. The patient has been symptom-free for 1 year since the second aspiration. CT-guided needle aspiration is a safe and effective alternative to re-operation in the context of dorsal EG formation after MD.

Risk factors for cage migration and cage retropulsion following transforaminal lumbar interbody fusion.

BACKGROUND CONTEXT: Transforaminal lumbar interbody fusion (TLIF) is a widely accepted surgical procedure, but cage migration (CM) and cage retropulsion (CR) are associated with poor outcomes. PURPOSE: This study seeks to identify risk factors associated with these serious events. STUDY DESIGN: A prospective observational longitudinal study. PATIENT SAMPLE: Over a 5-year period, 881 lumbar levels in 784 patients were treated using TLIF at three spinal surgery centers. OUTCOME MEASURES: We evaluated the odds ratio of the risk factors for CM with and without subsidence and CR in multivariate analysis. METHODS: Our study classified CM into two subgroups: CM without subsidence and CM with subsidence. Cases of spinal canal and/or foramen intrusion of the cage was defined separately as CR. Patient records, operative notes, and radiographs were analyzed for factors potentially related to CM with subsidence, CM without subsidence, and CR. RESULTS: Of 881 lumbar levels treated with TLIFs, CM without subsidence was observed in 20 (2.3%) and CM with subsidence was observed in 36 (4.1%) patients. Among the CM cases, CR was observed in 17 (17/56, 30.4%). The risk factors of CM without subsidence were osteoporosis (OR 8.73, p < .001) and use of a unilateral single cage (OR 3.57, p < .001). Osteoporosis (OR 5.77, p < .001) and endplate injury (OR 26.87, p < .001) were found to be significant risk factors for CM with subsidence. Risk factors of CR were osteoporosis (OR 7.86, p < .001), pear-shaped disc (OR 8.28, p = .001), endplate injury (OR 18.70, p < .001), unilateral single cage use (OR 4.40, p = .03), and posterior cage position (OR 6.45, p = .04). A difference in overall fusion rates was identified, with a rate of 97.1% (801 of 825) for no CM, 55.0% (11 of 20) for CM without subsidence, 41.7% (15 of 36) for CM with subsidence, and 17.6% (3 of 17) for CR at 1.5 years postoperatively. CONCLUSIONS: Our results suggest that osteoporosis is a significant risk factor for both CM and CR. In addition, a pear-shaped disc, posterior positioning of the cage, the presence of endplate injury and the use of a single cage were correlated with the CM with and without subsidence and CR.

Recurrent esophageal perforation after anterior cervical spine surgery: case report.

PURPOSE: Delayed esophageal perforation after anterior cervical discectomy and fusion (ACDF) is an extremely rare cause of infection such as spondylodiscitis. We present a rare case in which a patient had two delayed esophageal perforations occurring 20 and 25 years after ACDF. By sharing our experience of this rare case, we hope to provide new information related to delayed esophageal perforation. METHODS: We present the case of a 72-year-old patient who underwent ACDF due to cervical spondylosis 25 years ago. Delayed esophageal perforation occurred 20 years postoperatively and healed spontaneously with conservative treatment. RESULTS: Five years later, a second esophageal perforation occurred, which required surgical intervention and involved recurrent infection. CONCLUSIONS: We suggest that it is important to consider follow-up in patients with spontaneously healed esophageal perforations. Furthermore, any patient with symptoms subsequent to a spontaneously healed esophageal perforation, even after an interval of several years, should receive a thorough evaluation for possible recurrent esophageal perforation.

Curcumin Increase the Expression of Neural Stem/Progenitor Cells and Improves Functional Recovery after Spinal Cord Injury.

OBJECTIVE: To investigates the effect of curcumin on proliferation of spinal cord neural stem/progenitor cells (SC-NSPCs) and functional outcome in a rat spinal cord injury (SCI) model. METHODS: Sixty adult male Sprague-Dawley rats were randomly and blindly allocated into three groups (sham control group; curcumin treated group after SCI; vehicle treated group after SCI). Functional recovery was evaluated by the Basso, Beattie, and Bresnahan (BBB) scale during 6 weeks after SCI. The expression of SC-NSPC proliferation and astrogliosis were analyzed by nestin/Bromodeoxyuridine (BrdU) and Glial fibrillary acidic protein (GFAP) staining. The injured spinal cord was then examined histologically, including quantification of cavitation. RESULTS: The BBB score of the SCI-curcumin group was better than that of SCI-vehicle group up to 14 days (p<0.05). The co-immunoreactivity of nestin/BrdU in the SCI-curcumin group was much higher than that of the SCI-vehicle group 1 week after surgery (p<0.05). The GFAP immunoreactivity of the SCI-curcumin group was remarkably lower than that of the SCI-vehicle group 4 weeks after surgery (p<0.05). The lesion cavity was significantly reduced in the curcumin group as compared to the control group (p<0.05). CONCLUSION: These results indicate that curcumin could increase the expression of SC-NSPCs, and reduce the activity of reactive astrogliosis and lesion cavity. Consequently curcumin could improve the functional recovery after SCI via SC-NSPC properties.

Relationships between vitamin D and paraspinal muscle: human data and experimental rat model analysis.

BACKGROUND CONTEXT: Vitamin D deficiency (VDD) has been closely linked with skeletal muscle atrophy in many studies, but to date no study has focused on the paraspinal muscle. PURPOSE: To verify paraspinal muscle changes according to serum vitamin D level. STUDY DESIGN: A cross-sectional study of patients who visited our hospital and an in vivo animal study. METHODS: We measured serum vitamin D concentration in 91 elderly women and stratified them according to their vitamin D status in three groups, control, vitamin D insufficiency, and VDD, and obtained magnetic resonance imaging data of the lumbar spine and evaluated the quality and quantity of the paraspinal muscles. Additionally, we designed experimental rat models for VDD and VDD replacement. Then, we analyzed the microcomputed tomography data and histologic data of paraspinal muscles, and the histologic data and reverse transcription-quantitative polymerase chain reaction data of intramyonuclear vitamin D receptor (VDR) in paraspinal muscle through comparison with control rats (n=25, each group). This work was supported by a Biomedical Research Institute grant ($40,000), Kyungpook National University Hospital (2014). RESULTS: In the human studies, a significant decrease was noted in the overall paraspinal muscularity (p<.05) and increase in fatty infiltration in the VDD group as compared with the other groups (p<.05). In the rat experiment, a decrease was noted in paraspinal muscle fiber size and VDR concentration and VDR gene expression level, and total muscle volume of the VDD rats as compared with the control rats (p<.05). Vitamin D replacement after VDD could partially restore the muscle volume, muscle fiber size, and intramyonuclear VDR concentration levels (p<.05) of the paraspinal muscles. CONCLUSIONS: VDD induces paraspinal muscle atrophy and decreases the intramyonuclear VDR concentration and VDR gene expression level in these muscles. Vitamin D replacement contributes to the recovery from atrophy and restoration of intramyonuclear VDR concentration in VDD status.

Valproic Acid increases expression of neuronal stem/progenitor cell in spinal cord injury.

OBJECTIVE: This study investigates the effect of valproic acid (VPA) on expression of neural stem/progenitor cells (NSPCs) in a rat spinal cord injury (SCI) model. METHODS: Adult male rats (n=24) were randomly and blindly allocated into three groups. Laminectomy at T9 was performed in all three groups. In group 1 (sham), only laminectomy was performed. In group 2 (SCI-VPA), the animals received a dose of 200 mg/kg of VPA. In group 3 (SCI-saline), animals received 1.0 mL of the saline vehicle solution. A modified aneurysm clip with a closing force of 30 grams was applied extradurally around the spinal cord at T9, and then rapidly released with cord compression persisting for 2 minutes. The rats were sacrificed and the spinal cord were collected one week after SCI. Immunohistochemistry (IHC) and western blotting sample were obtained from 5 mm rostral region to the lesion and prepared. We analyzed the nestin immunoreactivity from the white matter of ventral cord and the ependyma of central canal. Nestin and SOX2 were used for markers for NSPCs and analyzed by IHC and western blotting, respectively. RESULTS: Nestin and SOX2 were expressed significantly in the SCI groups but not in the sham group. Comparing SCI groups, nestin and SOX2 expression were much stronger in SCI-VPA group than in SCI-saline group. CONCLUSION: Nestin and SOX2 as markers for NSPCs showed increased expression in SCI-VPA group in comparison with SCI-saline group. This result suggests VPA increases expression of spinal NSPCs in SCI.

Primary eosinophilic granuloma of adult cervical spine presenting as a radiculomyelopathy.

We report a case of 29-year-old man diagnosed as a primary eosinophilic granuloma (EG) lesion of the seventh cervical vertebra. He had paresthesia on both arms, and grasping weakness for 10 days. Cervical magnetic resonance image (MRI) showed an enhancing mass with ventral epidural bulging and cord compression on the seventh cervical vertebra. Additionally, we performed spine series MRI, bone scan and positive emission tomography for confirmation of other bone lesions. These studies showed no other pathological lesions. He underwent anterior cervical corpectomy of the seventh cervical vertebra and plate fixation with iliac bone graft. After surgical management, neurological symptoms were much improved. Histopathologic evaluation confirmed the diagnosis of EG. There was no evidence of tumor recurrence at 12 months postoperative cervical MRI follow-up. We reported symptomatic primary EG of cervical spine successfully treated with surgical resection.